Reland 10216 - Optimize the equality check case of ICCompare stubs.

src/arm/code-stubs-arm.cc

Index: src/arm/code-stubs-arm.cc
===================================================================
--- src/arm/code-stubs-arm.cc	(revision 10217)
+++ src/arm/code-stubs-arm.cc	(working copy)
@@ -6716,6 +6716,26 @@
 }
 
 
+void ICCompareStub::GenerateKnownObjects(MacroAssembler* masm) {
+  Label miss;
+  __ and_(r2, r1, Operand(r0));
+  __ JumpIfSmi(r2, &miss);
+  __ ldr(r2, FieldMemOperand(r0, HeapObject::kMapOffset));
+  __ ldr(r3, FieldMemOperand(r1, HeapObject::kMapOffset));
+  __ cmp(r2, Operand(known_map_));
+  __ b(ne, &miss);
+  __ cmp(r3, Operand(known_map_));
+  __ b(ne, &miss);
+
+  __ sub(r0, r0, Operand(r1));
+  __ Ret();
+
+  __ bind(&miss);
+  GenerateMiss(masm);
+}
+
+
+
 void ICCompareStub::GenerateMiss(MacroAssembler* masm) {
   __ Push(r1, r0);

[Kevin Millikin (Chromium), 2011/12/09 09:10:31]

You could move this (and the corresponding pops) to use the internal frame
instead of using the caller's frame.

[Rico, 2011/12/09 09:28:31]

Done.

   __ push(lr);