source: trunk/libs/newlib/src/include/opcode/i386.h @ 495

Last change on this file since 495 was 444, checked in by satin@…, 7 years ago

add newlib,libalmos-mkh, restructure shared_syscalls.h and mini-libc

File size: 5.0 KB
Line 
1/* opcode/i386.h -- Intel 80386 opcode macros
2   Copyright 1989, 1991, 1992, 1993, 1994, 1995, 1996, 1997, 1998, 1999,
3   2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010
4   Free Software Foundation, Inc.
5
6   This file is part of GAS, the GNU Assembler, and GDB, the GNU Debugger.
7
8   This program is free software; you can redistribute it and/or modify
9   it under the terms of the GNU General Public License as published by
10   the Free Software Foundation; either version 3 of the License, or
11   (at your option) any later version.
12
13   This program is distributed in the hope that it will be useful,
14   but WITHOUT ANY WARRANTY; without even the implied warranty of
15   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
16   GNU General Public License for more details.
17
18   You should have received a copy of the GNU General Public License
19   along with this program; if not, write to the Free Software
20   Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston,
21   MA 02110-1301, USA.  */
22
23/* The SystemV/386 SVR3.2 assembler, and probably all AT&T derived
24   ix86 Unix assemblers, generate floating point instructions with
25   reversed source and destination registers in certain cases.
26   Unfortunately, gcc and possibly many other programs use this
27   reversed syntax, so we're stuck with it.
28
29   eg. `fsub %st(3),%st' results in st = st - st(3) as expected, but
30   `fsub %st,%st(3)' results in st(3) = st - st(3), rather than
31   the expected st(3) = st(3) - st
32
33   This happens with all the non-commutative arithmetic floating point
34   operations with two register operands, where the source register is
35   %st, and destination register is %st(i).
36
37   The affected opcode map is dceX, dcfX, deeX, defX.  */
38
39#ifndef OPCODE_I386_H
40#define OPCODE_I386_H
41
42#ifndef SYSV386_COMPAT
43/* Set non-zero for broken, compatible instructions.  Set to zero for
44   non-broken opcodes at your peril.  gcc generates SystemV/386
45   compatible instructions.  */
46#define SYSV386_COMPAT 1
47#endif
48#ifndef OLDGCC_COMPAT
49/* Set non-zero to cater for old (<= 2.8.1) versions of gcc that could
50   generate nonsense fsubp, fsubrp, fdivp and fdivrp with operands
51   reversed.  */
52#define OLDGCC_COMPAT SYSV386_COMPAT
53#endif
54
55#define MOV_AX_DISP32 0xa0
56#define POP_SEG_SHORT 0x07
57#define JUMP_PC_RELATIVE 0xeb
58#define INT_OPCODE  0xcd
59#define INT3_OPCODE 0xcc
60/* The opcode for the fwait instruction, which disassembler treats as a
61   prefix when it can.  */
62#define FWAIT_OPCODE 0x9b
63
64/* Instruction prefixes.
65   NOTE: For certain SSE* instructions, 0x66,0xf2,0xf3 are treated as
66   part of the opcode.  Other prefixes may still appear between them
67   and the 0x0f part of the opcode.  */
68#define ADDR_PREFIX_OPCODE 0x67
69#define DATA_PREFIX_OPCODE 0x66
70#define LOCK_PREFIX_OPCODE 0xf0
71#define CS_PREFIX_OPCODE 0x2e
72#define DS_PREFIX_OPCODE 0x3e
73#define ES_PREFIX_OPCODE 0x26
74#define FS_PREFIX_OPCODE 0x64
75#define GS_PREFIX_OPCODE 0x65
76#define SS_PREFIX_OPCODE 0x36
77#define REPNE_PREFIX_OPCODE 0xf2
78#define REPE_PREFIX_OPCODE  0xf3
79#define XACQUIRE_PREFIX_OPCODE 0xf2
80#define XRELEASE_PREFIX_OPCODE 0xf3
81#define BND_PREFIX_OPCODE 0xf2
82
83#define TWO_BYTE_OPCODE_ESCAPE 0x0f
84#define NOP_OPCODE (char) 0x90
85
86/* register numbers */
87#define EAX_REG_NUM 0
88#define ECX_REG_NUM 1
89#define EDX_REG_NUM 2
90#define EBX_REG_NUM 3
91#define ESP_REG_NUM 4
92#define EBP_REG_NUM 5
93#define ESI_REG_NUM 6
94#define EDI_REG_NUM 7
95
96/* modrm_byte.regmem for twobyte escape */
97#define ESCAPE_TO_TWO_BYTE_ADDRESSING ESP_REG_NUM
98/* index_base_byte.index for no index register addressing */
99#define NO_INDEX_REGISTER ESP_REG_NUM
100/* index_base_byte.base for no base register addressing */
101#define NO_BASE_REGISTER EBP_REG_NUM
102#define NO_BASE_REGISTER_16 6
103
104/* modrm.mode = REGMEM_FIELD_HAS_REG when a register is in there */
105#define REGMEM_FIELD_HAS_REG 0x3/* always = 0x3 */
106#define REGMEM_FIELD_HAS_MEM (~REGMEM_FIELD_HAS_REG)
107
108/* Extract fields from the mod/rm byte.  */
109#define MODRM_MOD_FIELD(modrm) (((modrm) >> 6) & 3)
110#define MODRM_REG_FIELD(modrm) (((modrm) >> 3) & 7)
111#define MODRM_RM_FIELD(modrm)  (((modrm) >> 0) & 7)
112
113/* Extract fields from the sib byte.  */
114#define SIB_SCALE_FIELD(sib) (((sib) >> 6) & 3)
115#define SIB_INDEX_FIELD(sib) (((sib) >> 3) & 7)
116#define SIB_BASE_FIELD(sib)  (((sib) >> 0) & 7)
117
118/* x86-64 extension prefix.  */
119#define REX_OPCODE      0x40
120
121/* Non-zero if OPCODE is the rex prefix.  */
122#define REX_PREFIX_P(opcode) (((opcode) & 0xf0) == REX_OPCODE)
123
124/* Indicates 64 bit operand size.  */
125#define REX_W   8
126/* High extension to reg field of modrm byte.  */
127#define REX_R   4
128/* High extension to SIB index field.  */
129#define REX_X   2
130/* High extension to base field of modrm or SIB, or reg field of opcode.  */
131#define REX_B   1
132
133/* max operands per insn */
134#define MAX_OPERANDS 5
135
136/* max immediates per insn (lcall, ljmp, insertq, extrq) */
137#define MAX_IMMEDIATE_OPERANDS 2
138
139/* max memory refs per insn (string ops) */
140#define MAX_MEMORY_OPERANDS 2
141
142/* max size of insn mnemonics.  */
143#define MAX_MNEM_SIZE 20
144
145/* max size of register name in insn mnemonics.  */
146#define MAX_REG_NAME_SIZE 8
147
148#endif /* OPCODE_I386_H */
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