MIPS: Use signaling NaN for holes in fixed double arrays.

src/mips64/codegen-mips64.cc

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "src/v8.h"
 
 #if V8_TARGET_ARCH_MIPS64
 
 #include "src/codegen.h"
 #include "src/macro-assembler.h"
@@ skipping 647 matching lines @@
   __ Daddu(scratch1, elements,
       Operand(FixedArray::kHeaderSize - kHeapObjectTag));
   __ Daddu(scratch3, array, Operand(FixedDoubleArray::kHeaderSize));
   __ SmiScale(array_end, length, kDoubleSizeLog2);
   __ Daddu(array_end, array_end, scratch3);
 
   // Repurpose registers no longer in use.
   Register hole_lower = elements;
   Register hole_upper = length;
   __ li(hole_lower, Operand(kHoleNanLower32));
+  __ li(hole_upper, Operand(kHoleNanUpper32));
+
   // scratch1: begin of source FixedArray element fields, not tagged
   // hole_lower: kHoleNanLower32
   // hole_upper: kHoleNanUpper32
   // array_end: end of destination FixedDoubleArray, not tagged
   // scratch3: begin of FixedDoubleArray element fields, not tagged
-  __ Branch(USE_DELAY_SLOT, &entry);
-  __ li(hole_upper, Operand(kHoleNanUpper32));  // In delay slot.
+
+  __ Branch(&entry);
 
   __ bind(&only_change_map);
   __ sd(target_map, FieldMemOperand(receiver, HeapObject::kMapOffset));
   __ RecordWriteField(receiver,
                       HeapObject::kMapOffset,
                       target_map,
                       scratch2,
                       kRAHasBeenSaved,
                       kDontSaveFPRegs,
                       OMIT_REMEMBERED_SET,
@@ skipping 462 matching lines @@
     patcher.masm()->nop();  // Pad the empty space.
   }
 }
 
 
 #undef __
 
 } }  // namespace v8::internal
 
 #endif  // V8_TARGET_ARCH_MIPS64