[x86] Allow (v)divsd->(v)mulsd to execute in parallel.

src/compiler/x64/code-generator-x64.cc

Index: src/compiler/x64/code-generator-x64.cc
diff --git a/src/compiler/x64/code-generator-x64.cc b/src/compiler/x64/code-generator-x64.cc
index 1e5d62f7e3c522a336c29bbf9214d5d24afc5d3a..4213c9f135131957dc51e93505a2b7f4444df20f 100644
--- a/src/compiler/x64/code-generator-x64.cc
+++ b/src/compiler/x64/code-generator-x64.cc
@@ -726,6 +726,9 @@ void CodeGenerator::AssembleArchInstruction(Instruction* instr) {
       break;
     case kSSEFloat32Div:
       ASSEMBLE_SSE_BINOP(divss);
+      // Don't delete this mov. It may improve performance on some CPUs,
+      // when there is a (v)mulss depending on the result.
+      __ movaps(i.OutputDoubleRegister(), i.OutputDoubleRegister());
       break;
     case kSSEFloat32Abs: {
       // TODO(bmeurer): Use RIP relative 128-bit constants.
@@ -767,6 +770,9 @@ void CodeGenerator::AssembleArchInstruction(Instruction* instr) {
       break;
     case kSSEFloat64Div:
       ASSEMBLE_SSE_BINOP(divsd);
+      // Don't delete this mov. It may improve performance on some CPUs,
+      // when there is a (v)mulsd depending on the result.
+      __ movaps(i.OutputDoubleRegister(), i.OutputDoubleRegister());
       break;
     case kSSEFloat64Mod: {
       __ subq(rsp, Immediate(kDoubleSize));
@@ -919,6 +925,9 @@ void CodeGenerator::AssembleArchInstruction(Instruction* instr) {
       break;
     case kAVXFloat32Div:
       ASSEMBLE_AVX_BINOP(vdivss);
+      // Don't delete this mov. It may improve performance on some CPUs,
+      // when there is a (v)mulss depending on the result.
+      __ movaps(i.OutputDoubleRegister(), i.OutputDoubleRegister());
       break;
     case kAVXFloat32Max:
       ASSEMBLE_AVX_BINOP(vmaxss);
@@ -946,6 +955,9 @@ void CodeGenerator::AssembleArchInstruction(Instruction* instr) {
       break;
     case kAVXFloat64Div:
       ASSEMBLE_AVX_BINOP(vdivsd);
+      // Don't delete this mov. It may improve performance on some CPUs,
+      // when there is a (v)mulsd depending on the result.
+      __ movaps(i.OutputDoubleRegister(), i.OutputDoubleRegister());
       break;
     case kAVXFloat64Max:
       ASSEMBLE_AVX_BINOP(vmaxsd);