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

src/mips64/macro-assembler-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 <limits.h>  // For LONG_MIN, LONG_MAX.
 
 #include "src/v8.h"
 
 #if V8_TARGET_ARCH_MIPS64
 
@@ skipping 3866 matching lines @@
 
   // Ensure that the object is a heap number
   CheckMap(value_reg,
            scratch1,
            Heap::kHeapNumberMapRootIndex,
            fail,
            DONT_DO_SMI_CHECK);
 
   // Check for nan: all NaN values have a value greater (signed) than 0x7ff00000
   // in the exponent.
-  li(scratch1, Operand(kNaNOrInfinityLowerBoundUpper32));
+  li(scratch1, Operand(kHoleNanUpper32 & HeapNumber::kExponentMask));
   lw(exponent_reg, FieldMemOperand(value_reg, HeapNumber::kExponentOffset));
   Branch(&maybe_nan, ge, exponent_reg, Operand(scratch1));
 
   lwu(mantissa_reg, FieldMemOperand(value_reg, HeapNumber::kMantissaOffset));
 
   bind(&have_double_value);
   // dsll(scratch1, key_reg, kDoubleSizeLog2 - kSmiTagSize);
   dsra(scratch1, key_reg, 32 - kDoubleSizeLog2);
   Daddu(scratch1, scratch1, elements_reg);
   sw(mantissa_reg, FieldMemOperand(
@@ skipping 2290 matching lines @@
   }
   if (mag.shift > 0) sra(result, result, mag.shift);
   srl(at, dividend, 31);
   Addu(result, result, Operand(at));
 }
 
 
 } }  // namespace v8::internal
 
 #endif  // V8_TARGET_ARCH_MIPS64