Reviewers: Igor Sheludko, Michael Achenbach,
Description:
Revert "Eliminatable CheckMaps replaced with if(true) or if(false)."
This reverts r18592 for breaking the GC stress bots.
Please review this at https://codereview.chromium.org/137783011/
SVN Base: https://v8.googlecode.com/svn/branches/bleeding_edge
Affected files (+15, -68 lines):
M src/hydrogen-check-elimination.cc
M src/hydrogen-flow-engine.h
M src/hydrogen-instructions.cc
M src/hydrogen.h
M src/hydrogen.cc
Index: src/hydrogen-check-elimination.cc
diff --git a/src/hydrogen-check-elimination.cc
b/src/hydrogen-check-elimination.cc
index
90e8450c821a17081c8bbd7dc9991ee28e792070..ae11042ba1e449b3c33b2d036ca36477165142d6
100644
--- a/src/hydrogen-check-elimination.cc
+++ b/src/hydrogen-check-elimination.cc
@@ -132,10 +132,8 @@ class HCheckTable : public ZoneObject {
// Branch-sensitive analysis for certain comparisons may add more facts
// to the state for the successor on the true branch.
- HBasicBlock* pred_block = succ->predecessors()->at(0);
- HControlInstruction* end = pred_block->end();
- if (succ->predecessors()->length() == 1 && end->SuccessorAt(0) == succ
&&
- pred_block->IsReachable()) {
+ HControlInstruction* end = succ->predecessors()->at(0)->end();
+ if (succ->predecessors()->length() == 1 && end->SuccessorAt(0) ==
succ) {
if (end->IsCompareMap()) {
// Learn on the true branch of if(CompareMap(x)).
HCompareMap* cmp = HCompareMap::cast(end);
@@ -313,27 +311,14 @@ class HCheckTable : public ZoneObject {
void ReduceCompareMap(HCompareMap* instr) {
MapSet maps = FindMaps(instr->value()->ActualValue());
if (maps == NULL) return;
-
- TRACE(("CompareMap for #%d at B%d ",
- instr->value()->ActualValue()->id(), instr->block()->block_id()));
-
if (maps->Contains(instr->map())) {
if (maps->size() == 1) {
+ // TODO(titzer): replace with goto true branch
INC_STAT(compares_true_);
-
- TRACE(("replaced with goto B%d (true target)\n",
- instr->SuccessorAt(0)->block_id()));
-
- instr->block()->ReplaceControlWithGotoSuccessor(0);
- } else {
- TRACE(("can't be replaced with goto: ambiguous set of maps\n"));
}
} else {
+ // TODO(titzer): replace with goto false branch
INC_STAT(compares_false_);
- TRACE(("replaced with goto B%d (false target)\n",
- instr->SuccessorAt(1)->block_id()));
-
- instr->block()->ReplaceControlWithGotoSuccessor(1);
}
}
Index: src/hydrogen-flow-engine.h
diff --git a/src/hydrogen-flow-engine.h b/src/hydrogen-flow-engine.h
index
477fdb1b7fe99c89f71b53f48aa035737287efaa..4e1275546f611e2401e467484976f73d59b3e784
100644
--- a/src/hydrogen-flow-engine.h
+++ b/src/hydrogen-flow-engine.h
@@ -124,19 +124,17 @@ class HFlowEngine {
if (SkipNonDominatedBlock(root, block)) continue;
State* state = StateAt(block);
- if (block->IsReachable()) {
- if (block->IsLoopHeader()) {
- // Apply loop effects before analyzing loop body.
- ComputeLoopEffects(block)->Apply(state);
- } else {
- // Must have visited all predecessors before this block.
- CheckPredecessorCount(block);
- }
+ if (block->IsLoopHeader()) {
+ // Apply loop effects before analyzing loop body.
+ ComputeLoopEffects(block)->Apply(state);
+ } else {
+ // Must have visited all predecessors before this block.
+ CheckPredecessorCount(block);
+ }
- // Go through all instructions of the current block, updating the
state.
- for (HInstructionIterator it(block); !it.Done(); it.Advance()) {
- state = state->Process(it.Current(), zone_);
- }
+ // Go through all instructions of the current block, updating the
state.
+ for (HInstructionIterator it(block); !it.Done(); it.Advance()) {
+ state = state->Process(it.Current(), zone_);
}
// Propagate the block state forward to all successor blocks.
@@ -187,7 +185,6 @@ class HFlowEngine {
i = member->loop_information()->GetLastBackEdge()->block_id();
} else {
// Process all the effects of the block.
- if (member->IsUnreachable()) continue;
ASSERT(member->current_loop() == loop);
for (HInstructionIterator it(member); !it.Done(); it.Advance()) {
effects->Process(it.Current(), zone_);
Index: src/hydrogen-instructions.cc
diff --git a/src/hydrogen-instructions.cc b/src/hydrogen-instructions.cc
index
59341c032a65042feca41112fba2fc9ef7afa460..f9e09c0c7aa146dbc1aa64e605c5220b0169f598
100644
--- a/src/hydrogen-instructions.cc
+++ b/src/hydrogen-instructions.cc
@@ -707,6 +707,7 @@ void HInstruction::PrintMnemonicTo(StringStream*
stream) {
void HInstruction::Unlink() {
ASSERT(IsLinked());
+ ASSERT(!IsControlInstruction()); // Must never move control
instructions.
ASSERT(!IsBlockEntry()); // Doesn't make sense to delete these.
ASSERT(previous_ != NULL);
previous_->next_ = next_;
Index: src/hydrogen.cc
diff --git a/src/hydrogen.cc b/src/hydrogen.cc
index
1b8e4f5ddd7eac72c854524c7753a34a4f9caec3..0c2b28bf8c301baed63bb0fcb47898626d41ecd2
100644
--- a/src/hydrogen.cc
+++ b/src/hydrogen.cc
@@ -313,30 +313,6 @@ int HBasicBlock::LoopNestingDepth() const {
}
-void HBasicBlock::ReplaceControlWithGotoSuccessor(int succ) {
- ASSERT(IsFinished());
- ASSERT(end()->SuccessorCount() == 2); // Only this case is supported
yet.
- ASSERT(succ < end()->SuccessorCount());
-
- int unreachable_succ = 1 - succ;
-
- // Replace control instruction with if (true) {succ} else
{unreachable_succ}.
- HBranch* new_branch = HBranch::New(
- zone(),
- NULL,
- graph()->GetConstantTrue(),
- ToBooleanStub::Types(ToBooleanStub::BOOLEAN),
- end()->SuccessorAt(succ),
- end()->SuccessorAt(unreachable_succ));
-
- MarkSuccEdgeUnreachable(unreachable_succ);
-
- end()->DeleteAndReplaceWith(end()->ActualValue());
- new_branch->InsertAfter(last());
- end_ = new_branch;
-}
-
-
void HBasicBlock::PostProcessLoopHeader(IterationStatement* stmt) {
ASSERT(IsLoopHeader());
@@ -355,15 +331,6 @@ void
HBasicBlock::PostProcessLoopHeader(IterationStatement* stmt) {
}
-void HBasicBlock::MarkSuccEdgeUnreachable(int succ) {
- ASSERT(IsFinished());
- HBasicBlock* succ_block = end()->SuccessorAt(succ);
-
- ASSERT(succ_block->predecessors()->length() == 1);
- succ_block->MarkUnreachable();
-}
-
-
void HBasicBlock::RegisterPredecessor(HBasicBlock* pred) {
if (HasPredecessor()) {
// Only loop header blocks can have a predecessor added after
Index: src/hydrogen.h
diff --git a/src/hydrogen.h b/src/hydrogen.h
index
cb99b555f5044ba5fa62df089d185944294c28fe..22394dcb5546dc1deea36ae7df8cd93757f85c6a
100644
--- a/src/hydrogen.h
+++ b/src/hydrogen.h
@@ -114,8 +114,6 @@ class HBasicBlock V8_FINAL : public ZoneObject {
bool Dominates(HBasicBlock* other) const;
int LoopNestingDepth() const;
- void ReplaceControlWithGotoSuccessor(int succ);
-
void SetInitialEnvironment(HEnvironment* env);
void ClearEnvironment() {
ASSERT(IsFinished());
@@ -202,7 +200,6 @@ class HBasicBlock V8_FINAL : public ZoneObject {
int position);
private:
- void MarkSuccEdgeUnreachable(int succ);
void RegisterPredecessor(HBasicBlock* pred);
void AddDominatedBlock(HBasicBlock* block);
--
--
v8-dev mailing list
[email protected]
http://groups.google.com/group/v8-dev
---
You received this message because you are subscribed to the Google Groups "v8-dev" group.
To unsubscribe from this group and stop receiving emails from it, send an email
to [email protected].
For more options, visit https://groups.google.com/groups/opt_out.
