6743188: incomplete fix for 6700047 C2 failed in idom_no_update
Reviewed-by: rasbold, kvn
--- a/hotspot/src/share/vm/opto/loopTransform.cpp Thu Oct 02 08:37:44 2008 -0700
+++ b/hotspot/src/share/vm/opto/loopTransform.cpp Fri Oct 03 13:58:20 2008 -0700
@@ -1590,10 +1590,10 @@
//=============================================================================
//------------------------------iteration_split_impl---------------------------
-void IdealLoopTree::iteration_split_impl( PhaseIdealLoop *phase, Node_List &old_new ) {
+bool IdealLoopTree::iteration_split_impl( PhaseIdealLoop *phase, Node_List &old_new ) {
// Check and remove empty loops (spam micro-benchmarks)
if( policy_do_remove_empty_loop(phase) )
- return; // Here we removed an empty loop
+ return true; // Here we removed an empty loop
bool should_peel = policy_peeling(phase); // Should we peel?
@@ -1603,7 +1603,8 @@
// This removes loop-invariant tests (usually null checks).
if( !_head->is_CountedLoop() ) { // Non-counted loop
if (PartialPeelLoop && phase->partial_peel(this, old_new)) {
- return;
+ // Partial peel succeeded so terminate this round of loop opts
+ return false;
}
if( should_peel ) { // Should we peel?
#ifndef PRODUCT
@@ -1613,14 +1614,14 @@
} else if( should_unswitch ) {
phase->do_unswitching(this, old_new);
}
- return;
+ return true;
}
CountedLoopNode *cl = _head->as_CountedLoop();
- if( !cl->loopexit() ) return; // Ignore various kinds of broken loops
+ if( !cl->loopexit() ) return true; // Ignore various kinds of broken loops
// Do nothing special to pre- and post- loops
- if( cl->is_pre_loop() || cl->is_post_loop() ) return;
+ if( cl->is_pre_loop() || cl->is_post_loop() ) return true;
// Compute loop trip count from profile data
compute_profile_trip_cnt(phase);
@@ -1633,11 +1634,11 @@
// Here we did some unrolling and peeling. Eventually we will
// completely unroll this loop and it will no longer be a loop.
phase->do_maximally_unroll(this,old_new);
- return;
+ return true;
}
if (should_unswitch) {
phase->do_unswitching(this, old_new);
- return;
+ return true;
}
}
@@ -1698,14 +1699,16 @@
if( should_peel ) // Might want to peel but do nothing else
phase->do_peeling(this,old_new);
}
+ return true;
}
//=============================================================================
//------------------------------iteration_split--------------------------------
-void IdealLoopTree::iteration_split( PhaseIdealLoop *phase, Node_List &old_new ) {
+bool IdealLoopTree::iteration_split( PhaseIdealLoop *phase, Node_List &old_new ) {
// Recursively iteration split nested loops
- if( _child ) _child->iteration_split( phase, old_new );
+ if( _child && !_child->iteration_split( phase, old_new ))
+ return false;
// Clean out prior deadwood
DCE_loop_body();
@@ -1727,7 +1730,9 @@
_allow_optimizations &&
!tail()->is_top() ) { // Also ignore the occasional dead backedge
if (!_has_call) {
- iteration_split_impl( phase, old_new );
+ if (!iteration_split_impl( phase, old_new )) {
+ return false;
+ }
} else if (policy_unswitching(phase)) {
phase->do_unswitching(this, old_new);
}
@@ -1736,5 +1741,7 @@
// Minor offset re-organization to remove loop-fallout uses of
// trip counter.
if( _head->is_CountedLoop() ) phase->reorg_offsets( this );
- if( _next ) _next->iteration_split( phase, old_new );
+ if( _next && !_next->iteration_split( phase, old_new ))
+ return false;
+ return true;
}
--- a/hotspot/src/share/vm/opto/loopnode.hpp Thu Oct 02 08:37:44 2008 -0700
+++ b/hotspot/src/share/vm/opto/loopnode.hpp Fri Oct 03 13:58:20 2008 -0700
@@ -325,12 +325,14 @@
// Returns TRUE if loop tree is structurally changed.
bool beautify_loops( PhaseIdealLoop *phase );
- // Perform iteration-splitting on inner loops. Split iterations to avoid
- // range checks or one-shot null checks.
- void iteration_split( PhaseIdealLoop *phase, Node_List &old_new );
+ // Perform iteration-splitting on inner loops. Split iterations to
+ // avoid range checks or one-shot null checks. Returns false if the
+ // current round of loop opts should stop.
+ bool iteration_split( PhaseIdealLoop *phase, Node_List &old_new );
- // Driver for various flavors of iteration splitting
- void iteration_split_impl( PhaseIdealLoop *phase, Node_List &old_new );
+ // Driver for various flavors of iteration splitting. Returns false
+ // if the current round of loop opts should stop.
+ bool iteration_split_impl( PhaseIdealLoop *phase, Node_List &old_new );
// Given dominators, try to find loops with calls that must always be
// executed (call dominates loop tail). These loops do not need non-call
--- a/hotspot/src/share/vm/opto/loopopts.cpp Thu Oct 02 08:37:44 2008 -0700
+++ b/hotspot/src/share/vm/opto/loopopts.cpp Fri Oct 03 13:58:20 2008 -0700
@@ -1903,9 +1903,6 @@
// Use in a phi is considered a use in the associated predecessor block
use_c = use->in(0)->in(j);
}
- if (use_c->is_CountedLoop()) {
- use_c = use_c->in(LoopNode::EntryControl);
- }
set_ctrl(n_clone, use_c);
assert(!loop->is_member(get_loop(use_c)), "should be outside loop");
get_loop(use_c)->_body.push(n_clone);
--- a/hotspot/test/compiler/6700047/Test6700047.java Thu Oct 02 08:37:44 2008 -0700
+++ b/hotspot/test/compiler/6700047/Test6700047.java Fri Oct 03 13:58:20 2008 -0700
@@ -29,6 +29,8 @@
*/
public class Test6700047 {
+ static byte[] dummy = new byte[256];
+
public static void main(String[] args) {
for (int i = 0; i < 100000; i++) {
intToLeftPaddedAsciiBytes();
@@ -53,6 +55,7 @@
if (offset > 0) {
for(int j = 0; j < offset; j++) {
result++;
+ dummy[i] = 0;
}
}
return result;