Improve generated code for HDoCompareObjectEqAndBranch on ia32/x64

src/x64/lithium-x64.cc

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 1592 matching lines @@
       right = UseRegisterAtStart(instr->right());
     }
     return new(zone()) LCmpIDAndBranch(left, right);
   }
 }
 
 
 LInstruction* LChunkBuilder::DoCompareObjectEqAndBranch(
     HCompareObjectEqAndBranch* instr) {
   LOperand* left = UseRegisterAtStart(instr->left());
-  LOperand* right = UseRegisterAtStart(instr->right());
+  LOperand* right = UseRegisterOrConstantAtStart(instr->right());
   return new(zone()) LCmpObjectEqAndBranch(left, right);
 }
 
 
 LInstruction* LChunkBuilder::DoCompareConstantEqAndBranch(
     HCompareConstantEqAndBranch* instr) {
   LOperand* value = UseRegisterAtStart(instr->value());
   return new(zone()) LCmpConstantEqAndBranch(value);
 }
 
@@ skipping 896 matching lines @@
 LInstruction* LChunkBuilder::DoLoadFieldByIndex(HLoadFieldByIndex* instr) {
   LOperand* object = UseRegister(instr->object());
   LOperand* index = UseTempRegister(instr->index());
   return DefineSameAsFirst(new(zone()) LLoadFieldByIndex(object, index));
 }
 
 
 } }  // namespace v8::internal
 
 #endif  // V8_TARGET_ARCH_X64