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1 | /* i386.h -- Header file for i386.c |
2 | Copyright (C) 1989, Free Software Foundation. | |
3 | ||
4 | This file is part of GAS, the GNU Assembler. | |
5 | ||
6 | GAS is free software; you can redistribute it and/or modify | |
7 | it under the terms of the GNU General Public License as published by | |
8 | the Free Software Foundation; either version 1, or (at your option) | |
9 | any later version. | |
10 | ||
11 | GAS is distributed in the hope that it will be useful, | |
12 | but WITHOUT ANY WARRANTY; without even the implied warranty of | |
13 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
14 | GNU General Public License for more details. | |
15 | ||
16 | You should have received a copy of the GNU General Public License | |
17 | along with GAS; see the file COPYING. If not, write to | |
18 | the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA. */ | |
19 | ||
20 | #define MAX_OPERANDS 3 /* max operands per insn */ | |
21 | #define MAX_PREFIXES 4 /* max prefixes per opcode */ | |
22 | #define MAX_IMMEDIATE_OPERANDS 2 /* max immediates per insn */ | |
23 | #define MAX_MEMORY_OPERANDS 2 /* max memory ref per insn | |
24 | * lcall uses 2 | |
25 | */ | |
26 | /* we define the syntax here (modulo base,index,scale syntax) */ | |
27 | #define REGISTER_PREFIX '%' | |
28 | #define IMMEDIATE_PREFIX '$' | |
29 | #define ABSOLUTE_PREFIX '*' | |
30 | #define PREFIX_SEPERATOR '/' | |
31 | ||
32 | #define TWO_BYTE_OPCODE_ESCAPE 0x0f | |
33 | ||
34 | /* register numbers */ | |
35 | #define EBP_REG_NUM 5 | |
36 | #define ESP_REG_NUM 4 | |
37 | ||
38 | /* modrm_byte.regmem for twobyte escape */ | |
39 | #define ESCAPE_TO_TWO_BYTE_ADDRESSING ESP_REG_NUM | |
40 | /* index_base_byte.index for no index register addressing */ | |
41 | #define NO_INDEX_REGISTER ESP_REG_NUM | |
42 | /* index_base_byte.base for no base register addressing */ | |
43 | #define NO_BASE_REGISTER EBP_REG_NUM | |
44 | ||
45 | /* these are the att as opcode suffixes, making movl --> mov, for example */ | |
46 | #define DWORD_OPCODE_SUFFIX 'l' | |
47 | #define WORD_OPCODE_SUFFIX 'w' | |
48 | #define BYTE_OPCODE_SUFFIX 'b' | |
49 | ||
50 | /* modrm.mode = REGMEM_FIELD_HAS_REG when a register is in there */ | |
51 | #define REGMEM_FIELD_HAS_REG 0x3 /* always = 0x3 */ | |
52 | #define REGMEM_FIELD_HAS_MEM (~REGMEM_FIELD_HAS_REG) | |
53 | ||
54 | #define END_OF_INSN '\0' | |
55 | ||
56 | /* | |
57 | When an operand is read in it is classified by its type. This type includes | |
58 | all the possible ways an operand can be used. Thus, '%eax' is both 'register | |
59 | # 0' and 'The Accumulator'. In our language this is expressed by OR'ing | |
60 | 'Reg32' (any 32 bit register) and 'Acc' (the accumulator). | |
61 | Operands are classified so that we can match given operand types with | |
62 | the opcode table in i386-opcode.h. | |
63 | */ | |
64 | #define Unknown 0x0 | |
65 | /* register */ | |
66 | #define Reg8 0x1 /* 8 bit reg */ | |
67 | #define Reg16 0x2 /* 16 bit reg */ | |
68 | #define Reg32 0x4 /* 32 bit reg */ | |
69 | #define Reg (Reg8|Reg16|Reg32) /* gen'l register */ | |
70 | #define WordReg (Reg16|Reg32) /* for push/pop operands */ | |
71 | /* immediate */ | |
72 | #define Imm8 0x8 /* 8 bit immediate */ | |
73 | #define Imm8S 0x10 /* 8 bit immediate sign extended */ | |
74 | #define Imm16 0x20 /* 16 bit immediate */ | |
75 | #define Imm32 0x40 /* 32 bit immediate */ | |
76 | #define Imm1 0x80 /* 1 bit immediate */ | |
77 | #define ImmUnknown Imm32 /* for unknown expressions */ | |
78 | #define Imm (Imm8|Imm8S|Imm16|Imm32) /* gen'l immediate */ | |
79 | /* memory */ | |
80 | #define Disp8 0x200 /* 8 bit displacement (for jumps) */ | |
81 | #define Disp16 0x400 /* 16 bit displacement */ | |
82 | #define Disp32 0x800 /* 32 bit displacement */ | |
83 | #define Disp (Disp8|Disp16|Disp32) /* General displacement */ | |
84 | #define DispUnknown Disp32 /* for unknown size displacements */ | |
85 | #define Mem8 0x1000 | |
86 | #define Mem16 0x2000 | |
87 | #define Mem32 0x4000 | |
88 | #define BaseIndex 0x8000 | |
89 | #define Mem (Disp|Mem8|Mem16|Mem32|BaseIndex) /* General memory */ | |
90 | #define WordMem (Mem16|Mem32|Disp|BaseIndex) | |
91 | #define ByteMem (Mem8|Disp|BaseIndex) | |
92 | /* specials */ | |
93 | #define InOutPortReg 0x10000 /* register to hold in/out port addr = dx */ | |
94 | #define ShiftCount 0x20000 /* register to hold shift cound = cl */ | |
95 | #define Control 0x40000 /* Control register */ | |
96 | #define Debug 0x80000 /* Debug register */ | |
97 | #define Test 0x100000 /* Test register */ | |
98 | #define FloatReg 0x200000 /* Float register */ | |
99 | #define FloatAcc 0x400000 /* Float stack top %st(0) */ | |
100 | #define SReg2 0x800000 /* 2 bit segment register */ | |
101 | #define SReg3 0x1000000 /* 3 bit segment register */ | |
102 | #define Acc 0x2000000 /* Accumulator %al or %ax or %eax */ | |
103 | #define ImplicitRegister (InOutPortReg|ShiftCount|Acc|FloatAcc) | |
104 | #define JumpAbsolute 0x4000000 | |
105 | #define Abs8 0x08000000 | |
106 | #define Abs16 0x10000000 | |
107 | #define Abs32 0x20000000 | |
108 | #define Abs (Abs8|Abs16|Abs32) | |
109 | ||
110 | #define MODE_FROM_DISP_SIZE(t) \ | |
111 | ((t&(Disp8)) ? 1 : \ | |
112 | ((t&(Disp32)) ? 2 : 0)) | |
113 | ||
114 | #define Byte (Reg8|Imm8|Imm8S) | |
115 | #define Word (Reg16|Imm16) | |
116 | #define DWord (Reg32|Imm32) | |
117 | ||
118 | /* convert opcode suffix ('b' 'w' 'l' typically) into type specifyer */ | |
119 | #define OPCODE_SUFFIX_TO_TYPE(s) \ | |
120 | (s == BYTE_OPCODE_SUFFIX ? Byte : \ | |
121 | (s == WORD_OPCODE_SUFFIX ? Word : DWord)) | |
122 | ||
123 | #define FITS_IN_SIGNED_BYTE(num) ((num) >= -128 && (num) <= 127) | |
124 | #define FITS_IN_UNSIGNED_BYTE(num) ((num) >= 0 && (num) <= 255) | |
125 | #define FITS_IN_UNSIGNED_WORD(num) ((num) >= 0 && (num) <= 65535) | |
126 | #define FITS_IN_SIGNED_WORD(num) ((num) >= -32768 && (num) <= 32767) | |
127 | ||
128 | #define SMALLEST_DISP_TYPE(num) \ | |
129 | FITS_IN_SIGNED_BYTE(num) ? (Disp8|Disp32|Abs8|Abs32) : (Disp32|Abs32) | |
130 | ||
131 | #define SMALLEST_IMM_TYPE(num) \ | |
132 | (num == 1) ? (Imm1|Imm8|Imm8S|Imm16|Imm32): \ | |
133 | FITS_IN_SIGNED_BYTE(num) ? (Imm8S|Imm8|Imm16|Imm32) : \ | |
134 | FITS_IN_UNSIGNED_BYTE(num) ? (Imm8|Imm16|Imm32): \ | |
135 | (FITS_IN_SIGNED_WORD(num)||FITS_IN_UNSIGNED_WORD(num)) ? (Imm16|Imm32) : \ | |
136 | (Imm32) | |
137 | ||
138 | typedef unsigned char uchar; | |
139 | typedef unsigned int uint; | |
140 | ||
141 | typedef struct { | |
142 | /* instruction name sans width suffix ("mov" for movl insns) */ | |
143 | char *name; | |
144 | ||
145 | /* how many operands */ | |
146 | uint operands; | |
147 | ||
148 | /* base_opcode is the fundamental opcode byte with a optional prefix(es). */ | |
149 | uint base_opcode; | |
150 | ||
151 | /* extension_opcode is the 3 bit extension for group <n> insns. | |
152 | If this template has no extension opcode (the usual case) use None */ | |
153 | uchar extension_opcode; | |
154 | #define None 0xff /* If no extension_opcode is possible. */ | |
155 | ||
156 | /* the bits in opcode_modifier are used to generate the final opcode from | |
157 | the base_opcode. These bits also are used to detect alternate forms of | |
158 | the same instruction */ | |
159 | uint opcode_modifier; | |
160 | ||
161 | /* opcode_modifier bits: */ | |
162 | #define W 0x1 /* set if operands are words or dwords */ | |
163 | #define D 0x2 /* D = 0 if Reg --> Regmem; D = 1 if Regmem --> Reg */ | |
164 | /* direction flag for floating insns: MUST BE 0x400 */ | |
165 | #define FloatD 0x400 | |
166 | /* shorthand */ | |
167 | #define DW (D|W) | |
168 | #define ShortForm 0x10 /* register is in low 3 bits of opcode */ | |
169 | #define ShortFormW 0x20 /* ShortForm and W bit is 0x8 */ | |
170 | #define Seg2ShortForm 0x40 /* encoding of load segment reg insns */ | |
171 | #define Seg3ShortForm 0x80 /* fs/gs segment register insns. */ | |
172 | #define Jump 0x100 /* special case for jump insns. */ | |
173 | #define JumpInterSegment 0x200 /* special case for intersegment leaps/calls */ | |
174 | /* 0x400 CANNOT BE USED since it's already used by FloatD above */ | |
175 | #define DONT_USE 0x400 | |
176 | #define NoModrm 0x800 | |
177 | #define Modrm 0x1000 | |
178 | #define imulKludge 0x2000 | |
179 | #define JumpByte 0x4000 | |
180 | #define JumpDword 0x8000 | |
181 | #define ReverseRegRegmem 0x10000 | |
182 | ||
183 | /* (opcode_modifier & COMES_IN_ALL_SIZES) is true if the | |
184 | instuction comes in byte, word, and dword sizes and is encoded into | |
185 | machine code in the canonical way. */ | |
186 | #define COMES_IN_ALL_SIZES (W) | |
187 | ||
188 | /* (opcode_modifier & COMES_IN_BOTH_DIRECTIONS) indicates that the | |
189 | source and destination operands can be reversed by setting either | |
190 | the D (for integer insns) or the FloatD (for floating insns) bit | |
191 | in base_opcode. */ | |
192 | #define COMES_IN_BOTH_DIRECTIONS (D|FloatD) | |
193 | ||
194 | /* operand_types[i] describes the type of operand i. This is made | |
195 | by OR'ing together all of the possible type masks. (e.g. | |
196 | 'operand_types[i] = Reg|Imm' specifies that operand i can be | |
197 | either a register or an immediate operand */ | |
198 | uint operand_types[3]; | |
199 | } template; | |
200 | ||
201 | /* | |
202 | 'templates' is for grouping together 'template' structures for opcodes | |
203 | of the same name. This is only used for storing the insns in the grand | |
204 | ole hash table of insns. | |
205 | The templates themselves start at START and range up to (but not including) | |
206 | END. | |
207 | */ | |
208 | typedef struct { | |
209 | template *start; | |
210 | template *end; | |
211 | } templates; | |
212 | ||
213 | /* these are for register name --> number & type hash lookup */ | |
214 | typedef struct { | |
215 | char * reg_name; | |
216 | uint reg_type; | |
217 | uint reg_num; | |
218 | } reg_entry; | |
219 | ||
220 | typedef struct { | |
221 | char * seg_name; | |
222 | uint seg_prefix; | |
223 | } seg_entry; | |
224 | ||
225 | /* these are for prefix name --> prefix code hash lookup */ | |
226 | typedef struct { | |
227 | char * prefix_name; | |
228 | uchar prefix_code; | |
229 | } prefix_entry; | |
230 | ||
231 | /* 386 operand encoding bytes: see 386 book for details of this. */ | |
232 | typedef struct { | |
233 | unsigned regmem:3; /* codes register or memory operand */ | |
234 | unsigned reg:3; /* codes register operand (or extended opcode) */ | |
235 | unsigned mode:2; /* how to interpret regmem & reg */ | |
236 | } modrm_byte; | |
237 | ||
238 | /* 386 opcode byte to code indirect addressing. */ | |
239 | typedef struct { | |
240 | unsigned base:3; | |
241 | unsigned index:3; | |
242 | unsigned scale:2; | |
243 | } base_index_byte; | |
244 | ||
245 | /* 'md_assemble ()' gathers together information and puts it into a | |
246 | i386_insn. */ | |
247 | ||
248 | typedef struct { | |
249 | /* TM holds the template for the insn were currently assembling. */ | |
250 | template tm; | |
251 | /* SUFFIX holds the opcode suffix (e.g. 'l' for 'movl') if given. */ | |
252 | char suffix; | |
253 | /* Operands are coded with OPERANDS, TYPES, DISPS, IMMS, and REGS. */ | |
254 | ||
255 | /* OPERANDS gives the number of given operands. */ | |
256 | uint operands; | |
257 | ||
258 | /* REG_OPERANDS, DISP_OPERANDS, MEM_OPERANDS, IMM_OPERANDS give the number of | |
259 | given register, displacement, memory operands and immediate operands. */ | |
260 | uint reg_operands, disp_operands, mem_operands, imm_operands; | |
261 | ||
262 | /* TYPES [i] is the type (see above #defines) which tells us how to | |
263 | search through DISPS [i] & IMMS [i] & REGS [i] for the required | |
264 | operand. */ | |
265 | uint types [MAX_OPERANDS]; | |
266 | ||
267 | /* Displacements (if given) for each operand. */ | |
268 | expressionS * disps [MAX_OPERANDS]; | |
269 | ||
270 | /* Immediate operands (if given) for each operand. */ | |
271 | expressionS * imms [MAX_OPERANDS]; | |
272 | ||
273 | /* Register operands (if given) for each operand. */ | |
274 | reg_entry * regs [MAX_OPERANDS]; | |
275 | ||
276 | /* BASE_REG, INDEX_REG, and LOG2_SCALE_FACTOR are used to encode | |
277 | the base index byte below. */ | |
278 | reg_entry * base_reg; | |
279 | reg_entry * index_reg; | |
280 | uint log2_scale_factor; | |
281 | ||
282 | /* SEG gives the seg_entry of this insn. It is equal to zero unless | |
283 | an explicit segment override is given. */ | |
284 | seg_entry * seg; /* segment for memory operands (if given) */ | |
285 | ||
286 | /* PREFIX holds all the given prefix opcodes (usually null). | |
287 | PREFIXES is the size of PREFIX. */ | |
288 | char prefix [MAX_PREFIXES]; | |
289 | uint prefixes; | |
290 | ||
291 | /* RM and IB are the modrm byte and the base index byte where the addressing | |
292 | modes of this insn are encoded. */ | |
293 | ||
294 | modrm_byte rm; | |
295 | base_index_byte bi; | |
296 | } i386_insn; |