IA32: Small assembler tweak for divsd->mulsd sequence

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 1775 matching lines @@
       __ addsd(left, right);
       break;
     case Token::SUB:
        __ subsd(left, right);
        break;
     case Token::MUL:
       __ mulsd(left, right);
       break;
     case Token::DIV:
       __ divsd(left, right);
+      // Don't delete this mov. It may improve performance on some CPUs,
+      // when there is a mulsd depending on the result
       __ movaps(left, left);
       break;
     case Token::MOD:
       __ PrepareCallCFunction(2);
       __ movaps(xmm0, left);
       ASSERT(right.is(xmm1));
       __ CallCFunction(
           ExternalReference::double_fp_operation(Token::MOD, isolate()), 2);
       __ movq(rsi, Operand(rbp, StandardFrameConstants::kContextOffset));
       __ movaps(result, xmm0);
@@ skipping 4039 matching lines @@
                                FixedArray::kHeaderSize - kPointerSize));
   __ bind(&done);
 }
 
 
 #undef __
 
 } }  // namespace v8::internal
 
 #endif  // V8_TARGET_ARCH_X64