hotspot/src/share/vm/opto/loopnode.cpp
author duke
Sat, 01 Dec 2007 00:00:00 +0000
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/*
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 * Copyright 1998-2007 Sun Microsystems, Inc.  All Rights Reserved.
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 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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 *
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 * This code is free software; you can redistribute it and/or modify it
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 * under the terms of the GNU General Public License version 2 only, as
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 * published by the Free Software Foundation.
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 *
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 * This code is distributed in the hope that it will be useful, but WITHOUT
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 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
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 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
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 * version 2 for more details (a copy is included in the LICENSE file that
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 * accompanied this code).
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 *
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 * You should have received a copy of the GNU General Public License version
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 * 2 along with this work; if not, write to the Free Software Foundation,
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 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
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 *
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 * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
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 * CA 95054 USA or visit www.sun.com if you need additional information or
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 * have any questions.
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 *
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 */
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#include "incls/_precompiled.incl"
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#include "incls/_loopnode.cpp.incl"
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//=============================================================================
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//------------------------------is_loop_iv-------------------------------------
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// Determine if a node is Counted loop induction variable.
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// The method is declared in node.hpp.
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const Node* Node::is_loop_iv() const {
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  if (this->is_Phi() && !this->as_Phi()->is_copy() &&
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      this->as_Phi()->region()->is_CountedLoop() &&
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      this->as_Phi()->region()->as_CountedLoop()->phi() == this) {
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    return this;
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  } else {
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    return NULL;
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  }
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}
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//=============================================================================
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//------------------------------dump_spec--------------------------------------
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// Dump special per-node info
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#ifndef PRODUCT
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void LoopNode::dump_spec(outputStream *st) const {
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  if( is_inner_loop () ) st->print( "inner " );
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  if( is_partial_peel_loop () ) st->print( "partial_peel " );
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  if( partial_peel_has_failed () ) st->print( "partial_peel_failed " );
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}
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#endif
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//------------------------------get_early_ctrl---------------------------------
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// Compute earliest legal control
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Node *PhaseIdealLoop::get_early_ctrl( Node *n ) {
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  assert( !n->is_Phi() && !n->is_CFG(), "this code only handles data nodes" );
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  uint i;
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  Node *early;
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  if( n->in(0) ) {
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    early = n->in(0);
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    if( !early->is_CFG() ) // Might be a non-CFG multi-def
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      early = get_ctrl(early);        // So treat input as a straight data input
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    i = 1;
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  } else {
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    early = get_ctrl(n->in(1));
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    i = 2;
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  }
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  uint e_d = dom_depth(early);
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  assert( early, "" );
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  for( ; i < n->req(); i++ ) {
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    Node *cin = get_ctrl(n->in(i));
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    assert( cin, "" );
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    // Keep deepest dominator depth
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    uint c_d = dom_depth(cin);
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    if( c_d > e_d ) {           // Deeper guy?
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      early = cin;              // Keep deepest found so far
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      e_d = c_d;
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    } else if( c_d == e_d &&    // Same depth?
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               early != cin ) { // If not equal, must use slower algorithm
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      // If same depth but not equal, one _must_ dominate the other
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      // and we want the deeper (i.e., dominated) guy.
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      Node *n1 = early;
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      Node *n2 = cin;
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      while( 1 ) {
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        n1 = idom(n1);          // Walk up until break cycle
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        n2 = idom(n2);
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        if( n1 == cin ||        // Walked early up to cin
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            dom_depth(n2) < c_d )
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          break;                // early is deeper; keep him
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        if( n2 == early ||      // Walked cin up to early
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            dom_depth(n1) < c_d ) {
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          early = cin;          // cin is deeper; keep him
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          break;
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        }
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      }
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      e_d = dom_depth(early);   // Reset depth register cache
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    }
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  }
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  // Return earliest legal location
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  assert(early == find_non_split_ctrl(early), "unexpected early control");
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  return early;
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}
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//------------------------------set_early_ctrl---------------------------------
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// Set earliest legal control
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void PhaseIdealLoop::set_early_ctrl( Node *n ) {
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  Node *early = get_early_ctrl(n);
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  // Record earliest legal location
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  set_ctrl(n, early);
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}
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//------------------------------set_subtree_ctrl-------------------------------
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// set missing _ctrl entries on new nodes
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void PhaseIdealLoop::set_subtree_ctrl( Node *n ) {
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  // Already set?  Get out.
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  if( _nodes[n->_idx] ) return;
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  // Recursively set _nodes array to indicate where the Node goes
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  uint i;
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  for( i = 0; i < n->req(); ++i ) {
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    Node *m = n->in(i);
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    if( m && m != C->root() )
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      set_subtree_ctrl( m );
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  }
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  // Fixup self
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  set_early_ctrl( n );
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}
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//------------------------------is_counted_loop--------------------------------
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Node *PhaseIdealLoop::is_counted_loop( Node *x, IdealLoopTree *loop ) {
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  PhaseGVN *gvn = &_igvn;
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  // Counted loop head must be a good RegionNode with only 3 not NULL
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  // control input edges: Self, Entry, LoopBack.
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  if ( x->in(LoopNode::Self) == NULL || x->req() != 3 )
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    return NULL;
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  Node *init_control = x->in(LoopNode::EntryControl);
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  Node *back_control = x->in(LoopNode::LoopBackControl);
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  if( init_control == NULL || back_control == NULL )    // Partially dead
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    return NULL;
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  // Must also check for TOP when looking for a dead loop
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  if( init_control->is_top() || back_control->is_top() )
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    return NULL;
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  // Allow funny placement of Safepoint
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  if( back_control->Opcode() == Op_SafePoint )
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    back_control = back_control->in(TypeFunc::Control);
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  // Controlling test for loop
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  Node *iftrue = back_control;
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  uint iftrue_op = iftrue->Opcode();
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  if( iftrue_op != Op_IfTrue &&
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      iftrue_op != Op_IfFalse )
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    // I have a weird back-control.  Probably the loop-exit test is in
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    // the middle of the loop and I am looking at some trailing control-flow
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    // merge point.  To fix this I would have to partially peel the loop.
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    return NULL; // Obscure back-control
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  // Get boolean guarding loop-back test
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  Node *iff = iftrue->in(0);
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  if( get_loop(iff) != loop || !iff->in(1)->is_Bool() ) return NULL;
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  BoolNode *test = iff->in(1)->as_Bool();
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  BoolTest::mask bt = test->_test._test;
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  float cl_prob = iff->as_If()->_prob;
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  if( iftrue_op == Op_IfFalse ) {
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    bt = BoolTest(bt).negate();
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    cl_prob = 1.0 - cl_prob;
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  }
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  // Get backedge compare
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  Node *cmp = test->in(1);
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  int cmp_op = cmp->Opcode();
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  if( cmp_op != Op_CmpI )
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    return NULL;                // Avoid pointer & float compares
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  // Find the trip-counter increment & limit.  Limit must be loop invariant.
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  Node *incr  = cmp->in(1);
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  Node *limit = cmp->in(2);
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  // ---------
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  // need 'loop()' test to tell if limit is loop invariant
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  // ---------
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  if( !is_member( loop, get_ctrl(incr) ) ) { // Swapped trip counter and limit?
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    Node *tmp = incr;           // Then reverse order into the CmpI
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    incr = limit;
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    limit = tmp;
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    bt = BoolTest(bt).commute(); // And commute the exit test
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  }
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  if( is_member( loop, get_ctrl(limit) ) ) // Limit must loop-invariant
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    return NULL;
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  // Trip-counter increment must be commutative & associative.
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  uint incr_op = incr->Opcode();
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  if( incr_op == Op_Phi && incr->req() == 3 ) {
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    incr = incr->in(2);         // Assume incr is on backedge of Phi
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   200
    incr_op = incr->Opcode();
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   201
  }
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  Node* trunc1 = NULL;
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   203
  Node* trunc2 = NULL;
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  const TypeInt* iv_trunc_t = NULL;
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  if (!(incr = CountedLoopNode::match_incr_with_optional_truncation(incr, &trunc1, &trunc2, &iv_trunc_t))) {
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    return NULL; // Funny increment opcode
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   207
  }
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   208
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   209
  // Get merge point
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   210
  Node *xphi = incr->in(1);
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   211
  Node *stride = incr->in(2);
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   212
  if( !stride->is_Con() ) {     // Oops, swap these
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   213
    if( !xphi->is_Con() )       // Is the other guy a constant?
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   214
      return NULL;              // Nope, unknown stride, bail out
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   215
    Node *tmp = xphi;           // 'incr' is commutative, so ok to swap
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   216
    xphi = stride;
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    stride = tmp;
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   218
  }
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   219
  //if( loop(xphi) != l) return NULL;// Merge point is in inner loop??
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   220
  if( !xphi->is_Phi() ) return NULL; // Too much math on the trip counter
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   221
  PhiNode *phi = xphi->as_Phi();
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   222
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  // Stride must be constant
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   224
  const Type *stride_t = stride->bottom_type();
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   225
  int stride_con = stride_t->is_int()->get_con();
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   226
  assert( stride_con, "missed some peephole opt" );
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   227
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   228
  // Phi must be of loop header; backedge must wrap to increment
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   229
  if( phi->region() != x ) return NULL;
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   230
  if( trunc1 == NULL && phi->in(LoopNode::LoopBackControl) != incr ||
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   231
      trunc1 != NULL && phi->in(LoopNode::LoopBackControl) != trunc1 ) {
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   232
    return NULL;
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   233
  }
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   234
  Node *init_trip = phi->in(LoopNode::EntryControl);
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   235
  //if (!init_trip->is_Con()) return NULL; // avoid rolling over MAXINT/MININT
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   236
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   237
  // If iv trunc type is smaller than int, check for possible wrap.
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   238
  if (!TypeInt::INT->higher_equal(iv_trunc_t)) {
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   239
    assert(trunc1 != NULL, "must have found some truncation");
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   240
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   241
    // Get a better type for the phi (filtered thru if's)
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   242
    const TypeInt* phi_ft = filtered_type(phi);
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   243
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   244
    // Can iv take on a value that will wrap?
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   245
    //
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   246
    // Ensure iv's limit is not within "stride" of the wrap value.
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   247
    //
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   248
    // Example for "short" type
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   249
    //    Truncation ensures value is in the range -32768..32767 (iv_trunc_t)
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   250
    //    If the stride is +10, then the last value of the induction
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   251
    //    variable before the increment (phi_ft->_hi) must be
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   252
    //    <= 32767 - 10 and (phi_ft->_lo) must be >= -32768 to
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   253
    //    ensure no truncation occurs after the increment.
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   254
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   255
    if (stride_con > 0) {
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   256
      if (iv_trunc_t->_hi - phi_ft->_hi < stride_con ||
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   257
          iv_trunc_t->_lo > phi_ft->_lo) {
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   258
        return NULL;  // truncation may occur
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   259
      }
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   260
    } else if (stride_con < 0) {
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   261
      if (iv_trunc_t->_lo - phi_ft->_lo > stride_con ||
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   262
          iv_trunc_t->_hi < phi_ft->_hi) {
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   263
        return NULL;  // truncation may occur
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   264
      }
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   265
    }
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   266
    // No possibility of wrap so truncation can be discarded
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   267
    // Promote iv type to Int
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   268
  } else {
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   269
    assert(trunc1 == NULL && trunc2 == NULL, "no truncation for int");
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   270
  }
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   271
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   272
  // =================================================
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   273
  // ---- SUCCESS!   Found A Trip-Counted Loop!  -----
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   274
  //
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   275
  // Canonicalize the condition on the test.  If we can exactly determine
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   276
  // the trip-counter exit value, then set limit to that value and use
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   277
  // a '!=' test.  Otherwise use conditon '<' for count-up loops and
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   278
  // '>' for count-down loops.  If the condition is inverted and we will
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   279
  // be rolling through MININT to MAXINT, then bail out.
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   280
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   281
  C->print_method("Before CountedLoop", 3);
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   282
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   283
  // Check for SafePoint on backedge and remove
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   284
  Node *sfpt = x->in(LoopNode::LoopBackControl);
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   285
  if( sfpt->Opcode() == Op_SafePoint && is_deleteable_safept(sfpt)) {
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   286
    lazy_replace( sfpt, iftrue );
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   287
    loop->_tail = iftrue;
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   288
  }
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   289
489c9b5090e2 Initial load
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   290
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   291
  // If compare points to incr, we are ok.  Otherwise the compare
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   292
  // can directly point to the phi; in this case adjust the compare so that
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diff changeset
   293
  // it points to the incr by adusting the limit.
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   294
  if( cmp->in(1) == phi || cmp->in(2) == phi )
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   295
    limit = gvn->transform(new (C, 3) AddINode(limit,stride));
489c9b5090e2 Initial load
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   296
489c9b5090e2 Initial load
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   297
  // trip-count for +-tive stride should be: (limit - init_trip + stride - 1)/stride.
489c9b5090e2 Initial load
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   298
  // Final value for iterator should be: trip_count * stride + init_trip.
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   299
  const Type *limit_t = limit->bottom_type();
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   300
  const Type *init_t = init_trip->bottom_type();
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   301
  Node *one_p = gvn->intcon( 1);
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   302
  Node *one_m = gvn->intcon(-1);
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   303
489c9b5090e2 Initial load
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   304
  Node *trip_count = NULL;
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   305
  Node *hook = new (C, 6) Node(6);
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   306
  switch( bt ) {
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   307
  case BoolTest::eq:
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diff changeset
   308
    return NULL;                // Bail out, but this loop trips at most twice!
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   309
  case BoolTest::ne:            // Ahh, the case we desire
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diff changeset
   310
    if( stride_con == 1 )
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   311
      trip_count = gvn->transform(new (C, 3) SubINode(limit,init_trip));
489c9b5090e2 Initial load
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diff changeset
   312
    else if( stride_con == -1 )
489c9b5090e2 Initial load
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diff changeset
   313
      trip_count = gvn->transform(new (C, 3) SubINode(init_trip,limit));
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diff changeset
   314
    else
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diff changeset
   315
      return NULL;              // Odd stride; must prove we hit limit exactly
489c9b5090e2 Initial load
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diff changeset
   316
    set_subtree_ctrl( trip_count );
489c9b5090e2 Initial load
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diff changeset
   317
    //_loop.map(trip_count->_idx,loop(limit));
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diff changeset
   318
    break;
489c9b5090e2 Initial load
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diff changeset
   319
  case BoolTest::le:            // Maybe convert to '<' case
489c9b5090e2 Initial load
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diff changeset
   320
    limit = gvn->transform(new (C, 3) AddINode(limit,one_p));
489c9b5090e2 Initial load
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parents:
diff changeset
   321
    set_subtree_ctrl( limit );
489c9b5090e2 Initial load
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diff changeset
   322
    hook->init_req(4, limit);
489c9b5090e2 Initial load
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diff changeset
   323
489c9b5090e2 Initial load
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diff changeset
   324
    bt = BoolTest::lt;
489c9b5090e2 Initial load
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diff changeset
   325
    // Make the new limit be in the same loop nest as the old limit
489c9b5090e2 Initial load
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diff changeset
   326
    //_loop.map(limit->_idx,limit_loop);
489c9b5090e2 Initial load
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diff changeset
   327
    // Fall into next case
489c9b5090e2 Initial load
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diff changeset
   328
  case BoolTest::lt: {          // Maybe convert to '!=' case
489c9b5090e2 Initial load
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parents:
diff changeset
   329
    if( stride_con < 0 ) return NULL; // Count down loop rolls through MAXINT
489c9b5090e2 Initial load
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parents:
diff changeset
   330
    Node *range = gvn->transform(new (C, 3) SubINode(limit,init_trip));
489c9b5090e2 Initial load
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parents:
diff changeset
   331
    set_subtree_ctrl( range );
489c9b5090e2 Initial load
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parents:
diff changeset
   332
    hook->init_req(0, range);
489c9b5090e2 Initial load
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parents:
diff changeset
   333
489c9b5090e2 Initial load
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parents:
diff changeset
   334
    Node *bias  = gvn->transform(new (C, 3) AddINode(range,stride));
489c9b5090e2 Initial load
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parents:
diff changeset
   335
    set_subtree_ctrl( bias );
489c9b5090e2 Initial load
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parents:
diff changeset
   336
    hook->init_req(1, bias);
489c9b5090e2 Initial load
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parents:
diff changeset
   337
489c9b5090e2 Initial load
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parents:
diff changeset
   338
    Node *bias1 = gvn->transform(new (C, 3) AddINode(bias,one_m));
489c9b5090e2 Initial load
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parents:
diff changeset
   339
    set_subtree_ctrl( bias1 );
489c9b5090e2 Initial load
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parents:
diff changeset
   340
    hook->init_req(2, bias1);
489c9b5090e2 Initial load
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diff changeset
   341
489c9b5090e2 Initial load
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parents:
diff changeset
   342
    trip_count  = gvn->transform(new (C, 3) DivINode(0,bias1,stride));
489c9b5090e2 Initial load
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diff changeset
   343
    set_subtree_ctrl( trip_count );
489c9b5090e2 Initial load
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diff changeset
   344
    hook->init_req(3, trip_count);
489c9b5090e2 Initial load
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diff changeset
   345
    break;
489c9b5090e2 Initial load
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diff changeset
   346
  }
489c9b5090e2 Initial load
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parents:
diff changeset
   347
489c9b5090e2 Initial load
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parents:
diff changeset
   348
  case BoolTest::ge:            // Maybe convert to '>' case
489c9b5090e2 Initial load
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diff changeset
   349
    limit = gvn->transform(new (C, 3) AddINode(limit,one_m));
489c9b5090e2 Initial load
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diff changeset
   350
    set_subtree_ctrl( limit );
489c9b5090e2 Initial load
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parents:
diff changeset
   351
    hook->init_req(4 ,limit);
489c9b5090e2 Initial load
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parents:
diff changeset
   352
489c9b5090e2 Initial load
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diff changeset
   353
    bt = BoolTest::gt;
489c9b5090e2 Initial load
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parents:
diff changeset
   354
    // Make the new limit be in the same loop nest as the old limit
489c9b5090e2 Initial load
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parents:
diff changeset
   355
    //_loop.map(limit->_idx,limit_loop);
489c9b5090e2 Initial load
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parents:
diff changeset
   356
    // Fall into next case
489c9b5090e2 Initial load
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parents:
diff changeset
   357
  case BoolTest::gt: {          // Maybe convert to '!=' case
489c9b5090e2 Initial load
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parents:
diff changeset
   358
    if( stride_con > 0 ) return NULL; // count up loop rolls through MININT
489c9b5090e2 Initial load
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parents:
diff changeset
   359
    Node *range = gvn->transform(new (C, 3) SubINode(limit,init_trip));
489c9b5090e2 Initial load
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parents:
diff changeset
   360
    set_subtree_ctrl( range );
489c9b5090e2 Initial load
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parents:
diff changeset
   361
    hook->init_req(0, range);
489c9b5090e2 Initial load
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parents:
diff changeset
   362
489c9b5090e2 Initial load
duke
parents:
diff changeset
   363
    Node *bias  = gvn->transform(new (C, 3) AddINode(range,stride));
489c9b5090e2 Initial load
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parents:
diff changeset
   364
    set_subtree_ctrl( bias );
489c9b5090e2 Initial load
duke
parents:
diff changeset
   365
    hook->init_req(1, bias);
489c9b5090e2 Initial load
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parents:
diff changeset
   366
489c9b5090e2 Initial load
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parents:
diff changeset
   367
    Node *bias1 = gvn->transform(new (C, 3) AddINode(bias,one_p));
489c9b5090e2 Initial load
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parents:
diff changeset
   368
    set_subtree_ctrl( bias1 );
489c9b5090e2 Initial load
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parents:
diff changeset
   369
    hook->init_req(2, bias1);
489c9b5090e2 Initial load
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parents:
diff changeset
   370
489c9b5090e2 Initial load
duke
parents:
diff changeset
   371
    trip_count  = gvn->transform(new (C, 3) DivINode(0,bias1,stride));
489c9b5090e2 Initial load
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parents:
diff changeset
   372
    set_subtree_ctrl( trip_count );
489c9b5090e2 Initial load
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parents:
diff changeset
   373
    hook->init_req(3, trip_count);
489c9b5090e2 Initial load
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parents:
diff changeset
   374
    break;
489c9b5090e2 Initial load
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parents:
diff changeset
   375
  }
489c9b5090e2 Initial load
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parents:
diff changeset
   376
  }
489c9b5090e2 Initial load
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parents:
diff changeset
   377
489c9b5090e2 Initial load
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parents:
diff changeset
   378
  Node *span = gvn->transform(new (C, 3) MulINode(trip_count,stride));
489c9b5090e2 Initial load
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parents:
diff changeset
   379
  set_subtree_ctrl( span );
489c9b5090e2 Initial load
duke
parents:
diff changeset
   380
  hook->init_req(5, span);
489c9b5090e2 Initial load
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parents:
diff changeset
   381
489c9b5090e2 Initial load
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parents:
diff changeset
   382
  limit = gvn->transform(new (C, 3) AddINode(span,init_trip));
489c9b5090e2 Initial load
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parents:
diff changeset
   383
  set_subtree_ctrl( limit );
489c9b5090e2 Initial load
duke
parents:
diff changeset
   384
489c9b5090e2 Initial load
duke
parents:
diff changeset
   385
  // Build a canonical trip test.
489c9b5090e2 Initial load
duke
parents:
diff changeset
   386
  // Clone code, as old values may be in use.
489c9b5090e2 Initial load
duke
parents:
diff changeset
   387
  incr = incr->clone();
489c9b5090e2 Initial load
duke
parents:
diff changeset
   388
  incr->set_req(1,phi);
489c9b5090e2 Initial load
duke
parents:
diff changeset
   389
  incr->set_req(2,stride);
489c9b5090e2 Initial load
duke
parents:
diff changeset
   390
  incr = _igvn.register_new_node_with_optimizer(incr);
489c9b5090e2 Initial load
duke
parents:
diff changeset
   391
  set_early_ctrl( incr );
489c9b5090e2 Initial load
duke
parents:
diff changeset
   392
  _igvn.hash_delete(phi);
489c9b5090e2 Initial load
duke
parents:
diff changeset
   393
  phi->set_req_X( LoopNode::LoopBackControl, incr, &_igvn );
489c9b5090e2 Initial load
duke
parents:
diff changeset
   394
489c9b5090e2 Initial load
duke
parents:
diff changeset
   395
  // If phi type is more restrictive than Int, raise to
489c9b5090e2 Initial load
duke
parents:
diff changeset
   396
  // Int to prevent (almost) infinite recursion in igvn
489c9b5090e2 Initial load
duke
parents:
diff changeset
   397
  // which can only handle integer types for constants or minint..maxint.
489c9b5090e2 Initial load
duke
parents:
diff changeset
   398
  if (!TypeInt::INT->higher_equal(phi->bottom_type())) {
489c9b5090e2 Initial load
duke
parents:
diff changeset
   399
    Node* nphi = PhiNode::make(phi->in(0), phi->in(LoopNode::EntryControl), TypeInt::INT);
489c9b5090e2 Initial load
duke
parents:
diff changeset
   400
    nphi->set_req(LoopNode::LoopBackControl, phi->in(LoopNode::LoopBackControl));
489c9b5090e2 Initial load
duke
parents:
diff changeset
   401
    nphi = _igvn.register_new_node_with_optimizer(nphi);
489c9b5090e2 Initial load
duke
parents:
diff changeset
   402
    set_ctrl(nphi, get_ctrl(phi));
489c9b5090e2 Initial load
duke
parents:
diff changeset
   403
    _igvn.subsume_node(phi, nphi);
489c9b5090e2 Initial load
duke
parents:
diff changeset
   404
    phi = nphi->as_Phi();
489c9b5090e2 Initial load
duke
parents:
diff changeset
   405
  }
489c9b5090e2 Initial load
duke
parents:
diff changeset
   406
  cmp = cmp->clone();
489c9b5090e2 Initial load
duke
parents:
diff changeset
   407
  cmp->set_req(1,incr);
489c9b5090e2 Initial load
duke
parents:
diff changeset
   408
  cmp->set_req(2,limit);
489c9b5090e2 Initial load
duke
parents:
diff changeset
   409
  cmp = _igvn.register_new_node_with_optimizer(cmp);
489c9b5090e2 Initial load
duke
parents:
diff changeset
   410
  set_ctrl(cmp, iff->in(0));
489c9b5090e2 Initial load
duke
parents:
diff changeset
   411
489c9b5090e2 Initial load
duke
parents:
diff changeset
   412
  Node *tmp = test->clone();
489c9b5090e2 Initial load
duke
parents:
diff changeset
   413
  assert( tmp->is_Bool(), "" );
489c9b5090e2 Initial load
duke
parents:
diff changeset
   414
  test = (BoolNode*)tmp;
489c9b5090e2 Initial load
duke
parents:
diff changeset
   415
  (*(BoolTest*)&test->_test)._test = bt; //BoolTest::ne;
489c9b5090e2 Initial load
duke
parents:
diff changeset
   416
  test->set_req(1,cmp);
489c9b5090e2 Initial load
duke
parents:
diff changeset
   417
  _igvn.register_new_node_with_optimizer(test);
489c9b5090e2 Initial load
duke
parents:
diff changeset
   418
  set_ctrl(test, iff->in(0));
489c9b5090e2 Initial load
duke
parents:
diff changeset
   419
  // If the exit test is dead, STOP!
489c9b5090e2 Initial load
duke
parents:
diff changeset
   420
  if( test == NULL ) return NULL;
489c9b5090e2 Initial load
duke
parents:
diff changeset
   421
  _igvn.hash_delete(iff);
489c9b5090e2 Initial load
duke
parents:
diff changeset
   422
  iff->set_req_X( 1, test, &_igvn );
489c9b5090e2 Initial load
duke
parents:
diff changeset
   423
489c9b5090e2 Initial load
duke
parents:
diff changeset
   424
  // Replace the old IfNode with a new LoopEndNode
489c9b5090e2 Initial load
duke
parents:
diff changeset
   425
  Node *lex = _igvn.register_new_node_with_optimizer(new (C, 2) CountedLoopEndNode( iff->in(0), iff->in(1), cl_prob, iff->as_If()->_fcnt ));
489c9b5090e2 Initial load
duke
parents:
diff changeset
   426
  IfNode *le = lex->as_If();
489c9b5090e2 Initial load
duke
parents:
diff changeset
   427
  uint dd = dom_depth(iff);
489c9b5090e2 Initial load
duke
parents:
diff changeset
   428
  set_idom(le, le->in(0), dd); // Update dominance for loop exit
489c9b5090e2 Initial load
duke
parents:
diff changeset
   429
  set_loop(le, loop);
489c9b5090e2 Initial load
duke
parents:
diff changeset
   430
489c9b5090e2 Initial load
duke
parents:
diff changeset
   431
  // Get the loop-exit control
489c9b5090e2 Initial load
duke
parents:
diff changeset
   432
  Node *if_f = iff->as_If()->proj_out(!(iftrue_op == Op_IfTrue));
489c9b5090e2 Initial load
duke
parents:
diff changeset
   433
489c9b5090e2 Initial load
duke
parents:
diff changeset
   434
  // Need to swap loop-exit and loop-back control?
489c9b5090e2 Initial load
duke
parents:
diff changeset
   435
  if( iftrue_op == Op_IfFalse ) {
489c9b5090e2 Initial load
duke
parents:
diff changeset
   436
    Node *ift2=_igvn.register_new_node_with_optimizer(new (C, 1) IfTrueNode (le));
489c9b5090e2 Initial load
duke
parents:
diff changeset
   437
    Node *iff2=_igvn.register_new_node_with_optimizer(new (C, 1) IfFalseNode(le));
489c9b5090e2 Initial load
duke
parents:
diff changeset
   438
489c9b5090e2 Initial load
duke
parents:
diff changeset
   439
    loop->_tail = back_control = ift2;
489c9b5090e2 Initial load
duke
parents:
diff changeset
   440
    set_loop(ift2, loop);
489c9b5090e2 Initial load
duke
parents:
diff changeset
   441
    set_loop(iff2, get_loop(if_f));
489c9b5090e2 Initial load
duke
parents:
diff changeset
   442
489c9b5090e2 Initial load
duke
parents:
diff changeset
   443
    // Lazy update of 'get_ctrl' mechanism.
489c9b5090e2 Initial load
duke
parents:
diff changeset
   444
    lazy_replace_proj( if_f  , iff2 );
489c9b5090e2 Initial load
duke
parents:
diff changeset
   445
    lazy_replace_proj( iftrue, ift2 );
489c9b5090e2 Initial load
duke
parents:
diff changeset
   446
489c9b5090e2 Initial load
duke
parents:
diff changeset
   447
    // Swap names
489c9b5090e2 Initial load
duke
parents:
diff changeset
   448
    if_f   = iff2;
489c9b5090e2 Initial load
duke
parents:
diff changeset
   449
    iftrue = ift2;
489c9b5090e2 Initial load
duke
parents:
diff changeset
   450
  } else {
489c9b5090e2 Initial load
duke
parents:
diff changeset
   451
    _igvn.hash_delete(if_f  );
489c9b5090e2 Initial load
duke
parents:
diff changeset
   452
    _igvn.hash_delete(iftrue);
489c9b5090e2 Initial load
duke
parents:
diff changeset
   453
    if_f  ->set_req_X( 0, le, &_igvn );
489c9b5090e2 Initial load
duke
parents:
diff changeset
   454
    iftrue->set_req_X( 0, le, &_igvn );
489c9b5090e2 Initial load
duke
parents:
diff changeset
   455
  }
489c9b5090e2 Initial load
duke
parents:
diff changeset
   456
489c9b5090e2 Initial load
duke
parents:
diff changeset
   457
  set_idom(iftrue, le, dd+1);
489c9b5090e2 Initial load
duke
parents:
diff changeset
   458
  set_idom(if_f,   le, dd+1);
489c9b5090e2 Initial load
duke
parents:
diff changeset
   459
489c9b5090e2 Initial load
duke
parents:
diff changeset
   460
  // Now setup a new CountedLoopNode to replace the existing LoopNode
489c9b5090e2 Initial load
duke
parents:
diff changeset
   461
  CountedLoopNode *l = new (C, 3) CountedLoopNode(init_control, back_control);
489c9b5090e2 Initial load
duke
parents:
diff changeset
   462
  // The following assert is approximately true, and defines the intention
489c9b5090e2 Initial load
duke
parents:
diff changeset
   463
  // of can_be_counted_loop.  It fails, however, because phase->type
489c9b5090e2 Initial load
duke
parents:
diff changeset
   464
  // is not yet initialized for this loop and its parts.
489c9b5090e2 Initial load
duke
parents:
diff changeset
   465
  //assert(l->can_be_counted_loop(this), "sanity");
489c9b5090e2 Initial load
duke
parents:
diff changeset
   466
  _igvn.register_new_node_with_optimizer(l);
489c9b5090e2 Initial load
duke
parents:
diff changeset
   467
  set_loop(l, loop);
489c9b5090e2 Initial load
duke
parents:
diff changeset
   468
  loop->_head = l;
489c9b5090e2 Initial load
duke
parents:
diff changeset
   469
  // Fix all data nodes placed at the old loop head.
489c9b5090e2 Initial load
duke
parents:
diff changeset
   470
  // Uses the lazy-update mechanism of 'get_ctrl'.
489c9b5090e2 Initial load
duke
parents:
diff changeset
   471
  lazy_replace( x, l );
489c9b5090e2 Initial load
duke
parents:
diff changeset
   472
  set_idom(l, init_control, dom_depth(x));
489c9b5090e2 Initial load
duke
parents:
diff changeset
   473
489c9b5090e2 Initial load
duke
parents:
diff changeset
   474
  // Check for immediately preceeding SafePoint and remove
489c9b5090e2 Initial load
duke
parents:
diff changeset
   475
  Node *sfpt2 = le->in(0);
489c9b5090e2 Initial load
duke
parents:
diff changeset
   476
  if( sfpt2->Opcode() == Op_SafePoint && is_deleteable_safept(sfpt2))
489c9b5090e2 Initial load
duke
parents:
diff changeset
   477
    lazy_replace( sfpt2, sfpt2->in(TypeFunc::Control));
489c9b5090e2 Initial load
duke
parents:
diff changeset
   478
489c9b5090e2 Initial load
duke
parents:
diff changeset
   479
  // Free up intermediate goo
489c9b5090e2 Initial load
duke
parents:
diff changeset
   480
  _igvn.remove_dead_node(hook);
489c9b5090e2 Initial load
duke
parents:
diff changeset
   481
489c9b5090e2 Initial load
duke
parents:
diff changeset
   482
  C->print_method("After CountedLoop", 3);
489c9b5090e2 Initial load
duke
parents:
diff changeset
   483
489c9b5090e2 Initial load
duke
parents:
diff changeset
   484
  // Return trip counter
489c9b5090e2 Initial load
duke
parents:
diff changeset
   485
  return trip_count;
489c9b5090e2 Initial load
duke
parents:
diff changeset
   486
}
489c9b5090e2 Initial load
duke
parents:
diff changeset
   487
489c9b5090e2 Initial load
duke
parents:
diff changeset
   488
489c9b5090e2 Initial load
duke
parents:
diff changeset
   489
//------------------------------Ideal------------------------------------------
489c9b5090e2 Initial load
duke
parents:
diff changeset
   490
// Return a node which is more "ideal" than the current node.
489c9b5090e2 Initial load
duke
parents:
diff changeset
   491
// Attempt to convert into a counted-loop.
489c9b5090e2 Initial load
duke
parents:
diff changeset
   492
Node *LoopNode::Ideal(PhaseGVN *phase, bool can_reshape) {
489c9b5090e2 Initial load
duke
parents:
diff changeset
   493
  if (!can_be_counted_loop(phase)) {
489c9b5090e2 Initial load
duke
parents:
diff changeset
   494
    phase->C->set_major_progress();
489c9b5090e2 Initial load
duke
parents:
diff changeset
   495
  }
489c9b5090e2 Initial load
duke
parents:
diff changeset
   496
  return RegionNode::Ideal(phase, can_reshape);
489c9b5090e2 Initial load
duke
parents:
diff changeset
   497
}
489c9b5090e2 Initial load
duke
parents:
diff changeset
   498
489c9b5090e2 Initial load
duke
parents:
diff changeset
   499
489c9b5090e2 Initial load
duke
parents:
diff changeset
   500
//=============================================================================
489c9b5090e2 Initial load
duke
parents:
diff changeset
   501
//------------------------------Ideal------------------------------------------
489c9b5090e2 Initial load
duke
parents:
diff changeset
   502
// Return a node which is more "ideal" than the current node.
489c9b5090e2 Initial load
duke
parents:
diff changeset
   503
// Attempt to convert into a counted-loop.
489c9b5090e2 Initial load
duke
parents:
diff changeset
   504
Node *CountedLoopNode::Ideal(PhaseGVN *phase, bool can_reshape) {
489c9b5090e2 Initial load
duke
parents:
diff changeset
   505
  return RegionNode::Ideal(phase, can_reshape);
489c9b5090e2 Initial load
duke
parents:
diff changeset
   506
}
489c9b5090e2 Initial load
duke
parents:
diff changeset
   507
489c9b5090e2 Initial load
duke
parents:
diff changeset
   508
//------------------------------dump_spec--------------------------------------
489c9b5090e2 Initial load
duke
parents:
diff changeset
   509
// Dump special per-node info
489c9b5090e2 Initial load
duke
parents:
diff changeset
   510
#ifndef PRODUCT
489c9b5090e2 Initial load
duke
parents:
diff changeset
   511
void CountedLoopNode::dump_spec(outputStream *st) const {
489c9b5090e2 Initial load
duke
parents:
diff changeset
   512
  LoopNode::dump_spec(st);
489c9b5090e2 Initial load
duke
parents:
diff changeset
   513
  if( stride_is_con() ) {
489c9b5090e2 Initial load
duke
parents:
diff changeset
   514
    st->print("stride: %d ",stride_con());
489c9b5090e2 Initial load
duke
parents:
diff changeset
   515
  } else {
489c9b5090e2 Initial load
duke
parents:
diff changeset
   516
    st->print("stride: not constant ");
489c9b5090e2 Initial load
duke
parents:
diff changeset
   517
  }
489c9b5090e2 Initial load
duke
parents:
diff changeset
   518
  if( is_pre_loop () ) st->print("pre of N%d" , _main_idx );
489c9b5090e2 Initial load
duke
parents:
diff changeset
   519
  if( is_main_loop() ) st->print("main of N%d", _idx );
489c9b5090e2 Initial load
duke
parents:
diff changeset
   520
  if( is_post_loop() ) st->print("post of N%d", _main_idx );
489c9b5090e2 Initial load
duke
parents:
diff changeset
   521
}
489c9b5090e2 Initial load
duke
parents:
diff changeset
   522
#endif
489c9b5090e2 Initial load
duke
parents:
diff changeset
   523
489c9b5090e2 Initial load
duke
parents:
diff changeset
   524
//=============================================================================
489c9b5090e2 Initial load
duke
parents:
diff changeset
   525
int CountedLoopEndNode::stride_con() const {
489c9b5090e2 Initial load
duke
parents:
diff changeset
   526
  return stride()->bottom_type()->is_int()->get_con();
489c9b5090e2 Initial load
duke
parents:
diff changeset
   527
}
489c9b5090e2 Initial load
duke
parents:
diff changeset
   528
489c9b5090e2 Initial load
duke
parents:
diff changeset
   529
489c9b5090e2 Initial load
duke
parents:
diff changeset
   530
//----------------------match_incr_with_optional_truncation--------------------
489c9b5090e2 Initial load
duke
parents:
diff changeset
   531
// Match increment with optional truncation:
489c9b5090e2 Initial load
duke
parents:
diff changeset
   532
// CHAR: (i+1)&0x7fff, BYTE: ((i+1)<<8)>>8, or SHORT: ((i+1)<<16)>>16
489c9b5090e2 Initial load
duke
parents:
diff changeset
   533
// Return NULL for failure. Success returns the increment node.
489c9b5090e2 Initial load
duke
parents:
diff changeset
   534
Node* CountedLoopNode::match_incr_with_optional_truncation(
489c9b5090e2 Initial load
duke
parents:
diff changeset
   535
                      Node* expr, Node** trunc1, Node** trunc2, const TypeInt** trunc_type) {
489c9b5090e2 Initial load
duke
parents:
diff changeset
   536
  // Quick cutouts:
489c9b5090e2 Initial load
duke
parents:
diff changeset
   537
  if (expr == NULL || expr->req() != 3)  return false;
489c9b5090e2 Initial load
duke
parents:
diff changeset
   538
489c9b5090e2 Initial load
duke
parents:
diff changeset
   539
  Node *t1 = NULL;
489c9b5090e2 Initial load
duke
parents:
diff changeset
   540
  Node *t2 = NULL;
489c9b5090e2 Initial load
duke
parents:
diff changeset
   541
  const TypeInt* trunc_t = TypeInt::INT;
489c9b5090e2 Initial load
duke
parents:
diff changeset
   542
  Node* n1 = expr;
489c9b5090e2 Initial load
duke
parents:
diff changeset
   543
  int   n1op = n1->Opcode();
489c9b5090e2 Initial load
duke
parents:
diff changeset
   544
489c9b5090e2 Initial load
duke
parents:
diff changeset
   545
  // Try to strip (n1 & M) or (n1 << N >> N) from n1.
489c9b5090e2 Initial load
duke
parents:
diff changeset
   546
  if (n1op == Op_AndI &&
489c9b5090e2 Initial load
duke
parents:
diff changeset
   547
      n1->in(2)->is_Con() &&
489c9b5090e2 Initial load
duke
parents:
diff changeset
   548
      n1->in(2)->bottom_type()->is_int()->get_con() == 0x7fff) {
489c9b5090e2 Initial load
duke
parents:
diff changeset
   549
    // %%% This check should match any mask of 2**K-1.
489c9b5090e2 Initial load
duke
parents:
diff changeset
   550
    t1 = n1;
489c9b5090e2 Initial load
duke
parents:
diff changeset
   551
    n1 = t1->in(1);
489c9b5090e2 Initial load
duke
parents:
diff changeset
   552
    n1op = n1->Opcode();
489c9b5090e2 Initial load
duke
parents:
diff changeset
   553
    trunc_t = TypeInt::CHAR;
489c9b5090e2 Initial load
duke
parents:
diff changeset
   554
  } else if (n1op == Op_RShiftI &&
489c9b5090e2 Initial load
duke
parents:
diff changeset
   555
             n1->in(1) != NULL &&
489c9b5090e2 Initial load
duke
parents:
diff changeset
   556
             n1->in(1)->Opcode() == Op_LShiftI &&
489c9b5090e2 Initial load
duke
parents:
diff changeset
   557
             n1->in(2) == n1->in(1)->in(2) &&
489c9b5090e2 Initial load
duke
parents:
diff changeset
   558
             n1->in(2)->is_Con()) {
489c9b5090e2 Initial load
duke
parents:
diff changeset
   559
    jint shift = n1->in(2)->bottom_type()->is_int()->get_con();
489c9b5090e2 Initial load
duke
parents:
diff changeset
   560
    // %%% This check should match any shift in [1..31].
489c9b5090e2 Initial load
duke
parents:
diff changeset
   561
    if (shift == 16 || shift == 8) {
489c9b5090e2 Initial load
duke
parents:
diff changeset
   562
      t1 = n1;
489c9b5090e2 Initial load
duke
parents:
diff changeset
   563
      t2 = t1->in(1);
489c9b5090e2 Initial load
duke
parents:
diff changeset
   564
      n1 = t2->in(1);
489c9b5090e2 Initial load
duke
parents:
diff changeset
   565
      n1op = n1->Opcode();
489c9b5090e2 Initial load
duke
parents:
diff changeset
   566
      if (shift == 16) {
489c9b5090e2 Initial load
duke
parents:
diff changeset
   567
        trunc_t = TypeInt::SHORT;
489c9b5090e2 Initial load
duke
parents:
diff changeset
   568
      } else if (shift == 8) {
489c9b5090e2 Initial load
duke
parents:
diff changeset
   569
        trunc_t = TypeInt::BYTE;
489c9b5090e2 Initial load
duke
parents:
diff changeset
   570
      }
489c9b5090e2 Initial load
duke
parents:
diff changeset
   571
    }
489c9b5090e2 Initial load
duke
parents:
diff changeset
   572
  }
489c9b5090e2 Initial load
duke
parents:
diff changeset
   573
489c9b5090e2 Initial load
duke
parents:
diff changeset
   574
  // If (maybe after stripping) it is an AddI, we won:
489c9b5090e2 Initial load
duke
parents:
diff changeset
   575
  if (n1op == Op_AddI) {
489c9b5090e2 Initial load
duke
parents:
diff changeset
   576
    *trunc1 = t1;
489c9b5090e2 Initial load
duke
parents:
diff changeset
   577
    *trunc2 = t2;
489c9b5090e2 Initial load
duke
parents:
diff changeset
   578
    *trunc_type = trunc_t;
489c9b5090e2 Initial load
duke
parents:
diff changeset
   579
    return n1;
489c9b5090e2 Initial load
duke
parents:
diff changeset
   580
  }
489c9b5090e2 Initial load
duke
parents:
diff changeset
   581
489c9b5090e2 Initial load
duke
parents:
diff changeset
   582
  // failed
489c9b5090e2 Initial load
duke
parents:
diff changeset
   583
  return NULL;
489c9b5090e2 Initial load
duke
parents:
diff changeset
   584
}
489c9b5090e2 Initial load
duke
parents:
diff changeset
   585
489c9b5090e2 Initial load
duke
parents:
diff changeset
   586
489c9b5090e2 Initial load
duke
parents:
diff changeset
   587
//------------------------------filtered_type--------------------------------
489c9b5090e2 Initial load
duke
parents:
diff changeset
   588
// Return a type based on condition control flow
489c9b5090e2 Initial load
duke
parents:
diff changeset
   589
// A successful return will be a type that is restricted due
489c9b5090e2 Initial load
duke
parents:
diff changeset
   590
// to a series of dominating if-tests, such as:
489c9b5090e2 Initial load
duke
parents:
diff changeset
   591
//    if (i < 10) {
489c9b5090e2 Initial load
duke
parents:
diff changeset
   592
//       if (i > 0) {
489c9b5090e2 Initial load
duke
parents:
diff changeset
   593
//          here: "i" type is [1..10)
489c9b5090e2 Initial load
duke
parents:
diff changeset
   594
//       }
489c9b5090e2 Initial load
duke
parents:
diff changeset
   595
//    }
489c9b5090e2 Initial load
duke
parents:
diff changeset
   596
// or a control flow merge
489c9b5090e2 Initial load
duke
parents:
diff changeset
   597
//    if (i < 10) {
489c9b5090e2 Initial load
duke
parents:
diff changeset
   598
//       do {
489c9b5090e2 Initial load
duke
parents:
diff changeset
   599
//          phi( , ) -- at top of loop type is [min_int..10)
489c9b5090e2 Initial load
duke
parents:
diff changeset
   600
//         i = ?
489c9b5090e2 Initial load
duke
parents:
diff changeset
   601
//       } while ( i < 10)
489c9b5090e2 Initial load
duke
parents:
diff changeset
   602
//
489c9b5090e2 Initial load
duke
parents:
diff changeset
   603
const TypeInt* PhaseIdealLoop::filtered_type( Node *n, Node* n_ctrl) {
489c9b5090e2 Initial load
duke
parents:
diff changeset
   604
  assert(n && n->bottom_type()->is_int(), "must be int");
489c9b5090e2 Initial load
duke
parents:
diff changeset
   605
  const TypeInt* filtered_t = NULL;
489c9b5090e2 Initial load
duke
parents:
diff changeset
   606
  if (!n->is_Phi()) {
489c9b5090e2 Initial load
duke
parents:
diff changeset
   607
    assert(n_ctrl != NULL || n_ctrl == C->top(), "valid control");
489c9b5090e2 Initial load
duke
parents:
diff changeset
   608
    filtered_t = filtered_type_from_dominators(n, n_ctrl);
489c9b5090e2 Initial load
duke
parents:
diff changeset
   609
489c9b5090e2 Initial load
duke
parents:
diff changeset
   610
  } else {
489c9b5090e2 Initial load
duke
parents:
diff changeset
   611
    Node* phi    = n->as_Phi();
489c9b5090e2 Initial load
duke
parents:
diff changeset
   612
    Node* region = phi->in(0);
489c9b5090e2 Initial load
duke
parents:
diff changeset
   613
    assert(n_ctrl == NULL || n_ctrl == region, "ctrl parameter must be region");
489c9b5090e2 Initial load
duke
parents:
diff changeset
   614
    if (region && region != C->top()) {
489c9b5090e2 Initial load
duke
parents:
diff changeset
   615
      for (uint i = 1; i < phi->req(); i++) {
489c9b5090e2 Initial load
duke
parents:
diff changeset
   616
        Node* val   = phi->in(i);
489c9b5090e2 Initial load
duke
parents:
diff changeset
   617
        Node* use_c = region->in(i);
489c9b5090e2 Initial load
duke
parents:
diff changeset
   618
        const TypeInt* val_t = filtered_type_from_dominators(val, use_c);
489c9b5090e2 Initial load
duke
parents:
diff changeset
   619
        if (val_t != NULL) {
489c9b5090e2 Initial load
duke
parents:
diff changeset
   620
          if (filtered_t == NULL) {
489c9b5090e2 Initial load
duke
parents:
diff changeset
   621
            filtered_t = val_t;
489c9b5090e2 Initial load
duke
parents:
diff changeset
   622
          } else {
489c9b5090e2 Initial load
duke
parents:
diff changeset
   623
            filtered_t = filtered_t->meet(val_t)->is_int();
489c9b5090e2 Initial load
duke
parents:
diff changeset
   624
          }
489c9b5090e2 Initial load
duke
parents:
diff changeset
   625
        }
489c9b5090e2 Initial load
duke
parents:
diff changeset
   626
      }
489c9b5090e2 Initial load
duke
parents:
diff changeset
   627
    }
489c9b5090e2 Initial load
duke
parents:
diff changeset
   628
  }
489c9b5090e2 Initial load
duke
parents:
diff changeset
   629
  const TypeInt* n_t = _igvn.type(n)->is_int();
489c9b5090e2 Initial load
duke
parents:
diff changeset
   630
  if (filtered_t != NULL) {
489c9b5090e2 Initial load
duke
parents:
diff changeset
   631
    n_t = n_t->join(filtered_t)->is_int();
489c9b5090e2 Initial load
duke
parents:
diff changeset
   632
  }
489c9b5090e2 Initial load
duke
parents:
diff changeset
   633
  return n_t;
489c9b5090e2 Initial load
duke
parents:
diff changeset
   634
}
489c9b5090e2 Initial load
duke
parents:
diff changeset
   635
489c9b5090e2 Initial load
duke
parents:
diff changeset
   636
489c9b5090e2 Initial load
duke
parents:
diff changeset
   637
//------------------------------filtered_type_from_dominators--------------------------------
489c9b5090e2 Initial load
duke
parents:
diff changeset
   638
// Return a possibly more restrictive type for val based on condition control flow of dominators
489c9b5090e2 Initial load
duke
parents:
diff changeset
   639
const TypeInt* PhaseIdealLoop::filtered_type_from_dominators( Node* val, Node *use_ctrl) {
489c9b5090e2 Initial load
duke
parents:
diff changeset
   640
  if (val->is_Con()) {
489c9b5090e2 Initial load
duke
parents:
diff changeset
   641
     return val->bottom_type()->is_int();
489c9b5090e2 Initial load
duke
parents:
diff changeset
   642
  }
489c9b5090e2 Initial load
duke
parents:
diff changeset
   643
  uint if_limit = 10; // Max number of dominating if's visited
489c9b5090e2 Initial load
duke
parents:
diff changeset
   644
  const TypeInt* rtn_t = NULL;
489c9b5090e2 Initial load
duke
parents:
diff changeset
   645
489c9b5090e2 Initial load
duke
parents:
diff changeset
   646
  if (use_ctrl && use_ctrl != C->top()) {
489c9b5090e2 Initial load
duke
parents:
diff changeset
   647
    Node* val_ctrl = get_ctrl(val);
489c9b5090e2 Initial load
duke
parents:
diff changeset
   648
    uint val_dom_depth = dom_depth(val_ctrl);
489c9b5090e2 Initial load
duke
parents:
diff changeset
   649
    Node* pred = use_ctrl;
489c9b5090e2 Initial load
duke
parents:
diff changeset
   650
    uint if_cnt = 0;
489c9b5090e2 Initial load
duke
parents:
diff changeset
   651
    while (if_cnt < if_limit) {
489c9b5090e2 Initial load
duke
parents:
diff changeset
   652
      if ((pred->Opcode() == Op_IfTrue || pred->Opcode() == Op_IfFalse)) {
489c9b5090e2 Initial load
duke
parents:
diff changeset
   653
        if_cnt++;
489c9b5090e2 Initial load
duke
parents:
diff changeset
   654
        const TypeInt* if_t = filtered_type_at_if(val, pred);
489c9b5090e2 Initial load
duke
parents:
diff changeset
   655
        if (if_t != NULL) {
489c9b5090e2 Initial load
duke
parents:
diff changeset
   656
          if (rtn_t == NULL) {
489c9b5090e2 Initial load
duke
parents:
diff changeset
   657
            rtn_t = if_t;
489c9b5090e2 Initial load
duke
parents:
diff changeset
   658
          } else {
489c9b5090e2 Initial load
duke
parents:
diff changeset
   659
            rtn_t = rtn_t->join(if_t)->is_int();
489c9b5090e2 Initial load
duke
parents:
diff changeset
   660
          }
489c9b5090e2 Initial load
duke
parents:
diff changeset
   661
        }
489c9b5090e2 Initial load
duke
parents:
diff changeset
   662
      }
489c9b5090e2 Initial load
duke
parents:
diff changeset
   663
      pred = idom(pred);
489c9b5090e2 Initial load
duke
parents:
diff changeset
   664
      if (pred == NULL || pred == C->top()) {
489c9b5090e2 Initial load
duke
parents:
diff changeset
   665
        break;
489c9b5090e2 Initial load
duke
parents:
diff changeset
   666
      }
489c9b5090e2 Initial load
duke
parents:
diff changeset
   667
      // Stop if going beyond definition block of val
489c9b5090e2 Initial load
duke
parents:
diff changeset
   668
      if (dom_depth(pred) < val_dom_depth) {
489c9b5090e2 Initial load
duke
parents:
diff changeset
   669
        break;
489c9b5090e2 Initial load
duke
parents:
diff changeset
   670
      }
489c9b5090e2 Initial load
duke
parents:
diff changeset
   671
    }
489c9b5090e2 Initial load
duke
parents:
diff changeset
   672
  }
489c9b5090e2 Initial load
duke
parents:
diff changeset
   673
  return rtn_t;
489c9b5090e2 Initial load
duke
parents:
diff changeset
   674
}
489c9b5090e2 Initial load
duke
parents:
diff changeset
   675
489c9b5090e2 Initial load
duke
parents:
diff changeset
   676
489c9b5090e2 Initial load
duke
parents:
diff changeset
   677
//------------------------------filtered_type_at_if--------------------------------
489c9b5090e2 Initial load
duke
parents:
diff changeset
   678
// Return a possibly more restrictive type for val based on condition control flow for an if
489c9b5090e2 Initial load
duke
parents:
diff changeset
   679
const TypeInt* PhaseIdealLoop::filtered_type_at_if( Node* val, Node *if_proj) {
489c9b5090e2 Initial load
duke
parents:
diff changeset
   680
  assert(if_proj &&
489c9b5090e2 Initial load
duke
parents:
diff changeset
   681
         (if_proj->Opcode() == Op_IfTrue || if_proj->Opcode() == Op_IfFalse), "expecting an if projection");
489c9b5090e2 Initial load
duke
parents:
diff changeset
   682
  if (if_proj->in(0) && if_proj->in(0)->is_If()) {
489c9b5090e2 Initial load
duke
parents:
diff changeset
   683
    IfNode* iff = if_proj->in(0)->as_If();
489c9b5090e2 Initial load
duke
parents:
diff changeset
   684
    if (iff->in(1) && iff->in(1)->is_Bool()) {
489c9b5090e2 Initial load
duke
parents:
diff changeset
   685
      BoolNode* bol = iff->in(1)->as_Bool();
489c9b5090e2 Initial load
duke
parents:
diff changeset
   686
      if (bol->in(1) && bol->in(1)->is_Cmp()) {
489c9b5090e2 Initial load
duke
parents:
diff changeset
   687
        const CmpNode* cmp  = bol->in(1)->as_Cmp();
489c9b5090e2 Initial load
duke
parents:
diff changeset
   688
        if (cmp->in(1) == val) {
489c9b5090e2 Initial load
duke
parents:
diff changeset
   689
          const TypeInt* cmp2_t = _igvn.type(cmp->in(2))->isa_int();
489c9b5090e2 Initial load
duke
parents:
diff changeset
   690
          if (cmp2_t != NULL) {
489c9b5090e2 Initial load
duke
parents:
diff changeset
   691
            jint lo = cmp2_t->_lo;
489c9b5090e2 Initial load
duke
parents:
diff changeset
   692
            jint hi = cmp2_t->_hi;
489c9b5090e2 Initial load
duke
parents:
diff changeset
   693
            BoolTest::mask msk = if_proj->Opcode() == Op_IfTrue ? bol->_test._test : bol->_test.negate();
489c9b5090e2 Initial load
duke
parents:
diff changeset
   694
            switch (msk) {
489c9b5090e2 Initial load
duke
parents:
diff changeset
   695
            case BoolTest::ne:
489c9b5090e2 Initial load
duke
parents:
diff changeset
   696
              // Can't refine type
489c9b5090e2 Initial load
duke
parents:
diff changeset
   697
              return NULL;
489c9b5090e2 Initial load
duke
parents:
diff changeset
   698
            case BoolTest::eq:
489c9b5090e2 Initial load
duke
parents:
diff changeset
   699
              return cmp2_t;
489c9b5090e2 Initial load
duke
parents:
diff changeset
   700
            case BoolTest::lt:
489c9b5090e2 Initial load
duke
parents:
diff changeset
   701
              lo = TypeInt::INT->_lo;
489c9b5090e2 Initial load
duke
parents:
diff changeset
   702
              if (hi - 1 < hi) {
489c9b5090e2 Initial load
duke
parents:
diff changeset
   703
                hi = hi - 1;
489c9b5090e2 Initial load
duke
parents:
diff changeset
   704
              }
489c9b5090e2 Initial load
duke
parents:
diff changeset
   705
              break;
489c9b5090e2 Initial load
duke
parents:
diff changeset
   706
            case BoolTest::le:
489c9b5090e2 Initial load
duke
parents:
diff changeset
   707
              lo = TypeInt::INT->_lo;
489c9b5090e2 Initial load
duke
parents:
diff changeset
   708
              break;
489c9b5090e2 Initial load
duke
parents:
diff changeset
   709
            case BoolTest::gt:
489c9b5090e2 Initial load
duke
parents:
diff changeset
   710
              if (lo + 1 > lo) {
489c9b5090e2 Initial load
duke
parents:
diff changeset
   711
                lo = lo + 1;
489c9b5090e2 Initial load
duke
parents:
diff changeset
   712
              }
489c9b5090e2 Initial load
duke
parents:
diff changeset
   713
              hi = TypeInt::INT->_hi;
489c9b5090e2 Initial load
duke
parents:
diff changeset
   714
              break;
489c9b5090e2 Initial load
duke
parents:
diff changeset
   715
            case BoolTest::ge:
489c9b5090e2 Initial load
duke
parents:
diff changeset
   716
              // lo unchanged
489c9b5090e2 Initial load
duke
parents:
diff changeset
   717
              hi = TypeInt::INT->_hi;
489c9b5090e2 Initial load
duke
parents:
diff changeset
   718
              break;
489c9b5090e2 Initial load
duke
parents:
diff changeset
   719
            }
489c9b5090e2 Initial load
duke
parents:
diff changeset
   720
            const TypeInt* rtn_t = TypeInt::make(lo, hi, cmp2_t->_widen);
489c9b5090e2 Initial load
duke
parents:
diff changeset
   721
            return rtn_t;
489c9b5090e2 Initial load
duke
parents:
diff changeset
   722
          }
489c9b5090e2 Initial load
duke
parents:
diff changeset
   723
        }
489c9b5090e2 Initial load
duke
parents:
diff changeset
   724
      }
489c9b5090e2 Initial load
duke
parents:
diff changeset
   725
    }
489c9b5090e2 Initial load
duke
parents:
diff changeset
   726
  }
489c9b5090e2 Initial load
duke
parents:
diff changeset
   727
  return NULL;
489c9b5090e2 Initial load
duke
parents:
diff changeset
   728
}
489c9b5090e2 Initial load
duke
parents:
diff changeset
   729
489c9b5090e2 Initial load
duke
parents:
diff changeset
   730
//------------------------------dump_spec--------------------------------------
489c9b5090e2 Initial load
duke
parents:
diff changeset
   731
// Dump special per-node info
489c9b5090e2 Initial load
duke
parents:
diff changeset
   732
#ifndef PRODUCT
489c9b5090e2 Initial load
duke
parents:
diff changeset
   733
void CountedLoopEndNode::dump_spec(outputStream *st) const {
489c9b5090e2 Initial load
duke
parents:
diff changeset
   734
  if( in(TestValue)->is_Bool() ) {
489c9b5090e2 Initial load
duke
parents:
diff changeset
   735
    BoolTest bt( test_trip()); // Added this for g++.
489c9b5090e2 Initial load
duke
parents:
diff changeset
   736
489c9b5090e2 Initial load
duke
parents:
diff changeset
   737
    st->print("[");
489c9b5090e2 Initial load
duke
parents:
diff changeset
   738
    bt.dump_on(st);
489c9b5090e2 Initial load
duke
parents:
diff changeset
   739
    st->print("]");
489c9b5090e2 Initial load
duke
parents:
diff changeset
   740
  }
489c9b5090e2 Initial load
duke
parents:
diff changeset
   741
  st->print(" ");
489c9b5090e2 Initial load
duke
parents:
diff changeset
   742
  IfNode::dump_spec(st);
489c9b5090e2 Initial load
duke
parents:
diff changeset
   743
}
489c9b5090e2 Initial load
duke
parents:
diff changeset
   744
#endif
489c9b5090e2 Initial load
duke
parents:
diff changeset
   745
489c9b5090e2 Initial load
duke
parents:
diff changeset
   746
//=============================================================================
489c9b5090e2 Initial load
duke
parents:
diff changeset
   747
//------------------------------is_member--------------------------------------
489c9b5090e2 Initial load
duke
parents:
diff changeset
   748
// Is 'l' a member of 'this'?
489c9b5090e2 Initial load
duke
parents:
diff changeset
   749
int IdealLoopTree::is_member( const IdealLoopTree *l ) const {
489c9b5090e2 Initial load
duke
parents:
diff changeset
   750
  while( l->_nest > _nest ) l = l->_parent;
489c9b5090e2 Initial load
duke
parents:
diff changeset
   751
  return l == this;
489c9b5090e2 Initial load
duke
parents:
diff changeset
   752
}
489c9b5090e2 Initial load
duke
parents:
diff changeset
   753
489c9b5090e2 Initial load
duke
parents:
diff changeset
   754
//------------------------------set_nest---------------------------------------
489c9b5090e2 Initial load
duke
parents:
diff changeset
   755
// Set loop tree nesting depth.  Accumulate _has_call bits.
489c9b5090e2 Initial load
duke
parents:
diff changeset
   756
int IdealLoopTree::set_nest( uint depth ) {
489c9b5090e2 Initial load
duke
parents:
diff changeset
   757
  _nest = depth;
489c9b5090e2 Initial load
duke
parents:
diff changeset
   758
  int bits = _has_call;
489c9b5090e2 Initial load
duke
parents:
diff changeset
   759
  if( _child ) bits |= _child->set_nest(depth+1);
489c9b5090e2 Initial load
duke
parents:
diff changeset
   760
  if( bits ) _has_call = 1;
489c9b5090e2 Initial load
duke
parents:
diff changeset
   761
  if( _next  ) bits |= _next ->set_nest(depth  );
489c9b5090e2 Initial load
duke
parents:
diff changeset
   762
  return bits;
489c9b5090e2 Initial load
duke
parents:
diff changeset
   763
}
489c9b5090e2 Initial load
duke
parents:
diff changeset
   764
489c9b5090e2 Initial load
duke
parents:
diff changeset
   765
//------------------------------split_fall_in----------------------------------
489c9b5090e2 Initial load
duke
parents:
diff changeset
   766
// Split out multiple fall-in edges from the loop header.  Move them to a
489c9b5090e2 Initial load
duke
parents:
diff changeset
   767
// private RegionNode before the loop.  This becomes the loop landing pad.
489c9b5090e2 Initial load
duke
parents:
diff changeset
   768
void IdealLoopTree::split_fall_in( PhaseIdealLoop *phase, int fall_in_cnt ) {
489c9b5090e2 Initial load
duke
parents:
diff changeset
   769
  PhaseIterGVN &igvn = phase->_igvn;
489c9b5090e2 Initial load
duke
parents:
diff changeset
   770
  uint i;
489c9b5090e2 Initial load
duke
parents:
diff changeset
   771
489c9b5090e2 Initial load
duke
parents:
diff changeset
   772
  // Make a new RegionNode to be the landing pad.
489c9b5090e2 Initial load
duke
parents:
diff changeset
   773
  Node *landing_pad = new (phase->C, fall_in_cnt+1) RegionNode( fall_in_cnt+1 );
489c9b5090e2 Initial load
duke
parents:
diff changeset
   774
  phase->set_loop(landing_pad,_parent);
489c9b5090e2 Initial load
duke
parents:
diff changeset
   775
  // Gather all the fall-in control paths into the landing pad
489c9b5090e2 Initial load
duke
parents:
diff changeset
   776
  uint icnt = fall_in_cnt;
489c9b5090e2 Initial load
duke
parents:
diff changeset
   777
  uint oreq = _head->req();
489c9b5090e2 Initial load
duke
parents:
diff changeset
   778
  for( i = oreq-1; i>0; i-- )
489c9b5090e2 Initial load
duke
parents:
diff changeset
   779
    if( !phase->is_member( this, _head->in(i) ) )
489c9b5090e2 Initial load
duke
parents:
diff changeset
   780
      landing_pad->set_req(icnt--,_head->in(i));
489c9b5090e2 Initial load
duke
parents:
diff changeset
   781
489c9b5090e2 Initial load
duke
parents:
diff changeset
   782
  // Peel off PhiNode edges as well
489c9b5090e2 Initial load
duke
parents:
diff changeset
   783
  for (DUIterator_Fast jmax, j = _head->fast_outs(jmax); j < jmax; j++) {
489c9b5090e2 Initial load
duke
parents:
diff changeset
   784
    Node *oj = _head->fast_out(j);
489c9b5090e2 Initial load
duke
parents:
diff changeset
   785
    if( oj->is_Phi() ) {
489c9b5090e2 Initial load
duke
parents:
diff changeset
   786
      PhiNode* old_phi = oj->as_Phi();
489c9b5090e2 Initial load
duke
parents:
diff changeset
   787
      assert( old_phi->region() == _head, "" );
489c9b5090e2 Initial load
duke
parents:
diff changeset
   788
      igvn.hash_delete(old_phi);   // Yank from hash before hacking edges
489c9b5090e2 Initial load
duke
parents:
diff changeset
   789
      Node *p = PhiNode::make_blank(landing_pad, old_phi);
489c9b5090e2 Initial load
duke
parents:
diff changeset
   790
      uint icnt = fall_in_cnt;
489c9b5090e2 Initial load
duke
parents:
diff changeset
   791
      for( i = oreq-1; i>0; i-- ) {
489c9b5090e2 Initial load
duke
parents:
diff changeset
   792
        if( !phase->is_member( this, _head->in(i) ) ) {
489c9b5090e2 Initial load
duke
parents:
diff changeset
   793
          p->init_req(icnt--, old_phi->in(i));
489c9b5090e2 Initial load
duke
parents:
diff changeset
   794
          // Go ahead and clean out old edges from old phi
489c9b5090e2 Initial load
duke
parents:
diff changeset
   795
          old_phi->del_req(i);
489c9b5090e2 Initial load
duke
parents:
diff changeset
   796
        }
489c9b5090e2 Initial load
duke
parents:
diff changeset
   797
      }
489c9b5090e2 Initial load
duke
parents:
diff changeset
   798
      // Search for CSE's here, because ZKM.jar does a lot of
489c9b5090e2 Initial load
duke
parents:
diff changeset
   799
      // loop hackery and we need to be a little incremental
489c9b5090e2 Initial load
duke
parents:
diff changeset
   800
      // with the CSE to avoid O(N^2) node blow-up.
489c9b5090e2 Initial load
duke
parents:
diff changeset
   801
      Node *p2 = igvn.hash_find_insert(p); // Look for a CSE
489c9b5090e2 Initial load
duke
parents:
diff changeset
   802
      if( p2 ) {                // Found CSE
489c9b5090e2 Initial load
duke
parents:
diff changeset
   803
        p->destruct();          // Recover useless new node
489c9b5090e2 Initial load
duke
parents:
diff changeset
   804
        p = p2;                 // Use old node
489c9b5090e2 Initial load
duke
parents:
diff changeset
   805
      } else {
489c9b5090e2 Initial load
duke
parents:
diff changeset
   806
        igvn.register_new_node_with_optimizer(p, old_phi);
489c9b5090e2 Initial load
duke
parents:
diff changeset
   807
      }
489c9b5090e2 Initial load
duke
parents:
diff changeset
   808
      // Make old Phi refer to new Phi.
489c9b5090e2 Initial load
duke
parents:
diff changeset
   809
      old_phi->add_req(p);
489c9b5090e2 Initial load
duke
parents:
diff changeset
   810
      // Check for the special case of making the old phi useless and
489c9b5090e2 Initial load
duke
parents:
diff changeset
   811
      // disappear it.  In JavaGrande I have a case where this useless
489c9b5090e2 Initial load
duke
parents:
diff changeset
   812
      // Phi is the loop limit and prevents recognizing a CountedLoop
489c9b5090e2 Initial load
duke
parents:
diff changeset
   813
      // which in turn prevents removing an empty loop.
489c9b5090e2 Initial load
duke
parents:
diff changeset
   814
      Node *id_old_phi = old_phi->Identity( &igvn );
489c9b5090e2 Initial load
duke
parents:
diff changeset
   815
      if( id_old_phi != old_phi ) { // Found a simple identity?
489c9b5090e2 Initial load
duke
parents:
diff changeset
   816
        // Note that I cannot call 'subsume_node' here, because
489c9b5090e2 Initial load
duke
parents:
diff changeset
   817
        // that will yank the edge from old_phi to the Region and
489c9b5090e2 Initial load
duke
parents:
diff changeset
   818
        // I'm mid-iteration over the Region's uses.
489c9b5090e2 Initial load
duke
parents:
diff changeset
   819
        for (DUIterator_Last imin, i = old_phi->last_outs(imin); i >= imin; ) {
489c9b5090e2 Initial load
duke
parents:
diff changeset
   820
          Node* use = old_phi->last_out(i);
489c9b5090e2 Initial load
duke
parents:
diff changeset
   821
          igvn.hash_delete(use);
489c9b5090e2 Initial load
duke
parents:
diff changeset
   822
          igvn._worklist.push(use);
489c9b5090e2 Initial load
duke
parents:
diff changeset
   823
          uint uses_found = 0;
489c9b5090e2 Initial load
duke
parents:
diff changeset
   824
          for (uint j = 0; j < use->len(); j++) {
489c9b5090e2 Initial load
duke
parents:
diff changeset
   825
            if (use->in(j) == old_phi) {
489c9b5090e2 Initial load
duke
parents:
diff changeset
   826
              if (j < use->req()) use->set_req (j, id_old_phi);
489c9b5090e2 Initial load
duke
parents:
diff changeset
   827
              else                use->set_prec(j, id_old_phi);
489c9b5090e2 Initial load
duke
parents:
diff changeset
   828
              uses_found++;
489c9b5090e2 Initial load
duke
parents:
diff changeset
   829
            }
489c9b5090e2 Initial load
duke
parents:
diff changeset
   830
          }
489c9b5090e2 Initial load
duke
parents:
diff changeset
   831
          i -= uses_found;    // we deleted 1 or more copies of this edge
489c9b5090e2 Initial load
duke
parents:
diff changeset
   832
        }
489c9b5090e2 Initial load
duke
parents:
diff changeset
   833
      }
489c9b5090e2 Initial load
duke
parents:
diff changeset
   834
      igvn._worklist.push(old_phi);
489c9b5090e2 Initial load
duke
parents:
diff changeset
   835
    }
489c9b5090e2 Initial load
duke
parents:
diff changeset
   836
  }
489c9b5090e2 Initial load
duke
parents:
diff changeset
   837
  // Finally clean out the fall-in edges from the RegionNode
489c9b5090e2 Initial load
duke
parents:
diff changeset
   838
  for( i = oreq-1; i>0; i-- ) {
489c9b5090e2 Initial load
duke
parents:
diff changeset
   839
    if( !phase->is_member( this, _head->in(i) ) ) {
489c9b5090e2 Initial load
duke
parents:
diff changeset
   840
      _head->del_req(i);
489c9b5090e2 Initial load
duke
parents:
diff changeset
   841
    }
489c9b5090e2 Initial load
duke
parents:
diff changeset
   842
  }
489c9b5090e2 Initial load
duke
parents:
diff changeset
   843
  // Transform landing pad
489c9b5090e2 Initial load
duke
parents:
diff changeset
   844
  igvn.register_new_node_with_optimizer(landing_pad, _head);
489c9b5090e2 Initial load
duke
parents:
diff changeset
   845
  // Insert landing pad into the header
489c9b5090e2 Initial load
duke
parents:
diff changeset
   846
  _head->add_req(landing_pad);
489c9b5090e2 Initial load
duke
parents:
diff changeset
   847
}
489c9b5090e2 Initial load
duke
parents:
diff changeset
   848
489c9b5090e2 Initial load
duke
parents:
diff changeset
   849
//------------------------------split_outer_loop-------------------------------
489c9b5090e2 Initial load
duke
parents:
diff changeset
   850
// Split out the outermost loop from this shared header.
489c9b5090e2 Initial load
duke
parents:
diff changeset
   851
void IdealLoopTree::split_outer_loop( PhaseIdealLoop *phase ) {
489c9b5090e2 Initial load
duke
parents:
diff changeset
   852
  PhaseIterGVN &igvn = phase->_igvn;
489c9b5090e2 Initial load
duke
parents:
diff changeset
   853
489c9b5090e2 Initial load
duke
parents:
diff changeset
   854
  // Find index of outermost loop; it should also be my tail.
489c9b5090e2 Initial load
duke
parents:
diff changeset
   855
  uint outer_idx = 1;
489c9b5090e2 Initial load
duke
parents:
diff changeset
   856
  while( _head->in(outer_idx) != _tail ) outer_idx++;
489c9b5090e2 Initial load
duke
parents:
diff changeset
   857
489c9b5090e2 Initial load
duke
parents:
diff changeset
   858
  // Make a LoopNode for the outermost loop.
489c9b5090e2 Initial load
duke
parents:
diff changeset
   859
  Node *ctl = _head->in(LoopNode::EntryControl);
489c9b5090e2 Initial load
duke
parents:
diff changeset
   860
  Node *outer = new (phase->C, 3) LoopNode( ctl, _head->in(outer_idx) );
489c9b5090e2 Initial load
duke
parents:
diff changeset
   861
  outer = igvn.register_new_node_with_optimizer(outer, _head);
489c9b5090e2 Initial load
duke
parents:
diff changeset
   862
  phase->set_created_loop_node();
489c9b5090e2 Initial load
duke
parents:
diff changeset
   863
  // Outermost loop falls into '_head' loop
489c9b5090e2 Initial load
duke
parents:
diff changeset
   864
  _head->set_req(LoopNode::EntryControl, outer);
489c9b5090e2 Initial load
duke
parents:
diff changeset
   865
  _head->del_req(outer_idx);
489c9b5090e2 Initial load
duke
parents:
diff changeset
   866
  // Split all the Phis up between '_head' loop and 'outer' loop.
489c9b5090e2 Initial load
duke
parents:
diff changeset
   867
  for (DUIterator_Fast jmax, j = _head->fast_outs(jmax); j < jmax; j++) {
489c9b5090e2 Initial load
duke
parents:
diff changeset
   868
    Node *out = _head->fast_out(j);
489c9b5090e2 Initial load
duke
parents:
diff changeset
   869
    if( out->is_Phi() ) {
489c9b5090e2 Initial load
duke
parents:
diff changeset
   870
      PhiNode *old_phi = out->as_Phi();
489c9b5090e2 Initial load
duke
parents:
diff changeset
   871
      assert( old_phi->region() == _head, "" );
489c9b5090e2 Initial load
duke
parents:
diff changeset
   872
      Node *phi = PhiNode::make_blank(outer, old_phi);
489c9b5090e2 Initial load
duke
parents:
diff changeset
   873
      phi->init_req(LoopNode::EntryControl,    old_phi->in(LoopNode::EntryControl));
489c9b5090e2 Initial load
duke
parents:
diff changeset
   874
      phi->init_req(LoopNode::LoopBackControl, old_phi->in(outer_idx));
489c9b5090e2 Initial load
duke
parents:
diff changeset
   875
      phi = igvn.register_new_node_with_optimizer(phi, old_phi);
489c9b5090e2 Initial load
duke
parents:
diff changeset
   876
      // Make old Phi point to new Phi on the fall-in path
489c9b5090e2 Initial load
duke
parents:
diff changeset
   877
      igvn.hash_delete(old_phi);
489c9b5090e2 Initial load
duke
parents:
diff changeset
   878
      old_phi->set_req(LoopNode::EntryControl, phi);
489c9b5090e2 Initial load
duke
parents:
diff changeset
   879
      old_phi->del_req(outer_idx);
489c9b5090e2 Initial load
duke
parents:
diff changeset
   880
      igvn._worklist.push(old_phi);
489c9b5090e2 Initial load
duke
parents:
diff changeset
   881
    }
489c9b5090e2 Initial load
duke
parents:
diff changeset
   882
  }
489c9b5090e2 Initial load
duke
parents:
diff changeset
   883
489c9b5090e2 Initial load
duke
parents:
diff changeset
   884
  // Use the new loop head instead of the old shared one
489c9b5090e2 Initial load
duke
parents:
diff changeset
   885
  _head = outer;
489c9b5090e2 Initial load
duke
parents:
diff changeset
   886
  phase->set_loop(_head, this);
489c9b5090e2 Initial load
duke
parents:
diff changeset
   887
}
489c9b5090e2 Initial load
duke
parents:
diff changeset
   888
489c9b5090e2 Initial load
duke
parents:
diff changeset
   889
//------------------------------fix_parent-------------------------------------
489c9b5090e2 Initial load
duke
parents:
diff changeset
   890
static void fix_parent( IdealLoopTree *loop, IdealLoopTree *parent ) {
489c9b5090e2 Initial load
duke
parents:
diff changeset
   891
  loop->_parent = parent;
489c9b5090e2 Initial load
duke
parents:
diff changeset
   892
  if( loop->_child ) fix_parent( loop->_child, loop   );
489c9b5090e2 Initial load
duke
parents:
diff changeset
   893
  if( loop->_next  ) fix_parent( loop->_next , parent );
489c9b5090e2 Initial load
duke
parents:
diff changeset
   894
}
489c9b5090e2 Initial load
duke
parents:
diff changeset
   895
489c9b5090e2 Initial load
duke
parents:
diff changeset
   896
//------------------------------estimate_path_freq-----------------------------
489c9b5090e2 Initial load
duke
parents:
diff changeset
   897
static float estimate_path_freq( Node *n ) {
489c9b5090e2 Initial load
duke
parents:
diff changeset
   898
  // Try to extract some path frequency info
489c9b5090e2 Initial load
duke
parents:
diff changeset
   899
  IfNode *iff;
489c9b5090e2 Initial load
duke
parents:
diff changeset
   900
  for( int i = 0; i < 50; i++ ) { // Skip through a bunch of uncommon tests
489c9b5090e2 Initial load
duke
parents:
diff changeset
   901
    uint nop = n->Opcode();
489c9b5090e2 Initial load
duke
parents:
diff changeset
   902
    if( nop == Op_SafePoint ) {   // Skip any safepoint
489c9b5090e2 Initial load
duke
parents:
diff changeset
   903
      n = n->in(0);
489c9b5090e2 Initial load
duke
parents:
diff changeset
   904
      continue;
489c9b5090e2 Initial load
duke
parents:
diff changeset
   905
    }
489c9b5090e2 Initial load
duke
parents:
diff changeset
   906
    if( nop == Op_CatchProj ) {   // Get count from a prior call
489c9b5090e2 Initial load
duke
parents:
diff changeset
   907
      // Assume call does not always throw exceptions: means the call-site
489c9b5090e2 Initial load
duke
parents:
diff changeset
   908
      // count is also the frequency of the fall-through path.
489c9b5090e2 Initial load
duke
parents:
diff changeset
   909
      assert( n->is_CatchProj(), "" );
489c9b5090e2 Initial load
duke
parents:
diff changeset
   910
      if( ((CatchProjNode*)n)->_con != CatchProjNode::fall_through_index )
489c9b5090e2 Initial load
duke
parents:
diff changeset
   911
        return 0.0f;            // Assume call exception path is rare
489c9b5090e2 Initial load
duke
parents:
diff changeset
   912
      Node *call = n->in(0)->in(0)->in(0);
489c9b5090e2 Initial load
duke
parents:
diff changeset
   913
      assert( call->is_Call(), "expect a call here" );
489c9b5090e2 Initial load
duke
parents:
diff changeset
   914
      const JVMState *jvms = ((CallNode*)call)->jvms();
489c9b5090e2 Initial load
duke
parents:
diff changeset
   915
      ciMethodData* methodData = jvms->method()->method_data();
489c9b5090e2 Initial load
duke
parents:
diff changeset
   916
      if (!methodData->is_mature())  return 0.0f; // No call-site data
489c9b5090e2 Initial load
duke
parents:
diff changeset
   917
      ciProfileData* data = methodData->bci_to_data(jvms->bci());
489c9b5090e2 Initial load
duke
parents:
diff changeset
   918
      if ((data == NULL) || !data->is_CounterData()) {
489c9b5090e2 Initial load
duke
parents:
diff changeset
   919
        // no call profile available, try call's control input
489c9b5090e2 Initial load
duke
parents:
diff changeset
   920
        n = n->in(0);
489c9b5090e2 Initial load
duke
parents:
diff changeset
   921
        continue;
489c9b5090e2 Initial load
duke
parents:
diff changeset
   922
      }
489c9b5090e2 Initial load
duke
parents:
diff changeset
   923
      return data->as_CounterData()->count()/FreqCountInvocations;
489c9b5090e2 Initial load
duke
parents:
diff changeset
   924
    }
489c9b5090e2 Initial load
duke
parents:
diff changeset
   925
    // See if there's a gating IF test
489c9b5090e2 Initial load
duke
parents:
diff changeset
   926
    Node *n_c = n->in(0);
489c9b5090e2 Initial load
duke
parents:
diff changeset
   927
    if( !n_c->is_If() ) break;       // No estimate available
489c9b5090e2 Initial load
duke
parents:
diff changeset
   928
    iff = n_c->as_If();
489c9b5090e2 Initial load
duke
parents:
diff changeset
   929
    if( iff->_fcnt != COUNT_UNKNOWN )   // Have a valid count?
489c9b5090e2 Initial load
duke
parents:
diff changeset
   930
      // Compute how much count comes on this path
489c9b5090e2 Initial load
duke
parents:
diff changeset
   931
      return ((nop == Op_IfTrue) ? iff->_prob : 1.0f - iff->_prob) * iff->_fcnt;
489c9b5090e2 Initial load
duke
parents:
diff changeset
   932
    // Have no count info.  Skip dull uncommon-trap like branches.
489c9b5090e2 Initial load
duke
parents:
diff changeset
   933
    if( (nop == Op_IfTrue  && iff->_prob < PROB_LIKELY_MAG(5)) ||
489c9b5090e2 Initial load
duke
parents:
diff changeset
   934
        (nop == Op_IfFalse && iff->_prob > PROB_UNLIKELY_MAG(5)) )
489c9b5090e2 Initial load
duke
parents:
diff changeset
   935
      break;
489c9b5090e2 Initial load
duke
parents:
diff changeset
   936
    // Skip through never-taken branch; look for a real loop exit.
489c9b5090e2 Initial load
duke
parents:
diff changeset
   937
    n = iff->in(0);
489c9b5090e2 Initial load
duke
parents:
diff changeset
   938
  }
489c9b5090e2 Initial load
duke
parents:
diff changeset
   939
  return 0.0f;                  // No estimate available
489c9b5090e2 Initial load
duke
parents:
diff changeset
   940
}
489c9b5090e2 Initial load
duke
parents:
diff changeset
   941
489c9b5090e2 Initial load
duke
parents:
diff changeset
   942
//------------------------------merge_many_backedges---------------------------
489c9b5090e2 Initial load
duke
parents:
diff changeset
   943
// Merge all the backedges from the shared header into a private Region.
489c9b5090e2 Initial load
duke
parents:
diff changeset
   944
// Feed that region as the one backedge to this loop.
489c9b5090e2 Initial load
duke
parents:
diff changeset
   945
void IdealLoopTree::merge_many_backedges( PhaseIdealLoop *phase ) {
489c9b5090e2 Initial load
duke
parents:
diff changeset
   946
  uint i;
489c9b5090e2 Initial load
duke
parents:
diff changeset
   947
489c9b5090e2 Initial load
duke
parents:
diff changeset
   948
  // Scan for the top 2 hottest backedges
489c9b5090e2 Initial load
duke
parents:
diff changeset
   949
  float hotcnt = 0.0f;
489c9b5090e2 Initial load
duke
parents:
diff changeset
   950
  float warmcnt = 0.0f;
489c9b5090e2 Initial load
duke
parents:
diff changeset
   951
  uint hot_idx = 0;
489c9b5090e2 Initial load
duke
parents:
diff changeset
   952
  // Loop starts at 2 because slot 1 is the fall-in path
489c9b5090e2 Initial load
duke
parents:
diff changeset
   953
  for( i = 2; i < _head->req(); i++ ) {
489c9b5090e2 Initial load
duke
parents:
diff changeset
   954
    float cnt = estimate_path_freq(_head->in(i));
489c9b5090e2 Initial load
duke
parents:
diff changeset
   955
    if( cnt > hotcnt ) {       // Grab hottest path
489c9b5090e2 Initial load
duke
parents:
diff changeset
   956
      warmcnt = hotcnt;
489c9b5090e2 Initial load
duke
parents:
diff changeset
   957
      hotcnt = cnt;
489c9b5090e2 Initial load
duke
parents:
diff changeset
   958
      hot_idx = i;
489c9b5090e2 Initial load
duke
parents:
diff changeset
   959
    } else if( cnt > warmcnt ) { // And 2nd hottest path
489c9b5090e2 Initial load
duke
parents:
diff changeset
   960
      warmcnt = cnt;
489c9b5090e2 Initial load
duke
parents:
diff changeset
   961
    }
489c9b5090e2 Initial load
duke
parents:
diff changeset
   962
  }
489c9b5090e2 Initial load
duke
parents:
diff changeset
   963
489c9b5090e2 Initial load
duke
parents:
diff changeset
   964
  // See if the hottest backedge is worthy of being an inner loop
489c9b5090e2 Initial load
duke
parents:
diff changeset
   965
  // by being much hotter than the next hottest backedge.
489c9b5090e2 Initial load
duke
parents:
diff changeset
   966
  if( hotcnt <= 0.0001 ||
489c9b5090e2 Initial load
duke
parents:
diff changeset
   967
      hotcnt < 2.0*warmcnt ) hot_idx = 0;// No hot backedge
489c9b5090e2 Initial load
duke
parents:
diff changeset
   968
489c9b5090e2 Initial load
duke
parents:
diff changeset
   969
  // Peel out the backedges into a private merge point; peel
489c9b5090e2 Initial load
duke
parents:
diff changeset
   970
  // them all except optionally hot_idx.
489c9b5090e2 Initial load
duke
parents:
diff changeset
   971
  PhaseIterGVN &igvn = phase->_igvn;
489c9b5090e2 Initial load
duke
parents:
diff changeset
   972
489c9b5090e2 Initial load
duke
parents:
diff changeset
   973
  Node *hot_tail = NULL;
489c9b5090e2 Initial load
duke
parents:
diff changeset
   974
  // Make a Region for the merge point
489c9b5090e2 Initial load
duke
parents:
diff changeset
   975
  Node *r = new (phase->C, 1) RegionNode(1);
489c9b5090e2 Initial load
duke
parents:
diff changeset
   976
  for( i = 2; i < _head->req(); i++ ) {
489c9b5090e2 Initial load
duke
parents:
diff changeset
   977
    if( i != hot_idx )
489c9b5090e2 Initial load
duke
parents:
diff changeset
   978
      r->add_req( _head->in(i) );
489c9b5090e2 Initial load
duke
parents:
diff changeset
   979
    else hot_tail = _head->in(i);
489c9b5090e2 Initial load
duke
parents:
diff changeset
   980
  }
489c9b5090e2 Initial load
duke
parents:
diff changeset
   981
  igvn.register_new_node_with_optimizer(r, _head);
489c9b5090e2 Initial load
duke
parents:
diff changeset
   982
  // Plug region into end of loop _head, followed by hot_tail
489c9b5090e2 Initial load
duke
parents:
diff changeset
   983
  while( _head->req() > 3 ) _head->del_req( _head->req()-1 );
489c9b5090e2 Initial load
duke
parents:
diff changeset
   984
  _head->set_req(2, r);
489c9b5090e2 Initial load
duke
parents:
diff changeset
   985
  if( hot_idx ) _head->add_req(hot_tail);
489c9b5090e2 Initial load
duke
parents:
diff changeset
   986
489c9b5090e2 Initial load
duke
parents:
diff changeset
   987
  // Split all the Phis up between '_head' loop and the Region 'r'
489c9b5090e2 Initial load
duke
parents:
diff changeset
   988
  for (DUIterator_Fast jmax, j = _head->fast_outs(jmax); j < jmax; j++) {
489c9b5090e2 Initial load
duke
parents:
diff changeset
   989
    Node *out = _head->fast_out(j);
489c9b5090e2 Initial load
duke
parents:
diff changeset
   990
    if( out->is_Phi() ) {
489c9b5090e2 Initial load
duke
parents:
diff changeset
   991
      PhiNode* n = out->as_Phi();
489c9b5090e2 Initial load
duke
parents:
diff changeset
   992
      igvn.hash_delete(n);      // Delete from hash before hacking edges
489c9b5090e2 Initial load
duke
parents:
diff changeset
   993
      Node *hot_phi = NULL;
489c9b5090e2 Initial load
duke
parents:
diff changeset
   994
      Node *phi = new (phase->C, r->req()) PhiNode(r, n->type(), n->adr_type());
489c9b5090e2 Initial load
duke
parents:
diff changeset
   995
      // Check all inputs for the ones to peel out
489c9b5090e2 Initial load
duke
parents:
diff changeset
   996
      uint j = 1;
489c9b5090e2 Initial load
duke
parents:
diff changeset
   997
      for( uint i = 2; i < n->req(); i++ ) {
489c9b5090e2 Initial load
duke
parents:
diff changeset
   998
        if( i != hot_idx )
489c9b5090e2 Initial load
duke
parents:
diff changeset
   999
          phi->set_req( j++, n->in(i) );
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1000
        else hot_phi = n->in(i);
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1001
      }
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1002
      // Register the phi but do not transform until whole place transforms
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1003
      igvn.register_new_node_with_optimizer(phi, n);
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1004
      // Add the merge phi to the old Phi
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1005
      while( n->req() > 3 ) n->del_req( n->req()-1 );
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1006
      n->set_req(2, phi);
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1007
      if( hot_idx ) n->add_req(hot_phi);
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1008
    }
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1009
  }
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1010
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1011
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1012
  // Insert a new IdealLoopTree inserted below me.  Turn it into a clone
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1013
  // of self loop tree.  Turn self into a loop headed by _head and with
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1014
  // tail being the new merge point.
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1015
  IdealLoopTree *ilt = new IdealLoopTree( phase, _head, _tail );
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1016
  phase->set_loop(_tail,ilt);   // Adjust tail
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1017
  _tail = r;                    // Self's tail is new merge point
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1018
  phase->set_loop(r,this);
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1019
  ilt->_child = _child;         // New guy has my children
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1020
  _child = ilt;                 // Self has new guy as only child
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1021
  ilt->_parent = this;          // new guy has self for parent
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1022
  ilt->_nest = _nest;           // Same nesting depth (for now)
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1023
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1024
  // Starting with 'ilt', look for child loop trees using the same shared
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1025
  // header.  Flatten these out; they will no longer be loops in the end.
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1026
  IdealLoopTree **pilt = &_child;
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1027
  while( ilt ) {
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1028
    if( ilt->_head == _head ) {
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1029
      uint i;
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1030
      for( i = 2; i < _head->req(); i++ )
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1031
        if( _head->in(i) == ilt->_tail )
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1032
          break;                // Still a loop
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1033
      if( i == _head->req() ) { // No longer a loop
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1034
        // Flatten ilt.  Hang ilt's "_next" list from the end of
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1035
        // ilt's '_child' list.  Move the ilt's _child up to replace ilt.
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1036
        IdealLoopTree **cp = &ilt->_child;
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1037
        while( *cp ) cp = &(*cp)->_next;   // Find end of child list
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1038
        *cp = ilt->_next;       // Hang next list at end of child list
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1039
        *pilt = ilt->_child;    // Move child up to replace ilt
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1040
        ilt->_head = NULL;      // Flag as a loop UNIONED into parent
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1041
        ilt = ilt->_child;      // Repeat using new ilt
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1042
        continue;               // do not advance over ilt->_child
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1043
      }
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1044
      assert( ilt->_tail == hot_tail, "expected to only find the hot inner loop here" );
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1045
      phase->set_loop(_head,ilt);
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1046
    }
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1047
    pilt = &ilt->_child;        // Advance to next
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1048
    ilt = *pilt;
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1049
  }
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1050
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1051
  if( _child ) fix_parent( _child, this );
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1052
}
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1053
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1054
//------------------------------beautify_loops---------------------------------
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1055
// Split shared headers and insert loop landing pads.
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1056
// Insert a LoopNode to replace the RegionNode.
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1057
// Return TRUE if loop tree is structurally changed.
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1058
bool IdealLoopTree::beautify_loops( PhaseIdealLoop *phase ) {
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1059
  bool result = false;
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1060
  // Cache parts in locals for easy
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1061
  PhaseIterGVN &igvn = phase->_igvn;
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1062
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1063
  phase->C->print_method("Before beautify loops", 3);
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1064
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1065
  igvn.hash_delete(_head);      // Yank from hash before hacking edges
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1066
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1067
  // Check for multiple fall-in paths.  Peel off a landing pad if need be.
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1068
  int fall_in_cnt = 0;
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1069
  for( uint i = 1; i < _head->req(); i++ )
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1070
    if( !phase->is_member( this, _head->in(i) ) )
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1071
      fall_in_cnt++;
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1072
  assert( fall_in_cnt, "at least 1 fall-in path" );
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1073
  if( fall_in_cnt > 1 )         // Need a loop landing pad to merge fall-ins
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1074
    split_fall_in( phase, fall_in_cnt );
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1075
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1076
  // Swap inputs to the _head and all Phis to move the fall-in edge to
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1077
  // the left.
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1078
  fall_in_cnt = 1;
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1079
  while( phase->is_member( this, _head->in(fall_in_cnt) ) )
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1080
    fall_in_cnt++;
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1081
  if( fall_in_cnt > 1 ) {
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1082
    // Since I am just swapping inputs I do not need to update def-use info
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1083
    Node *tmp = _head->in(1);
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1084
    _head->set_req( 1, _head->in(fall_in_cnt) );
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1085
    _head->set_req( fall_in_cnt, tmp );
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1086
    // Swap also all Phis
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1087
    for (DUIterator_Fast imax, i = _head->fast_outs(imax); i < imax; i++) {
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1088
      Node* phi = _head->fast_out(i);
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1089
      if( phi->is_Phi() ) {
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1090
        igvn.hash_delete(phi); // Yank from hash before hacking edges
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1091
        tmp = phi->in(1);
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1092
        phi->set_req( 1, phi->in(fall_in_cnt) );
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1093
        phi->set_req( fall_in_cnt, tmp );
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1094
      }
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1095
    }
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1096
  }
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1097
  assert( !phase->is_member( this, _head->in(1) ), "left edge is fall-in" );
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1098
  assert(  phase->is_member( this, _head->in(2) ), "right edge is loop" );
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1099
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1100
  // If I am a shared header (multiple backedges), peel off the many
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1101
  // backedges into a private merge point and use the merge point as
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1102
  // the one true backedge.
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1103
  if( _head->req() > 3 ) {
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1104
    // Merge the many backedges into a single backedge.
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1105
    merge_many_backedges( phase );
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1106
    result = true;
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1107
  }
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1108
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1109
  // If I am a shared header (multiple backedges), peel off myself loop.
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1110
  // I better be the outermost loop.
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1111
  if( _head->req() > 3 ) {
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1112
    split_outer_loop( phase );
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1113
    result = true;
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1114
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1115
  } else if( !_head->is_Loop() && !_irreducible ) {
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1116
    // Make a new LoopNode to replace the old loop head
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1117
    Node *l = new (phase->C, 3) LoopNode( _head->in(1), _head->in(2) );
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1118
    l = igvn.register_new_node_with_optimizer(l, _head);
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1119
    phase->set_created_loop_node();
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1120
    // Go ahead and replace _head
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1121
    phase->_igvn.subsume_node( _head, l );
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1122
    _head = l;
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1123
    phase->set_loop(_head, this);
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1124
    for (DUIterator_Fast imax, i = l->fast_outs(imax); i < imax; i++)
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1125
      phase->_igvn.add_users_to_worklist(l->fast_out(i));
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1126
  }
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1127
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1128
  phase->C->print_method("After beautify loops", 3);
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1129
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1130
  // Now recursively beautify nested loops
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1131
  if( _child ) result |= _child->beautify_loops( phase );
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1132
  if( _next  ) result |= _next ->beautify_loops( phase );
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1133
  return result;
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1134
}
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1135
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1136
//------------------------------allpaths_check_safepts----------------------------
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1137
// Allpaths backwards scan from loop tail, terminating each path at first safepoint
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1138
// encountered.  Helper for check_safepts.
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1139
void IdealLoopTree::allpaths_check_safepts(VectorSet &visited, Node_List &stack) {
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1140
  assert(stack.size() == 0, "empty stack");
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1141
  stack.push(_tail);
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1142
  visited.Clear();
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1143
  visited.set(_tail->_idx);
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1144
  while (stack.size() > 0) {
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1145
    Node* n = stack.pop();
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1146
    if (n->is_Call() && n->as_Call()->guaranteed_safepoint()) {
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1147
      // Terminate this path
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1148
    } else if (n->Opcode() == Op_SafePoint) {
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1149
      if (_phase->get_loop(n) != this) {
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1150
        if (_required_safept == NULL) _required_safept = new Node_List();
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1151
        _required_safept->push(n);  // save the one closest to the tail
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1152
      }
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1153
      // Terminate this path
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1154
    } else {
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1155
      uint start = n->is_Region() ? 1 : 0;
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1156
      uint end   = n->is_Region() && !n->is_Loop() ? n->req() : start + 1;
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1157
      for (uint i = start; i < end; i++) {
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1158
        Node* in = n->in(i);
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1159
        assert(in->is_CFG(), "must be");
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1160
        if (!visited.test_set(in->_idx) && is_member(_phase->get_loop(in))) {
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1161
          stack.push(in);
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1162
        }
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1163
      }
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1164
    }
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1165
  }
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1166
}
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1167
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1168
//------------------------------check_safepts----------------------------
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1169
// Given dominators, try to find loops with calls that must always be
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1170
// executed (call dominates loop tail).  These loops do not need non-call
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1171
// safepoints (ncsfpt).
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1172
//
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1173
// A complication is that a safepoint in a inner loop may be needed
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1174
// by an outer loop. In the following, the inner loop sees it has a
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1175
// call (block 3) on every path from the head (block 2) to the
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1176
// backedge (arc 3->2).  So it deletes the ncsfpt (non-call safepoint)
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1177
// in block 2, _but_ this leaves the outer loop without a safepoint.
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1178
//
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1179
//          entry  0
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1180
//                 |
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1181
//                 v
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1182
// outer 1,2    +->1
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1183
//              |  |
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1184
//              |  v
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1185
//              |  2<---+  ncsfpt in 2
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1186
//              |_/|\   |
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1187
//                 | v  |
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1188
// inner 2,3      /  3  |  call in 3
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1189
//               /   |  |
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1190
//              v    +--+
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1191
//        exit  4
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1192
//
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1193
//
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1194
// This method creates a list (_required_safept) of ncsfpt nodes that must
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1195
// be protected is created for each loop. When a ncsfpt maybe deleted, it
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1196
// is first looked for in the lists for the outer loops of the current loop.
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1197
//
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1198
// The insights into the problem:
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1199
//  A) counted loops are okay
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1200
//  B) innermost loops are okay (only an inner loop can delete
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1201
//     a ncsfpt needed by an outer loop)
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1202
//  C) a loop is immune from an inner loop deleting a safepoint
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1203
//     if the loop has a call on the idom-path
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1204
//  D) a loop is also immune if it has a ncsfpt (non-call safepoint) on the
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1205
//     idom-path that is not in a nested loop
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1206
//  E) otherwise, an ncsfpt on the idom-path that is nested in an inner
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1207
//     loop needs to be prevented from deletion by an inner loop
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1208
//
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1209
// There are two analyses:
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1210
//  1) The first, and cheaper one, scans the loop body from
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1211
//     tail to head following the idom (immediate dominator)
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1212
//     chain, looking for the cases (C,D,E) above.
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1213
//     Since inner loops are scanned before outer loops, there is summary
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1214
//     information about inner loops.  Inner loops can be skipped over
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1215
//     when the tail of an inner loop is encountered.
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1216
//
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1217
//  2) The second, invoked if the first fails to find a call or ncsfpt on
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1218
//     the idom path (which is rare), scans all predecessor control paths
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1219
//     from the tail to the head, terminating a path when a call or sfpt
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1220
//     is encountered, to find the ncsfpt's that are closest to the tail.
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1221
//
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1222
void IdealLoopTree::check_safepts(VectorSet &visited, Node_List &stack) {
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1223
  // Bottom up traversal
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1224
  IdealLoopTree* ch = _child;
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1225
  while (ch != NULL) {
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1226
    ch->check_safepts(visited, stack);
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1227
    ch = ch->_next;
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1228
  }
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1229
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1230
  if (!_head->is_CountedLoop() && !_has_sfpt && _parent != NULL && !_irreducible) {
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1231
    bool  has_call         = false; // call on dom-path
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1232
    bool  has_local_ncsfpt = false; // ncsfpt on dom-path at this loop depth
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1233
    Node* nonlocal_ncsfpt  = NULL;  // ncsfpt on dom-path at a deeper depth
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1234
    // Scan the dom-path nodes from tail to head
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1235
    for (Node* n = tail(); n != _head; n = _phase->idom(n)) {
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1236
      if (n->is_Call() && n->as_Call()->guaranteed_safepoint()) {
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1237
        has_call = true;
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1238
        _has_sfpt = 1;          // Then no need for a safept!
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1239
        break;
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1240
      } else if (n->Opcode() == Op_SafePoint) {
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1241
        if (_phase->get_loop(n) == this) {
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1242
          has_local_ncsfpt = true;
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1243
          break;
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1244
        }
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1245
        if (nonlocal_ncsfpt == NULL) {
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1246
          nonlocal_ncsfpt = n; // save the one closest to the tail
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1247
        }
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1248
      } else {
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1249
        IdealLoopTree* nlpt = _phase->get_loop(n);
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1250
        if (this != nlpt) {
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1251
          // If at an inner loop tail, see if the inner loop has already
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1252
          // recorded seeing a call on the dom-path (and stop.)  If not,
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1253
          // jump to the head of the inner loop.
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1254
          assert(is_member(nlpt), "nested loop");
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1255
          Node* tail = nlpt->_tail;
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1256
          if (tail->in(0)->is_If()) tail = tail->in(0);
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1257
          if (n == tail) {
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1258
            // If inner loop has call on dom-path, so does outer loop
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1259
            if (nlpt->_has_sfpt) {
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1260
              has_call = true;
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1261
              _has_sfpt = 1;
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1262
              break;
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1263
            }
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1264
            // Skip to head of inner loop
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1265
            assert(_phase->is_dominator(_head, nlpt->_head), "inner head dominated by outer head");
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1266
            n = nlpt->_head;
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1267
          }
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1268
        }
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1269
      }
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1270
    }
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1271
    // Record safept's that this loop needs preserved when an
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1272
    // inner loop attempts to delete it's safepoints.
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1273
    if (_child != NULL && !has_call && !has_local_ncsfpt) {
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1274
      if (nonlocal_ncsfpt != NULL) {
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1275
        if (_required_safept == NULL) _required_safept = new Node_List();
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1276
        _required_safept->push(nonlocal_ncsfpt);
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1277
      } else {
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1278
        // Failed to find a suitable safept on the dom-path.  Now use
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1279
        // an all paths walk from tail to head, looking for safepoints to preserve.
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1280
        allpaths_check_safepts(visited, stack);
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1281
      }
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1282
    }
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1283
  }
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1284
}
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1285
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1286
//---------------------------is_deleteable_safept----------------------------
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1287
// Is safept not required by an outer loop?
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1288
bool PhaseIdealLoop::is_deleteable_safept(Node* sfpt) {
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1289
  assert(sfpt->Opcode() == Op_SafePoint, "");
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1290
  IdealLoopTree* lp = get_loop(sfpt)->_parent;
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1291
  while (lp != NULL) {
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1292
    Node_List* sfpts = lp->_required_safept;
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1293
    if (sfpts != NULL) {
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1294
      for (uint i = 0; i < sfpts->size(); i++) {
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1295
        if (sfpt == sfpts->at(i))
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1296
          return false;
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1297
      }
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1298
    }
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1299
    lp = lp->_parent;
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1300
  }
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1301
  return true;
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1302
}
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1303
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1304
//------------------------------counted_loop-----------------------------------
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1305
// Convert to counted loops where possible
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1306
void IdealLoopTree::counted_loop( PhaseIdealLoop *phase ) {
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1307
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1308
  // For grins, set the inner-loop flag here
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1309
  if( !_child ) {
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1310
    if( _head->is_Loop() ) _head->as_Loop()->set_inner_loop();
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1311
  }
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1312
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1313
  if( _head->is_CountedLoop() ||
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1314
      phase->is_counted_loop( _head, this ) ) {
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1315
    _has_sfpt = 1;              // Indicate we do not need a safepoint here
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1316
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1317
    // Look for a safepoint to remove
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1318
    for (Node* n = tail(); n != _head; n = phase->idom(n))
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1319
      if (n->Opcode() == Op_SafePoint && phase->get_loop(n) == this &&
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1320
          phase->is_deleteable_safept(n))
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1321
        phase->lazy_replace(n,n->in(TypeFunc::Control));
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1322
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1323
    CountedLoopNode *cl = _head->as_CountedLoop();
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1324
    Node *incr = cl->incr();
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1325
    if( !incr ) return;         // Dead loop?
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1326
    Node *init = cl->init_trip();
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1327
    Node *phi  = cl->phi();
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1328
    // protect against stride not being a constant
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1329
    if( !cl->stride_is_con() ) return;
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1330
    int stride_con = cl->stride_con();
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1331
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1332
    // Look for induction variables
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1333
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1334
    // Visit all children, looking for Phis
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1335
    for (DUIterator i = cl->outs(); cl->has_out(i); i++) {
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1336
      Node *out = cl->out(i);
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1337
      if (!out->is_Phi())  continue; // Looking for phis
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1338
      PhiNode* phi2 = out->as_Phi();
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1339
      Node *incr2 = phi2->in( LoopNode::LoopBackControl );
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1340
      // Look for induction variables of the form:  X += constant
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1341
      if( phi2->region() != _head ||
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1342
          incr2->req() != 3 ||
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1343
          incr2->in(1) != phi2 ||
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1344
          incr2 == incr ||
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1345
          incr2->Opcode() != Op_AddI ||
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1346
          !incr2->in(2)->is_Con() )
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1347
        continue;
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1348
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1349
      // Check for parallel induction variable (parallel to trip counter)
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1350
      // via an affine function.  In particular, count-down loops with
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1351
      // count-up array indices are common. We only RCE references off
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1352
      // the trip-counter, so we need to convert all these to trip-counter
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1353
      // expressions.
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1354
      Node *init2 = phi2->in( LoopNode::EntryControl );
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1355
      int stride_con2 = incr2->in(2)->get_int();
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1356
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1357
      // The general case here gets a little tricky.  We want to find the
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1358
      // GCD of all possible parallel IV's and make a new IV using this
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1359
      // GCD for the loop.  Then all possible IVs are simple multiples of
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1360
      // the GCD.  In practice, this will cover very few extra loops.
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1361
      // Instead we require 'stride_con2' to be a multiple of 'stride_con',
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1362
      // where +/-1 is the common case, but other integer multiples are
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1363
      // also easy to handle.
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1364
      int ratio_con = stride_con2/stride_con;
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1365
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1366
      if( ratio_con * stride_con == stride_con2 ) { // Check for exact
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1367
        // Convert to using the trip counter.  The parallel induction
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1368
        // variable differs from the trip counter by a loop-invariant
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1369
        // amount, the difference between their respective initial values.
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1370
        // It is scaled by the 'ratio_con'.
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1371
        Compile* C = phase->C;
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1372
        Node* ratio = phase->_igvn.intcon(ratio_con);
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1373
        phase->set_ctrl(ratio, C->root());
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1374
        Node* ratio_init = new (C, 3) MulINode(init, ratio);
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1375
        phase->_igvn.register_new_node_with_optimizer(ratio_init, init);
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1376
        phase->set_early_ctrl(ratio_init);
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1377
        Node* diff = new (C, 3) SubINode(init2, ratio_init);
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1378
        phase->_igvn.register_new_node_with_optimizer(diff, init2);
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1379
        phase->set_early_ctrl(diff);
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1380
        Node* ratio_idx = new (C, 3) MulINode(phi, ratio);
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1381
        phase->_igvn.register_new_node_with_optimizer(ratio_idx, phi);
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1382
        phase->set_ctrl(ratio_idx, cl);
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1383
        Node* add  = new (C, 3) AddINode(ratio_idx, diff);
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1384
        phase->_igvn.register_new_node_with_optimizer(add);
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1385
        phase->set_ctrl(add, cl);
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1386
        phase->_igvn.hash_delete( phi2 );
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1387
        phase->_igvn.subsume_node( phi2, add );
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1388
        // Sometimes an induction variable is unused
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1389
        if (add->outcnt() == 0) {
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1390
          phase->_igvn.remove_dead_node(add);
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1391
        }
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1392
        --i; // deleted this phi; rescan starting with next position
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1393
        continue;
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1394
      }
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1395
    }
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1396
  } else if (_parent != NULL && !_irreducible) {
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1397
    // Not a counted loop.
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1398
    // Look for a safepoint on the idom-path to remove, preserving the first one
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1399
    bool found = false;
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1400
    Node* n = tail();
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1401
    for (; n != _head && !found; n = phase->idom(n)) {
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1402
      if (n->Opcode() == Op_SafePoint && phase->get_loop(n) == this)
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1403
        found = true; // Found one
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1404
    }
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1405
    // Skip past it and delete the others
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1406
    for (; n != _head; n = phase->idom(n)) {
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1407
      if (n->Opcode() == Op_SafePoint && phase->get_loop(n) == this &&
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1408
          phase->is_deleteable_safept(n))
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1409
        phase->lazy_replace(n,n->in(TypeFunc::Control));
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1410
    }
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1411
  }
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1412
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1413
  // Recursively
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1414
  if( _child ) _child->counted_loop( phase );
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1415
  if( _next  ) _next ->counted_loop( phase );
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1416
}
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1417
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1418
#ifndef PRODUCT
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1419
//------------------------------dump_head--------------------------------------
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1420
// Dump 1 liner for loop header info
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1421
void IdealLoopTree::dump_head( ) const {
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1422
  for( uint i=0; i<_nest; i++ )
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1423
    tty->print("  ");
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1424
  tty->print("Loop: N%d/N%d ",_head->_idx,_tail->_idx);
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1425
  if( _irreducible ) tty->print(" IRREDUCIBLE");
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1426
  if( _head->is_CountedLoop() ) {
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1427
    CountedLoopNode *cl = _head->as_CountedLoop();
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1428
    tty->print(" counted");
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1429
    if( cl->is_pre_loop () ) tty->print(" pre" );
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1430
    if( cl->is_main_loop() ) tty->print(" main");
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1431
    if( cl->is_post_loop() ) tty->print(" post");
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1432
  }
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1433
  tty->cr();
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1434
}
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1435
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1436
//------------------------------dump-------------------------------------------
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1437
// Dump loops by loop tree
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1438
void IdealLoopTree::dump( ) const {
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1439
  dump_head();
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1440
  if( _child ) _child->dump();
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1441
  if( _next  ) _next ->dump();
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1442
}
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1443
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1444
#endif
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1445
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1446
//=============================================================================
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1447
//------------------------------PhaseIdealLoop---------------------------------
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1448
// Create a PhaseLoop.  Build the ideal Loop tree.  Map each Ideal Node to
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1449
// its corresponding LoopNode.  If 'optimize' is true, do some loop cleanups.
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1450
PhaseIdealLoop::PhaseIdealLoop( PhaseIterGVN &igvn, const PhaseIdealLoop *verify_me, bool do_split_ifs )
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1451
  : PhaseTransform(Ideal_Loop),
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1452
    _igvn(igvn),
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1453
    _dom_lca_tags(C->comp_arena()) {
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1454
  // Reset major-progress flag for the driver's heuristics
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1455
  C->clear_major_progress();
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1456
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1457
#ifndef PRODUCT
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1458
  // Capture for later assert
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1459
  uint unique = C->unique();
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1460
  _loop_invokes++;
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1461
  _loop_work += unique;
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1462
#endif
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1463
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1464
  // True if the method has at least 1 irreducible loop
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1465
  _has_irreducible_loops = false;
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1466
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1467
  _created_loop_node = false;
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1468
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1469
  Arena *a = Thread::current()->resource_area();
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1470
  VectorSet visited(a);
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1471
  // Pre-grow the mapping from Nodes to IdealLoopTrees.
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1472
  _nodes.map(C->unique(), NULL);
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1473
  memset(_nodes.adr(), 0, wordSize * C->unique());
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1474
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1475
  // Pre-build the top-level outermost loop tree entry
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1476
  _ltree_root = new IdealLoopTree( this, C->root(), C->root() );
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1477
  // Do not need a safepoint at the top level
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1478
  _ltree_root->_has_sfpt = 1;
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1479
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1480
  // Empty pre-order array
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1481
  allocate_preorders();
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1482
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1483
  // Build a loop tree on the fly.  Build a mapping from CFG nodes to
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1484
  // IdealLoopTree entries.  Data nodes are NOT walked.
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1485
  build_loop_tree();
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1486
  // Check for bailout, and return
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1487
  if (C->failing()) {
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1488
    return;
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1489
  }
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1490
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1491
  // No loops after all
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1492
  if( !_ltree_root->_child ) C->set_has_loops(false);
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1493
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1494
  // There should always be an outer loop containing the Root and Return nodes.
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1495
  // If not, we have a degenerate empty program.  Bail out in this case.
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1496
  if (!has_node(C->root())) {
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1497
    C->clear_major_progress();
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1498
    C->record_method_not_compilable("empty program detected during loop optimization");
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1499
    return;
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1500
  }
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1501
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1502
  // Nothing to do, so get out
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1503
  if( !C->has_loops() && !do_split_ifs && !verify_me) {
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1504
    _igvn.optimize();           // Cleanup NeverBranches
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1505
    return;
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1506
  }
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1507
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1508
  // Set loop nesting depth
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1509
  _ltree_root->set_nest( 0 );
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1510
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1511
  // Split shared headers and insert loop landing pads.
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1512
  // Do not bother doing this on the Root loop of course.
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1513
  if( !verify_me && _ltree_root->_child ) {
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1514
    if( _ltree_root->_child->beautify_loops( this ) ) {
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1515
      // Re-build loop tree!
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1516
      _ltree_root->_child = NULL;
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1517
      _nodes.clear();
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1518
      reallocate_preorders();
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1519
      build_loop_tree();
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1520
      // Check for bailout, and return
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1521
      if (C->failing()) {
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1522
        return;
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1523
      }
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1524
      // Reset loop nesting depth
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1525
      _ltree_root->set_nest( 0 );
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1526
    }
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1527
  }
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1528
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1529
  // Build Dominators for elision of NULL checks & loop finding.
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1530
  // Since nodes do not have a slot for immediate dominator, make
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1531
  // a persistant side array for that info indexed on node->_idx.
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1532
  _idom_size = C->unique();
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1533
  _idom      = NEW_RESOURCE_ARRAY( Node*, _idom_size );
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1534
  _dom_depth = NEW_RESOURCE_ARRAY( uint,  _idom_size );
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1535
  _dom_stk   = NULL; // Allocated on demand in recompute_dom_depth
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1536
  memset( _dom_depth, 0, _idom_size * sizeof(uint) );
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1537
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1538
  Dominators();
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1539
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1540
  // As a side effect, Dominators removed any unreachable CFG paths
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1541
  // into RegionNodes.  It doesn't do this test against Root, so
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1542
  // we do it here.
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1543
  for( uint i = 1; i < C->root()->req(); i++ ) {
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1544
    if( !_nodes[C->root()->in(i)->_idx] ) {    // Dead path into Root?
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1545
      _igvn.hash_delete(C->root());
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1546
      C->root()->del_req(i);
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1547
      _igvn._worklist.push(C->root());
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1548
      i--;                      // Rerun same iteration on compressed edges
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1549
    }
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1550
  }
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1551
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1552
  // Given dominators, try to find inner loops with calls that must
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1553
  // always be executed (call dominates loop tail).  These loops do
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1554
  // not need a seperate safepoint.
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1555
  Node_List cisstack(a);
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1556
  _ltree_root->check_safepts(visited, cisstack);
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1557
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1558
  // Walk the DATA nodes and place into loops.  Find earliest control
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1559
  // node.  For CFG nodes, the _nodes array starts out and remains
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1560
  // holding the associated IdealLoopTree pointer.  For DATA nodes, the
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1561
  // _nodes array holds the earliest legal controlling CFG node.
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1562
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1563
  // Allocate stack with enough space to avoid frequent realloc
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1564
  int stack_size = (C->unique() >> 1) + 16; // (unique>>1)+16 from Java2D stats
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1565
  Node_Stack nstack( a, stack_size );
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1566
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1567
  visited.Clear();
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1568
  Node_List worklist(a);
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1569
  // Don't need C->root() on worklist since
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1570
  // it will be processed among C->top() inputs
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1571
  worklist.push( C->top() );
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1572
  visited.set( C->top()->_idx ); // Set C->top() as visited now
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1573
  build_loop_early( visited, worklist, nstack, verify_me );
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1574
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1575
  // Given early legal placement, try finding counted loops.  This placement
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1576
  // is good enough to discover most loop invariants.
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1577
  if( !verify_me )
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1578
    _ltree_root->counted_loop( this );
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1579
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1580
  // Find latest loop placement.  Find ideal loop placement.
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1581
  visited.Clear();
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1582
  init_dom_lca_tags();
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1583
  // Need C->root() on worklist when processing outs
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1584
  worklist.push( C->root() );
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1585
  NOT_PRODUCT( C->verify_graph_edges(); )
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1586
  worklist.push( C->top() );
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1587
  build_loop_late( visited, worklist, nstack, verify_me );
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1588
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1589
  // clear out the dead code
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1590
  while(_deadlist.size()) {
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1591
    igvn.remove_globally_dead_node(_deadlist.pop());
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1592
  }
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1593
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1594
#ifndef PRODUCT
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1595
  C->verify_graph_edges();
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1596
  if( verify_me ) {             // Nested verify pass?
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1597
    // Check to see if the verify mode is broken
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1598
    assert(C->unique() == unique, "non-optimize mode made Nodes? ? ?");
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1599
    return;
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1600
  }
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1601
  if( VerifyLoopOptimizations ) verify();
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1602
#endif
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1603
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1604
  if (ReassociateInvariants) {
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1605
    // Reassociate invariants and prep for split_thru_phi
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1606
    for (LoopTreeIterator iter(_ltree_root); !iter.done(); iter.next()) {
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1607
      IdealLoopTree* lpt = iter.current();
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1608
      if (!lpt->is_counted() || !lpt->is_inner()) continue;
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1609
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1610
      lpt->reassociate_invariants(this);
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1611
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1612
      // Because RCE opportunities can be masked by split_thru_phi,
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1613
      // look for RCE candidates and inhibit split_thru_phi
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1614
      // on just their loop-phi's for this pass of loop opts
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1615
      if( SplitIfBlocks && do_split_ifs ) {
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1616
        if (lpt->policy_range_check(this)) {
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1617
          lpt->_rce_candidate = true;
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1618
        }
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1619
      }
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1620
    }
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1621
  }
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1622
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1623
  // Check for aggressive application of split-if and other transforms
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1624
  // that require basic-block info (like cloning through Phi's)
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1625
  if( SplitIfBlocks && do_split_ifs ) {
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1626
    visited.Clear();
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1627
    split_if_with_blocks( visited, nstack );
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1628
    NOT_PRODUCT( if( VerifyLoopOptimizations ) verify(); );
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1629
  }
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1630
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1631
  // Perform iteration-splitting on inner loops.  Split iterations to avoid
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1632
  // range checks or one-shot null checks.
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1633
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1634
  // If split-if's didn't hack the graph too bad (no CFG changes)
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1635
  // then do loop opts.
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1636
  if( C->has_loops() && !C->major_progress() ) {
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1637
    memset( worklist.adr(), 0, worklist.Size()*sizeof(Node*) );
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1638
    _ltree_root->_child->iteration_split( this, worklist );
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1639
    // No verify after peeling!  GCM has hoisted code out of the loop.
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1640
    // After peeling, the hoisted code could sink inside the peeled area.
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1641
    // The peeling code does not try to recompute the best location for
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1642
    // all the code before the peeled area, so the verify pass will always
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1643
    // complain about it.
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1644
  }
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1645
  // Do verify graph edges in any case
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1646
  NOT_PRODUCT( C->verify_graph_edges(); );
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1647
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1648
  if( !do_split_ifs ) {
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1649
    // We saw major progress in Split-If to get here.  We forced a
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1650
    // pass with unrolling and not split-if, however more split-if's
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1651
    // might make progress.  If the unrolling didn't make progress
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1652
    // then the major-progress flag got cleared and we won't try
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1653
    // another round of Split-If.  In particular the ever-common
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1654
    // instance-of/check-cast pattern requires at least 2 rounds of
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1655
    // Split-If to clear out.
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1656
    C->set_major_progress();
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1657
  }
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1658
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1659
  // Repeat loop optimizations if new loops were seen
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1660
  if (created_loop_node()) {
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1661
    C->set_major_progress();
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1662
  }
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1663
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1664
  // Convert scalar to superword operations
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1665
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1666
  if (UseSuperWord && C->has_loops() && !C->major_progress()) {
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1667
    // SuperWord transform
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1668
    SuperWord sw(this);
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1669
    for (LoopTreeIterator iter(_ltree_root); !iter.done(); iter.next()) {
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1670
      IdealLoopTree* lpt = iter.current();
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1671
      if (lpt->is_counted()) {
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1672
        sw.transform_loop(lpt);
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1673
      }
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1674
    }
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1675
  }
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1676
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1677
  // Cleanup any modified bits
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1678
  _igvn.optimize();
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1679
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1680
  // Do not repeat loop optimizations if irreducible loops are present
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1681
  // by claiming no-progress.
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1682
  if( _has_irreducible_loops )
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1683
    C->clear_major_progress();
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1684
}
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1685
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1686
#ifndef PRODUCT
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1687
//------------------------------print_statistics-------------------------------
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1688
int PhaseIdealLoop::_loop_invokes=0;// Count of PhaseIdealLoop invokes
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1689
int PhaseIdealLoop::_loop_work=0; // Sum of PhaseIdealLoop x unique
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1690
void PhaseIdealLoop::print_statistics() {
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1691
  tty->print_cr("PhaseIdealLoop=%d, sum _unique=%d", _loop_invokes, _loop_work);
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1692
}
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1693
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1694
//------------------------------verify-----------------------------------------
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1695
// Build a verify-only PhaseIdealLoop, and see that it agrees with me.
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1696
static int fail;                // debug only, so its multi-thread dont care
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1697
void PhaseIdealLoop::verify() const {
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1698
  int old_progress = C->major_progress();
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1699
  ResourceMark rm;
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1700
  PhaseIdealLoop loop_verify( _igvn, this, false );
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1701
  VectorSet visited(Thread::current()->resource_area());
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1702
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1703
  fail = 0;
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1704
  verify_compare( C->root(), &loop_verify, visited );
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1705
  assert( fail == 0, "verify loops failed" );
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1706
  // Verify loop structure is the same
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1707
  _ltree_root->verify_tree(loop_verify._ltree_root, NULL);
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1708
  // Reset major-progress.  It was cleared by creating a verify version of
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1709
  // PhaseIdealLoop.
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1710
  for( int i=0; i<old_progress; i++ )
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1711
    C->set_major_progress();
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1712
}
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1713
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1714
//------------------------------verify_compare---------------------------------
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1715
// Make sure me and the given PhaseIdealLoop agree on key data structures
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1716
void PhaseIdealLoop::verify_compare( Node *n, const PhaseIdealLoop *loop_verify, VectorSet &visited ) const {
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1717
  if( !n ) return;
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1718
  if( visited.test_set( n->_idx ) ) return;
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1719
  if( !_nodes[n->_idx] ) {      // Unreachable
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1720
    assert( !loop_verify->_nodes[n->_idx], "both should be unreachable" );
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1721
    return;
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1722
  }
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1723
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1724
  uint i;
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1725
  for( i = 0; i < n->req(); i++ )
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1726
    verify_compare( n->in(i), loop_verify, visited );
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1727
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1728
  // Check the '_nodes' block/loop structure
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1729
  i = n->_idx;
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1730
  if( has_ctrl(n) ) {           // We have control; verify has loop or ctrl
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1731
    if( _nodes[i] != loop_verify->_nodes[i] &&
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1732
        get_ctrl_no_update(n) != loop_verify->get_ctrl_no_update(n) ) {
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1733
      tty->print("Mismatched control setting for: ");
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1734
      n->dump();
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1735
      if( fail++ > 10 ) return;
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1736
      Node *c = get_ctrl_no_update(n);
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1737
      tty->print("We have it as: ");
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1738
      if( c->in(0) ) c->dump();
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1739
        else tty->print_cr("N%d",c->_idx);
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1740
      tty->print("Verify thinks: ");
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1741
      if( loop_verify->has_ctrl(n) )
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1742
        loop_verify->get_ctrl_no_update(n)->dump();
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1743
      else
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1744
        loop_verify->get_loop_idx(n)->dump();
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1745
      tty->cr();
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1746
    }
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1747
  } else {                    // We have a loop
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1748
    IdealLoopTree *us = get_loop_idx(n);
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1749
    if( loop_verify->has_ctrl(n) ) {
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1750
      tty->print("Mismatched loop setting for: ");
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1751
      n->dump();
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1752
      if( fail++ > 10 ) return;
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1753
      tty->print("We have it as: ");
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1754
      us->dump();
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1755
      tty->print("Verify thinks: ");
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1756
      loop_verify->get_ctrl_no_update(n)->dump();
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1757
      tty->cr();
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1758
    } else if (!C->major_progress()) {
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1759
      // Loop selection can be messed up if we did a major progress
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1760
      // operation, like split-if.  Do not verify in that case.
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1761
      IdealLoopTree *them = loop_verify->get_loop_idx(n);
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1762
      if( us->_head != them->_head ||  us->_tail != them->_tail ) {
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1763
        tty->print("Unequals loops for: ");
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1764
        n->dump();
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1765
        if( fail++ > 10 ) return;
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1766
        tty->print("We have it as: ");
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1767
        us->dump();
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1768
        tty->print("Verify thinks: ");
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1769
        them->dump();
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1770
        tty->cr();
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1771
      }
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1772
    }
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1773
  }
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1774
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1775
  // Check for immediate dominators being equal
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1776
  if( i >= _idom_size ) {
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1777
    if( !n->is_CFG() ) return;
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1778
    tty->print("CFG Node with no idom: ");
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1779
    n->dump();
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1780
    return;
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1781
  }
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1782
  if( !n->is_CFG() ) return;
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1783
  if( n == C->root() ) return; // No IDOM here
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1784
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1785
  assert(n->_idx == i, "sanity");
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1786
  Node *id = idom_no_update(n);
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1787
  if( id != loop_verify->idom_no_update(n) ) {
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1788
    tty->print("Unequals idoms for: ");
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1789
    n->dump();
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1790
    if( fail++ > 10 ) return;
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1791
    tty->print("We have it as: ");
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1792
    id->dump();
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1793
    tty->print("Verify thinks: ");
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1794
    loop_verify->idom_no_update(n)->dump();
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1795
    tty->cr();
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1796
  }
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1797
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1798
}
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1799
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1800
//------------------------------verify_tree------------------------------------
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1801
// Verify that tree structures match.  Because the CFG can change, siblings
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1802
// within the loop tree can be reordered.  We attempt to deal with that by
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1803
// reordering the verify's loop tree if possible.
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1804
void IdealLoopTree::verify_tree(IdealLoopTree *loop, const IdealLoopTree *parent) const {
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1805
  assert( _parent == parent, "Badly formed loop tree" );
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1806
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1807
  // Siblings not in same order?  Attempt to re-order.
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1808
  if( _head != loop->_head ) {
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1809
    // Find _next pointer to update
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1810
    IdealLoopTree **pp = &loop->_parent->_child;
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1811
    while( *pp != loop )
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1812
      pp = &((*pp)->_next);
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1813
    // Find proper sibling to be next
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1814
    IdealLoopTree **nn = &loop->_next;
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1815
    while( (*nn) && (*nn)->_head != _head )
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1816
      nn = &((*nn)->_next);
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1817
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1818
    // Check for no match.
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1819
    if( !(*nn) ) {
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1820
      // Annoyingly, irreducible loops can pick different headers
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1821
      // after a major_progress operation, so the rest of the loop
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1822
      // tree cannot be matched.
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1823
      if (_irreducible && Compile::current()->major_progress())  return;
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1824
      assert( 0, "failed to match loop tree" );
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1825
    }
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1826
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1827
    // Move (*nn) to (*pp)
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1828
    IdealLoopTree *hit = *nn;
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1829
    *nn = hit->_next;
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1830
    hit->_next = loop;
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1831
    *pp = loop;
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1832
    loop = hit;
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1833
    // Now try again to verify
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1834
  }
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1835
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1836
  assert( _head  == loop->_head , "mismatched loop head" );
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1837
  Node *tail = _tail;           // Inline a non-updating version of
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1838
  while( !tail->in(0) )         // the 'tail()' call.
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1839
    tail = tail->in(1);
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1840
  assert( tail == loop->_tail, "mismatched loop tail" );
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1841
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1842
  // Counted loops that are guarded should be able to find their guards
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1843
  if( _head->is_CountedLoop() && _head->as_CountedLoop()->is_main_loop() ) {
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1844
    CountedLoopNode *cl = _head->as_CountedLoop();
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1845
    Node *init = cl->init_trip();
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1846
    Node *ctrl = cl->in(LoopNode::EntryControl);
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1847
    assert( ctrl->Opcode() == Op_IfTrue || ctrl->Opcode() == Op_IfFalse, "" );
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1848
    Node *iff  = ctrl->in(0);
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1849
    assert( iff->Opcode() == Op_If, "" );
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1850
    Node *bol  = iff->in(1);
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1851
    assert( bol->Opcode() == Op_Bool, "" );
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1852
    Node *cmp  = bol->in(1);
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1853
    assert( cmp->Opcode() == Op_CmpI, "" );
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1854
    Node *add  = cmp->in(1);
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1855
    Node *opaq;
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1856
    if( add->Opcode() == Op_Opaque1 ) {
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1857
      opaq = add;
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1858
    } else {
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1859
      assert( add->Opcode() == Op_AddI || add->Opcode() == Op_ConI , "" );
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1860
      assert( add == init, "" );
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1861
      opaq = cmp->in(2);
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1862
    }
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1863
    assert( opaq->Opcode() == Op_Opaque1, "" );
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1864
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1865
  }
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1866
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1867
  if (_child != NULL)  _child->verify_tree(loop->_child, this);
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1868
  if (_next  != NULL)  _next ->verify_tree(loop->_next,  parent);
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1869
  // Innermost loops need to verify loop bodies,
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1870
  // but only if no 'major_progress'
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1871
  int fail = 0;
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1872
  if (!Compile::current()->major_progress() && _child == NULL) {
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1873
    for( uint i = 0; i < _body.size(); i++ ) {
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1874
      Node *n = _body.at(i);
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1875
      if (n->outcnt() == 0)  continue; // Ignore dead
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1876
      uint j;
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1877
      for( j = 0; j < loop->_body.size(); j++ )
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1878
        if( loop->_body.at(j) == n )
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1879
          break;
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1880
      if( j == loop->_body.size() ) { // Not found in loop body
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1881
        // Last ditch effort to avoid assertion: Its possible that we
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1882
        // have some users (so outcnt not zero) but are still dead.
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1883
        // Try to find from root.
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1884
        if (Compile::current()->root()->find(n->_idx)) {
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1885
          fail++;
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1886
          tty->print("We have that verify does not: ");
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1887
          n->dump();
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1888
        }
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1889
      }
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1890
    }
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1891
    for( uint i2 = 0; i2 < loop->_body.size(); i2++ ) {
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1892
      Node *n = loop->_body.at(i2);
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1893
      if (n->outcnt() == 0)  continue; // Ignore dead
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1894
      uint j;
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1895
      for( j = 0; j < _body.size(); j++ )
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1896
        if( _body.at(j) == n )
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1897
          break;
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1898
      if( j == _body.size() ) { // Not found in loop body
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1899
        // Last ditch effort to avoid assertion: Its possible that we
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1900
        // have some users (so outcnt not zero) but are still dead.
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1901
        // Try to find from root.
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1902
        if (Compile::current()->root()->find(n->_idx)) {
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1903
          fail++;
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1904
          tty->print("Verify has that we do not: ");
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1905
          n->dump();
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1906
        }
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1907
      }
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1908
    }
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1909
    assert( !fail, "loop body mismatch" );
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1910
  }
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1911
}
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1912
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1913
#endif
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1914
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1915
//------------------------------set_idom---------------------------------------
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1916
void PhaseIdealLoop::set_idom(Node* d, Node* n, uint dom_depth) {
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1917
  uint idx = d->_idx;
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1918
  if (idx >= _idom_size) {
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1919
    uint newsize = _idom_size<<1;
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1920
    while( idx >= newsize ) {
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1921
      newsize <<= 1;
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1922
    }
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1923
    _idom      = REALLOC_RESOURCE_ARRAY( Node*,     _idom,_idom_size,newsize);
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1924
    _dom_depth = REALLOC_RESOURCE_ARRAY( uint, _dom_depth,_idom_size,newsize);
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1925
    memset( _dom_depth + _idom_size, 0, (newsize - _idom_size) * sizeof(uint) );
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1926
    _idom_size = newsize;
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1927
  }
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1928
  _idom[idx] = n;
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1929
  _dom_depth[idx] = dom_depth;
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1930
}
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1931
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1932
//------------------------------recompute_dom_depth---------------------------------------
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1933
// The dominator tree is constructed with only parent pointers.
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1934
// This recomputes the depth in the tree by first tagging all
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1935
// nodes as "no depth yet" marker.  The next pass then runs up
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1936
// the dom tree from each node marked "no depth yet", and computes
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1937
// the depth on the way back down.
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1938
void PhaseIdealLoop::recompute_dom_depth() {
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1939
  uint no_depth_marker = C->unique();
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1940
  uint i;
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1941
  // Initialize depth to "no depth yet"
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1942
  for (i = 0; i < _idom_size; i++) {
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1943
    if (_dom_depth[i] > 0 && _idom[i] != NULL) {
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1944
     _dom_depth[i] = no_depth_marker;
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1945
    }
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1946
  }
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1947
  if (_dom_stk == NULL) {
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1948
    uint init_size = C->unique() / 100; // Guess that 1/100 is a reasonable initial size.
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1949
    if (init_size < 10) init_size = 10;
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1950
    _dom_stk = new (C->node_arena()) GrowableArray<uint>(C->node_arena(), init_size, 0, 0);
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1951
  }
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1952
  // Compute new depth for each node.
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1953
  for (i = 0; i < _idom_size; i++) {
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1954
    uint j = i;
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1955
    // Run up the dom tree to find a node with a depth
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1956
    while (_dom_depth[j] == no_depth_marker) {
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1957
      _dom_stk->push(j);
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1958
      j = _idom[j]->_idx;
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1959
    }
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1960
    // Compute the depth on the way back down this tree branch
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1961
    uint dd = _dom_depth[j] + 1;
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1962
    while (_dom_stk->length() > 0) {
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1963
      uint j = _dom_stk->pop();
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1964
      _dom_depth[j] = dd;
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1965
      dd++;
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1966
    }
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1967
  }
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1968
}
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1969
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1970
//------------------------------sort-------------------------------------------
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1971
// Insert 'loop' into the existing loop tree.  'innermost' is a leaf of the
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1972
// loop tree, not the root.
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1973
IdealLoopTree *PhaseIdealLoop::sort( IdealLoopTree *loop, IdealLoopTree *innermost ) {
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1974
  if( !innermost ) return loop; // New innermost loop
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1975
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1976
  int loop_preorder = get_preorder(loop->_head); // Cache pre-order number
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1977
  assert( loop_preorder, "not yet post-walked loop" );
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1978
  IdealLoopTree **pp = &innermost;      // Pointer to previous next-pointer
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1979
  IdealLoopTree *l = *pp;               // Do I go before or after 'l'?
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1980
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1981
  // Insert at start of list
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1982
  while( l ) {                  // Insertion sort based on pre-order
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1983
    if( l == loop ) return innermost; // Already on list!
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1984
    int l_preorder = get_preorder(l->_head); // Cache pre-order number
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1985
    assert( l_preorder, "not yet post-walked l" );
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1986
    // Check header pre-order number to figure proper nesting
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1987
    if( loop_preorder > l_preorder )
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1988
      break;                    // End of insertion
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1989
    // If headers tie (e.g., shared headers) check tail pre-order numbers.
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1990
    // Since I split shared headers, you'd think this could not happen.
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1991
    // BUT: I must first do the preorder numbering before I can discover I
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1992
    // have shared headers, so the split headers all get the same preorder
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1993
    // number as the RegionNode they split from.
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1994
    if( loop_preorder == l_preorder &&
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1995
        get_preorder(loop->_tail) < get_preorder(l->_tail) )
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1996
      break;                    // Also check for shared headers (same pre#)
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1997
    pp = &l->_parent;           // Chain up list
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1998
    l = *pp;
489c9b5090e2 Initial load
duke
parents:
diff changeset
  1999
  }
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2000
  // Link into list
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2001
  // Point predecessor to me
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2002
  *pp = loop;
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2003
  // Point me to successor
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2004
  IdealLoopTree *p = loop->_parent;
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2005
  loop->_parent = l;            // Point me to successor
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2006
  if( p ) sort( p, innermost ); // Insert my parents into list as well
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2007
  return innermost;
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2008
}
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2009
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2010
//------------------------------build_loop_tree--------------------------------
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2011
// I use a modified Vick/Tarjan algorithm.  I need pre- and a post- visit
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2012
// bits.  The _nodes[] array is mapped by Node index and holds a NULL for
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2013
// not-yet-pre-walked, pre-order # for pre-but-not-post-walked and holds the
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2014
// tightest enclosing IdealLoopTree for post-walked.
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2015
//
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2016
// During my forward walk I do a short 1-layer lookahead to see if I can find
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2017
// a loop backedge with that doesn't have any work on the backedge.  This
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2018
// helps me construct nested loops with shared headers better.
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2019
//
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2020
// Once I've done the forward recursion, I do the post-work.  For each child
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2021
// I check to see if there is a backedge.  Backedges define a loop!  I
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2022
// insert an IdealLoopTree at the target of the backedge.
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2023
//
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2024
// During the post-work I also check to see if I have several children
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2025
// belonging to different loops.  If so, then this Node is a decision point
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2026
// where control flow can choose to change loop nests.  It is at this
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2027
// decision point where I can figure out how loops are nested.  At this
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2028
// time I can properly order the different loop nests from my children.
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2029
// Note that there may not be any backedges at the decision point!
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2030
//
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2031
// Since the decision point can be far removed from the backedges, I can't
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2032
// order my loops at the time I discover them.  Thus at the decision point
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2033
// I need to inspect loop header pre-order numbers to properly nest my
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2034
// loops.  This means I need to sort my childrens' loops by pre-order.
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2035
// The sort is of size number-of-control-children, which generally limits
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2036
// it to size 2 (i.e., I just choose between my 2 target loops).
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2037
void PhaseIdealLoop::build_loop_tree() {
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2038
  // Allocate stack of size C->unique()/2 to avoid frequent realloc
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2039
  GrowableArray <Node *> bltstack(C->unique() >> 1);
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2040
  Node *n = C->root();
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2041
  bltstack.push(n);
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2042
  int pre_order = 1;
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2043
  int stack_size;
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2044
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2045
  while ( ( stack_size = bltstack.length() ) != 0 ) {
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2046
    n = bltstack.top(); // Leave node on stack
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2047
    if ( !is_visited(n) ) {
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2048
      // ---- Pre-pass Work ----
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2049
      // Pre-walked but not post-walked nodes need a pre_order number.
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2050
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2051
      set_preorder_visited( n, pre_order ); // set as visited
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2052
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2053
      // ---- Scan over children ----
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2054
      // Scan first over control projections that lead to loop headers.
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2055
      // This helps us find inner-to-outer loops with shared headers better.
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2056
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2057
      // Scan children's children for loop headers.
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2058
      for ( int i = n->outcnt() - 1; i >= 0; --i ) {
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2059
        Node* m = n->raw_out(i);       // Child
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2060
        if( m->is_CFG() && !is_visited(m) ) { // Only for CFG children
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2061
          // Scan over children's children to find loop
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2062
          for (DUIterator_Fast jmax, j = m->fast_outs(jmax); j < jmax; j++) {
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2063
            Node* l = m->fast_out(j);
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2064
            if( is_visited(l) &&       // Been visited?
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2065
                !is_postvisited(l) &&  // But not post-visited
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2066
                get_preorder(l) < pre_order ) { // And smaller pre-order
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2067
              // Found!  Scan the DFS down this path before doing other paths
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2068
              bltstack.push(m);
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2069
              break;
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2070
            }
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2071
          }
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2072
        }
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2073
      }
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2074
      pre_order++;
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2075
    }
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2076
    else if ( !is_postvisited(n) ) {
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2077
      // Note: build_loop_tree_impl() adds out edges on rare occasions,
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2078
      // such as com.sun.rsasign.am::a.
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2079
      // For non-recursive version, first, process current children.
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2080
      // On next iteration, check if additional children were added.
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2081
      for ( int k = n->outcnt() - 1; k >= 0; --k ) {
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2082
        Node* u = n->raw_out(k);
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2083
        if ( u->is_CFG() && !is_visited(u) ) {
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2084
          bltstack.push(u);
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2085
        }
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2086
      }
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2087
      if ( bltstack.length() == stack_size ) {
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2088
        // There were no additional children, post visit node now
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2089
        (void)bltstack.pop(); // Remove node from stack
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2090
        pre_order = build_loop_tree_impl( n, pre_order );
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2091
        // Check for bailout
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2092
        if (C->failing()) {
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2093
          return;
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2094
        }
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2095
        // Check to grow _preorders[] array for the case when
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2096
        // build_loop_tree_impl() adds new nodes.
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2097
        check_grow_preorders();
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2098
      }
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2099
    }
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2100
    else {
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2101
      (void)bltstack.pop(); // Remove post-visited node from stack
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2102
    }
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2103
  }
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2104
}
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2105
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2106
//------------------------------build_loop_tree_impl---------------------------
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2107
int PhaseIdealLoop::build_loop_tree_impl( Node *n, int pre_order ) {
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2108
  // ---- Post-pass Work ----
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2109
  // Pre-walked but not post-walked nodes need a pre_order number.
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2110
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2111
  // Tightest enclosing loop for this Node
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2112
  IdealLoopTree *innermost = NULL;
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2113
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2114
  // For all children, see if any edge is a backedge.  If so, make a loop
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2115
  // for it.  Then find the tightest enclosing loop for the self Node.
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2116
  for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2117
    Node* m = n->fast_out(i);   // Child
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2118
    if( n == m ) continue;      // Ignore control self-cycles
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2119
    if( !m->is_CFG() ) continue;// Ignore non-CFG edges
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2120
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2121
    IdealLoopTree *l;           // Child's loop
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2122
    if( !is_postvisited(m) ) {  // Child visited but not post-visited?
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2123
      // Found a backedge
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2124
      assert( get_preorder(m) < pre_order, "should be backedge" );
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2125
      // Check for the RootNode, which is already a LoopNode and is allowed
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2126
      // to have multiple "backedges".
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2127
      if( m == C->root()) {     // Found the root?
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2128
        l = _ltree_root;        // Root is the outermost LoopNode
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2129
      } else {                  // Else found a nested loop
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2130
        // Insert a LoopNode to mark this loop.
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2131
        l = new IdealLoopTree(this, m, n);
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2132
      } // End of Else found a nested loop
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2133
      if( !has_loop(m) )        // If 'm' does not already have a loop set
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2134
        set_loop(m, l);         // Set loop header to loop now
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2135
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2136
    } else {                    // Else not a nested loop
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2137
      if( !_nodes[m->_idx] ) continue; // Dead code has no loop
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2138
      l = get_loop(m);          // Get previously determined loop
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2139
      // If successor is header of a loop (nest), move up-loop till it
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2140
      // is a member of some outer enclosing loop.  Since there are no
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2141
      // shared headers (I've split them already) I only need to go up
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2142
      // at most 1 level.
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2143
      while( l && l->_head == m ) // Successor heads loop?
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2144
        l = l->_parent;         // Move up 1 for me
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2145
      // If this loop is not properly parented, then this loop
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2146
      // has no exit path out, i.e. its an infinite loop.
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2147
      if( !l ) {
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2148
        // Make loop "reachable" from root so the CFG is reachable.  Basically
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2149
        // insert a bogus loop exit that is never taken.  'm', the loop head,
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2150
        // points to 'n', one (of possibly many) fall-in paths.  There may be
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2151
        // many backedges as well.
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2152
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2153
        // Here I set the loop to be the root loop.  I could have, after
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2154
        // inserting a bogus loop exit, restarted the recursion and found my
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2155
        // new loop exit.  This would make the infinite loop a first-class
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2156
        // loop and it would then get properly optimized.  What's the use of
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2157
        // optimizing an infinite loop?
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2158
        l = _ltree_root;        // Oops, found infinite loop
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2159
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2160
        // Insert the NeverBranch between 'm' and it's control user.
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2161
        NeverBranchNode *iff = new (C, 1) NeverBranchNode( m );
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2162
        _igvn.register_new_node_with_optimizer(iff);
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2163
        set_loop(iff, l);
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2164
        Node *if_t = new (C, 1) CProjNode( iff, 0 );
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2165
        _igvn.register_new_node_with_optimizer(if_t);
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2166
        set_loop(if_t, l);
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2167
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2168
        Node* cfg = NULL;       // Find the One True Control User of m
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2169
        for (DUIterator_Fast jmax, j = m->fast_outs(jmax); j < jmax; j++) {
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2170
          Node* x = m->fast_out(j);
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2171
          if (x->is_CFG() && x != m && x != iff)
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2172
            { cfg = x; break; }
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2173
        }
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2174
        assert(cfg != NULL, "must find the control user of m");
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2175
        uint k = 0;             // Probably cfg->in(0)
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2176
        while( cfg->in(k) != m ) k++; // But check incase cfg is a Region
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2177
        cfg->set_req( k, if_t ); // Now point to NeverBranch
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2178
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2179
        // Now create the never-taken loop exit
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2180
        Node *if_f = new (C, 1) CProjNode( iff, 1 );
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2181
        _igvn.register_new_node_with_optimizer(if_f);
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2182
        set_loop(if_f, l);
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2183
        // Find frame ptr for Halt.  Relies on the optimizer
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2184
        // V-N'ing.  Easier and quicker than searching through
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2185
        // the program structure.
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2186
        Node *frame = new (C, 1) ParmNode( C->start(), TypeFunc::FramePtr );
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2187
        _igvn.register_new_node_with_optimizer(frame);
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2188
        // Halt & Catch Fire
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2189
        Node *halt = new (C, TypeFunc::Parms) HaltNode( if_f, frame );
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2190
        _igvn.register_new_node_with_optimizer(halt);
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2191
        set_loop(halt, l);
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2192
        C->root()->add_req(halt);
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2193
        set_loop(C->root(), _ltree_root);
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2194
      }
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2195
    }
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2196
    // Weeny check for irreducible.  This child was already visited (this
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2197
    // IS the post-work phase).  Is this child's loop header post-visited
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2198
    // as well?  If so, then I found another entry into the loop.
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2199
    while( is_postvisited(l->_head) ) {
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2200
      // found irreducible
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2201
      l->_irreducible = true;
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2202
      l = l->_parent;
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2203
      _has_irreducible_loops = true;
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2204
      // Check for bad CFG here to prevent crash, and bailout of compile
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2205
      if (l == NULL) {
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2206
        C->record_method_not_compilable("unhandled CFG detected during loop optimization");
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2207
        return pre_order;
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2208
      }
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2209
    }
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2210
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2211
    // This Node might be a decision point for loops.  It is only if
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2212
    // it's children belong to several different loops.  The sort call
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2213
    // does a trivial amount of work if there is only 1 child or all
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2214
    // children belong to the same loop.  If however, the children
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2215
    // belong to different loops, the sort call will properly set the
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2216
    // _parent pointers to show how the loops nest.
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2217
    //
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2218
    // In any case, it returns the tightest enclosing loop.
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2219
    innermost = sort( l, innermost );
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2220
  }
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2221
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2222
  // Def-use info will have some dead stuff; dead stuff will have no
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2223
  // loop decided on.
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2224
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2225
  // Am I a loop header?  If so fix up my parent's child and next ptrs.
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2226
  if( innermost && innermost->_head == n ) {
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2227
    assert( get_loop(n) == innermost, "" );
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2228
    IdealLoopTree *p = innermost->_parent;
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2229
    IdealLoopTree *l = innermost;
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2230
    while( p && l->_head == n ) {
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2231
      l->_next = p->_child;     // Put self on parents 'next child'
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2232
      p->_child = l;            // Make self as first child of parent
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2233
      l = p;                    // Now walk up the parent chain
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2234
      p = l->_parent;
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2235
    }
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2236
  } else {
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2237
    // Note that it is possible for a LoopNode to reach here, if the
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2238
    // backedge has been made unreachable (hence the LoopNode no longer
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2239
    // denotes a Loop, and will eventually be removed).
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2240
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2241
    // Record tightest enclosing loop for self.  Mark as post-visited.
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2242
    set_loop(n, innermost);
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2243
    // Also record has_call flag early on
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2244
    if( innermost ) {
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2245
      if( n->is_Call() && !n->is_CallLeaf() && !n->is_macro() ) {
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2246
        // Do not count uncommon calls
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2247
        if( !n->is_CallStaticJava() || !n->as_CallStaticJava()->_name ) {
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2248
          Node *iff = n->in(0)->in(0);
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2249
          if( !iff->is_If() ||
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2250
              (n->in(0)->Opcode() == Op_IfFalse &&
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2251
               (1.0 - iff->as_If()->_prob) >= 0.01) ||
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2252
              (iff->as_If()->_prob >= 0.01) )
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2253
            innermost->_has_call = 1;
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2254
        }
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2255
      }
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2256
    }
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2257
  }
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2258
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2259
  // Flag as post-visited now
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2260
  set_postvisited(n);
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2261
  return pre_order;
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2262
}
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2263
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2264
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2265
//------------------------------build_loop_early-------------------------------
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2266
// Put Data nodes into some loop nest, by setting the _nodes[]->loop mapping.
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2267
// First pass computes the earliest controlling node possible.  This is the
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2268
// controlling input with the deepest dominating depth.
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2269
void PhaseIdealLoop::build_loop_early( VectorSet &visited, Node_List &worklist, Node_Stack &nstack, const PhaseIdealLoop *verify_me ) {
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2270
  while (worklist.size() != 0) {
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2271
    // Use local variables nstack_top_n & nstack_top_i to cache values
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2272
    // on nstack's top.
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2273
    Node *nstack_top_n = worklist.pop();
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2274
    uint  nstack_top_i = 0;
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2275
//while_nstack_nonempty:
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2276
    while (true) {
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2277
      // Get parent node and next input's index from stack's top.
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2278
      Node  *n = nstack_top_n;
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2279
      uint   i = nstack_top_i;
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2280
      uint cnt = n->req(); // Count of inputs
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2281
      if (i == 0) {        // Pre-process the node.
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2282
        if( has_node(n) &&            // Have either loop or control already?
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2283
            !has_ctrl(n) ) {          // Have loop picked out already?
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2284
          // During "merge_many_backedges" we fold up several nested loops
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2285
          // into a single loop.  This makes the members of the original
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2286
          // loop bodies pointing to dead loops; they need to move up
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2287
          // to the new UNION'd larger loop.  I set the _head field of these
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2288
          // dead loops to NULL and the _parent field points to the owning
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2289
          // loop.  Shades of UNION-FIND algorithm.
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2290
          IdealLoopTree *ilt;
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2291
          while( !(ilt = get_loop(n))->_head ) {
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2292
            // Normally I would use a set_loop here.  But in this one special
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2293
            // case, it is legal (and expected) to change what loop a Node
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2294
            // belongs to.
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2295
            _nodes.map(n->_idx, (Node*)(ilt->_parent) );
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2296
          }
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2297
          // Remove safepoints ONLY if I've already seen I don't need one.
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2298
          // (the old code here would yank a 2nd safepoint after seeing a
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2299
          // first one, even though the 1st did not dominate in the loop body
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2300
          // and thus could be avoided indefinitely)
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2301
          if( !verify_me && ilt->_has_sfpt && n->Opcode() == Op_SafePoint &&
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2302
              is_deleteable_safept(n)) {
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2303
            Node *in = n->in(TypeFunc::Control);
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2304
            lazy_replace(n,in);       // Pull safepoint now
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2305
            // Carry on with the recursion "as if" we are walking
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2306
            // only the control input
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2307
            if( !visited.test_set( in->_idx ) ) {
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2308
              worklist.push(in);      // Visit this guy later, using worklist
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2309
            }
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2310
            // Get next node from nstack:
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2311
            // - skip n's inputs processing by setting i > cnt;
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2312
            // - we also will not call set_early_ctrl(n) since
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2313
            //   has_node(n) == true (see the condition above).
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2314
            i = cnt + 1;
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2315
          }
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2316
        }
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2317
      } // if (i == 0)
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2318
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2319
      // Visit all inputs
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2320
      bool done = true;       // Assume all n's inputs will be processed
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2321
      while (i < cnt) {
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2322
        Node *in = n->in(i);
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2323
        ++i;
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2324
        if (in == NULL) continue;
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2325
        if (in->pinned() && !in->is_CFG())
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2326
          set_ctrl(in, in->in(0));
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2327
        int is_visited = visited.test_set( in->_idx );
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2328
        if (!has_node(in)) {  // No controlling input yet?
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2329
          assert( !in->is_CFG(), "CFG Node with no controlling input?" );
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2330
          assert( !is_visited, "visit only once" );
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2331
          nstack.push(n, i);  // Save parent node and next input's index.
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2332
          nstack_top_n = in;  // Process current input now.
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2333
          nstack_top_i = 0;
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2334
          done = false;       // Not all n's inputs processed.
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2335
          break; // continue while_nstack_nonempty;
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2336
        } else if (!is_visited) {
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2337
          // This guy has a location picked out for him, but has not yet
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2338
          // been visited.  Happens to all CFG nodes, for instance.
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2339
          // Visit him using the worklist instead of recursion, to break
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2340
          // cycles.  Since he has a location already we do not need to
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2341
          // find his location before proceeding with the current Node.
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2342
          worklist.push(in);  // Visit this guy later, using worklist
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2343
        }
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2344
      }
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2345
      if (done) {
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2346
        // All of n's inputs have been processed, complete post-processing.
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2347
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2348
        // Compute earilest point this Node can go.
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2349
        // CFG, Phi, pinned nodes already know their controlling input.
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2350
        if (!has_node(n)) {
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2351
          // Record earliest legal location
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2352
          set_early_ctrl( n );
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2353
        }
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2354
        if (nstack.is_empty()) {
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2355
          // Finished all nodes on stack.
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2356
          // Process next node on the worklist.
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2357
          break;
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2358
        }
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2359
        // Get saved parent node and next input's index.
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2360
        nstack_top_n = nstack.node();
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2361
        nstack_top_i = nstack.index();
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2362
        nstack.pop();
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2363
      }
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2364
    } // while (true)
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2365
  }
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2366
}
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2367
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2368
//------------------------------dom_lca_internal--------------------------------
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2369
// Pair-wise LCA
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2370
Node *PhaseIdealLoop::dom_lca_internal( Node *n1, Node *n2 ) const {
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2371
  if( !n1 ) return n2;          // Handle NULL original LCA
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2372
  assert( n1->is_CFG(), "" );
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2373
  assert( n2->is_CFG(), "" );
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2374
  // find LCA of all uses
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2375
  uint d1 = dom_depth(n1);
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2376
  uint d2 = dom_depth(n2);
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2377
  while (n1 != n2) {
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2378
    if (d1 > d2) {
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2379
      n1 =      idom(n1);
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2380
      d1 = dom_depth(n1);
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2381
    } else if (d1 < d2) {
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2382
      n2 =      idom(n2);
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2383
      d2 = dom_depth(n2);
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2384
    } else {
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2385
      // Here d1 == d2.  Due to edits of the dominator-tree, sections
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2386
      // of the tree might have the same depth.  These sections have
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2387
      // to be searched more carefully.
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2388
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2389
      // Scan up all the n1's with equal depth, looking for n2.
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2390
      Node *t1 = idom(n1);
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2391
      while (dom_depth(t1) == d1) {
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2392
        if (t1 == n2)  return n2;
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2393
        t1 = idom(t1);
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2394
      }
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2395
      // Scan up all the n2's with equal depth, looking for n1.
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2396
      Node *t2 = idom(n2);
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2397
      while (dom_depth(t2) == d2) {
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2398
        if (t2 == n1)  return n1;
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2399
        t2 = idom(t2);
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2400
      }
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2401
      // Move up to a new dominator-depth value as well as up the dom-tree.
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2402
      n1 = t1;
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2403
      n2 = t2;
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2404
      d1 = dom_depth(n1);
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2405
      d2 = dom_depth(n2);
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2406
    }
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2407
  }
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2408
  return n1;
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2409
}
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2410
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2411
//------------------------------compute_idom-----------------------------------
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2412
// Locally compute IDOM using dom_lca call.  Correct only if the incoming
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2413
// IDOMs are correct.
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2414
Node *PhaseIdealLoop::compute_idom( Node *region ) const {
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2415
  assert( region->is_Region(), "" );
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2416
  Node *LCA = NULL;
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2417
  for( uint i = 1; i < region->req(); i++ ) {
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2418
    if( region->in(i) != C->top() )
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2419
      LCA = dom_lca( LCA, region->in(i) );
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2420
  }
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2421
  return LCA;
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2422
}
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2423
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2424
//------------------------------get_late_ctrl----------------------------------
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2425
// Compute latest legal control.
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2426
Node *PhaseIdealLoop::get_late_ctrl( Node *n, Node *early ) {
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2427
  assert(early != NULL, "early control should not be NULL");
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2428
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2429
  // Compute LCA over list of uses
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2430
  Node *LCA = NULL;
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2431
  for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax && LCA != early; i++) {
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2432
    Node* c = n->fast_out(i);
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2433
    if (_nodes[c->_idx] == NULL)
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2434
      continue;                 // Skip the occasional dead node
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2435
    if( c->is_Phi() ) {         // For Phis, we must land above on the path
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2436
      for( uint j=1; j<c->req(); j++ ) {// For all inputs
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2437
        if( c->in(j) == n ) {   // Found matching input?
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2438
          Node *use = c->in(0)->in(j);
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2439
          LCA = dom_lca_for_get_late_ctrl( LCA, use, n );
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2440
        }
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2441
      }
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2442
    } else {
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2443
      // For CFG data-users, use is in the block just prior
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2444
      Node *use = has_ctrl(c) ? get_ctrl(c) : c->in(0);
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2445
      LCA = dom_lca_for_get_late_ctrl( LCA, use, n );
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2446
    }
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2447
  }
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2448
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2449
  // if this is a load, check for anti-dependent stores
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2450
  // We use a conservative algorithm to identify potential interfering
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2451
  // instructions and for rescheduling the load.  The users of the memory
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2452
  // input of this load are examined.  Any use which is not a load and is
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2453
  // dominated by early is considered a potentially interfering store.
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2454
  // This can produce false positives.
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2455
  if (n->is_Load() && LCA != early) {
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2456
    Node_List worklist;
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2457
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2458
    Node *mem = n->in(MemNode::Memory);
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2459
    for (DUIterator_Fast imax, i = mem->fast_outs(imax); i < imax; i++) {
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2460
      Node* s = mem->fast_out(i);
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2461
      worklist.push(s);
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2462
    }
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2463
    while(worklist.size() != 0 && LCA != early) {
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2464
      Node* s = worklist.pop();
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2465
      if (s->is_Load()) {
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2466
        continue;
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2467
      } else if (s->is_MergeMem()) {
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2468
        for (DUIterator_Fast imax, i = s->fast_outs(imax); i < imax; i++) {
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2469
          Node* s1 = s->fast_out(i);
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2470
          worklist.push(s1);
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2471
        }
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2472
      } else {
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2473
        Node *sctrl = has_ctrl(s) ? get_ctrl(s) : s->in(0);
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2474
        assert(sctrl != NULL || s->outcnt() == 0, "must have control");
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2475
        if (sctrl != NULL && !sctrl->is_top() && is_dominator(early, sctrl)) {
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2476
          LCA = dom_lca_for_get_late_ctrl(LCA, sctrl, n);
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2477
        }
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2478
      }
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2479
    }
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2480
  }
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2481
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2482
  assert(LCA == find_non_split_ctrl(LCA), "unexpected late control");
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2483
  return LCA;
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2484
}
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2485
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2486
// true if CFG node d dominates CFG node n
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2487
bool PhaseIdealLoop::is_dominator(Node *d, Node *n) {
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2488
  if (d == n)
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2489
    return true;
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2490
  assert(d->is_CFG() && n->is_CFG(), "must have CFG nodes");
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2491
  uint dd = dom_depth(d);
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2492
  while (dom_depth(n) >= dd) {
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2493
    if (n == d)
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2494
      return true;
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2495
    n = idom(n);
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2496
  }
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2497
  return false;
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2498
}
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2499
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2500
//------------------------------dom_lca_for_get_late_ctrl_internal-------------
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2501
// Pair-wise LCA with tags.
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2502
// Tag each index with the node 'tag' currently being processed
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2503
// before advancing up the dominator chain using idom().
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2504
// Later calls that find a match to 'tag' know that this path has already
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2505
// been considered in the current LCA (which is input 'n1' by convention).
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2506
// Since get_late_ctrl() is only called once for each node, the tag array
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2507
// does not need to be cleared between calls to get_late_ctrl().
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2508
// Algorithm trades a larger constant factor for better asymptotic behavior
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2509
//
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2510
Node *PhaseIdealLoop::dom_lca_for_get_late_ctrl_internal( Node *n1, Node *n2, Node *tag ) {
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2511
  uint d1 = dom_depth(n1);
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2512
  uint d2 = dom_depth(n2);
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2513
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2514
  do {
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2515
    if (d1 > d2) {
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2516
      // current lca is deeper than n2
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2517
      _dom_lca_tags.map(n1->_idx, tag);
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2518
      n1 =      idom(n1);
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2519
      d1 = dom_depth(n1);
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2520
    } else if (d1 < d2) {
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2521
      // n2 is deeper than current lca
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2522
      Node *memo = _dom_lca_tags[n2->_idx];
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2523
      if( memo == tag ) {
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2524
        return n1;    // Return the current LCA
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2525
      }
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2526
      _dom_lca_tags.map(n2->_idx, tag);
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2527
      n2 =      idom(n2);
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2528
      d2 = dom_depth(n2);
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2529
    } else {
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2530
      // Here d1 == d2.  Due to edits of the dominator-tree, sections
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2531
      // of the tree might have the same depth.  These sections have
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2532
      // to be searched more carefully.
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2533
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2534
      // Scan up all the n1's with equal depth, looking for n2.
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2535
      _dom_lca_tags.map(n1->_idx, tag);
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2536
      Node *t1 = idom(n1);
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2537
      while (dom_depth(t1) == d1) {
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2538
        if (t1 == n2)  return n2;
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2539
        _dom_lca_tags.map(t1->_idx, tag);
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2540
        t1 = idom(t1);
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2541
      }
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2542
      // Scan up all the n2's with equal depth, looking for n1.
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2543
      _dom_lca_tags.map(n2->_idx, tag);
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2544
      Node *t2 = idom(n2);
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2545
      while (dom_depth(t2) == d2) {
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2546
        if (t2 == n1)  return n1;
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2547
        _dom_lca_tags.map(t2->_idx, tag);
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2548
        t2 = idom(t2);
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2549
      }
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2550
      // Move up to a new dominator-depth value as well as up the dom-tree.
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2551
      n1 = t1;
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2552
      n2 = t2;
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2553
      d1 = dom_depth(n1);
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2554
      d2 = dom_depth(n2);
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2555
    }
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2556
  } while (n1 != n2);
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2557
  return n1;
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2558
}
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2559
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2560
//------------------------------init_dom_lca_tags------------------------------
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2561
// Tag could be a node's integer index, 32bits instead of 64bits in some cases
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2562
// Intended use does not involve any growth for the array, so it could
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2563
// be of fixed size.
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2564
void PhaseIdealLoop::init_dom_lca_tags() {
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2565
  uint limit = C->unique() + 1;
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2566
  _dom_lca_tags.map( limit, NULL );
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2567
#ifdef ASSERT
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2568
  for( uint i = 0; i < limit; ++i ) {
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2569
    assert(_dom_lca_tags[i] == NULL, "Must be distinct from each node pointer");
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2570
  }
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2571
#endif // ASSERT
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2572
}
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2573
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2574
//------------------------------clear_dom_lca_tags------------------------------
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2575
// Tag could be a node's integer index, 32bits instead of 64bits in some cases
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2576
// Intended use does not involve any growth for the array, so it could
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2577
// be of fixed size.
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2578
void PhaseIdealLoop::clear_dom_lca_tags() {
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2579
  uint limit = C->unique() + 1;
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2580
  _dom_lca_tags.map( limit, NULL );
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2581
  _dom_lca_tags.clear();
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2582
#ifdef ASSERT
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2583
  for( uint i = 0; i < limit; ++i ) {
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2584
    assert(_dom_lca_tags[i] == NULL, "Must be distinct from each node pointer");
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2585
  }
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2586
#endif // ASSERT
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2587
}
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2588
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2589
//------------------------------build_loop_late--------------------------------
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2590
// Put Data nodes into some loop nest, by setting the _nodes[]->loop mapping.
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2591
// Second pass finds latest legal placement, and ideal loop placement.
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2592
void PhaseIdealLoop::build_loop_late( VectorSet &visited, Node_List &worklist, Node_Stack &nstack, const PhaseIdealLoop *verify_me ) {
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2593
  while (worklist.size() != 0) {
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2594
    Node *n = worklist.pop();
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2595
    // Only visit once
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2596
    if (visited.test_set(n->_idx)) continue;
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2597
    uint cnt = n->outcnt();
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2598
    uint   i = 0;
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2599
    while (true) {
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2600
      assert( _nodes[n->_idx], "no dead nodes" );
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2601
      // Visit all children
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2602
      if (i < cnt) {
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2603
        Node* use = n->raw_out(i);
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2604
        ++i;
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2605
        // Check for dead uses.  Aggressively prune such junk.  It might be
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2606
        // dead in the global sense, but still have local uses so I cannot
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2607
        // easily call 'remove_dead_node'.
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2608
        if( _nodes[use->_idx] != NULL || use->is_top() ) { // Not dead?
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2609
          // Due to cycles, we might not hit the same fixed point in the verify
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2610
          // pass as we do in the regular pass.  Instead, visit such phis as
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2611
          // simple uses of the loop head.
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2612
          if( use->in(0) && (use->is_CFG() || use->is_Phi()) ) {
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2613
            if( !visited.test(use->_idx) )
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2614
              worklist.push(use);
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2615
          } else if( !visited.test_set(use->_idx) ) {
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2616
            nstack.push(n, i); // Save parent and next use's index.
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2617
            n   = use;         // Process all children of current use.
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2618
            cnt = use->outcnt();
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2619
            i   = 0;
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2620
          }
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2621
        } else {
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2622
          // Do not visit around the backedge of loops via data edges.
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2623
          // push dead code onto a worklist
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2624
          _deadlist.push(use);
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2625
        }
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2626
      } else {
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2627
        // All of n's children have been processed, complete post-processing.
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2628
        build_loop_late_post(n, verify_me);
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2629
        if (nstack.is_empty()) {
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2630
          // Finished all nodes on stack.
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2631
          // Process next node on the worklist.
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2632
          break;
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2633
        }
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2634
        // Get saved parent node and next use's index. Visit the rest of uses.
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2635
        n   = nstack.node();
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2636
        cnt = n->outcnt();
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2637
        i   = nstack.index();
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2638
        nstack.pop();
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2639
      }
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2640
    }
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2641
  }
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2642
}
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2643
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2644
//------------------------------build_loop_late_post---------------------------
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2645
// Put Data nodes into some loop nest, by setting the _nodes[]->loop mapping.
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2646
// Second pass finds latest legal placement, and ideal loop placement.
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2647
void PhaseIdealLoop::build_loop_late_post( Node *n, const PhaseIdealLoop *verify_me ) {
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2648
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2649
  if (n->req() == 2 && n->Opcode() == Op_ConvI2L && !C->major_progress()) {
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2650
    _igvn._worklist.push(n);  // Maybe we'll normalize it, if no more loops.
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2651
  }
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2652
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2653
  // CFG and pinned nodes already handled
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2654
  if( n->in(0) ) {
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2655
    if( n->in(0)->is_top() ) return; // Dead?
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2656
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2657
    // We'd like +VerifyLoopOptimizations to not believe that Mod's/Loads
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2658
    // _must_ be pinned (they have to observe their control edge of course).
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2659
    // Unlike Stores (which modify an unallocable resource, the memory
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2660
    // state), Mods/Loads can float around.  So free them up.
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2661
    bool pinned = true;
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2662
    switch( n->Opcode() ) {
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2663
    case Op_DivI:
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2664
    case Op_DivF:
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2665
    case Op_DivD:
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2666
    case Op_ModI:
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2667
    case Op_ModF:
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2668
    case Op_ModD:
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2669
    case Op_LoadB:              // Same with Loads; they can sink
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2670
    case Op_LoadC:              // during loop optimizations.
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2671
    case Op_LoadD:
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2672
    case Op_LoadF:
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2673
    case Op_LoadI:
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2674
    case Op_LoadKlass:
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2675
    case Op_LoadL:
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2676
    case Op_LoadS:
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2677
    case Op_LoadP:
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2678
    case Op_LoadRange:
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2679
    case Op_LoadD_unaligned:
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2680
    case Op_LoadL_unaligned:
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2681
    case Op_StrComp:            // Does a bunch of load-like effects
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2682
      pinned = false;
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2683
    }
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2684
    if( pinned ) {
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2685
      IdealLoopTree *choosen_loop = get_loop(n->is_CFG() ? n : get_ctrl(n));
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2686
      if( !choosen_loop->_child )       // Inner loop?
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2687
        choosen_loop->_body.push(n); // Collect inner loops
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2688
      return;
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2689
    }
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2690
  } else {                      // No slot zero
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2691
    if( n->is_CFG() ) {         // CFG with no slot 0 is dead
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2692
      _nodes.map(n->_idx,0);    // No block setting, it's globally dead
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2693
      return;
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2694
    }
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2695
    assert(!n->is_CFG() || n->outcnt() == 0, "");
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2696
  }
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2697
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2698
  // Do I have a "safe range" I can select over?
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2699
  Node *early = get_ctrl(n);// Early location already computed
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2700
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2701
  // Compute latest point this Node can go
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2702
  Node *LCA = get_late_ctrl( n, early );
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2703
  // LCA is NULL due to uses being dead
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2704
  if( LCA == NULL ) {
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2705
#ifdef ASSERT
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2706
    for (DUIterator i1 = n->outs(); n->has_out(i1); i1++) {
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2707
      assert( _nodes[n->out(i1)->_idx] == NULL, "all uses must also be dead");
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2708
    }
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2709
#endif
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2710
    _nodes.map(n->_idx, 0);     // This node is useless
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2711
    _deadlist.push(n);
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2712
    return;
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2713
  }
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2714
  assert(LCA != NULL && !LCA->is_top(), "no dead nodes");
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2715
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2716
  Node *legal = LCA;            // Walk 'legal' up the IDOM chain
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2717
  Node *least = legal;          // Best legal position so far
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2718
  while( early != legal ) {     // While not at earliest legal
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2719
    // Find least loop nesting depth
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2720
    legal = idom(legal);        // Bump up the IDOM tree
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2721
    // Check for lower nesting depth
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2722
    if( get_loop(legal)->_nest < get_loop(least)->_nest )
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2723
      least = legal;
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2724
  }
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2725
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2726
  // Try not to place code on a loop entry projection
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2727
  // which can inhibit range check elimination.
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2728
  if (least != early) {
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2729
    Node* ctrl_out = least->unique_ctrl_out();
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2730
    if (ctrl_out && ctrl_out->is_CountedLoop() &&
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2731
        least == ctrl_out->in(LoopNode::EntryControl)) {
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2732
      Node* least_dom = idom(least);
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2733
      if (get_loop(least_dom)->is_member(get_loop(least))) {
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2734
        least = least_dom;
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2735
      }
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2736
    }
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2737
  }
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2738
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2739
#ifdef ASSERT
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2740
  // If verifying, verify that 'verify_me' has a legal location
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2741
  // and choose it as our location.
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2742
  if( verify_me ) {
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2743
    Node *v_ctrl = verify_me->get_ctrl_no_update(n);
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2744
    Node *legal = LCA;
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2745
    while( early != legal ) {   // While not at earliest legal
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2746
      if( legal == v_ctrl ) break;  // Check for prior good location
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2747
      legal = idom(legal)      ;// Bump up the IDOM tree
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2748
    }
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2749
    // Check for prior good location
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2750
    if( legal == v_ctrl ) least = legal; // Keep prior if found
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2751
  }
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2752
#endif
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2753
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2754
  // Assign discovered "here or above" point
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2755
  least = find_non_split_ctrl(least);
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2756
  set_ctrl(n, least);
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2757
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2758
  // Collect inner loop bodies
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2759
  IdealLoopTree *choosen_loop = get_loop(least);
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2760
  if( !choosen_loop->_child )   // Inner loop?
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2761
    choosen_loop->_body.push(n);// Collect inner loops
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2762
}
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2763
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2764
#ifndef PRODUCT
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2765
//------------------------------dump-------------------------------------------
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2766
void PhaseIdealLoop::dump( ) const {
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2767
  ResourceMark rm;
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2768
  Arena* arena = Thread::current()->resource_area();
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2769
  Node_Stack stack(arena, C->unique() >> 2);
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2770
  Node_List rpo_list;
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2771
  VectorSet visited(arena);
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2772
  visited.set(C->top()->_idx);
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2773
  rpo( C->root(), stack, visited, rpo_list );
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2774
  // Dump root loop indexed by last element in PO order
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2775
  dump( _ltree_root, rpo_list.size(), rpo_list );
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2776
}
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2777
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2778
void PhaseIdealLoop::dump( IdealLoopTree *loop, uint idx, Node_List &rpo_list ) const {
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2779
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2780
  // Indent by loop nesting depth
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2781
  for( uint x = 0; x < loop->_nest; x++ )
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2782
    tty->print("  ");
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2783
  tty->print_cr("---- Loop N%d-N%d ----", loop->_head->_idx,loop->_tail->_idx);
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2784
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2785
  // Now scan for CFG nodes in the same loop
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2786
  for( uint j=idx; j > 0;  j-- ) {
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2787
    Node *n = rpo_list[j-1];
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2788
    if( !_nodes[n->_idx] )      // Skip dead nodes
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2789
      continue;
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2790
    if( get_loop(n) != loop ) { // Wrong loop nest
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2791
      if( get_loop(n)->_head == n &&    // Found nested loop?
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2792
          get_loop(n)->_parent == loop )
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2793
        dump(get_loop(n),rpo_list.size(),rpo_list);     // Print it nested-ly
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2794
      continue;
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2795
    }
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2796
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2797
    // Dump controlling node
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2798
    for( uint x = 0; x < loop->_nest; x++ )
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2799
      tty->print("  ");
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2800
    tty->print("C");
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2801
    if( n == C->root() ) {
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2802
      n->dump();
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2803
    } else {
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2804
      Node* cached_idom   = idom_no_update(n);
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2805
      Node *computed_idom = n->in(0);
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2806
      if( n->is_Region() ) {
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2807
        computed_idom = compute_idom(n);
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2808
        // computed_idom() will return n->in(0) when idom(n) is an IfNode (or
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2809
        // any MultiBranch ctrl node), so apply a similar transform to
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2810
        // the cached idom returned from idom_no_update.
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2811
        cached_idom = find_non_split_ctrl(cached_idom);
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2812
      }
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2813
      tty->print(" ID:%d",computed_idom->_idx);
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2814
      n->dump();
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2815
      if( cached_idom != computed_idom ) {
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2816
        tty->print_cr("*** BROKEN IDOM!  Computed as: %d, cached as: %d",
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2817
                      computed_idom->_idx, cached_idom->_idx);
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2818
      }
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2819
    }
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2820
    // Dump nodes it controls
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2821
    for( uint k = 0; k < _nodes.Size(); k++ ) {
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2822
      // (k < C->unique() && get_ctrl(find(k)) == n)
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2823
      if (k < C->unique() && _nodes[k] == (Node*)((intptr_t)n + 1)) {
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2824
        Node *m = C->root()->find(k);
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2825
        if( m && m->outcnt() > 0 ) {
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2826
          if (!(has_ctrl(m) && get_ctrl_no_update(m) == n)) {
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2827
            tty->print_cr("*** BROKEN CTRL ACCESSOR!  _nodes[k] is %p, ctrl is %p",
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2828
                          _nodes[k], has_ctrl(m) ? get_ctrl_no_update(m) : NULL);
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2829
          }
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2830
          for( uint j = 0; j < loop->_nest; j++ )
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2831
            tty->print("  ");
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2832
          tty->print(" ");
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2833
          m->dump();
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2834
        }
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2835
      }
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2836
    }
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2837
  }
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2838
}
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2839
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2840
// Collect a R-P-O for the whole CFG.
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2841
// Result list is in post-order (scan backwards for RPO)
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2842
void PhaseIdealLoop::rpo( Node *start, Node_Stack &stk, VectorSet &visited, Node_List &rpo_list ) const {
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2843
  stk.push(start, 0);
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2844
  visited.set(start->_idx);
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2845
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2846
  while (stk.is_nonempty()) {
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2847
    Node* m   = stk.node();
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2848
    uint  idx = stk.index();
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2849
    if (idx < m->outcnt()) {
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2850
      stk.set_index(idx + 1);
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2851
      Node* n = m->raw_out(idx);
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2852
      if (n->is_CFG() && !visited.test_set(n->_idx)) {
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2853
        stk.push(n, 0);
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2854
      }
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2855
    } else {
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2856
      rpo_list.push(m);
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2857
      stk.pop();
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2858
    }
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2859
  }
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2860
}
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2861
#endif
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2862
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2863
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2864
//=============================================================================
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2865
//------------------------------LoopTreeIterator-----------------------------------
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2866
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2867
// Advance to next loop tree using a preorder, left-to-right traversal.
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2868
void LoopTreeIterator::next() {
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2869
  assert(!done(), "must not be done.");
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2870
  if (_curnt->_child != NULL) {
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2871
    _curnt = _curnt->_child;
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2872
  } else if (_curnt->_next != NULL) {
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2873
    _curnt = _curnt->_next;
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2874
  } else {
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2875
    while (_curnt != _root && _curnt->_next == NULL) {
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2876
      _curnt = _curnt->_parent;
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2877
    }
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2878
    if (_curnt == _root) {
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2879
      _curnt = NULL;
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2880
      assert(done(), "must be done.");
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2881
    } else {
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2882
      assert(_curnt->_next != NULL, "must be more to do");
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2883
      _curnt = _curnt->_next;
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2884
    }
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2885
  }
489c9b5090e2 Initial load
duke
parents:
diff changeset
  2886
}