MIPS64: Add optimizations to li macro.

src/mips64/constants-mips64.h

 // 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.
 
 #ifndef  V8_MIPS_CONSTANTS_H_
 #define  V8_MIPS_CONSTANTS_H_
 
 #include "src/base/logging.h"
 #include "src/base/macros.h"
 #include "src/globals.h"
@@ skipping 255 matching lines @@
 const int kLsaSaBits = 2;
 const int kFunctionShift = 0;
 const int kFunctionBits  = 6;
 const int kLuiShift      = 16;
 const int kBp2Shift = 6;
 const int kBp2Bits = 2;
 const int kBp3Shift = 6;
 const int kBp3Bits = 3;
 
 const int kImm16Shift = 0;
-const int kImm16Bits  = 16;
+const int kImm16Bits = 16;
 const int kImm18Shift = 0;
 const int kImm18Bits = 18;
 const int kImm19Shift = 0;
 const int kImm19Bits = 19;
 const int kImm21Shift = 0;
-const int kImm21Bits  = 21;
+const int kImm21Bits = 21;
 const int kImm26Shift = 0;
-const int kImm26Bits  = 26;
+const int kImm26Bits = 26;
 const int kImm28Shift = 0;
-const int kImm28Bits  = 28;
+const int kImm28Bits = 28;
 const int kImm32Shift = 0;
-const int kImm32Bits  = 32;
+const int kImm32Bits = 32;
 const int kMsaImm8Shift = 16;
 const int kMsaImm8Bits = 8;
 const int kMsaImm5Shift = 16;
 const int kMsaImm5Bits = 5;
 const int kMsaImm10Shift = 11;
 const int kMsaImm10Bits = 10;
 const int kMsaImmMI10Shift = 16;
 const int kMsaImmMI10Bits = 10;
 
 // In branches and jumps immediate fields point to words, not bytes,
@@ skipping 16 matching lines @@
 const int kFBtrueBits    = 1;
 const int kWtBits = 5;
 const int kWtShift = 16;
 const int kWsBits = 5;
 const int kWsShift = 11;
 const int kWdBits = 5;
 const int kWdShift = 6;
 
 // ----- Miscellaneous useful masks.
 // Instruction bit masks.
-const int  kOpcodeMask   = ((1 << kOpcodeBits) - 1) << kOpcodeShift;
-const int  kImm16Mask    = ((1 << kImm16Bits) - 1) << kImm16Shift;
+const int kOpcodeMask = ((1 << kOpcodeBits) - 1) << kOpcodeShift;
+const int kImm16Mask = ((1 << kImm16Bits) - 1) << kImm16Shift;
 const int kImm18Mask = ((1 << kImm18Bits) - 1) << kImm18Shift;
 const int kImm19Mask = ((1 << kImm19Bits) - 1) << kImm19Shift;
 const int kImm21Mask = ((1 << kImm21Bits) - 1) << kImm21Shift;
-const int  kImm26Mask    = ((1 << kImm26Bits) - 1) << kImm26Shift;
-const int  kImm28Mask    = ((1 << kImm28Bits) - 1) << kImm28Shift;
+const int kImm26Mask = ((1 << kImm26Bits) - 1) << kImm26Shift;
+const int kImm28Mask = ((1 << kImm28Bits) - 1) << kImm28Shift;
 const int kImm5Mask = ((1 << 5) - 1);
 const int kImm8Mask = ((1 << 8) - 1);
 const int kImm10Mask = ((1 << 10) - 1);
 const int kMsaI5I10Mask = ((7U << 23) | ((1 << 6) - 1));
-const int  kRsFieldMask  = ((1 << kRsBits) - 1) << kRsShift;
-const int  kRtFieldMask  = ((1 << kRtBits) - 1) << kRtShift;
-const int  kRdFieldMask  = ((1 << kRdBits) - 1) << kRdShift;
-const int  kSaFieldMask  = ((1 << kSaBits) - 1) << kSaShift;
-const int  kFunctionFieldMask = ((1 << kFunctionBits) - 1) << kFunctionShift;
+const int kRsFieldMask = ((1 << kRsBits) - 1) << kRsShift;
+const int kRtFieldMask = ((1 << kRtBits) - 1) << kRtShift;
+const int kRdFieldMask = ((1 << kRdBits) - 1) << kRdShift;
+const int kSaFieldMask = ((1 << kSaBits) - 1) << kSaShift;
+const int kFunctionFieldMask = ((1 << kFunctionBits) - 1) << kFunctionShift;
 // Misc masks.
-const int  kHiMask       =   0xffff << 16;
-const int  kLoMask       =   0xffff;
-const int  kSignMask     =   0x80000000;
-const int  kJumpAddrMask = (1 << (kImm26Bits + kImmFieldShift)) - 1;
-const int64_t  kHi16MaskOf64 =   (int64_t)0xffff << 48;
-const int64_t  kSe16MaskOf64 =   (int64_t)0xffff << 32;
-const int64_t  kTh16MaskOf64 =   (int64_t)0xffff << 16;
+const int kHiMaskOf32 = 0xffff << 16;  // Only to be used with 32-bit values

[ivica.bogosavljevic, 2017/05/19 12:42:39]

If you mean by this
HiMaskOffset32 than you should either use full name HiMaskOffset32 because when
I see it like this, I think HiMask of 32 . This applies to all the constants you
renamed.

[miran.karic, 2017/05/19 13:23:53]

It is HiMask of 32, not offset. This is analogous to existing 16MaskOf64 naming
for 64 bit masks.

+const int kLoMaskOf32 = 0xffff;
+const int kSignMaskOf32 = 0x80000000;  // Only to be used with 32-bit values
+const int kJumpAddrMask = (1 << (kImm26Bits + kImmFieldShift)) - 1;
+const int64_t kTop16MaskOf64 = (int64_t)0xffff << 48;
+const int64_t kHigher16MaskOf64 = (int64_t)0xffff << 32;
+const int64_t kUpper16MaskOf64 = (int64_t)0xffff << 16;
 const int32_t kJalRawMark = 0x00000000;
 const int32_t kJRawMark = 0xf0000000;
 const int32_t kJumpRawMask = 0xf0000000;
 
 // ----- MIPS Opcodes and Function Fields.
 // We use this presentation to stay close to the table representation in
 // MIPS32 Architecture For Programmers, Volume II: The MIPS32 Instruction Set.
 enum Opcode : uint32_t {
   SPECIAL = 0U << kOpcodeShift,
   REGIMM = 1U << kOpcodeShift,
@@ skipping 1551 matching lines @@
       }
       break;
     default:
       return false;
   }
 }
 }  // namespace internal
 }  // namespace v8
 
 #endif    // #ifndef V8_MIPS_CONSTANTS_H_