Skip canonicalization check in LStoreKeyedFastDoubleElement when it is not needed:

src/x64/lithium-codegen-x64.cc

Index: src/x64/lithium-codegen-x64.cc
diff --git a/src/x64/lithium-codegen-x64.cc b/src/x64/lithium-codegen-x64.cc
index 56ba6f34585179df27e6b419809857e74b2b1981..d545a6de5901c2e7e8cfd563adee14e12178efec 100644
--- a/src/x64/lithium-codegen-x64.cc
+++ b/src/x64/lithium-codegen-x64.cc
@@ -3421,16 +3421,20 @@ void LCodeGen::DoStoreKeyedFastElement(LStoreKeyedFastElement* instr) {
 void LCodeGen::DoStoreKeyedFastDoubleElement(
     LStoreKeyedFastDoubleElement* instr) {
   XMMRegister value = ToDoubleRegister(instr->value());
-  Label have_value;
 
-  __ ucomisd(value, value);
-  __ j(parity_odd, &have_value);  // NaN.
+  if (instr->NeedsCanonicalization()) {
+    Label have_value;
 
-  __ Set(kScratchRegister, BitCast<uint64_t>(
-      FixedDoubleArray::canonical_not_the_hole_nan_as_double()));
-  __ movq(value, kScratchRegister);
+    __ ucomisd(value, value);
+    __ j(parity_odd, &have_value);  // NaN.
+
+    __ Set(kScratchRegister, BitCast<uint64_t>(
+        FixedDoubleArray::canonical_not_the_hole_nan_as_double()));
+    __ movq(value, kScratchRegister);
+
+    __ bind(&have_value);
+  }
 
-  __ bind(&have_value);
   Operand double_store_operand = BuildFastArrayOperand(
       instr->elements(), instr->key(), FAST_DOUBLE_ELEMENTS,
       FixedDoubleArray::kHeaderSize - kHeapObjectTag);