Bug 865153 - Remove resume point uses in dead blocks when restarting loop processing, r=h4writer.

This commit is contained in:
Brian Hackett 2013-04-25 09:08:36 -06:00
parent 72c7993062
commit 60124d1937
5 changed files with 57 additions and 2 deletions

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@ -1741,8 +1741,10 @@ IonBuilder::restartLoop(CFGState state)
// of the appropriate type and incoming edges to preserve.
graph().removeBlocksAfter(header);
// Remove all instructions from the header itself.
// Remove all instructions from the header itself, and all resume points
// except the entry resume point.
header->discardAllInstructions();
header->discardAllResumePoints(/* discardEntry = */ false);
header->setStackDepth(header->getPredecessor(0)->stackDepth());
popCfgStack();

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@ -1674,6 +1674,7 @@ MResumePoint::MResumePoint(MBasicBlock *block, jsbytecode *pc, MResumePoint *cal
instruction_(NULL),
mode_(mode)
{
block->addResumePoint(this);
}
void

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@ -101,6 +101,9 @@ class MUse : public TempObject, public InlineListNode<MUse>
JS_ASSERT(producer_ != NULL);
return producer_;
}
bool hasProducer() const {
return producer_ != NULL;
}
MNode *consumer() const {
JS_ASSERT(consumer_ != NULL);
return consumer_;
@ -7171,7 +7174,7 @@ class MParNewDenseArray : public MBinaryInstruction
// A resume point contains the information needed to reconstruct the interpreter
// state from a position in the JIT. See the big comment near resumeAfter() in
// IonBuilder.cpp.
class MResumePoint : public MNode
class MResumePoint : public MNode, public InlineForwardListNode<MResumePoint>
{
public:
enum Mode {
@ -7207,6 +7210,11 @@ class MResumePoint : public MNode
operand->addUse(&operands_[index]);
}
void clearOperand(size_t index) {
JS_ASSERT(index < stackDepth_);
operands_[index].set(NULL, this, index);
}
MUse *getUseFor(size_t index) {
return &operands_[index];
}
@ -7251,6 +7259,13 @@ class MResumePoint : public MNode
Mode mode() const {
return mode_;
}
void discardUses() {
for (size_t i = 0; i < stackDepth_; i++) {
if (operands_[i].hasProducer())
operands_[i].producer()->removeUse(&operands_[i]);
}
}
};
/*

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@ -78,6 +78,7 @@ MIRGraph::removeBlocksAfter(MBasicBlock *start)
osrBlock_ = NULL;
block->discardAllInstructions();
block->discardAllPhis();
block->discardAllResumePoints();
block->markAsDead();
removeBlock(block);
}
@ -292,6 +293,13 @@ MBasicBlock::inherit(MBasicBlock *pred, uint32_t popped)
for (size_t i = 0; i < stackDepth(); i++)
entryResumePoint()->setOperand(i, getSlot(i));
}
} else if (entryResumePoint()) {
/*
* Don't leave the operands uninitialized for the caller, as it may not
* initialize them later on.
*/
for (size_t i = 0; i < stackDepth(); i++)
entryResumePoint()->clearOperand(i);
}
return true;
@ -638,6 +646,20 @@ MBasicBlock::discardAllPhis()
(*pred)->setSuccessorWithPhis(NULL, 0);
}
void
MBasicBlock::discardAllResumePoints(bool discardEntry)
{
for (MResumePointIterator iter = resumePointsBegin(); iter != resumePointsEnd(); ) {
MResumePoint *rp = *iter;
if (rp == entryResumePoint() && !discardEntry) {
iter++;
} else {
rp->discardUses();
iter = resumePoints_.removeAt(iter);
}
}
}
void
MBasicBlock::insertBefore(MInstruction *at, MInstruction *ins)
{

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@ -26,6 +26,7 @@ class MDefinitionIterator;
typedef InlineListIterator<MInstruction> MInstructionIterator;
typedef InlineListReverseIterator<MInstruction> MInstructionReverseIterator;
typedef InlineForwardListIterator<MPhi> MPhiIterator;
typedef InlineForwardListIterator<MResumePoint> MResumePointIterator;
class LBlock;
@ -156,6 +157,11 @@ class MBasicBlock : public TempObject, public InlineListNode<MBasicBlock>
// Adds a phi instruction, but does not set successorWithPhis.
void addPhi(MPhi *phi);
// Adds a resume point to this block.
void addResumePoint(MResumePoint *resume) {
resumePoints_.pushFront(resume);
}
// Adds a predecessor. Every predecessor must have the same exit stack
// depth as the entry state to this block. Adding a predecessor
// automatically creates phi nodes and rewrites uses as needed.
@ -217,6 +223,7 @@ class MBasicBlock : public TempObject, public InlineListNode<MBasicBlock>
MDefinitionIterator discardDefAt(MDefinitionIterator &iter);
void discardAllInstructions();
void discardAllPhis();
void discardAllResumePoints(bool discardEntry = true);
// Discards a phi instruction and updates predecessor successorWithPhis.
MPhiIterator discardPhiAt(MPhiIterator &at);
@ -250,6 +257,7 @@ class MBasicBlock : public TempObject, public InlineListNode<MBasicBlock>
}
uint32_t domIndex() const {
JS_ASSERT(!isDead());
return domIndex_;
}
void setDomIndex(uint32_t d) {
@ -271,6 +279,12 @@ class MBasicBlock : public TempObject, public InlineListNode<MBasicBlock>
bool phisEmpty() const {
return phis_.empty();
}
MResumePointIterator resumePointsBegin() const {
return resumePoints_.begin();
}
MResumePointIterator resumePointsEnd() const {
return resumePoints_.end();
}
MInstructionIterator begin() {
return instructions_.begin();
}
@ -453,6 +467,7 @@ class MBasicBlock : public TempObject, public InlineListNode<MBasicBlock>
InlineList<MInstruction> instructions_;
Vector<MBasicBlock *, 1, IonAllocPolicy> predecessors_;
InlineForwardList<MPhi> phis_;
InlineForwardList<MResumePoint> resumePoints_;
FixedList<MDefinition *> slots_;
uint32_t stackPosition_;
MControlInstruction *lastIns_;