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1 /* |
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2 ** $Id: lopcodes.h,v 1.125.1.1 2007/12/27 13:02:25 roberto Exp $ |
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3 ** Opcodes for Lua virtual machine |
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4 ** See Copyright Notice in lua.h |
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5 */ |
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6 |
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7 #ifndef lopcodes_h |
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8 #define lopcodes_h |
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9 |
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10 #include "llimits.h" |
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11 |
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12 |
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13 /*=========================================================================== |
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14 We assume that instructions are unsigned numbers. |
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15 All instructions have an opcode in the first 6 bits. |
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16 Instructions can have the following fields: |
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17 `A' : 8 bits |
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18 `B' : 9 bits |
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19 `C' : 9 bits |
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20 `Bx' : 18 bits (`B' and `C' together) |
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21 `sBx' : signed Bx |
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22 |
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23 A signed argument is represented in excess K; that is, the number |
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24 value is the unsigned value minus K. K is exactly the maximum value |
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25 for that argument (so that -max is represented by 0, and +max is |
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26 represented by 2*max), which is half the maximum for the corresponding |
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27 unsigned argument. |
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28 ===========================================================================*/ |
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29 |
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30 |
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31 enum OpMode {iABC, iABx, iAsBx}; /* basic instruction format */ |
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32 |
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33 |
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34 /* |
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35 ** size and position of opcode arguments. |
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36 */ |
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37 #define SIZE_C 9 |
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38 #define SIZE_B 9 |
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39 #define SIZE_Bx (SIZE_C + SIZE_B) |
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40 #define SIZE_A 8 |
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41 |
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42 #define SIZE_OP 6 |
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43 |
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44 #define POS_OP 0 |
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45 #define POS_A (POS_OP + SIZE_OP) |
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46 #define POS_C (POS_A + SIZE_A) |
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47 #define POS_B (POS_C + SIZE_C) |
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48 #define POS_Bx POS_C |
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49 |
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50 |
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51 /* |
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52 ** limits for opcode arguments. |
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53 ** we use (signed) int to manipulate most arguments, |
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54 ** so they must fit in LUAI_BITSINT-1 bits (-1 for sign) |
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55 */ |
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56 #if SIZE_Bx < LUAI_BITSINT-1 |
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57 #define MAXARG_Bx ((1<<SIZE_Bx)-1) |
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58 #define MAXARG_sBx (MAXARG_Bx>>1) /* `sBx' is signed */ |
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59 #else |
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60 #define MAXARG_Bx MAX_INT |
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61 #define MAXARG_sBx MAX_INT |
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62 #endif |
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63 |
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64 |
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65 #define MAXARG_A ((1<<SIZE_A)-1) |
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66 #define MAXARG_B ((1<<SIZE_B)-1) |
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67 #define MAXARG_C ((1<<SIZE_C)-1) |
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68 |
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69 |
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70 /* creates a mask with `n' 1 bits at position `p' */ |
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71 #define MASK1(n,p) ((~((~(Instruction)0)<<n))<<p) |
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72 |
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73 /* creates a mask with `n' 0 bits at position `p' */ |
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74 #define MASK0(n,p) (~MASK1(n,p)) |
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75 |
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76 /* |
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77 ** the following macros help to manipulate instructions |
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78 */ |
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79 |
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80 #define GET_OPCODE(i) (cast(OpCode, ((i)>>POS_OP) & MASK1(SIZE_OP,0))) |
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81 #define SET_OPCODE(i,o) ((i) = (((i)&MASK0(SIZE_OP,POS_OP)) | \ |
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82 ((cast(Instruction, o)<<POS_OP)&MASK1(SIZE_OP,POS_OP)))) |
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83 |
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84 #define GETARG_A(i) (cast(int, ((i)>>POS_A) & MASK1(SIZE_A,0))) |
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85 #define SETARG_A(i,u) ((i) = (((i)&MASK0(SIZE_A,POS_A)) | \ |
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86 ((cast(Instruction, u)<<POS_A)&MASK1(SIZE_A,POS_A)))) |
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87 |
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88 #define GETARG_B(i) (cast(int, ((i)>>POS_B) & MASK1(SIZE_B,0))) |
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89 #define SETARG_B(i,b) ((i) = (((i)&MASK0(SIZE_B,POS_B)) | \ |
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90 ((cast(Instruction, b)<<POS_B)&MASK1(SIZE_B,POS_B)))) |
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91 |
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92 #define GETARG_C(i) (cast(int, ((i)>>POS_C) & MASK1(SIZE_C,0))) |
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93 #define SETARG_C(i,b) ((i) = (((i)&MASK0(SIZE_C,POS_C)) | \ |
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94 ((cast(Instruction, b)<<POS_C)&MASK1(SIZE_C,POS_C)))) |
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95 |
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96 #define GETARG_Bx(i) (cast(int, ((i)>>POS_Bx) & MASK1(SIZE_Bx,0))) |
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97 #define SETARG_Bx(i,b) ((i) = (((i)&MASK0(SIZE_Bx,POS_Bx)) | \ |
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98 ((cast(Instruction, b)<<POS_Bx)&MASK1(SIZE_Bx,POS_Bx)))) |
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99 |
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100 #define GETARG_sBx(i) (GETARG_Bx(i)-MAXARG_sBx) |
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101 #define SETARG_sBx(i,b) SETARG_Bx((i),cast(unsigned int, (b)+MAXARG_sBx)) |
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102 |
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103 |
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104 #define CREATE_ABC(o,a,b,c) ((cast(Instruction, o)<<POS_OP) \ |
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105 | (cast(Instruction, a)<<POS_A) \ |
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106 | (cast(Instruction, b)<<POS_B) \ |
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107 | (cast(Instruction, c)<<POS_C)) |
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108 |
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109 #define CREATE_ABx(o,a,bc) ((cast(Instruction, o)<<POS_OP) \ |
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110 | (cast(Instruction, a)<<POS_A) \ |
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111 | (cast(Instruction, bc)<<POS_Bx)) |
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112 |
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113 |
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114 /* |
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115 ** Macros to operate RK indices |
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116 */ |
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117 |
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118 /* this bit 1 means constant (0 means register) */ |
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119 #define BITRK (1 << (SIZE_B - 1)) |
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120 |
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121 /* test whether value is a constant */ |
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122 #define ISK(x) ((x) & BITRK) |
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123 |
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124 /* gets the index of the constant */ |
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125 #define INDEXK(r) ((int)(r) & ~BITRK) |
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126 |
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127 #define MAXINDEXRK (BITRK - 1) |
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128 |
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129 /* code a constant index as a RK value */ |
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130 #define RKASK(x) ((x) | BITRK) |
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131 |
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132 |
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133 /* |
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134 ** invalid register that fits in 8 bits |
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135 */ |
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136 #define NO_REG MAXARG_A |
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137 |
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138 |
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139 /* |
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140 ** R(x) - register |
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141 ** Kst(x) - constant (in constant table) |
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142 ** RK(x) == if ISK(x) then Kst(INDEXK(x)) else R(x) |
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143 */ |
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144 |
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145 |
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146 /* |
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147 ** grep "ORDER OP" if you change these enums |
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148 */ |
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149 |
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150 typedef enum { |
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151 /*---------------------------------------------------------------------- |
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152 name args description |
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153 ------------------------------------------------------------------------*/ |
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154 OP_MOVE,/* A B R(A) := R(B) */ |
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155 OP_LOADK,/* A Bx R(A) := Kst(Bx) */ |
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156 OP_LOADBOOL,/* A B C R(A) := (Bool)B; if (C) pc++ */ |
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157 OP_LOADNIL,/* A B R(A) := ... := R(B) := nil */ |
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158 OP_GETUPVAL,/* A B R(A) := UpValue[B] */ |
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159 |
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160 OP_GETGLOBAL,/* A Bx R(A) := Gbl[Kst(Bx)] */ |
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161 OP_GETTABLE,/* A B C R(A) := R(B)[RK(C)] */ |
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162 |
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163 OP_SETGLOBAL,/* A Bx Gbl[Kst(Bx)] := R(A) */ |
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164 OP_SETUPVAL,/* A B UpValue[B] := R(A) */ |
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165 OP_SETTABLE,/* A B C R(A)[RK(B)] := RK(C) */ |
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166 |
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167 OP_NEWTABLE,/* A B C R(A) := {} (size = B,C) */ |
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168 |
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169 OP_SELF,/* A B C R(A+1) := R(B); R(A) := R(B)[RK(C)] */ |
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170 |
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171 OP_ADD,/* A B C R(A) := RK(B) + RK(C) */ |
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172 OP_SUB,/* A B C R(A) := RK(B) - RK(C) */ |
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173 OP_MUL,/* A B C R(A) := RK(B) * RK(C) */ |
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174 OP_DIV,/* A B C R(A) := RK(B) / RK(C) */ |
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175 OP_MOD,/* A B C R(A) := RK(B) % RK(C) */ |
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176 OP_POW,/* A B C R(A) := RK(B) ^ RK(C) */ |
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177 OP_UNM,/* A B R(A) := -R(B) */ |
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178 OP_NOT,/* A B R(A) := not R(B) */ |
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179 OP_LEN,/* A B R(A) := length of R(B) */ |
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180 |
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181 OP_CONCAT,/* A B C R(A) := R(B).. ... ..R(C) */ |
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182 |
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183 OP_JMP,/* sBx pc+=sBx */ |
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184 |
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185 OP_EQ,/* A B C if ((RK(B) == RK(C)) ~= A) then pc++ */ |
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186 OP_LT,/* A B C if ((RK(B) < RK(C)) ~= A) then pc++ */ |
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187 OP_LE,/* A B C if ((RK(B) <= RK(C)) ~= A) then pc++ */ |
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188 |
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189 OP_TEST,/* A C if not (R(A) <=> C) then pc++ */ |
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190 OP_TESTSET,/* A B C if (R(B) <=> C) then R(A) := R(B) else pc++ */ |
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191 |
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192 OP_CALL,/* A B C R(A), ... ,R(A+C-2) := R(A)(R(A+1), ... ,R(A+B-1)) */ |
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193 OP_TAILCALL,/* A B C return R(A)(R(A+1), ... ,R(A+B-1)) */ |
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194 OP_RETURN,/* A B return R(A), ... ,R(A+B-2) (see note) */ |
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195 |
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196 OP_FORLOOP,/* A sBx R(A)+=R(A+2); |
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197 if R(A) <?= R(A+1) then { pc+=sBx; R(A+3)=R(A) }*/ |
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198 OP_FORPREP,/* A sBx R(A)-=R(A+2); pc+=sBx */ |
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199 |
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200 OP_TFORLOOP,/* A C R(A+3), ... ,R(A+2+C) := R(A)(R(A+1), R(A+2)); |
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201 if R(A+3) ~= nil then R(A+2)=R(A+3) else pc++ */ |
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202 OP_SETLIST,/* A B C R(A)[(C-1)*FPF+i] := R(A+i), 1 <= i <= B */ |
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203 |
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204 OP_CLOSE,/* A close all variables in the stack up to (>=) R(A)*/ |
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205 OP_CLOSURE,/* A Bx R(A) := closure(KPROTO[Bx], R(A), ... ,R(A+n)) */ |
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206 |
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207 OP_VARARG/* A B R(A), R(A+1), ..., R(A+B-1) = vararg */ |
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208 } OpCode; |
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209 |
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210 |
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211 #define NUM_OPCODES (cast(int, OP_VARARG) + 1) |
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212 |
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213 |
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214 |
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215 /*=========================================================================== |
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216 Notes: |
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217 (*) In OP_CALL, if (B == 0) then B = top. C is the number of returns - 1, |
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218 and can be 0: OP_CALL then sets `top' to last_result+1, so |
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219 next open instruction (OP_CALL, OP_RETURN, OP_SETLIST) may use `top'. |
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220 |
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221 (*) In OP_VARARG, if (B == 0) then use actual number of varargs and |
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222 set top (like in OP_CALL with C == 0). |
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223 |
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224 (*) In OP_RETURN, if (B == 0) then return up to `top' |
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225 |
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226 (*) In OP_SETLIST, if (B == 0) then B = `top'; |
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227 if (C == 0) then next `instruction' is real C |
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228 |
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229 (*) For comparisons, A specifies what condition the test should accept |
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230 (true or false). |
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231 |
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232 (*) All `skips' (pc++) assume that next instruction is a jump |
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233 ===========================================================================*/ |
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234 |
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235 |
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236 /* |
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237 ** masks for instruction properties. The format is: |
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238 ** bits 0-1: op mode |
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239 ** bits 2-3: C arg mode |
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240 ** bits 4-5: B arg mode |
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241 ** bit 6: instruction set register A |
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242 ** bit 7: operator is a test |
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243 */ |
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244 |
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245 enum OpArgMask { |
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246 OpArgN, /* argument is not used */ |
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247 OpArgU, /* argument is used */ |
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248 OpArgR, /* argument is a register or a jump offset */ |
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249 OpArgK /* argument is a constant or register/constant */ |
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250 }; |
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251 |
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252 LUAI_DATA const lu_byte luaP_opmodes[NUM_OPCODES]; |
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253 |
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254 #define getOpMode(m) (cast(enum OpMode, luaP_opmodes[m] & 3)) |
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255 #define getBMode(m) (cast(enum OpArgMask, (luaP_opmodes[m] >> 4) & 3)) |
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256 #define getCMode(m) (cast(enum OpArgMask, (luaP_opmodes[m] >> 2) & 3)) |
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257 #define testAMode(m) (luaP_opmodes[m] & (1 << 6)) |
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258 #define testTMode(m) (luaP_opmodes[m] & (1 << 7)) |
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259 |
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260 |
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261 LUAI_DATA const char *const luaP_opnames[NUM_OPCODES+1]; /* opcode names */ |
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262 |
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263 |
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264 /* number of list items to accumulate before a SETLIST instruction */ |
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265 #define LFIELDS_PER_FLUSH 50 |
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266 |
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267 |
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268 #endif |