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[x86] Improve code generation for context materialization.

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On Intel targets, it is cheaper to load the context from the frame
instead of loading the context as a constant (which usually involves a
PropertyCell because the context is in new space when we compile the
function).

R=jarin@chromium.org

Review URL: https://codereview.chromium.org/970803002

Cr-Commit-Position: refs/heads/master@{#26935}
This commit is contained in:
Benedikt Meurer 2015-03-02 10:09:33 +01:00
parent 155278d6f2
commit 502898ef60
2 changed files with 24 additions and 3 deletions
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14
src/compiler/ia32/code-generator-ia32.cc
View File

@ -1119,7 +1119,19 @@ void CodeGenerator::AssembleMove(InstructionOperand* source,
Constant src_constant = g.ToConstant(source);
if (src_constant.type() == Constant::kHeapObject) {
Handle<HeapObject> src = src_constant.ToHeapObject();
if (destination->IsRegister()) {
if (info()->IsOptimizing() && src.is_identical_to(info()->context())) {
// Loading the context from the frame is way cheaper than materializing
// the actual context heap object address.
if (destination->IsRegister()) {
Register dst = g.ToRegister(destination);
__ mov(dst, Operand(ebp, StandardFrameConstants::kContextOffset));
} else {
DCHECK(destination->IsStackSlot());
Operand dst = g.ToOperand(destination);
__ push(Operand(ebp, StandardFrameConstants::kContextOffset));
__ pop(dst);
}
} else if (destination->IsRegister()) {
Register dst = g.ToRegister(destination);
__ LoadHeapObject(dst, src);
} else {

13
src/compiler/x64/code-generator-x64.cc
View File

@ -1309,9 +1309,18 @@ void CodeGenerator::AssembleMove(InstructionOperand* source,
case Constant::kExternalReference:
__ Move(dst, src.ToExternalReference());
break;
case Constant::kHeapObject:
__ Move(dst, src.ToHeapObject());
case Constant::kHeapObject: {
Handle<HeapObject> src_object = src.ToHeapObject();
if (info()->IsOptimizing() &&
src_object.is_identical_to(info()->context())) {
// Loading the context from the frame is way cheaper than
// materializing the actual context heap object address.
__ movp(dst, Operand(rbp, StandardFrameConstants::kContextOffset));
} else {
__ Move(dst, src_object);
}
break;
}
case Constant::kRpoNumber:
UNREACHABLE(); // TODO(dcarney): load of labels on x64.
break;