Fix implementation of compare-minus-zero-and-branch on ia32 and x64.

src/x64/lithium-codegen-x64.cc

 // Copyright 2013 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 2245 matching lines @@
     XMMRegister xmm_scratch = double_scratch0();
     __ xorps(xmm_scratch, xmm_scratch);
     __ ucomisd(xmm_scratch, value);
     __ j(not_equal, &if_false);
     __ movmskpd(kScratchRegister, value);
     __ testl(kScratchRegister, Immediate(1));
     EmitBranch(instr, not_zero);
   } else {
     Register value = ToRegister(instr->value());
     Handle<Map> map = masm()->isolate()->factory()->heap_number_map();
-    __ CheckMap(rax, map, &if_false, DO_SMI_CHECK);
+    __ CheckMap(value, map, &if_false, DO_SMI_CHECK);
     __ cmpl(FieldOperand(value, HeapNumber::kExponentOffset),
             Immediate(0x80000000));
     __ j(not_equal, &if_false);
     __ cmpl(FieldOperand(value, HeapNumber::kMantissaOffset),
             Immediate(0x00000000));
     EmitBranch(instr, equal);
   }
 
   __ bind(&if_false);
   EmitFalseBranch(instr, always);
@@ skipping 3400 matching lines @@
                                FixedArray::kHeaderSize - kPointerSize));
   __ bind(&done);
 }
 
 
 #undef __
 
 } }  // namespace v8::internal
 
 #endif  // V8_TARGET_ARCH_X64