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X87: [fullcode] Switch passing of new.target to register.

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port 440a42b741 (r32548)

  original commit message:
  This passes the new.target value in a register instead of through a
  side-channel via the construct stub. Note that this marks the last
  consumer of said side-channel and the special slot in the construct
  stub frame can be removed as a follow-up.

BUG=

Review URL: https://codereview.chromium.org/1503923002

Cr-Commit-Position: refs/heads/master@{#32635}
This commit is contained in:
zhengxing.li 2015-12-06 19:24:21 -08:00 committed by Commit bot
parent d5a52b6636
commit e3b1cf1726
1 changed files with 26 additions and 37 deletions
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51
src/full-codegen/x87/full-codegen-x87.cc
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@ -83,6 +83,7 @@ class JumpPatchSite BASE_EMBEDDED {
//
// The live registers are:
// o edi: the JS function object being called (i.e. ourselves)
// o edx: the new target value
// o esi: our context
// o ebp: our caller's frame pointer
// o esp: stack pointer (pointing to return address)
@ -174,7 +175,13 @@ void FullCodeGenerator::Generate() {
__ Push(info->scope()->GetScopeInfo(info->isolate()));
__ CallRuntime(Runtime::kNewScriptContext, 2);
PrepareForBailoutForId(BailoutId::ScriptContext(), TOS_REG);
} else if (slots <= FastNewContextStub::kMaximumSlots) {
// The new target value is not used, clobbering is safe.
DCHECK_NULL(info->scope()->new_target_var());
} else {
if (info->scope()->new_target_var() != nullptr) {
__ push(edx); // Preserve new target.
}
if (slots <= FastNewContextStub::kMaximumSlots) {
FastNewContextStub stub(isolate(), slots);
__ CallStub(&stub);
// Result of FastNewContextStub is always in new space.
@ -183,6 +190,10 @@ void FullCodeGenerator::Generate() {
__ push(edi);
__ CallRuntime(Runtime::kNewFunctionContext, 1);
}
if (info->scope()->new_target_var() != nullptr) {
__ pop(edx); // Restore new target.
}
}
function_in_register = false;
// Context is returned in eax. It replaces the context passed to us.
// It's saved in the stack and kept live in esi.
@ -215,11 +226,11 @@ void FullCodeGenerator::Generate() {
}
}
}
PrepareForBailoutForId(BailoutId::FunctionContext(), NO_REGISTERS);
// Function register is trashed in case we bailout here. But since that
// could happen only when we allocate a context the value of
// |function_in_register| is correct.
// Register holding this function and new target are both trashed in case we
// bailout here. But since that can happen only when new target is not used
// and we allocate a context, the value of |function_in_register| is correct.
PrepareForBailoutForId(BailoutId::FunctionContext(), NO_REGISTERS);
// Possibly set up a local binding to the this function which is used in
// derived constructors with super calls.
@ -228,38 +239,16 @@ void FullCodeGenerator::Generate() {
Comment cmnt(masm_, "[ This function");
if (!function_in_register) {
__ mov(edi, Operand(ebp, JavaScriptFrameConstants::kFunctionOffset));
// The write barrier clobbers register again, keep is marked as such.
// The write barrier clobbers register again, keep it marked as such.
}
SetVar(this_function_var, edi, ebx, edx);
SetVar(this_function_var, edi, ebx, ecx);
}
// Possibly set up a local binding to the new target value.
Variable* new_target_var = scope()->new_target_var();
if (new_target_var != nullptr) {
Comment cmnt(masm_, "[ new.target");
__ mov(eax, Operand(ebp, StandardFrameConstants::kCallerFPOffset));
Label non_adaptor_frame;
__ cmp(Operand(eax, StandardFrameConstants::kContextOffset),
Immediate(Smi::FromInt(StackFrame::ARGUMENTS_ADAPTOR)));
__ j(not_equal, &non_adaptor_frame);
__ mov(eax, Operand(eax, StandardFrameConstants::kCallerFPOffset));
__ bind(&non_adaptor_frame);
__ cmp(Operand(eax, StandardFrameConstants::kMarkerOffset),
Immediate(Smi::FromInt(StackFrame::CONSTRUCT)));
Label non_construct_frame, done;
__ j(not_equal, &non_construct_frame);
// Construct frame
__ mov(eax, Operand(eax, ConstructFrameConstants::kNewTargetOffset));
__ jmp(&done);
// Non-construct frame
__ bind(&non_construct_frame);
__ mov(eax, Immediate(isolate()->factory()->undefined_value()));
__ bind(&done);
SetVar(new_target_var, eax, ebx, edx);
SetVar(new_target_var, edx, ebx, ecx);
}
Variable* arguments = scope()->arguments();