/*

 * Copyright (c) 2005, 2014, Oracle and/or its affiliates. All rights reserved.

 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

 *

 * This code is free software; you can redistribute it and/or modify it

 * under the terms of the GNU General Public License version 2 only, as

 * published by the Free Software Foundation.

 *

 * This code is distributed in the hope that it will be useful, but WITHOUT

 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or

 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License

 * version 2 for more details (a copy is included in the LICENSE file that

 * accompanied this code).

 *

 * You should have received a copy of the GNU General Public License version

 * 2 along with this work; if not, write to the Free Software Foundation,

 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.

 *

 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA

 * or visit www.oracle.com if you need additional information or have any

 * questions.

 *

 */

#include "precompiled.hpp"

#include "opto/addnode.hpp"

#include "opto/callnode.hpp"

#include "opto/cfgnode.hpp"

#include "opto/idealKit.hpp"

#include "opto/runtime.hpp"

// Static initialization

// This declares the position where vars are kept in the cvstate

// For some degree of consistency we use the TypeFunc enum to

// soak up spots in the inputs even though we only use early Control

// and Memory slots. (So far.)

const uint IdealKit::first_var = TypeFunc::Parms + 1;

//----------------------------IdealKit-----------------------------------------

IdealKit::IdealKit(GraphKit* gkit, bool delay_all_transforms, bool has_declarations) :

  _gvn(gkit->gvn()), C(gkit->C) {

  _initial_ctrl = gkit->control();

  _initial_memory = gkit->merged_memory();

  _initial_i_o = gkit->i_o();

  _delay_all_transforms = delay_all_transforms;

  _var_ct = 0;

  _cvstate = NULL;

  // We can go memory state free or else we need the entire memory state

  assert(_initial_memory == NULL || _initial_memory->Opcode() == Op_MergeMem, "memory must be pre-split");

  assert(!_gvn.is_IterGVN(), "IdealKit can't be used during Optimize phase");

  int init_size = 5;

  _pending_cvstates = new (C->node_arena()) GrowableArray<Node*>(C->node_arena(), init_size, 0, 0);

  DEBUG_ONLY(_state = new (C->node_arena()) GrowableArray<int>(C->node_arena(), init_size, 0, 0));

  if (!has_declarations) {

     declarations_done();

  }

}

//----------------------------sync_kit-----------------------------------------

void IdealKit::sync_kit(GraphKit* gkit) {

  set_all_memory(gkit->merged_memory());

  set_i_o(gkit->i_o());

  set_ctrl(gkit->control());

}

//-------------------------------if_then-------------------------------------

// Create:  if(left relop right)

//          /  \

//   iffalse    iftrue

// Push the iffalse cvstate onto the stack. The iftrue becomes the current cvstate.

void IdealKit::if_then(Node* left, BoolTest::mask relop,

                       Node* right, float prob, float cnt, bool push_new_state) {

  assert((state() & (BlockS|LoopS|IfThenS|ElseS)), "bad state for new If");

  Node* bol;

  if (left->bottom_type()->isa_ptr() == NULL) {

    if (left->bottom_type()->isa_int() != NULL) {

      bol = Bool(CmpI(left, right), relop);

    } else {

      assert(left->bottom_type()->isa_long() != NULL, "what else?");

      bol = Bool(CmpL(left, right), relop);

    }

  } else {

    bol = Bool(CmpP(left, right), relop);

  }

  // Delay gvn.tranform on if-nodes until construction is finished

  // to prevent a constant bool input from discarding a control output.

  IfNode* iff = delay_transform(new IfNode(ctrl(), bol, prob, cnt))->as_If();

  Node* then  = IfTrue(iff);

  Node* elsen = IfFalse(iff);

  Node* else_cvstate = copy_cvstate();

  else_cvstate->set_req(TypeFunc::Control, elsen);

  _pending_cvstates->push(else_cvstate);

  DEBUG_ONLY(if (push_new_state) _state->push(IfThenS));

  set_ctrl(then);

}

//-------------------------------else_-------------------------------------

// Pop the else cvstate off the stack, and push the (current) then cvstate.

// The else cvstate becomes the current cvstate.

void IdealKit::else_() {

  assert(state() == IfThenS, "bad state for new Else");

  Node* else_cvstate = _pending_cvstates->pop();

  DEBUG_ONLY(_state->pop());

  // save current (then) cvstate for later use at endif

  _pending_cvstates->push(_cvstate);

  DEBUG_ONLY(_state->push(ElseS));

  _cvstate = else_cvstate;

}

//-------------------------------end_if-------------------------------------

// Merge the "then" and "else" cvstates.

//

// The if_then() pushed a copy of the current state for later use

// as the initial state for a future "else" clause.  The

// current state then became the initial state for the

// then clause.  If an "else" clause was encountered, it will

// pop the top state and use it for it's initial state.

// It will also push the current state (the state at the end of

// the "then" clause) for latter use at the end_if.

//

// At the endif, the states are:

// 1) else exists a) current state is end of "else" clause

//                b) top stack state is end of "then" clause

//

// 2) no else:    a) current state is end of "then" clause

//                b) top stack state is from the "if_then" which

//                   would have been the initial state of the else.

//

// Merging the states is accomplished by:

//   1) make a label for the merge

//   2) terminate the current state with a goto to the label

//   3) pop the top state from the stack and make it the

//        current state

//   4) bind the label at the current state.  Binding a label

//        terminates the current state with a goto to the

//        label and makes the label's state the current state.

//

void IdealKit::end_if() {

  assert(state() & (IfThenS|ElseS), "bad state for new Endif");

  Node* lab = make_label(1);

  // Node* join_state = _pending_cvstates->pop();

                  /* merging, join */

  goto_(lab);

  _cvstate = _pending_cvstates->pop();

  bind(lab);

  DEBUG_ONLY(_state->pop());

}

//-------------------------------loop-------------------------------------

// Create the loop head portion (*) of:

//  *     iv = init

//  *  top: (region node)

//  *     if (iv relop limit) {

//           loop body

//           i = i + 1

//           goto top

//  *     } else // exits loop

//

// Pushes the loop top cvstate first, then the else (loop exit) cvstate

// onto the stack.

void IdealKit::loop(GraphKit* gkit, int nargs, IdealVariable& iv, Node* init, BoolTest::mask relop, Node* limit, float prob, float cnt) {

  assert((state() & (BlockS|LoopS|IfThenS|ElseS)), "bad state for new loop");

  if (UseLoopPredicate) {

    // Sync IdealKit and graphKit.

    gkit->sync_kit(*this);

    // Add loop predicate.

    gkit->add_predicate(nargs);

    // Update IdealKit memory.

    sync_kit(gkit);

  }

  set(iv, init);

  Node* head = make_label(1);

  bind(head);

  _pending_cvstates->push(head); // push for use at end_loop

  _cvstate = copy_cvstate();

  if_then(value(iv), relop, limit, prob, cnt, false /* no new state */);

  DEBUG_ONLY(_state->push(LoopS));

  assert(ctrl()->is_IfTrue(), "true branch stays in loop");

  assert(_pending_cvstates->top()->in(TypeFunc::Control)->is_IfFalse(), "false branch exits loop");

}

//-------------------------------end_loop-------------------------------------

// Creates the goto top label.

// Expects the else (loop exit) cvstate to be on top of the

// stack, and the loop top cvstate to be 2nd.

void IdealKit::end_loop() {

  assert((state() == LoopS), "bad state for new end_loop");

  Node* exit = _pending_cvstates->pop();

  Node* head = _pending_cvstates->pop();

  goto_(head);

  clear(head);

  DEBUG_ONLY(_state->pop());

  _cvstate = exit;

}

//-------------------------------make_label-------------------------------------

// Creates a label.  The number of goto's

// must be specified (which should be 1 less than

// the number of precedessors.)

Node* IdealKit::make_label(int goto_ct) {

  assert(_cvstate != NULL, "must declare variables before labels");

  Node* lab = new_cvstate();

  int sz = 1 + goto_ct + 1 /* fall thru */;

  Node* reg = delay_transform(new RegionNode(sz));

  lab->init_req(TypeFunc::Control, reg);

  return lab;

}

//-------------------------------bind-------------------------------------

// Bind a label at the current cvstate by simulating

// a goto to the label.

void IdealKit::bind(Node* lab) {

  goto_(lab, true /* bind */);

  _cvstate = lab;

}

//-------------------------------goto_-------------------------------------

// Make the current cvstate a predecessor of the label,

// creating phi's to merge values.  If bind is true and

// this is not the last control edge, then ensure that

// all live values have phis created. Used to create phis

// at loop-top regions.

void IdealKit::goto_(Node* lab, bool bind) {

  Node* reg = lab->in(TypeFunc::Control);

  // find next empty slot in region

  uint slot = 1;

  while (slot < reg->req() && reg->in(slot) != NULL) slot++;

  assert(slot < reg->req(), "too many gotos");

  // If this is last predecessor, then don't force phi creation

  if (slot == reg->req() - 1) bind = false;

  reg->init_req(slot, ctrl());

  assert(first_var + _var_ct == _cvstate->req(), "bad _cvstate size");

  for (uint i = first_var; i < _cvstate->req(); i++) {

    // l is the value of var reaching the label. Could be a single value

    // reaching the label, or a phi that merges multiples values reaching

    // the label.  The latter is true if the label's input: in(..) is

    // a phi whose control input is the region node for the label.

    Node* l = lab->in(i);

    // Get the current value of the var

    Node* m = _cvstate->in(i);

    // If the var went unused no need for a phi

    if (m == NULL) {

      continue;

    } else if (l == NULL || m == l) {

      // Only one unique value "m" is known to reach this label so a phi

      // is not yet necessary unless:

      //    the label is being bound and all predecessors have not been seen,

      //    in which case "bind" will be true.

      if (bind) {

        m = promote_to_phi(m, reg);

      }

      // Record the phi/value used for this var in the label's cvstate

      lab->set_req(i, m);

    } else {

      // More than one value for the variable reaches this label so

      // a create a phi if one does not already exist.

      if (!was_promoted_to_phi(l, reg)) {

        l = promote_to_phi(l, reg);

        lab->set_req(i, l);

      }

      // Record in the phi, the var's value from the current state

      l->set_req(slot, m);

    }

  }

  do_memory_merge(_cvstate, lab);

  stop();

}

//-----------------------------promote_to_phi-----------------------------------

Node* IdealKit::promote_to_phi(Node* n, Node* reg) {

  assert(!was_promoted_to_phi(n, reg), "n already promoted to phi on this region");

  // Get a conservative type for the phi

  const BasicType bt = n->bottom_type()->basic_type();

  const Type* ct = Type::get_const_basic_type(bt);

  return delay_transform(PhiNode::make(reg, n, ct));

}

//-----------------------------declarations_done-------------------------------

void IdealKit::declarations_done() {

  _cvstate = new_cvstate();   // initialize current cvstate

  set_ctrl(_initial_ctrl);    // initialize control in current cvstate

  set_all_memory(_initial_memory);// initialize memory in current cvstate

  set_i_o(_initial_i_o);      // initialize i_o in current cvstate

  DEBUG_ONLY(_state->push(BlockS));

}

//-----------------------------transform-----------------------------------

Node* IdealKit::transform(Node* n) {

  if (_delay_all_transforms) {

    return delay_transform(n);

  } else {

    n = gvn().transform(n);

    C->record_for_igvn(n);

    return n;

  }

}

//-----------------------------delay_transform-----------------------------------

Node* IdealKit::delay_transform(Node* n) {

  // Delay transform until IterativeGVN

  gvn().set_type(n, n->bottom_type());

  C->record_for_igvn(n);

  return n;

}

//-----------------------------new_cvstate-----------------------------------

Node* IdealKit::new_cvstate() {

  uint sz = _var_ct + first_var;

  return new Node(sz);

}

//-----------------------------copy_cvstate-----------------------------------

Node* IdealKit::copy_cvstate() {

  Node* ns = new_cvstate();

  for (uint i = 0; i < ns->req(); i++) ns->init_req(i, _cvstate->in(i));

  // We must clone memory since it will be updated as we do stores.

  ns->set_req(TypeFunc::Memory, MergeMemNode::make(ns->in(TypeFunc::Memory)));

  return ns;

}

//-----------------------------clear-----------------------------------

void IdealKit::clear(Node* m) {

  for (uint i = 0; i < m->req(); i++) m->set_req(i, NULL);

}

//-----------------------------IdealVariable----------------------------

IdealVariable::IdealVariable(IdealKit &k) {

  k.declare(this);

}

Node* IdealKit::memory(uint alias_idx) {

  MergeMemNode* mem = merged_memory();

  Node* p = mem->memory_at(alias_idx);

  _gvn.set_type(p, Type::MEMORY);  // must be mapped

  return p;

}

void IdealKit::set_memory(Node* mem, uint alias_idx) {

  merged_memory()->set_memory_at(alias_idx, mem);

}

//----------------------------- make_load ----------------------------

Node* IdealKit::load(Node* ctl,

                     Node* adr,

                     const Type* t,

                     BasicType bt,

                     int adr_idx,

                     bool require_atomic_access) {

  assert(adr_idx != Compile::AliasIdxTop, "use other make_load factory" );

  const TypePtr* adr_type = NULL; // debug-mode-only argument

  debug_only(adr_type = C->get_adr_type(adr_idx));

  Node* mem = memory(adr_idx);

  Node* ld;

  if (require_atomic_access && bt == T_LONG) {

    ld = LoadLNode::make_atomic(ctl, mem, adr, adr_type, t, MemNode::unordered);

  } else {

    ld = LoadNode::make(_gvn, ctl, mem, adr, adr_type, t, bt, MemNode::unordered);

  }

  return transform(ld);

}

Node* IdealKit::store(Node* ctl, Node* adr, Node *val, BasicType bt,

                      int adr_idx,

                      MemNode::MemOrd mo, bool require_atomic_access) {

  assert(adr_idx != Compile::AliasIdxTop, "use other store_to_memory factory");

  const TypePtr* adr_type = NULL;

  debug_only(adr_type = C->get_adr_type(adr_idx));

  Node *mem = memory(adr_idx);

  Node* st;

  if (require_atomic_access && bt == T_LONG) {

    st = StoreLNode::make_atomic(ctl, mem, adr, adr_type, val, mo);

  } else {

    st = StoreNode::make(_gvn, ctl, mem, adr, adr_type, val, bt, mo);

  }

  st = transform(st);

  set_memory(st, adr_idx);

  return st;

}

// Card mark store. Must be ordered so that it will come after the store of

// the oop.

Node* IdealKit::storeCM(Node* ctl, Node* adr, Node *val, Node* oop_store, int oop_adr_idx,

                        BasicType bt,

                        int adr_idx) {

  assert(adr_idx != Compile::AliasIdxTop, "use other store_to_memory factory" );

  const TypePtr* adr_type = NULL;

  debug_only(adr_type = C->get_adr_type(adr_idx));

  Node *mem = memory(adr_idx);

  // Add required edge to oop_store, optimizer does not support precedence edges.

  // Convert required edge to precedence edge before allocation.

  Node* st = new StoreCMNode(ctl, mem, adr, adr_type, val, oop_store, oop_adr_idx);

  st = transform(st);

  set_memory(st, adr_idx);

  return st;

}

//---------------------------- do_memory_merge --------------------------------

// The memory from one merging cvstate needs to be merged with the memory for another

// join cvstate. If the join cvstate doesn't have a merged memory yet then we

// can just copy the state from the merging cvstate

// Merge one slow path into the rest of memory.

void IdealKit::do_memory_merge(Node* merging, Node* join) {

  // Get the region for the join state

  Node* join_region = join->in(TypeFunc::Control);

  assert(join_region != NULL, "join region must exist");

  if (join->in(TypeFunc::I_O) == NULL ) {

    join->set_req(TypeFunc::I_O,  merging->in(TypeFunc::I_O));

  }

  if (join->in(TypeFunc::Memory) == NULL ) {

    join->set_req(TypeFunc::Memory,  merging->in(TypeFunc::Memory));

    return;

  }

  // The control flow for merging must have already been attached to the join region

  // we need its index for the phis.

  uint slot;

  for (slot = 1; slot < join_region->req() ; slot ++ ) {

    if (join_region->in(slot) == merging->in(TypeFunc::Control)) break;

  }

  assert(slot !=  join_region->req(), "edge must already exist");

  MergeMemNode* join_m    = join->in(TypeFunc::Memory)->as_MergeMem();

  MergeMemNode* merging_m = merging->in(TypeFunc::Memory)->as_MergeMem();

  // join_m should be an ancestor mergemem of merging

  // Slow path memory comes from the current map (which is from a slow call)

  // Fast path/null path memory comes from the call's input

  // Merge the other fast-memory inputs with the new slow-default memory.

  // for (MergeMemStream mms(merged_memory(), fast_mem->as_MergeMem()); mms.next_non_empty2(); ) {

  for (MergeMemStream mms(join_m, merging_m); mms.next_non_empty2(); ) {

    Node* join_slice = mms.force_memory();

    Node* merging_slice = mms.memory2();

    if (join_slice != merging_slice) {

      PhiNode* phi;

      // bool new_phi = false;

      // Is the phi for this slice one that we created for this join region or simply

      // one we copied? If it is ours then add

      if (join_slice->is_Phi() && join_slice->as_Phi()->region() == join_region) {

        phi = join_slice->as_Phi();

      } else {

        // create the phi with join_slice filling supplying memory for all of the

        // control edges to the join region

        phi = PhiNode::make(join_region, join_slice, Type::MEMORY, mms.adr_type(C));

        phi = (PhiNode*) delay_transform(phi);

        // gvn().set_type(phi, Type::MEMORY);

        // new_phi = true;

      }

      // Now update the phi with the slice for the merging slice

      phi->set_req(slot, merging_slice/* slow_path, slow_slice */);

      // this updates join_m with the phi

      mms.set_memory(phi);

    }

  }

  Node* join_io    = join->in(TypeFunc::I_O);

  Node* merging_io = merging->in(TypeFunc::I_O);

  if (join_io != merging_io) {

    PhiNode* phi;

    if (join_io->is_Phi() && join_io->as_Phi()->region() == join_region) {

      phi = join_io->as_Phi();

    } else {

      phi = PhiNode::make(join_region, join_io, Type::ABIO);

      phi = (PhiNode*) delay_transform(phi);

      join->set_req(TypeFunc::I_O, phi);

    }

    phi->set_req(slot, merging_io);

  }

}

//----------------------------- make_call  ----------------------------

// Trivial runtime call

void IdealKit::make_leaf_call(const TypeFunc *slow_call_type,

                              address slow_call,

                              const char *leaf_name,

                              Node* parm0,

                              Node* parm1,

                              Node* parm2,

                              Node* parm3) {

  // We only handle taking in RawMem and modifying RawMem

  const TypePtr* adr_type = TypeRawPtr::BOTTOM;

  uint adr_idx = C->get_alias_index(adr_type);

  // Slow-path leaf call

  CallNode *call =  (CallNode*)new CallLeafNode( slow_call_type, slow_call, leaf_name, adr_type);

  // Set fixed predefined input arguments

  call->init_req( TypeFunc::Control, ctrl() );

  call->init_req( TypeFunc::I_O    , top() )     ;   // does no i/o

  // Narrow memory as only memory input

  call->init_req( TypeFunc::Memory , memory(adr_idx));

  call->init_req( TypeFunc::FramePtr, top() /* frameptr() */ );

  call->init_req( TypeFunc::ReturnAdr, top() );

  if (parm0 != NULL)  call->init_req(TypeFunc::Parms+0, parm0);

  if (parm1 != NULL)  call->init_req(TypeFunc::Parms+1, parm1);

  if (parm2 != NULL)  call->init_req(TypeFunc::Parms+2, parm2);

  if (parm3 != NULL)  call->init_req(TypeFunc::Parms+3, parm3);

  // Node *c = _gvn.transform(call);

  call = (CallNode *) _gvn.transform(call);

  Node *c = call; // dbx gets confused with call call->dump()

  // Slow leaf call has no side-effects, sets few values