gas/config/tc-i386.h

   1 /* tc-i386.h -- Header file for tc-i386.c
   2    Copyright (C) 1989, 92, 93, 94, 95, 96, 1997 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 2, 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 the Free
  18    Software Foundation, 59 Temple Place - Suite 330, Boston, MA
  19    02111-1307, USA.  */
  20
  21 #ifndef TC_I386
  22 #define TC_I386 1
  23
  24 #define TARGET_BYTES_BIG_ENDIAN 0
  25
  26 #ifdef TE_LYNX
  27 #define TARGET_FORMAT           "coff-i386-lynx"
  28 #endif
  29
  30 #ifdef BFD_ASSEMBLER
  31 /* This is used to determine relocation types in tc-i386.c.  The first
  32    parameter is the current relocation type, the second one is the desired
  33    type.  The idea is that if the original type is already some kind of PIC
  34    relocation, we leave it alone, otherwise we give it the desired type */
  35
  36 #define TC_RELOC(X,Y) (((X) != BFD_RELOC_386_PLT32 && \
  37            (X) != BFD_RELOC_386_GOTOFF && \
  38            (X) != BFD_RELOC_386_GOT32 && \
  39            (X) != BFD_RELOC_386_GOTPC) ? Y : X)
  40
  41 #define tc_fix_adjustable(X)  tc_i386_fix_adjustable(X)
  42
  43 /* This is the relocation type for direct references to GLOBAL_OFFSET_TABLE.
  44  * It comes up in complicated expressions such as
  45  * _GLOBAL_OFFSET_TABLE_+[.-.L284], which cannot be expressed normally with
  46  * the regular expressions.  The fixup specified here when used at runtime
  47  * implies that we should add the address of the GOT to the specified location,
  48  * and as a result we have simplified the expression into something we can use.
  49  */
  50 #define TC_RELOC_GLOBAL_OFFSET_TABLE BFD_RELOC_386_GOTPC
  51
  52 /* This expression evaluates to false if the relocation is for a local object
  53    for which we still want to do the relocation at runtime.  True if we
  54    are willing to perform this relocation while building the .o file.
  55    This is only used for pcrel relocations, so GOTOFF does not need to be
  56    checked here.  I am not sure if some of the others are ever used with
  57    pcrel, but it is easier to be safe than sorry. */
  58
  59 #define TC_RELOC_RTSYM_LOC_FIXUP(FIX)  \
  60   ((FIX)->fx_r_type != BFD_RELOC_386_PLT32 \
  61    && (FIX)->fx_r_type != BFD_RELOC_386_GOT32 \
  62    && (FIX)->fx_r_type != BFD_RELOC_386_GOTPC)
  63
  64 #define TARGET_ARCH             bfd_arch_i386
  65
  66 #ifdef OBJ_AOUT
  67 #ifdef TE_NetBSD
  68 #define TARGET_FORMAT           "a.out-i386-netbsd"
  69 #endif
  70 #ifdef TE_386BSD
  71 #define TARGET_FORMAT           "a.out-i386-bsd"
  72 #endif
  73 #ifdef TE_LINUX
  74 #define TARGET_FORMAT           "a.out-i386-linux"
  75 #endif
  76 #ifdef TE_Mach
  77 #define TARGET_FORMAT           "a.out-mach3"
  78 #endif
  79 #ifndef TARGET_FORMAT
  80 #define TARGET_FORMAT           "a.out-i386"
  81 #endif
  82 #endif /* OBJ_AOUT */
  83
  84 #ifdef OBJ_ELF
  85 #define TARGET_FORMAT           "elf32-i386"
  86 #endif
  87
  88 #else /* ! BFD_ASSEMBLER */
  89
  90 /* COFF STUFF */
  91
  92 #define COFF_MAGIC I386MAGIC
  93 #define BFD_ARCH bfd_arch_i386
  94 #define COFF_FLAGS F_AR32WR
  95 #define TC_COUNT_RELOC(x) ((x)->fx_addsy || (x)->fx_r_type==7)
  96 #define TC_FORCE_RELOCATION(x) ((x)->fx_r_type==7)
  97 #define TC_COFF_FIX2RTYPE(fixP) tc_coff_fix2rtype(fixP)
  98 extern short tc_coff_fix2rtype ();
  99 #define TC_COFF_SIZEMACHDEP(frag) tc_coff_sizemachdep(frag)
 100 extern int tc_coff_sizemachdep PARAMS ((fragS *frag));
 101 #define SUB_SEGMENT_ALIGN(SEG) 2
 102 #define TC_RVA_RELOC 7
 103 /* Need this for PIC relocations */
 104 #define NEED_FX_R_TYPE
 105
 106
 107 #ifdef TE_386BSD
 108 /* The BSDI linker apparently rejects objects with a machine type of
 109    M_386 (100).  */
 110 #define AOUT_MACHTYPE 0
 111 #else
 112 #define AOUT_MACHTYPE 100
 113 #endif
 114
 115 #undef REVERSE_SORT_RELOCS
 116
 117 #endif /* ! BFD_ASSEMBLER */
 118
 119 #ifdef BFD_ASSEMBLER
 120 #define NO_RELOC BFD_RELOC_NONE
 121 #else
 122 #define NO_RELOC 0
 123 #endif
 124 #define tc_coff_symbol_emit_hook(a)     ;       /* not used */
 125
 126 #ifndef OBJ_AOUT
 127 #ifndef TE_PE
 128 /* Local labels starts with .L */
 129 #define LOCAL_LABEL(name) (name[0] == '.' \
 130                  && (name[1] == 'L' || name[1] == 'X' || name[1] == '.'))
 131 #define FAKE_LABEL_NAME ".L0\001"
 132 #endif
 133 #endif
 134 #define LOCAL_LABELS_FB 1
 135
 136 #define tc_aout_pre_write_hook(x)       {;}     /* not used */
 137 #define tc_crawl_symbol_chain(a)        {;}     /* not used */
 138 #define tc_headers_hook(a)              {;}     /* not used */
 139
 140 #define MAX_OPERANDS 3          /* max operands per insn */
 141 #define MAX_PREFIXES 5          /* max prefixes per opcode */
 142 #define MAX_IMMEDIATE_OPERANDS 2/* max immediates per insn */
 143 #define MAX_MEMORY_OPERANDS 2   /* max memory ref per insn (lcall uses 2) */
 144
 145 /* we define the syntax here (modulo base,index,scale syntax) */
 146 #define REGISTER_PREFIX '%'
 147 #define IMMEDIATE_PREFIX '$'
 148 #define ABSOLUTE_PREFIX '*'
 149 #define PREFIX_SEPERATOR '/'
 150
 151 #define TWO_BYTE_OPCODE_ESCAPE 0x0f
 152 #define NOP_OPCODE (char) 0x90
 153
 154 /* register numbers */
 155 #define EBP_REG_NUM 5
 156 #define ESP_REG_NUM 4
 157
 158 /* modrm_byte.regmem for twobyte escape */
 159 #define ESCAPE_TO_TWO_BYTE_ADDRESSING ESP_REG_NUM
 160 /* index_base_byte.index for no index register addressing */
 161 #define NO_INDEX_REGISTER ESP_REG_NUM
 162 /* index_base_byte.base for no base register addressing */
 163 #define NO_BASE_REGISTER EBP_REG_NUM
 164
 165 /* these are the att as opcode suffixes, making movl --> mov, for example */
 166 #define DWORD_OPCODE_SUFFIX 'l'
 167 #define WORD_OPCODE_SUFFIX  'w'
 168 #define BYTE_OPCODE_SUFFIX  'b'
 169
 170 /* modrm.mode = REGMEM_FIELD_HAS_REG when a register is in there */
 171 #define REGMEM_FIELD_HAS_REG 0x3/* always = 0x3 */
 172 #define REGMEM_FIELD_HAS_MEM (~REGMEM_FIELD_HAS_REG)
 173
 174 #define END_OF_INSN '\0'
 175
 176 /*
 177   When an operand is read in it is classified by its type.  This type includes
 178   all the possible ways an operand can be used.  Thus, '%eax' is both 'register
 179   # 0' and 'The Accumulator'.  In our language this is expressed by OR'ing
 180   'Reg32' (any 32 bit register) and 'Acc' (the accumulator).
 181   Operands are classified so that we can match given operand types with
 182   the opcode table in i386-opcode.h.
 183   */
 184 #define Unknown 0x0
 185 /* register */
 186 #define Reg8    0x1             /* 8 bit reg */
 187 #define Reg16   0x2             /* 16 bit reg */
 188 #define Reg32   0x4             /* 32 bit reg */
 189 #define Reg     (Reg8|Reg16|Reg32)      /* gen'l register */
 190 #define WordReg (Reg16|Reg32)   /* for push/pop operands */
 191 /* immediate */
 192 #define Imm8    0x8             /* 8 bit immediate */
 193 #define Imm8S   0x10            /* 8 bit immediate sign extended */
 194 #define Imm16   0x20            /* 16 bit immediate */
 195 #define Imm32   0x40            /* 32 bit immediate */
 196 #define Imm1    0x80            /* 1 bit immediate */
 197 #define ImmUnknown Imm32        /* for unknown expressions */
 198 #define Imm     (Imm8|Imm8S|Imm16|Imm32)        /* gen'l immediate */
 199 /* memory */
 200 #define Disp8   0x200           /* 8 bit displacement (for jumps) */
 201 #define Disp16  0x400           /* 16 bit displacement */
 202 #define Disp32  0x800           /* 32 bit displacement */
 203 #define Disp    (Disp8|Disp16|Disp32)   /* General displacement */
 204 #define DispUnknown Disp32      /* for unknown size displacements */
 205 #define Mem8    0x1000
 206 #define Mem16   0x2000
 207 #define Mem32   0x4000
 208 #define BaseIndex 0x8000
 209 #define Mem     (Disp|Mem8|Mem16|Mem32|BaseIndex)       /* General memory */
 210 #define WordMem   (Mem16|Mem32|Disp|BaseIndex)
 211 #define ByteMem   (Mem8|Disp|BaseIndex)
 212 /* specials */
 213 #define InOutPortReg 0x10000    /* register to hold in/out port addr = dx */
 214 #define ShiftCount 0x20000      /* register to hold shift cound = cl */
 215 #define Control 0x40000         /* Control register */
 216 #define Debug   0x80000         /* Debug register */
 217 #define Test    0x100000        /* Test register */
 218 #define FloatReg 0x200000       /* Float register */
 219 #define FloatAcc 0x400000       /* Float stack top %st(0) */
 220 #define SReg2   0x800000        /* 2 bit segment register */
 221 #define SReg3   0x1000000       /* 3 bit segment register */
 222 #define Acc     0x2000000       /* Accumulator %al or %ax or %eax */
 223 #define ImplicitRegister (InOutPortReg|ShiftCount|Acc|FloatAcc)
 224 #define JumpAbsolute 0x4000000
 225 #define Abs8  0x08000000
 226 #define Abs16 0x10000000
 227 #define Abs32 0x20000000
 228 #define Abs (Abs8|Abs16|Abs32)
 229
 230 #define Byte (Reg8|Imm8|Imm8S)
 231 #define Word (Reg16|Imm16)
 232 #define DWord (Reg32|Imm32)
 233
 234 #define SMALLEST_DISP_TYPE(num) \
 235     fits_in_signed_byte(num) ? (Disp8|Disp32|Abs8|Abs32) : (Disp32|Abs32)
 236
 237 typedef struct
 238 {
 239   /* instruction name sans width suffix ("mov" for movl insns) */
 240   char *name;
 241
 242   /* how many operands */
 243   unsigned int operands;
 244
 245   /* base_opcode is the fundamental opcode byte with a optional prefix(es). */
 246   unsigned int base_opcode;
 247
 248   /* extension_opcode is the 3 bit extension for group <n> insns.
 249      If this template has no extension opcode (the usual case) use None */
 250   unsigned char extension_opcode;
 251 #define None 0xff               /* If no extension_opcode is possible. */
 252
 253   /* the bits in opcode_modifier are used to generate the final opcode from
 254      the base_opcode.  These bits also are used to detect alternate forms of
 255      the same instruction */
 256   unsigned int opcode_modifier;
 257
 258   /* opcode_modifier bits: */
 259 #define W        0x1            /* set if operands are words or dwords */
 260 #define D        0x2            /* D = 0 if Reg --> Regmem; D = 1 if Regmem --> Reg */
 261   /* direction flag for floating insns:  MUST BE 0x400 */
 262 #define FloatD 0x400
 263   /* shorthand */
 264 #define DW (D|W)
 265 #define ShortForm 0x10          /* register is in low 3 bits of opcode */
 266 #define ShortFormW 0x20         /* ShortForm and W bit is 0x8 */
 267 #define Seg2ShortForm 0x40      /* encoding of load segment reg insns */
 268 #define Seg3ShortForm 0x80      /* fs/gs segment register insns. */
 269 #define Jump 0x100              /* special case for jump insns. */
 270 #define JumpInterSegment 0x200  /* special case for intersegment leaps/calls */
 271   /* 0x400 CANNOT BE USED since it's already used by FloatD above */
 272 #define DONT_USE 0x400
 273 #define NoModrm 0x800
 274 #define Modrm 0x1000
 275 #define imulKludge 0x2000
 276 #define JumpByte 0x4000
 277 #define JumpDword 0x8000
 278 #define ReverseRegRegmem 0x10000
 279 #define Data16 0x20000          /* needs data prefix if in 32-bit mode */
 280 #define Data32 0x40000          /* needs data prefix if in 16-bit mode */
 281
 282   /* (opcode_modifier & COMES_IN_ALL_SIZES) is true if the
 283      instuction comes in byte, word, and dword sizes and is encoded into
 284      machine code in the canonical way. */
 285 #define COMES_IN_ALL_SIZES (W)
 286
 287   /* (opcode_modifier & COMES_IN_BOTH_DIRECTIONS) indicates that the
 288      source and destination operands can be reversed by setting either
 289      the D (for integer insns) or the FloatD (for floating insns) bit
 290      in base_opcode. */
 291 #define COMES_IN_BOTH_DIRECTIONS (D|FloatD)
 292
 293   /* operand_types[i] describes the type of operand i.  This is made
 294      by OR'ing together all of the possible type masks.  (e.g.
 295      'operand_types[i] = Reg|Imm' specifies that operand i can be
 296      either a register or an immediate operand */
 297   unsigned int operand_types[3];
 298 }
 299 template;
 300
 301 /*
 302   'templates' is for grouping together 'template' structures for opcodes
 303   of the same name.  This is only used for storing the insns in the grand
 304   ole hash table of insns.
 305   The templates themselves start at START and range up to (but not including)
 306   END.
 307   */
 308 typedef struct
 309   {
 310     template *start;
 311     template *end;
 312   } templates;
 313
 314 /* these are for register name --> number & type hash lookup */
 315 typedef struct
 316   {
 317     char *reg_name;
 318     unsigned int reg_type;
 319     unsigned int reg_num;
 320   }
 321
 322 reg_entry;
 323
 324 typedef struct
 325   {
 326     char *seg_name;
 327     unsigned int seg_prefix;
 328   }
 329
 330 seg_entry;
 331
 332 /* these are for prefix name --> prefix code hash lookup */
 333 typedef struct
 334   {
 335     char *prefix_name;
 336     unsigned char prefix_code;
 337   }
 338
 339 prefix_entry;
 340
 341 /* 386 operand encoding bytes:  see 386 book for details of this. */
 342 typedef struct
 343   {
 344     unsigned regmem:3;          /* codes register or memory operand */
 345     unsigned reg:3;             /* codes register operand (or extended opcode) */
 346     unsigned mode:2;            /* how to interpret regmem & reg */
 347   }
 348
 349 modrm_byte;
 350
 351 /* 386 opcode byte to code indirect addressing. */
 352 typedef struct
 353   {
 354     unsigned base:3;
 355     unsigned index:3;
 356     unsigned scale:2;
 357   }
 358
 359 base_index_byte;
 360
 361 /* The name of the global offset table generated by the compiler. Allow
 362    this to be overridden if need be. */
 363 #ifndef GLOBAL_OFFSET_TABLE_NAME
 364 #define GLOBAL_OFFSET_TABLE_NAME "_GLOBAL_OFFSET_TABLE_"
 365 #endif
 366
 367 #ifdef BFD_ASSEMBLER
 368 void i386_validate_fix ();
 369 #define TC_VALIDATE_FIX(FIXP,SEGTYPE,SKIP) i386_validate_fix(FIXP)
 370 #endif
 371
 372 #endif /* TC_I386 */
 373
 374 #define md_operand(x)
 375
 376 extern const struct relax_type md_relax_table[];
 377 #define TC_GENERIC_RELAX_TABLE md_relax_table
 378
 379
 380 extern int flag_16bit_code;
 381
 382 #define md_do_align(n, fill, len, max, around)                          \
 383 if ((n) && !need_pass_2                                                 \
 384     && (!(fill) || ((char)*(fill) == (char)0x90 && (len) == 1))         \
 385     && now_seg != data_section && now_seg != bss_section)               \
 386   {                                                                     \
 387     char *p;                                                            \
 388     p = frag_var (rs_align_code, 15, 1, (relax_substateT) max,          \
 389                   (symbolS *) 0, (long) (n), (char *) 0);               \
 390     *p = 0x90;                                                          \
 391     goto around;                                                        \
 392   }
 393
 394 extern void i386_align_code PARAMS ((fragS *, int));
 395
 396 #define HANDLE_ALIGN(fragP)                                             \
 397 if (fragP->fr_type == rs_align_code)                                    \
 398   i386_align_code (fragP, (fragP->fr_next->fr_address                   \
 399                            - fragP->fr_address                          \
 400                            - fragP->fr_fix));
 401
 402 /* call md_apply_fix3 with segment instead of md_apply_fix */
 403 #define MD_APPLY_FIX3
 404
 405 void i386_print_statistics PARAMS ((FILE *));
 406 #define tc_print_statistics i386_print_statistics
 407
 408 #define md_number_to_chars number_to_chars_littleendian
 409
 410 #ifdef SCO_ELF
 411 #define tc_init_after_args() sco_id ()
 412 extern void sco_id PARAMS ((void));
 413 #endif
 414
 415 /* end of tc-i386.h */