Reviewers: Kasper Lund, Kevin Millikin,
Description:
slight HGraph::CreateGraph refactor
* src/hydrogen.h (HGraph): Privatize MarkAsDeoptimizingRecursively. Add
PropagateDeoptimizingMark as the interface.
* src/hydrogen.cc (AssignDominators): Add a comment.
(PropagateDeoptimizingMark): Move MarkAsDeoptimizingRecursively call
out of AssignDominators, and here into a new phase.
(CreateGraph): Call PropagateDeoptimizingMark.
BUG=
TEST=
Please review this at http://codereview.chromium.org/7514005/
SVN Base: http://v8.googlecode.com/svn/branches/bleeding_edge
Affected files:
M src/hydrogen.h
M src/hydrogen.cc
Index: src/hydrogen.cc
diff --git a/src/hydrogen.cc b/src/hydrogen.cc
index
199eac8f10f38c37c221cb0eacbecb0f59f811b6..345758ee1a8a578fb428bf6a89327c26391e9ca2
100644
--- a/src/hydrogen.cc
+++ b/src/hydrogen.cc
@@ -736,6 +736,8 @@ void HGraph::AssignDominators() {
HPhase phase("Assign dominators", this);
for (int i = 0; i < blocks_.length(); ++i) {
if (blocks_[i]->IsLoopHeader()) {
+ // Only the first predecessor of a loop header is from outside the
loop.
+ // All others are back edges, and thus cannot dominate the loop
header.
blocks_[i]->AssignCommonDominator(blocks_[i]->predecessors()->first());
} else {
for (int j = 0; j < blocks_[i]->predecessors()->length(); ++j) {
@@ -743,13 +745,16 @@ void HGraph::AssignDominators() {
}
}
}
+}
- // Propagate flag marking blocks containing unconditional deoptimize.
+// Mark all blocks that are dominated by an unconditional soft deoptimize
to
+// prevent code motion across those blocks.
+void HGraph::PropagateDeoptimizingMark()
+{
+ HPhase phase("Propagate deoptimizing mark", this);
MarkAsDeoptimizingRecursively(entry_block());
}
-
-// Mark all blocks that are dominated by an unconditional deoptimize.
void HGraph::MarkAsDeoptimizingRecursively(HBasicBlock* block) {
for (int i = 0; i < block->dominated_blocks()->length(); ++i) {
HBasicBlock* dominated = block->dominated_blocks()->at(i);
@@ -2295,6 +2300,7 @@ HGraph* HGraphBuilder::CreateGraph() {
graph()->OrderBlocks();
graph()->AssignDominators();
+ graph()->PropagateDeoptimizingMark();
graph()->EliminateRedundantPhis();
if (FLAG_eliminate_dead_phis) graph()->EliminateUnreachablePhis();
if (!graph()->CollectPhis()) {
Index: src/hydrogen.h
diff --git a/src/hydrogen.h b/src/hydrogen.h
index
c8e3f0a9cce3def217d9c6c43d4da4e5d43ef58d..e5dd8a93dde2bc79f08090af5bd9f0b7ade04a00
100644
--- a/src/hydrogen.h
+++ b/src/hydrogen.h
@@ -238,7 +238,7 @@ class HGraph: public ZoneObject {
void OrderBlocks();
void AssignDominators();
void ReplaceCheckedValues();
- void MarkAsDeoptimizingRecursively(HBasicBlock* block);
+ void PropagateDeoptimizingMark();
// Returns false if there are phi-uses of the arguments-object
// which are not supported by the optimizing compiler.
@@ -293,6 +293,7 @@ class HGraph: public ZoneObject {
HConstant* GetConstant(SetOncePointer<HConstant>* pointer,
Object* value);
+ void MarkAsDeoptimizingRecursively(HBasicBlock* block);
void InsertTypeConversions(HInstruction* instr);
void PropagateMinusZeroChecks(HValue* value, BitVector* visited);
void RecursivelyMarkPhiDeoptimizeOnUndefined(HPhi* phi);
--
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