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Unified Diff: src/ia32/code-stubs-ia32.cc

Issue 866493003: Retry "Use a WeakCell in the CallIC type vector." (Closed) Base URL: https://chromium.googlesource.com/v8/v8.git@master
Patch Set: REBASE. Created 5 years, 10 months ago
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Index: src/ia32/code-stubs-ia32.cc
diff --git a/src/ia32/code-stubs-ia32.cc b/src/ia32/code-stubs-ia32.cc
index 77269429821307466e85c9c87554e810808700ee..78e3a79e7924c7675165f97c54ec298cfa4981cb 100644
--- a/src/ia32/code-stubs-ia32.cc
+++ b/src/ia32/code-stubs-ia32.cc
@@ -2245,10 +2245,30 @@ void CallICStub::Generate(MacroAssembler* masm) {
ParameterCount actual(argc);
// The checks. First, does edi match the recorded monomorphic target?
- __ cmp(edi, FieldOperand(ebx, edx, times_half_pointer_size,
+ __ mov(ecx, FieldOperand(ebx, edx, times_half_pointer_size,
FixedArray::kHeaderSize));
+
+ // We don't know that we have a weak cell. We might have a private symbol
+ // or an AllocationSite, but the memory is safe to examine.
+ // AllocationSite::kTransitionInfoOffset - contains a Smi or pointer to
+ // FixedArray.
+ // WeakCell::kValueOffset - contains a JSFunction or Smi(0)
+ // Symbol::kHashFieldSlot - if the low bit is 1, then the hash is not
+ // computed, meaning that it can't appear to be a pointer. If the low bit is
+ // 0, then hash is computed, but the 0 bit prevents the field from appearing
+ // to be a pointer.
+ STATIC_ASSERT(WeakCell::kSize >= kPointerSize);
+ STATIC_ASSERT(AllocationSite::kTransitionInfoOffset ==
+ WeakCell::kValueOffset &&
+ WeakCell::kValueOffset == Symbol::kHashFieldSlot);
+
+ __ cmp(edi, FieldOperand(ecx, WeakCell::kValueOffset));
__ j(not_equal, &extra_checks_or_miss);
+ // The compare above could have been a SMI/SMI comparison. Guard against this
+ // convincing us that we have a monomorphic JSFunction.
+ __ JumpIfSmi(edi, &extra_checks_or_miss);
+
__ bind(&have_js_function);
if (CallAsMethod()) {
EmitContinueIfStrictOrNative(masm, &cont);
@@ -2277,8 +2297,6 @@ void CallICStub::Generate(MacroAssembler* masm) {
__ bind(&extra_checks_or_miss);
Label uninitialized, miss;
- __ mov(ecx, FieldOperand(ebx, edx, times_half_pointer_size,
- FixedArray::kHeaderSize));
__ cmp(ecx, Immediate(TypeFeedbackVector::MegamorphicSentinel(isolate)));
__ j(equal, &slow_start);
@@ -2322,15 +2340,18 @@ void CallICStub::Generate(MacroAssembler* masm) {
// Update stats.
__ add(FieldOperand(ebx, with_types_offset), Immediate(Smi::FromInt(1)));
- // Store the function.
- __ mov(
- FieldOperand(ebx, edx, times_half_pointer_size, FixedArray::kHeaderSize),
- edi);
+ // Store the function. Use a stub since we need a frame for allocation.
+ // ebx - vector
+ // edx - slot
+ // edi - function
+ {
+ FrameScope scope(masm, StackFrame::INTERNAL);
+ CreateWeakCellStub create_stub(isolate);
+ __ push(edi);
+ __ CallStub(&create_stub);
+ __ pop(edi);
+ }
- // Update the write barrier.
- __ mov(eax, edi);
- __ RecordWriteArray(ebx, eax, edx, kDontSaveFPRegs, EMIT_REMEMBERED_SET,
- OMIT_SMI_CHECK);
__ jmp(&have_js_function);
// We are here because tracing is on or we encountered a MISS case we can't
@@ -2393,6 +2414,7 @@ void CodeStub::GenerateStubsAheadOfTime(Isolate* isolate) {
// It is important that the store buffer overflow stubs are generated first.
ArrayConstructorStubBase::GenerateStubsAheadOfTime(isolate);
CreateAllocationSiteStub::GenerateAheadOfTime(isolate);
+ CreateWeakCellStub::GenerateAheadOfTime(isolate);
BinaryOpICStub::GenerateAheadOfTime(isolate);
BinaryOpICWithAllocationSiteStub::GenerateAheadOfTime(isolate);
}
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