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v8: fix stack overflow in recursive method
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HGlobalValueNumberingPhase::CollectSideEffectsOnPathsToDominatedBlock()
used to self-recurse before this commit, causing stack overflows on
systems with small stack sizes.  Make it non-recursive by storing
intermediate results in a heap-allocated list.

Fixes: #11991
PR-URL: #12460
Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Yang Guo <yangguo@chromium.org>
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bnoordhuis authored and evanlucas committed May 2, 2017
1 parent 96b2faa commit e77f1e2
Showing 1 changed file with 17 additions and 11 deletions.
28 changes: 17 additions & 11 deletions deps/v8/src/crankshaft/hydrogen-gvn.cc
Original file line number Diff line number Diff line change
Expand Up @@ -5,6 +5,8 @@
#include "src/crankshaft/hydrogen-gvn.h"

#include "src/crankshaft/hydrogen.h"
#include "src/list.h"
#include "src/list-inl.h"
#include "src/v8.h"

namespace v8 {
Expand Down Expand Up @@ -650,19 +652,23 @@ SideEffects
HGlobalValueNumberingPhase::CollectSideEffectsOnPathsToDominatedBlock(
HBasicBlock* dominator, HBasicBlock* dominated) {
SideEffects side_effects;
for (int i = 0; i < dominated->predecessors()->length(); ++i) {
HBasicBlock* block = dominated->predecessors()->at(i);
if (dominator->block_id() < block->block_id() &&
block->block_id() < dominated->block_id() &&
!visited_on_paths_.Contains(block->block_id())) {
visited_on_paths_.Add(block->block_id());
side_effects.Add(block_side_effects_[block->block_id()]);
if (block->IsLoopHeader()) {
side_effects.Add(loop_side_effects_[block->block_id()]);
List<HBasicBlock*> blocks;
for (;;) {
for (int i = 0; i < dominated->predecessors()->length(); ++i) {
HBasicBlock* block = dominated->predecessors()->at(i);
if (dominator->block_id() < block->block_id() &&
block->block_id() < dominated->block_id() &&
!visited_on_paths_.Contains(block->block_id())) {
visited_on_paths_.Add(block->block_id());
side_effects.Add(block_side_effects_[block->block_id()]);
if (block->IsLoopHeader()) {
side_effects.Add(loop_side_effects_[block->block_id()]);
}
blocks.Add(block);
}
side_effects.Add(CollectSideEffectsOnPathsToDominatedBlock(
dominator, block));
}
if (blocks.is_empty()) break;
dominated = blocks.RemoveLast();
}
return side_effects;
}
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