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Simplify ToBoolean if we know we have a Smi.

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Review URL: http://codereview.chromium.org/2808039

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@5007 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
This commit is contained in:
erik.corry@gmail.com 2010-07-02 08:42:22 +00:00
parent a835641dee
commit f9eb21f950
1 changed files with 26 additions and 20 deletions
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46
src/arm/codegen-arm.cc
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@ -748,37 +748,43 @@ void CodeGenerator::ToBoolean(JumpTarget* true_target,
JumpTarget* false_target) {
// Note: The generated code snippet does not change stack variables.
// Only the condition code should be set.
bool known_smi = frame_->KnownSmiAt(0);
Register tos = frame_->PopToRegister();
// Fast case checks
// Check if the value is 'false'.
__ LoadRoot(ip, Heap::kFalseValueRootIndex);
__ cmp(tos, ip);
false_target->Branch(eq);
if (!known_smi) {
__ LoadRoot(ip, Heap::kFalseValueRootIndex);
__ cmp(tos, ip);
false_target->Branch(eq);
// Check if the value is 'true'.
__ LoadRoot(ip, Heap::kTrueValueRootIndex);
__ cmp(tos, ip);
true_target->Branch(eq);
// Check if the value is 'true'.
__ LoadRoot(ip, Heap::kTrueValueRootIndex);
__ cmp(tos, ip);
true_target->Branch(eq);
// Check if the value is 'undefined'.
__ LoadRoot(ip, Heap::kUndefinedValueRootIndex);
__ cmp(tos, ip);
false_target->Branch(eq);
// Check if the value is 'undefined'.
__ LoadRoot(ip, Heap::kUndefinedValueRootIndex);
__ cmp(tos, ip);
false_target->Branch(eq);
}
// Check if the value is a smi.
__ cmp(tos, Operand(Smi::FromInt(0)));
false_target->Branch(eq);
__ tst(tos, Operand(kSmiTagMask));
true_target->Branch(eq);
// Slow case: call the runtime.
frame_->EmitPush(tos);
frame_->CallRuntime(Runtime::kToBool, 1);
// Convert the result (r0) to a condition code.
__ LoadRoot(ip, Heap::kFalseValueRootIndex);
__ cmp(r0, ip);
if (!known_smi) {
false_target->Branch(eq);
__ tst(tos, Operand(kSmiTagMask));
true_target->Branch(eq);
// Slow case: call the runtime.
frame_->EmitPush(tos);
frame_->CallRuntime(Runtime::kToBool, 1);
// Convert the result (r0) to a condition code.
__ LoadRoot(ip, Heap::kFalseValueRootIndex);
__ cmp(r0, ip);
}
cc_reg_ = ne;
}