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Unified Diff: src/x64/lithium-codegen-x64.cc

Issue 7918012: Unify the handling of comparinsons against null and undefined. (Closed) Base URL: http://v8.googlecode.com/svn/branches/bleeding_edge/
Patch Set: Created 9 years, 3 months ago
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Index: src/x64/lithium-codegen-x64.cc
===================================================================
--- src/x64/lithium-codegen-x64.cc (revision 9305)
+++ src/x64/lithium-codegen-x64.cc (working copy)
@@ -1583,30 +1583,33 @@
}
-void LCodeGen::DoIsNullAndBranch(LIsNullAndBranch* instr) {
+void LCodeGen::DoIsNilAndBranch(LIsNilAndBranch* instr) {
Register reg = ToRegister(instr->InputAt(0));
-
int false_block = chunk_->LookupDestination(instr->false_block_id());
+ // If the expression is known to be untagged or a smi, then it's definitely
+ // not null, and it can't be a an undetectable object.
if (instr->hydrogen()->representation().IsSpecialization() ||
instr->hydrogen()->type().IsSmi()) {
- // If the expression is known to untagged or smi, then it's definitely
- // not null, and it can't be a an undetectable object.
- // Jump directly to the false block.
EmitGoto(false_block);
return;
}
int true_block = chunk_->LookupDestination(instr->true_block_id());
-
- __ CompareRoot(reg, Heap::kNullValueRootIndex);
- if (instr->is_strict()) {
+ Heap::RootListIndex nil_value = instr->nil() == kNullValue ?
+ Heap::kNullValueRootIndex :
+ Heap::kUndefinedValueRootIndex;
+ __ CompareRoot(reg, nil_value);
+ if (instr->kind() == kStrictEquality) {
EmitBranch(true_block, false_block, equal);
} else {
+ Heap::RootListIndex other_nil_value = instr->nil() == kNullValue ?
+ Heap::kUndefinedValueRootIndex :
+ Heap::kNullValueRootIndex;
Label* true_label = chunk_->GetAssemblyLabel(true_block);
Label* false_label = chunk_->GetAssemblyLabel(false_block);
__ j(equal, true_label);
- __ CompareRoot(reg, Heap::kUndefinedValueRootIndex);
+ __ CompareRoot(reg, other_nil_value);
__ j(equal, true_label);
__ JumpIfSmi(reg, false_label);
// Check for undetectable objects by looking in the bit field in
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