gas/config/tc-i386.h

   1 /* tc-i386.h -- Header file for tc-i386.c
   2    Copyright (C) 1989, 92, 93, 94, 95, 96, 97, 1998 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 #ifdef ANSI_PROTOTYPES
  25 struct fix;
  26 #endif
  27
  28 #define TARGET_BYTES_BIG_ENDIAN 0
  29
  30 #ifdef TE_LYNX
  31 #define TARGET_FORMAT           "coff-i386-lynx"
  32 #endif
  33
  34 #ifdef BFD_ASSEMBLER
  35 /* This is used to determine relocation types in tc-i386.c.  The first
  36    parameter is the current relocation type, the second one is the desired
  37    type.  The idea is that if the original type is already some kind of PIC
  38    relocation, we leave it alone, otherwise we give it the desired type */
  39
  40 #define TC_RELOC(X,Y) (((X) != BFD_RELOC_386_PLT32 && \
  41            (X) != BFD_RELOC_386_GOTOFF && \
  42            (X) != BFD_RELOC_386_GOT32 && \
  43            (X) != BFD_RELOC_386_GOTPC) ? Y : X)
  44
  45 #define tc_fix_adjustable(X)  tc_i386_fix_adjustable(X)
  46 extern int tc_i386_fix_adjustable PARAMS ((struct fix *));
  47
  48 /* This is the relocation type for direct references to GLOBAL_OFFSET_TABLE.
  49  * It comes up in complicated expressions such as
  50  * _GLOBAL_OFFSET_TABLE_+[.-.L284], which cannot be expressed normally with
  51  * the regular expressions.  The fixup specified here when used at runtime
  52  * implies that we should add the address of the GOT to the specified location,
  53  * and as a result we have simplified the expression into something we can use.
  54  */
  55 #define TC_RELOC_GLOBAL_OFFSET_TABLE BFD_RELOC_386_GOTPC
  56
  57 /* This expression evaluates to false if the relocation is for a local object
  58    for which we still want to do the relocation at runtime.  True if we
  59    are willing to perform this relocation while building the .o file.
  60    This is only used for pcrel relocations, so GOTOFF does not need to be
  61    checked here.  I am not sure if some of the others are ever used with
  62    pcrel, but it is easier to be safe than sorry. */
  63
  64 #define TC_RELOC_RTSYM_LOC_FIXUP(FIX)                           \
  65   ((FIX)->fx_r_type != BFD_RELOC_386_PLT32                      \
  66    && (FIX)->fx_r_type != BFD_RELOC_386_GOT32                   \
  67    && (FIX)->fx_r_type != BFD_RELOC_386_GOTPC                   \
  68    && ((FIX)->fx_addsy == NULL                                  \
  69        || (! S_IS_EXTERNAL ((FIX)->fx_addsy)                    \
  70            && ! S_IS_WEAK ((FIX)->fx_addsy)                     \
  71            && S_IS_DEFINED ((FIX)->fx_addsy)                    \
  72            && ! S_IS_COMMON ((FIX)->fx_addsy))))
  73
  74 #define TARGET_ARCH             bfd_arch_i386
  75
  76 #ifdef OBJ_AOUT
  77 #ifdef TE_NetBSD
  78 #define TARGET_FORMAT           "a.out-i386-netbsd"
  79 #endif
  80 #ifdef TE_386BSD
  81 #define TARGET_FORMAT           "a.out-i386-bsd"
  82 #endif
  83 #ifdef TE_LINUX
  84 #define TARGET_FORMAT           "a.out-i386-linux"
  85 #endif
  86 #ifdef TE_Mach
  87 #define TARGET_FORMAT           "a.out-mach3"
  88 #endif
  89 #ifdef TE_DYNIX
  90 #define TARGET_FORMAT           "a.out-i386-dynix"
  91 #endif
  92 #ifndef TARGET_FORMAT
  93 #define TARGET_FORMAT           "a.out-i386"
  94 #endif
  95 #endif /* OBJ_AOUT */
  96
  97 #ifdef OBJ_ELF
  98 #define TARGET_FORMAT           "elf32-i386"
  99 #endif
 100
 101 #ifdef OBJ_MAYBE_ELF
 102 #ifdef OBJ_MAYBE_COFF
 103 extern const char *i386_target_format PARAMS ((void));
 104 #define TARGET_FORMAT i386_target_format ()
 105 #endif
 106 #endif
 107
 108 #else /* ! BFD_ASSEMBLER */
 109
 110 /* COFF STUFF */
 111
 112 #define COFF_MAGIC I386MAGIC
 113 #define BFD_ARCH bfd_arch_i386
 114 #define COFF_FLAGS F_AR32WR
 115 #define TC_COUNT_RELOC(x) ((x)->fx_addsy || (x)->fx_r_type==7)
 116 #define TC_FORCE_RELOCATION(x) ((x)->fx_r_type==7)
 117 #define TC_COFF_FIX2RTYPE(fixP) tc_coff_fix2rtype(fixP)
 118 extern short tc_coff_fix2rtype PARAMS ((struct fix *));
 119 #define TC_COFF_SIZEMACHDEP(frag) tc_coff_sizemachdep(frag)
 120 extern int tc_coff_sizemachdep PARAMS ((fragS *frag));
 121 #define SUB_SEGMENT_ALIGN(SEG) 2
 122 #define TC_RVA_RELOC 7
 123 /* Need this for PIC relocations */
 124 #define NEED_FX_R_TYPE
 125
 126
 127 #ifdef TE_386BSD
 128 /* The BSDI linker apparently rejects objects with a machine type of
 129    M_386 (100).  */
 130 #define AOUT_MACHTYPE 0
 131 #else
 132 #define AOUT_MACHTYPE 100
 133 #endif
 134
 135 #undef REVERSE_SORT_RELOCS
 136
 137 #endif /* ! BFD_ASSEMBLER */
 138
 139 #ifdef BFD_ASSEMBLER
 140 #define NO_RELOC BFD_RELOC_NONE
 141 #else
 142 #define NO_RELOC 0
 143 #endif
 144 #define tc_coff_symbol_emit_hook(a)     ;       /* not used */
 145
 146 #ifndef BFD_ASSEMBLER
 147 #ifndef OBJ_AOUT
 148 #ifndef TE_PE
 149 #ifndef TE_GO32
 150 /* Local labels starts with .L */
 151 #define LOCAL_LABEL(name) (name[0] == '.' \
 152                  && (name[1] == 'L' || name[1] == 'X' || name[1] == '.'))
 153 #endif
 154 #endif
 155 #endif
 156 #endif
 157
 158 #define LOCAL_LABELS_FB 1
 159
 160 #define tc_aout_pre_write_hook(x)       {;}     /* not used */
 161 #define tc_crawl_symbol_chain(a)        {;}     /* not used */
 162 #define tc_headers_hook(a)              {;}     /* not used */
 163
 164 #define MAX_OPERANDS 3          /* max operands per insn */
 165 #define MAX_PREFIXES 5          /* max prefixes per opcode */
 166 #define MAX_IMMEDIATE_OPERANDS 2/* max immediates per insn */
 167 #define MAX_MEMORY_OPERANDS 2   /* max memory refs per insn (string ops) */
 168
 169 /* we define the syntax here (modulo base,index,scale syntax) */
 170 #define REGISTER_PREFIX '%'
 171 #define IMMEDIATE_PREFIX '$'
 172 #define ABSOLUTE_PREFIX '*'
 173 #define PREFIX_SEPERATOR '/'
 174
 175 #define TWO_BYTE_OPCODE_ESCAPE 0x0f
 176 #define NOP_OPCODE (char) 0x90
 177
 178 /* register numbers */
 179 #define EBP_REG_NUM 5
 180 #define ESP_REG_NUM 4
 181
 182 /* modrm_byte.regmem for twobyte escape */
 183 #define ESCAPE_TO_TWO_BYTE_ADDRESSING ESP_REG_NUM
 184 /* index_base_byte.index for no index register addressing */
 185 #define NO_INDEX_REGISTER ESP_REG_NUM
 186 /* index_base_byte.base for no base register addressing */
 187 #define NO_BASE_REGISTER EBP_REG_NUM
 188
 189 /* these are the att as opcode suffixes, making movl --> mov, for example */
 190 #define DWORD_OPCODE_SUFFIX 'l'
 191 #define WORD_OPCODE_SUFFIX  'w'
 192 #define BYTE_OPCODE_SUFFIX  'b'
 193
 194 /* modrm.mode = REGMEM_FIELD_HAS_REG when a register is in there */
 195 #define REGMEM_FIELD_HAS_REG 0x3/* always = 0x3 */
 196 #define REGMEM_FIELD_HAS_MEM (~REGMEM_FIELD_HAS_REG)
 197
 198 #define END_OF_INSN '\0'
 199
 200 /*
 201   When an operand is read in it is classified by its type.  This type includes
 202   all the possible ways an operand can be used.  Thus, '%eax' is both 'register
 203   # 0' and 'The Accumulator'.  In our language this is expressed by OR'ing
 204   'Reg32' (any 32 bit register) and 'Acc' (the accumulator).
 205   Operands are classified so that we can match given operand types with
 206   the opcode table in i386-opcode.h.
 207   */
 208 /* register */
 209 #define Reg8               0x1  /* 8 bit reg */
 210 #define Reg16              0x2  /* 16 bit reg */
 211 #define Reg32              0x4  /* 32 bit reg */
 212 /* immediate */
 213 #define Imm8               0x8  /* 8 bit immediate */
 214 #define Imm8S             0x10  /* 8 bit immediate sign extended */
 215 #define Imm16             0x20  /* 16 bit immediate */
 216 #define Imm32             0x40  /* 32 bit immediate */
 217 #define Imm1              0x80  /* 1 bit immediate */
 218 /* memory */
 219 #define BaseIndex        0x100
 220 /* Disp8,16,32 are used in different ways, depending on the
 221    instruction.  For jumps, they specify the size of the PC relative
 222    displacement, for baseindex type instructions, they specify the
 223    size of the offset relative to the base register, and for memory
 224    offset instructions such as `mov 1234,%al' they specify the size of
 225    the offset relative to the segment base.  */
 226 #define Disp8            0x200  /* 8 bit displacement */
 227 #define Disp16           0x400  /* 16 bit displacement */
 228 #define Disp32           0x800  /* 32 bit displacement */
 229 /* Mem8,16,32 are used to limit the allowed sizes of memory operands */
 230 #define Mem8            0x1000
 231 #define Mem16           0x2000
 232 #define Mem32           0x4000
 233 /* specials */
 234 #define InOutPortReg   0x10000  /* register to hold in/out port addr = dx */
 235 #define ShiftCount     0x20000  /* register to hold shift cound = cl */
 236 #define Control        0x40000  /* Control register */
 237 #define Debug          0x80000  /* Debug register */
 238 #define Test          0x100000  /* Test register */
 239 #define FloatReg      0x200000  /* Float register */
 240 #define FloatAcc      0x400000  /* Float stack top %st(0) */
 241 #define SReg2         0x800000  /* 2 bit segment register */
 242 #define SReg3        0x1000000  /* 3 bit segment register */
 243 #define Acc          0x2000000  /* Accumulator %al or %ax or %eax */
 244 #define JumpAbsolute 0x4000000
 245 #define Abs8         0x8000000
 246 #define Abs16       0x10000000
 247 #define Abs32       0x20000000
 248 #define RegMMX      0x40000000  /* MMX register */
 249 #define EsSeg       0x80000000  /* String insn operand with fixed es segment */
 250
 251 #define Reg     (Reg8|Reg16|Reg32)      /* gen'l register */
 252 #define WordReg (Reg16|Reg32)
 253 #define Imm     (Imm8|Imm8S|Imm16|Imm32) /* gen'l immediate */
 254 #define Disp    (Disp8|Disp16|Disp32)   /* General displacement */
 255 #define Mem     (Mem8|Mem16|Mem32|Disp|BaseIndex)       /* General memory */
 256 #define WordMem (Mem16|Mem32|Disp|BaseIndex)
 257 #define ByteMem (Mem8|Disp|BaseIndex)
 258 #define ImplicitRegister (InOutPortReg|ShiftCount|Acc|FloatAcc)
 259 #define Abs     (Abs8|Abs16|Abs32)
 260
 261 #define Byte (Reg8|Imm8|Imm8S)
 262 #define Word (Reg16|Imm16)
 263 #define DWord (Reg32|Imm32)
 264
 265 #define SMALLEST_DISP_TYPE(num) \
 266     fits_in_signed_byte(num) ? (Disp8|Disp32|Abs8|Abs32) : (Disp32|Abs32)
 267
 268 typedef struct
 269 {
 270   /* instruction name sans width suffix ("mov" for movl insns) */
 271   char *name;
 272
 273   /* how many operands */
 274   unsigned int operands;
 275
 276   /* base_opcode is the fundamental opcode byte with a optional prefix(es). */
 277   unsigned int base_opcode;
 278
 279   /* extension_opcode is the 3 bit extension for group <n> insns.
 280      If this template has no extension opcode (the usual case) use None */
 281   unsigned char extension_opcode;
 282 #define None 0xff               /* If no extension_opcode is possible. */
 283
 284   /* the bits in opcode_modifier are used to generate the final opcode from
 285      the base_opcode.  These bits also are used to detect alternate forms of
 286      the same instruction */
 287   unsigned int opcode_modifier;
 288
 289   /* opcode_modifier bits: */
 290 #define W                  0x1  /* set if operands can be words or dwords
 291                                    encoded the canonical way:  MUST BE 0x1 */
 292 #define D                  0x2  /* D = 0 if Reg --> Regmem;
 293                                    D = 1 if Regmem --> Reg:    MUST BE 0x2 */
 294 #define Modrm              0x4
 295 #define ReverseRegRegmem   0x8
 296 #define ShortForm         0x10  /* register is in low 3 bits of opcode */
 297 #define ShortFormW        0x20  /* ShortForm and W bit is 0x8 */
 298 #define Seg2ShortForm     0x40  /* encoding of load segment reg insns */
 299 #define Seg3ShortForm     0x80  /* fs/gs segment register insns. */
 300 #define Jump             0x100  /* special case for jump insns. */
 301 #define JumpInterSegment 0x200  /* special case for intersegment leaps/calls */
 302 #define FloatD           0x400  /* direction for float insns:  MUST BE 0x400 */
 303 #define JumpByte         0x800
 304 #define JumpDword       0x1000
 305 #define FWait           0x2000  /* instruction needs FWAIT */
 306 #define Data16          0x4000  /* needs data prefix if in 32-bit mode */
 307 #define Data32          0x8000  /* needs data prefix if in 16-bit mode */
 308 #define IsString      0x100000  /* quick test for string instructions */
 309 #define regKludge     0x200000  /* fake an extra reg operand for clr, imul */
 310
 311 #define DW (D|W)                /* shorthand */
 312
 313   /* (opcode_modifier & COMES_IN_BOTH_DIRECTIONS) indicates that the
 314      source and destination operands can be reversed by setting either
 315      the D (for integer insns) or the FloatD (for floating insns) bit
 316      in base_opcode. */
 317 #define COMES_IN_BOTH_DIRECTIONS (D|FloatD)
 318
 319   /* operand_types[i] describes the type of operand i.  This is made
 320      by OR'ing together all of the possible type masks.  (e.g.
 321      'operand_types[i] = Reg|Imm' specifies that operand i can be
 322      either a register or an immediate operand */
 323   unsigned int operand_types[3];
 324 }
 325 template;
 326
 327 /*
 328   'templates' is for grouping together 'template' structures for opcodes
 329   of the same name.  This is only used for storing the insns in the grand
 330   ole hash table of insns.
 331   The templates themselves start at START and range up to (but not including)
 332   END.
 333   */
 334 typedef struct
 335   {
 336     template *start;
 337     template *end;
 338   } templates;
 339
 340 /* these are for register name --> number & type hash lookup */
 341 typedef struct
 342   {
 343     char *reg_name;
 344     unsigned int reg_type;
 345     unsigned int reg_num;
 346   }
 347
 348 reg_entry;
 349
 350 typedef struct
 351   {
 352     char *seg_name;
 353     unsigned int seg_prefix;
 354   }
 355
 356 seg_entry;
 357
 358 /* these are for prefix name --> prefix code hash lookup */
 359 typedef struct
 360   {
 361     char *prefix_name;
 362     unsigned char prefix_code;
 363   }
 364
 365 prefix_entry;
 366
 367 /* 386 operand encoding bytes:  see 386 book for details of this. */
 368 typedef struct
 369   {
 370     unsigned regmem:3;          /* codes register or memory operand */
 371     unsigned reg:3;             /* codes register operand (or extended opcode) */
 372     unsigned mode:2;            /* how to interpret regmem & reg */
 373   }
 374
 375 modrm_byte;
 376
 377 /* 386 opcode byte to code indirect addressing. */
 378 typedef struct
 379   {
 380     unsigned base:3;
 381     unsigned index:3;
 382     unsigned scale:2;
 383   }
 384
 385 base_index_byte;
 386
 387 /* The name of the global offset table generated by the compiler. Allow
 388    this to be overridden if need be. */
 389 #ifndef GLOBAL_OFFSET_TABLE_NAME
 390 #define GLOBAL_OFFSET_TABLE_NAME "_GLOBAL_OFFSET_TABLE_"
 391 #endif
 392
 393 #ifdef BFD_ASSEMBLER
 394 void i386_validate_fix PARAMS ((struct fix *));
 395 #define TC_VALIDATE_FIX(FIXP,SEGTYPE,SKIP) i386_validate_fix(FIXP)
 396 #endif
 397
 398 #endif /* TC_I386 */
 399
 400 #define md_operand(x)
 401
 402 extern const struct relax_type md_relax_table[];
 403 #define TC_GENERIC_RELAX_TABLE md_relax_table
 404
 405
 406 extern int flag_16bit_code;
 407
 408 #ifdef BFD_ASSEMBLER
 409 #define md_maybe_text() \
 410   ((bfd_get_section_flags (stdoutput, now_seg) & SEC_CODE) != 0)
 411 #else
 412 #define md_maybe_text() \
 413   (now_seg != data_section && now_seg != bss_section)
 414 #endif
 415
 416 #define md_do_align(n, fill, len, max, around)                          \
 417 if ((n) && !need_pass_2                                                 \
 418     && (!(fill) || ((char)*(fill) == (char)0x90 && (len) == 1))         \
 419     && md_maybe_text ())                                                \
 420   {                                                                     \
 421     char *p;                                                            \
 422     p = frag_var (rs_align_code, 15, 1, (relax_substateT) max,          \
 423                   (symbolS *) 0, (offsetT) (n), (char *) 0);            \
 424     *p = 0x90;                                                          \
 425     goto around;                                                        \
 426   }
 427
 428 extern void i386_align_code PARAMS ((fragS *, int));
 429
 430 #define HANDLE_ALIGN(fragP)                                             \
 431 if (fragP->fr_type == rs_align_code)                                    \
 432   i386_align_code (fragP, (fragP->fr_next->fr_address                   \
 433                            - fragP->fr_address                          \
 434                            - fragP->fr_fix));
 435
 436 /* call md_apply_fix3 with segment instead of md_apply_fix */
 437 #define MD_APPLY_FIX3
 438
 439 void i386_print_statistics PARAMS ((FILE *));
 440 #define tc_print_statistics i386_print_statistics
 441
 442 #define md_number_to_chars number_to_chars_littleendian
 443
 444 #ifdef SCO_ELF
 445 #define tc_init_after_args() sco_id ()
 446 extern void sco_id PARAMS ((void));
 447 #endif
 448
 449 #define DIFF_EXPR_OK    /* foo-. gets turned into PC relative relocs */
 450
 451 /* end of tc-i386.h */