A64: Fix a few simulation inaccuracies.

src/a64/constants-a64.h

 // Copyright 2013 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 67 matching lines @@
 const unsigned kDRegSizeInBits = 64;
 const unsigned kDRegSizeInBitsLog2 = 6;
 const unsigned kDRegSize = kDRegSizeInBits >> 3;
 const unsigned kDRegSizeLog2 = kDRegSizeInBitsLog2 - 3;
 const int64_t kWRegMask = 0x00000000ffffffffL;
 const int64_t kXRegMask = 0xffffffffffffffffL;
 const int64_t kSRegMask = 0x00000000ffffffffL;
 const int64_t kDRegMask = 0xffffffffffffffffL;
 // TODO(all) check if the expression below works on all compilers or if it
 // triggers an overflow error.
-const int64_t kDSignMask = 0x1L << 63;
 const int64_t kDSignBit = 63;
-const int64_t kXSignMask = 0x1L << 63;
+const int64_t kDSignMask = 0x1L << kDSignBit;
+const int64_t kSSignBit = 31;
+const int64_t kSSignMask = 0x1L << kSSignBit;
 const int64_t kXSignBit = 63;
-const int64_t kWSignMask = 0x1L << 31;
+const int64_t kXSignMask = 0x1L << kXSignBit;
 const int64_t kWSignBit = 31;
+const int64_t kWSignMask = 0x1L << kWSignBit;
+const int64_t kDQuietNanBit = 51;
+const int64_t kDQuietNanMask = 0x1L << kDQuietNanBit;
+const int64_t kSQuietNanBit = 22;
+const int64_t kSQuietNanMask = 0x1L << kSQuietNanBit;
 const int64_t kByteMask = 0xffL;
 const int64_t kHalfWordMask = 0xffffL;
 const int64_t kWordMask = 0xffffffffL;
 const uint64_t kXMaxUInt = 0xffffffffffffffffUL;
 const uint64_t kWMaxUInt = 0xffffffffUL;
 const int64_t kXMaxInt = 0x7fffffffffffffffL;
 const int64_t kXMinInt = 0x8000000000000000L;
 const int32_t kWMaxInt = 0x7fffffff;
 const int32_t kWMinInt = 0x80000000;
 const unsigned kFramePointerRegCode = 29;
@@ skipping 1149 matching lines @@
 };
 
 enum UnallocatedOp {
   UnallocatedFixed = 0x00000000,
   UnallocatedFMask = 0x00000000
 };
 
 } }  // namespace v8::internal
 
 #endif  // V8_A64_CONSTANTS_A64_H_