Handle Math.log(NaN) correctly in Crankshaft on Intel platforms.

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 3708 matching lines @@
 
 
 void LCodeGen::DoMathLog(LMathLog* instr) {
   ASSERT(instr->value()->Equals(instr->result()));
   XMMRegister input_reg = ToDoubleRegister(instr->value());
   XMMRegister xmm_scratch = double_scratch0();
   Label positive, done, zero;
   __ xorps(xmm_scratch, xmm_scratch);
   __ ucomisd(input_reg, xmm_scratch);
   __ j(above, &positive, Label::kNear);
-  __ j(equal, &zero, Label::kNear);
+  __ j(not_carry, &zero, Label::kNear);
   ExternalReference nan =
       ExternalReference::address_of_canonical_non_hole_nan();
   Operand nan_operand = masm()->ExternalOperand(nan);
   __ movsd(input_reg, nan_operand);
   __ jmp(&done, Label::kNear);
   __ bind(&zero);
   ExternalReference ninf =
       ExternalReference::address_of_negative_infinity();
   Operand ninf_operand = masm()->ExternalOperand(ninf);
   __ movsd(input_reg, ninf_operand);
@@ skipping 1846 matching lines @@
                                FixedArray::kHeaderSize - kPointerSize));
   __ bind(&done);
 }
 
 
 #undef __
 
 } }  // namespace v8::internal
 
 #endif  // V8_TARGET_ARCH_X64