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_IMMEDIATE_OPERANDS 2/* max immediates per insn (lcall, ljmp) */
 166 #define MAX_MEMORY_OPERANDS 2   /* max memory refs per insn (string ops) */
 167
 168 /* Prefixes will be emitted in the order defined below.
 169    WAIT_PREFIX must be the first prefix since FWAIT is really is an
 170    instruction, and so must come before any prefixes. */
 171 #define WAIT_PREFIX     0
 172 #define LOCKREP_PREFIX  1
 173 #define ADDR_PREFIX     2
 174 #define DATA_PREFIX     3
 175 #define SEG_PREFIX      4
 176 #define MAX_PREFIXES    5       /* max prefixes per opcode */
 177
 178 /* we define the syntax here (modulo base,index,scale syntax) */
 179 #define REGISTER_PREFIX '%'
 180 #define IMMEDIATE_PREFIX '$'
 181 #define ABSOLUTE_PREFIX '*'
 182
 183 #define TWO_BYTE_OPCODE_ESCAPE 0x0f
 184 #define NOP_OPCODE (char) 0x90
 185
 186 /* register numbers */
 187 #define EBP_REG_NUM 5
 188 #define ESP_REG_NUM 4
 189
 190 /* modrm_byte.regmem for twobyte escape */
 191 #define ESCAPE_TO_TWO_BYTE_ADDRESSING ESP_REG_NUM
 192 /* index_base_byte.index for no index register addressing */
 193 #define NO_INDEX_REGISTER ESP_REG_NUM
 194 /* index_base_byte.base for no base register addressing */
 195 #define NO_BASE_REGISTER EBP_REG_NUM
 196 #define NO_BASE_REGISTER_16 6
 197
 198 /* these are the opcode suffixes, making movl --> mov, for example */
 199 #define DWORD_OPCODE_SUFFIX 'l'
 200 #define WORD_OPCODE_SUFFIX  'w'
 201 #define BYTE_OPCODE_SUFFIX  'b'
 202 #define SHORT_OPCODE_SUFFIX 's'
 203 #define LONG_OPCODE_SUFFIX  'l'
 204
 205 /* modrm.mode = REGMEM_FIELD_HAS_REG when a register is in there */
 206 #define REGMEM_FIELD_HAS_REG 0x3/* always = 0x3 */
 207 #define REGMEM_FIELD_HAS_MEM (~REGMEM_FIELD_HAS_REG)
 208
 209 #define END_OF_INSN '\0'
 210
 211 /*
 212   When an operand is read in it is classified by its type.  This type includes
 213   all the possible ways an operand can be used.  Thus, '%eax' is both 'register
 214   # 0' and 'The Accumulator'.  In our language this is expressed by OR'ing
 215   'Reg32' (any 32 bit register) and 'Acc' (the accumulator).
 216   Operands are classified so that we can match given operand types with
 217   the opcode table in i386-opcode.h.
 218   */
 219 /* register */
 220 #define Reg8               0x1  /* 8 bit reg */
 221 #define Reg16              0x2  /* 16 bit reg */
 222 #define Reg32              0x4  /* 32 bit reg */
 223 /* immediate */
 224 #define Imm8               0x8  /* 8 bit immediate */
 225 #define Imm8S             0x10  /* 8 bit immediate sign extended */
 226 #define Imm16             0x20  /* 16 bit immediate */
 227 #define Imm32             0x40  /* 32 bit immediate */
 228 #define Imm1              0x80  /* 1 bit immediate */
 229 /* memory */
 230 #define BaseIndex        0x100
 231 /* Disp8,16,32 are used in different ways, depending on the
 232    instruction.  For jumps, they specify the size of the PC relative
 233    displacement, for baseindex type instructions, they specify the
 234    size of the offset relative to the base register, and for memory
 235    offset instructions such as `mov 1234,%al' they specify the size of
 236    the offset relative to the segment base.  */
 237 #define Disp8            0x200  /* 8 bit displacement */
 238 #define Disp16           0x400  /* 16 bit displacement */
 239 #define Disp32           0x800  /* 32 bit displacement */
 240 /* specials */
 241 #define InOutPortReg    0x1000  /* register to hold in/out port addr = dx */
 242 #define ShiftCount      0x2000  /* register to hold shift cound = cl */
 243 #define Control         0x4000  /* Control register */
 244 #define Debug           0x8000  /* Debug register */
 245 #define Test           0x10000  /* Test register */
 246 #define FloatReg       0x20000  /* Float register */
 247 #define FloatAcc       0x40000  /* Float stack top %st(0) */
 248 #define SReg2          0x80000  /* 2 bit segment register */
 249 #define SReg3         0x100000  /* 3 bit segment register */
 250 #define Acc           0x200000  /* Accumulator %al or %ax or %eax */
 251 #define JumpAbsolute  0x400000
 252 #define RegMMX        0x800000  /* MMX register */
 253 #define EsSeg        0x1000000  /* String insn operand with fixed es segment */
 254
 255 #define Reg     (Reg8|Reg16|Reg32)      /* gen'l register */
 256 #define WordReg (Reg16|Reg32)
 257 #define ImplicitRegister (InOutPortReg|ShiftCount|Acc|FloatAcc)
 258 #define Imm     (Imm8|Imm8S|Imm16|Imm32) /* gen'l immediate */
 259 #define Disp    (Disp8|Disp16|Disp32)   /* General displacement */
 260 #define AnyMem  (Disp|BaseIndex)        /* General memory */
 261 /* The following aliases are defined because the opcode table
 262    carefully specifies the allowed memory types for each instruction.
 263    At the moment we can only tell a memory reference size by the
 264    instruction suffix, so there's not much point in defining Mem8,
 265    Mem16, Mem32 and Mem64 opcode modifiers - We might as well just use
 266    the suffix directly to check memory operands.  */
 267 #define LLongMem AnyMem         /* 64 bits (or more) */
 268 #define LongMem AnyMem          /* 32 bit memory ref */
 269 #define ShortMem AnyMem         /* 16 bit memory ref */
 270 #define WordMem AnyMem          /* 16 or 32 bit memory ref */
 271 #define ByteMem AnyMem          /* 8 bit memory ref */
 272
 273 #define SMALLEST_DISP_TYPE(num) \
 274     (fits_in_signed_byte(num) ? (Disp8|Disp32) : Disp32)
 275
 276 typedef struct
 277 {
 278   /* instruction name sans width suffix ("mov" for movl insns) */
 279   char *name;
 280
 281   /* how many operands */
 282   unsigned int operands;
 283
 284   /* base_opcode is the fundamental opcode byte without optional
 285      prefix(es).  */
 286   unsigned int base_opcode;
 287
 288   /* extension_opcode is the 3 bit extension for group <n> insns.
 289      If this template has no extension opcode (the usual case) use None */
 290   unsigned char extension_opcode;
 291 #define None 0xff               /* If no extension_opcode is possible. */
 292
 293   /* the bits in opcode_modifier are used to generate the final opcode from
 294      the base_opcode.  These bits also are used to detect alternate forms of
 295      the same instruction */
 296   unsigned int opcode_modifier;
 297
 298   /* opcode_modifier bits: */
 299 #define W                  0x1  /* set if operands can be words or dwords
 300                                    encoded the canonical way */
 301 #define D                  0x2  /* D = 0 if Reg --> Regmem;
 302                                    D = 1 if Regmem --> Reg:    MUST BE 0x2 */
 303 #define Modrm              0x4
 304 #define ReverseRegRegmem   0x8  /* swap reg,regmem fields for 2 reg case */
 305 #define FloatR             0x8  /* src/dest swap for floats:   MUST BE 0x8 */
 306 #define ShortForm         0x10  /* register is in low 3 bits of opcode */
 307 #define FloatMF           0x20  /* FP insn memory format bit, sized by 0x4 */
 308 #define Jump              0x40  /* special case for jump insns. */
 309 #define JumpDword         0x80  /* call and jump */
 310 #define JumpByte         0x100  /* loop and jecxz */
 311 #define JumpInterSegment 0x200  /* special case for intersegment leaps/calls */
 312 #define FloatD           0x400  /* direction for float insns:  MUST BE 0x400 */
 313 #define Seg2ShortForm    0x800  /* encoding of load segment reg insns */
 314 #define Seg3ShortForm   0x1000  /* fs/gs segment register insns. */
 315 #define Data16          0x2000  /* needs data prefix if in 32-bit mode */
 316 #define Data32          0x4000  /* needs data prefix if in 16-bit mode */
 317 #define IgnoreDataSize  0x8000  /* instruction ignores operand size prefix */
 318 #define No_bSuf        0x10000  /* b suffix on instruction illegal */
 319 #define No_wSuf        0x20000  /* w suffix on instruction illegal */
 320 #define No_lSuf        0x40000  /* l suffix on instruction illegal */
 321 #define No_sSuf        0x80000  /* s suffix on instruction illegal */
 322 #define FWait         0x100000  /* instruction needs FWAIT */
 323 #define IsString      0x200000  /* quick test for string instructions */
 324 #define regKludge     0x400000  /* fake an extra reg operand for clr, imul */
 325 #define IsPrefix      0x800000  /* opcode is a prefix */
 326 #define Ugh         0x80000000  /* deprecated fp insn, gets a warning */
 327
 328   /* operand_types[i] describes the type of operand i.  This is made
 329      by OR'ing together all of the possible type masks.  (e.g.
 330      'operand_types[i] = Reg|Imm' specifies that operand i can be
 331      either a register or an immediate operand */
 332   unsigned int operand_types[3];
 333 }
 334 template;
 335
 336 /*
 337   'templates' is for grouping together 'template' structures for opcodes
 338   of the same name.  This is only used for storing the insns in the grand
 339   ole hash table of insns.
 340   The templates themselves start at START and range up to (but not including)
 341   END.
 342   */
 343 typedef struct
 344   {
 345     const template *start;
 346     const template *end;
 347   } templates;
 348
 349 /* these are for register name --> number & type hash lookup */
 350 typedef struct
 351   {
 352     char *reg_name;
 353     unsigned int reg_type;
 354     unsigned int reg_num;
 355   }
 356 reg_entry;
 357
 358 typedef struct
 359   {
 360     char *seg_name;
 361     unsigned int seg_prefix;
 362   }
 363 seg_entry;
 364
 365 /* 386 operand encoding bytes:  see 386 book for details of this. */
 366 typedef struct
 367   {
 368     unsigned int regmem;        /* codes register or memory operand */
 369     unsigned int reg;           /* codes register operand (or extended opcode) */
 370     unsigned int mode;          /* how to interpret regmem & reg */
 371   }
 372 modrm_byte;
 373
 374 /* 386 opcode byte to code indirect addressing. */
 375 typedef struct
 376   {
 377     unsigned base;
 378     unsigned index;
 379     unsigned scale;
 380   }
 381 sib_byte;
 382
 383 /* The name of the global offset table generated by the compiler. Allow
 384    this to be overridden if need be. */
 385 #ifndef GLOBAL_OFFSET_TABLE_NAME
 386 #define GLOBAL_OFFSET_TABLE_NAME "_GLOBAL_OFFSET_TABLE_"
 387 #endif
 388
 389 #ifdef BFD_ASSEMBLER
 390 void i386_validate_fix PARAMS ((struct fix *));
 391 #define TC_VALIDATE_FIX(FIXP,SEGTYPE,SKIP) i386_validate_fix(FIXP)
 392 #endif
 393
 394 #endif /* TC_I386 */
 395
 396 #define md_operand(x)
 397
 398 extern const struct relax_type md_relax_table[];
 399 #define TC_GENERIC_RELAX_TABLE md_relax_table
 400
 401
 402 extern int flag_16bit_code;
 403
 404 #ifdef BFD_ASSEMBLER
 405 #define md_maybe_text() \
 406   ((bfd_get_section_flags (stdoutput, now_seg) & SEC_CODE) != 0)
 407 #else
 408 #define md_maybe_text() \
 409   (now_seg != data_section && now_seg != bss_section)
 410 #endif
 411
 412 #define md_do_align(n, fill, len, max, around)                          \
 413 if ((n) && !need_pass_2                                                 \
 414     && (!(fill) || ((char)*(fill) == (char)0x90 && (len) == 1))         \
 415     && md_maybe_text ())                                                \
 416   {                                                                     \
 417     char *p;                                                            \
 418     p = frag_var (rs_align_code, 15, 1, (relax_substateT) max,          \
 419                   (symbolS *) 0, (offsetT) (n), (char *) 0);            \
 420     *p = 0x90;                                                          \
 421     goto around;                                                        \
 422   }
 423
 424 extern void i386_align_code PARAMS ((fragS *, int));
 425
 426 #define HANDLE_ALIGN(fragP)                                             \
 427 if (fragP->fr_type == rs_align_code)                                    \
 428   i386_align_code (fragP, (fragP->fr_next->fr_address                   \
 429                            - fragP->fr_address                          \
 430                            - fragP->fr_fix));
 431
 432 /* call md_apply_fix3 with segment instead of md_apply_fix */
 433 #define MD_APPLY_FIX3
 434
 435 void i386_print_statistics PARAMS ((FILE *));
 436 #define tc_print_statistics i386_print_statistics
 437
 438 #define md_number_to_chars number_to_chars_littleendian
 439
 440 #ifdef SCO_ELF
 441 #define tc_init_after_args() sco_id ()
 442 extern void sco_id PARAMS ((void));
 443 #endif
 444
 445 #define DIFF_EXPR_OK    /* foo-. gets turned into PC relative relocs */
 446
 447 /* end of tc-i386.h */