Revision: 5007
Author: [email protected]
Date: Fri Jul 2 01:42:22 2010
Log: Simplify ToBoolean if we know we have a Smi.
Review URL: http://codereview.chromium.org/2808039
http://code.google.com/p/v8/source/detail?r=5007
Modified:
/branches/bleeding_edge/src/arm/codegen-arm.cc
=======================================
--- /branches/bleeding_edge/src/arm/codegen-arm.cc Thu Jul 1 08:06:24 2010
+++ /branches/bleeding_edge/src/arm/codegen-arm.cc Fri Jul 2 01:42:22 2010
@@ -748,37 +748,43 @@
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);
-
- // 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);
+ 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 '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;
}
--
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