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| 1 // Copyright 2011-2012 the V8 project authors. All rights reserved. |
| 2 // Redistribution and use in source and binary forms, with or without |
| 3 // modification, are permitted provided that the following conditions are |
| 4 // met: |
| 5 // |
| 6 // * Redistributions of source code must retain the above copyright |
| 7 // notice, this list of conditions and the following disclaimer. |
| 8 // * Redistributions in binary form must reproduce the above |
| 9 // copyright notice, this list of conditions and the following |
| 10 // disclaimer in the documentation and/or other materials provided |
| 11 // with the distribution. |
| 12 // * Neither the name of Google Inc. nor the names of its |
| 13 // contributors may be used to endorse or promote products derived |
| 14 // from this software without specific prior written permission. |
| 15 // |
| 16 // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS |
| 17 // "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT |
| 18 // LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR |
| 19 // A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT |
| 20 // OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, |
| 21 // SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT |
| 22 // LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, |
| 23 // DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY |
| 24 // THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT |
| 25 // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE |
| 26 // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
| 27 |
| 28 #ifndef V8_SH4_CONSTANTS_SH4_H_ |
| 29 #define V8_SH4_CONSTANTS_SH4_H_ |
| 30 |
| 31 namespace v8 { |
| 32 namespace internal { |
| 33 |
| 34 // Number of registers in normal SH4 mode. |
| 35 static const int kNumRegisters = 16; |
| 36 |
| 37 // Marker for end of register list. |
| 38 static const int kNoRegister = -1; |
| 39 |
| 40 // ----------------------------------------------------------------------------- |
| 41 // Instructions encoding. |
| 42 |
| 43 // Instr is merely used by the Assembler to distinguish 32bit integers |
| 44 // representing instructions from usual 32 bit values. |
| 45 // Instruction objects are pointers to 32bit values, and provide methods to |
| 46 // access the various ISA fields. |
| 47 typedef uint16_t Instr; |
| 48 |
| 49 |
| 50 // ----------------------------------------------------------------------------- |
| 51 // Instruction abstraction. |
| 52 |
| 53 class Instruction { |
| 54 public: |
| 55 enum { |
| 56 kInstrSize = 2, |
| 57 kInstrSizeLog2 = 1 |
| 58 }; |
| 59 |
| 60 // Helper macro to define static accessors. |
| 61 // We use the cast to char* trick to bypass the strict anti-aliasing rules. |
| 62 #define DECLARE_STATIC_TYPED_ACCESSOR(return_type, Name) \ |
| 63 static inline return_type Name(Instr instr) { \ |
| 64 char* temp = reinterpret_cast<char*>(&instr); \ |
| 65 return reinterpret_cast<Instruction*>(temp)->Name(); \ |
| 66 } |
| 67 |
| 68 #define DECLARE_STATIC_ACCESSOR(Name) DECLARE_STATIC_TYPED_ACCESSOR(int, Name) |
| 69 |
| 70 // Get the raw instruction bits. |
| 71 inline Instr InstructionBits() const { |
| 72 return *reinterpret_cast<const Instr*>(this); |
| 73 } |
| 74 |
| 75 // Set the raw instruction bits to value. |
| 76 inline void SetInstructionBits(Instr value) { |
| 77 *reinterpret_cast<Instr*>(this) = value; |
| 78 } |
| 79 |
| 80 // Read one particular bit out of the instruction bits. |
| 81 inline int Bit(int nr) const { |
| 82 return (InstructionBits() >> nr) & 1; |
| 83 } |
| 84 |
| 85 // Read a bit field's value out of the instruction bits. |
| 86 inline int Bits(int hi, int lo) const { |
| 87 return (InstructionBits() >> lo) & ((2 << (hi - lo)) - 1); |
| 88 } |
| 89 |
| 90 // Read a signed bit field's value out of the instruction bits. |
| 91 inline int SBits(int hi, int lo) const { |
| 92 return (Bits(hi, lo) << (sizeof(int)*8 - hi - 1)) >> |
| 93 (sizeof(int)*8 - hi - 1); |
| 94 } |
| 95 |
| 96 // Read a bit field out of the instruction bits. |
| 97 inline int BitField(int hi, int lo) const { |
| 98 return InstructionBits() & (((2 << (hi - lo)) - 1) << lo); |
| 99 } |
| 100 |
| 101 // Static support. |
| 102 |
| 103 // Read one particular bit out of the instruction bits. |
| 104 static inline int Bit(Instr instr, int nr) { |
| 105 return (instr >> nr) & 1; |
| 106 } |
| 107 |
| 108 // Read the value of a bit field out of the instruction bits. |
| 109 static inline int Bits(Instr instr, int hi, int lo) { |
| 110 return (instr >> lo) & ((2 << (hi - lo)) - 1); |
| 111 } |
| 112 |
| 113 |
| 114 // Read the value of a signed bit field out of the instruction bits. |
| 115 inline int SBits(Instr instr, int hi, int lo) const { |
| 116 return (Bits(instr, hi, lo) << (sizeof(int)*8 - hi - 1)) >> |
| 117 (sizeof(int)*8 - hi - 1); |
| 118 } |
| 119 |
| 120 // Read a bit field out of the instruction bits. |
| 121 static inline int BitField(Instr instr, int hi, int lo) { |
| 122 return instr & (((2 << (hi - lo)) - 1) << lo); |
| 123 } |
| 124 |
| 125 |
| 126 |
| 127 // Instructions are read of out a code stream. The only way to get a |
| 128 // reference to an instruction is to convert a pointer. There is no way |
| 129 // to allocate or create instances of class Instruction. |
| 130 // Use the At(pc) function to create references to Instruction. |
| 131 static Instruction* At(byte* pc) { |
| 132 return reinterpret_cast<Instruction*>(pc); |
| 133 } |
| 134 |
| 135 |
| 136 private: |
| 137 // We need to prevent the creation of instances of class Instruction. |
| 138 DISALLOW_IMPLICIT_CONSTRUCTORS(Instruction); |
| 139 }; |
| 140 |
| 141 |
| 142 // Helper functions for converting between register numbers and names. |
| 143 class Registers { |
| 144 public: |
| 145 // Return the name of the register. |
| 146 static const char* Name(int reg); |
| 147 |
| 148 // Lookup the register number for the name provided. |
| 149 static int Number(const char* name); |
| 150 |
| 151 struct RegisterAlias { |
| 152 int reg; |
| 153 const char* name; |
| 154 }; |
| 155 |
| 156 private: |
| 157 static const char* names_[kNumRegisters]; |
| 158 static const RegisterAlias aliases_[]; |
| 159 }; |
| 160 |
| 161 |
| 162 } } // namespace v8::internal |
| 163 |
| 164 #endif // V8_SH4_CONSTANTS_SH4_H_ |
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