MIPS: Skip canonicalization check in LStoreKeyedFastDoubleElement when it is not needed

src/mips/lithium-codegen-mips.cc

 // Copyright 2012 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 3528 matching lines @@
   if (key_is_constant) {
     __ Addu(scratch, elements, Operand(constant_key * (1 << shift_size) +
             FixedDoubleArray::kHeaderSize - kHeapObjectTag));
   } else {
     __ sll(scratch, key, shift_size);
     __ Addu(scratch, elements, Operand(scratch));
     __ Addu(scratch, scratch,
             Operand(FixedDoubleArray::kHeaderSize - kHeapObjectTag));
   }
 
-  Label is_nan;
-  // Check for NaN. All NaNs must be canonicalized.
-  __ BranchF(NULL, &is_nan, eq, value, value);
-  __ Branch(&not_nan);
+  if (instr->NeedsCanonicalization()) {
+    Label is_nan;
+    // Check for NaN. All NaNs must be canonicalized.
+    __ BranchF(NULL, &is_nan, eq, value, value);
+    __ Branch(&not_nan);
 
-  // Only load canonical NaN if the comparison above set the overflow.
-  __ bind(&is_nan);
-  __ Move(value, FixedDoubleArray::canonical_not_the_hole_nan_as_double());
+    // Only load canonical NaN if the comparison above set the overflow.
+    __ bind(&is_nan);
+    __ Move(value, FixedDoubleArray::canonical_not_the_hole_nan_as_double());
+  }
 
   __ bind(&not_nan);
   __ sdc1(value, MemOperand(scratch));
 }
 
 
 void LCodeGen::DoStoreKeyedSpecializedArrayElement(
     LStoreKeyedSpecializedArrayElement* instr) {
 
   Register external_pointer = ToRegister(instr->external_pointer());
@@ skipping 1522 matching lines @@
   __ Subu(scratch, result, scratch);
   __ lw(result, FieldMemOperand(scratch,
                                 FixedArray::kHeaderSize - kPointerSize));
   __ bind(&done);
 }
 
 
 #undef __
 
 } }  // namespace v8::internal