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 #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
  69 #define TARGET_ARCH             bfd_arch_i386
  70
  71 #ifdef OBJ_AOUT
  72 #ifdef TE_NetBSD
  73 #define TARGET_FORMAT           "a.out-i386-netbsd"
  74 #endif
  75 #ifdef TE_386BSD
  76 #define TARGET_FORMAT           "a.out-i386-bsd"
  77 #endif
  78 #ifdef TE_LINUX
  79 #define TARGET_FORMAT           "a.out-i386-linux"
  80 #endif
  81 #ifdef TE_Mach
  82 #define TARGET_FORMAT           "a.out-mach3"
  83 #endif
  84 #ifdef TE_DYNIX
  85 #define TARGET_FORMAT           "a.out-i386-dynix"
  86 #endif
  87 #ifndef TARGET_FORMAT
  88 #define TARGET_FORMAT           "a.out-i386"
  89 #endif
  90 #endif /* OBJ_AOUT */
  91
  92 #ifdef OBJ_ELF
  93 #define TARGET_FORMAT           "elf32-i386"
  94 #endif
  95
  96 #ifdef OBJ_MAYBE_ELF
  97 #ifdef OBJ_MAYBE_COFF
  98 extern const char *i386_target_format PARAMS ((void));
  99 #define TARGET_FORMAT i386_target_format ()
 100 #endif
 101 #endif
 102
 103 #else /* ! BFD_ASSEMBLER */
 104
 105 /* COFF STUFF */
 106
 107 #define COFF_MAGIC I386MAGIC
 108 #define BFD_ARCH bfd_arch_i386
 109 #define COFF_FLAGS F_AR32WR
 110 #define TC_COUNT_RELOC(x) ((x)->fx_addsy || (x)->fx_r_type==7)
 111 #define TC_FORCE_RELOCATION(x) ((x)->fx_r_type==7)
 112 #define TC_COFF_FIX2RTYPE(fixP) tc_coff_fix2rtype(fixP)
 113 extern short tc_coff_fix2rtype PARAMS ((struct fix *));
 114 #define TC_COFF_SIZEMACHDEP(frag) tc_coff_sizemachdep(frag)
 115 extern int tc_coff_sizemachdep PARAMS ((fragS *frag));
 116 #define SUB_SEGMENT_ALIGN(SEG) 2
 117 #define TC_RVA_RELOC 7
 118 /* Need this for PIC relocations */
 119 #define NEED_FX_R_TYPE
 120
 121
 122 #ifdef TE_386BSD
 123 /* The BSDI linker apparently rejects objects with a machine type of
 124    M_386 (100).  */
 125 #define AOUT_MACHTYPE 0
 126 #else
 127 #define AOUT_MACHTYPE 100
 128 #endif
 129
 130 #undef REVERSE_SORT_RELOCS
 131
 132 #endif /* ! BFD_ASSEMBLER */
 133
 134 #ifdef BFD_ASSEMBLER
 135 #define NO_RELOC BFD_RELOC_NONE
 136 #else
 137 #define NO_RELOC 0
 138 #endif
 139 #define tc_coff_symbol_emit_hook(a)     ;       /* not used */
 140
 141 #ifndef BFD_ASSEMBLER
 142 #ifndef OBJ_AOUT
 143 #ifndef TE_PE
 144 /* Local labels starts with .L */
 145 #define LOCAL_LABEL(name) (name[0] == '.' \
 146                  && (name[1] == 'L' || name[1] == 'X' || name[1] == '.'))
 147 #endif
 148 #endif
 149 #endif
 150
 151 #define LOCAL_LABELS_FB 1
 152
 153 #define tc_aout_pre_write_hook(x)       {;}     /* not used */
 154 #define tc_crawl_symbol_chain(a)        {;}     /* not used */
 155 #define tc_headers_hook(a)              {;}     /* not used */
 156
 157 #define MAX_OPERANDS 3          /* max operands per insn */
 158 #define MAX_PREFIXES 5          /* max prefixes per opcode */
 159 #define MAX_IMMEDIATE_OPERANDS 2/* max immediates per insn */
 160 #define MAX_MEMORY_OPERANDS 2   /* max memory ref per insn (lcall uses 2) */
 161
 162 /* we define the syntax here (modulo base,index,scale syntax) */
 163 #define REGISTER_PREFIX '%'
 164 #define IMMEDIATE_PREFIX '$'
 165 #define ABSOLUTE_PREFIX '*'
 166 #define PREFIX_SEPERATOR '/'
 167
 168 #define TWO_BYTE_OPCODE_ESCAPE 0x0f
 169 #define NOP_OPCODE (char) 0x90
 170
 171 /* register numbers */
 172 #define EBP_REG_NUM 5
 173 #define ESP_REG_NUM 4
 174
 175 /* modrm_byte.regmem for twobyte escape */
 176 #define ESCAPE_TO_TWO_BYTE_ADDRESSING ESP_REG_NUM
 177 /* index_base_byte.index for no index register addressing */
 178 #define NO_INDEX_REGISTER ESP_REG_NUM
 179 /* index_base_byte.base for no base register addressing */
 180 #define NO_BASE_REGISTER EBP_REG_NUM
 181
 182 /* these are the att as opcode suffixes, making movl --> mov, for example */
 183 #define DWORD_OPCODE_SUFFIX 'l'
 184 #define WORD_OPCODE_SUFFIX  'w'
 185 #define BYTE_OPCODE_SUFFIX  'b'
 186
 187 /* modrm.mode = REGMEM_FIELD_HAS_REG when a register is in there */
 188 #define REGMEM_FIELD_HAS_REG 0x3/* always = 0x3 */
 189 #define REGMEM_FIELD_HAS_MEM (~REGMEM_FIELD_HAS_REG)
 190
 191 #define END_OF_INSN '\0'
 192
 193 /*
 194   When an operand is read in it is classified by its type.  This type includes
 195   all the possible ways an operand can be used.  Thus, '%eax' is both 'register
 196   # 0' and 'The Accumulator'.  In our language this is expressed by OR'ing
 197   'Reg32' (any 32 bit register) and 'Acc' (the accumulator).
 198   Operands are classified so that we can match given operand types with
 199   the opcode table in i386-opcode.h.
 200   */
 201 #define Unknown 0x0
 202 /* register */
 203 #define Reg8    0x1             /* 8 bit reg */
 204 #define Reg16   0x2             /* 16 bit reg */
 205 #define Reg32   0x4             /* 32 bit reg */
 206 #define Reg     (Reg8|Reg16|Reg32)      /* gen'l register */
 207 #define WordReg (Reg16|Reg32)   /* for push/pop operands */
 208 /* immediate */
 209 #define Imm8    0x8             /* 8 bit immediate */
 210 #define Imm8S   0x10            /* 8 bit immediate sign extended */
 211 #define Imm16   0x20            /* 16 bit immediate */
 212 #define Imm32   0x40            /* 32 bit immediate */
 213 #define Imm1    0x80            /* 1 bit immediate */
 214 #define ImmUnknown Imm32        /* for unknown expressions */
 215 #define Imm     (Imm8|Imm8S|Imm16|Imm32)        /* gen'l immediate */
 216 /* memory */
 217 #define Disp8   0x200           /* 8 bit displacement (for jumps) */
 218 #define Disp16  0x400           /* 16 bit displacement */
 219 #define Disp32  0x800           /* 32 bit displacement */
 220 #define Disp    (Disp8|Disp16|Disp32)   /* General displacement */
 221 #define DispUnknown Disp32      /* for unknown size displacements */
 222 #define Mem8    0x1000
 223 #define Mem16   0x2000
 224 #define Mem32   0x4000
 225 #define BaseIndex 0x8000
 226 #define Mem     (Disp|Mem8|Mem16|Mem32|BaseIndex)       /* General memory */
 227 #define WordMem   (Mem16|Mem32|Disp|BaseIndex)
 228 #define ByteMem   (Mem8|Disp|BaseIndex)
 229 /* specials */
 230 #define InOutPortReg 0x10000    /* register to hold in/out port addr = dx */
 231 #define ShiftCount 0x20000      /* register to hold shift cound = cl */
 232 #define Control 0x40000         /* Control register */
 233 #define Debug   0x80000         /* Debug register */
 234 #define Test    0x100000        /* Test register */
 235 #define FloatReg 0x200000       /* Float register */
 236 #define FloatAcc 0x400000       /* Float stack top %st(0) */
 237 #define SReg2   0x800000        /* 2 bit segment register */
 238 #define SReg3   0x1000000       /* 3 bit segment register */
 239 #define Acc     0x2000000       /* Accumulator %al or %ax or %eax */
 240 #define ImplicitRegister (InOutPortReg|ShiftCount|Acc|FloatAcc)
 241 #define JumpAbsolute 0x4000000
 242 #define Abs8  0x08000000
 243 #define Abs16 0x10000000
 244 #define Abs32 0x20000000
 245 #define Abs (Abs8|Abs16|Abs32)
 246
 247 #define Byte (Reg8|Imm8|Imm8S)
 248 #define Word (Reg16|Imm16)
 249 #define DWord (Reg32|Imm32)
 250
 251 #define SMALLEST_DISP_TYPE(num) \
 252     fits_in_signed_byte(num) ? (Disp8|Disp32|Abs8|Abs32) : (Disp32|Abs32)
 253
 254 typedef struct
 255 {
 256   /* instruction name sans width suffix ("mov" for movl insns) */
 257   char *name;
 258
 259   /* how many operands */
 260   unsigned int operands;
 261
 262   /* base_opcode is the fundamental opcode byte with a optional prefix(es). */
 263   unsigned int base_opcode;
 264
 265   /* extension_opcode is the 3 bit extension for group <n> insns.
 266      If this template has no extension opcode (the usual case) use None */
 267   unsigned char extension_opcode;
 268 #define None 0xff               /* If no extension_opcode is possible. */
 269
 270   /* the bits in opcode_modifier are used to generate the final opcode from
 271      the base_opcode.  These bits also are used to detect alternate forms of
 272      the same instruction */
 273   unsigned int opcode_modifier;
 274
 275   /* opcode_modifier bits: */
 276 #define W        0x1            /* set if operands are words or dwords */
 277 #define D        0x2            /* D = 0 if Reg --> Regmem; D = 1 if Regmem --> Reg */
 278   /* direction flag for floating insns:  MUST BE 0x400 */
 279 #define FloatD 0x400
 280   /* shorthand */
 281 #define DW (D|W)
 282 #define ShortForm 0x10          /* register is in low 3 bits of opcode */
 283 #define ShortFormW 0x20         /* ShortForm and W bit is 0x8 */
 284 #define Seg2ShortForm 0x40      /* encoding of load segment reg insns */
 285 #define Seg3ShortForm 0x80      /* fs/gs segment register insns. */
 286 #define Jump 0x100              /* special case for jump insns. */
 287 #define JumpInterSegment 0x200  /* special case for intersegment leaps/calls */
 288   /* 0x400 CANNOT BE USED since it's already used by FloatD above */
 289 #define DONT_USE 0x400
 290 #define NoModrm 0x800
 291 #define Modrm 0x1000
 292 #define imulKludge 0x2000
 293 #define JumpByte 0x4000
 294 #define JumpDword 0x8000
 295 #define ReverseRegRegmem 0x10000
 296 #define Data16 0x20000          /* needs data prefix if in 32-bit mode */
 297 #define Data32 0x40000          /* needs data prefix if in 16-bit mode */
 298
 299   /* (opcode_modifier & COMES_IN_ALL_SIZES) is true if the
 300      instuction comes in byte, word, and dword sizes and is encoded into
 301      machine code in the canonical way. */
 302 #define COMES_IN_ALL_SIZES (W)
 303
 304   /* (opcode_modifier & COMES_IN_BOTH_DIRECTIONS) indicates that the
 305      source and destination operands can be reversed by setting either
 306      the D (for integer insns) or the FloatD (for floating insns) bit
 307      in base_opcode. */
 308 #define COMES_IN_BOTH_DIRECTIONS (D|FloatD)
 309
 310   /* operand_types[i] describes the type of operand i.  This is made
 311      by OR'ing together all of the possible type masks.  (e.g.
 312      'operand_types[i] = Reg|Imm' specifies that operand i can be
 313      either a register or an immediate operand */
 314   unsigned int operand_types[3];
 315 }
 316 template;
 317
 318 /*
 319   'templates' is for grouping together 'template' structures for opcodes
 320   of the same name.  This is only used for storing the insns in the grand
 321   ole hash table of insns.
 322   The templates themselves start at START and range up to (but not including)
 323   END.
 324   */
 325 typedef struct
 326   {
 327     template *start;
 328     template *end;
 329   } templates;
 330
 331 /* these are for register name --> number & type hash lookup */
 332 typedef struct
 333   {
 334     char *reg_name;
 335     unsigned int reg_type;
 336     unsigned int reg_num;
 337   }
 338
 339 reg_entry;
 340
 341 typedef struct
 342   {
 343     char *seg_name;
 344     unsigned int seg_prefix;
 345   }
 346
 347 seg_entry;
 348
 349 /* these are for prefix name --> prefix code hash lookup */
 350 typedef struct
 351   {
 352     char *prefix_name;
 353     unsigned char prefix_code;
 354   }
 355
 356 prefix_entry;
 357
 358 /* 386 operand encoding bytes:  see 386 book for details of this. */
 359 typedef struct
 360   {
 361     unsigned regmem:3;          /* codes register or memory operand */
 362     unsigned reg:3;             /* codes register operand (or extended opcode) */
 363     unsigned mode:2;            /* how to interpret regmem & reg */
 364   }
 365
 366 modrm_byte;
 367
 368 /* 386 opcode byte to code indirect addressing. */
 369 typedef struct
 370   {
 371     unsigned base:3;
 372     unsigned index:3;
 373     unsigned scale:2;
 374   }
 375
 376 base_index_byte;
 377
 378 /* The name of the global offset table generated by the compiler. Allow
 379    this to be overridden if need be. */
 380 #ifndef GLOBAL_OFFSET_TABLE_NAME
 381 #define GLOBAL_OFFSET_TABLE_NAME "_GLOBAL_OFFSET_TABLE_"
 382 #endif
 383
 384 #ifdef BFD_ASSEMBLER
 385 void i386_validate_fix PARAMS ((struct fix *));
 386 #define TC_VALIDATE_FIX(FIXP,SEGTYPE,SKIP) i386_validate_fix(FIXP)
 387 #endif
 388
 389 #endif /* TC_I386 */
 390
 391 #define md_operand(x)
 392
 393 extern const struct relax_type md_relax_table[];
 394 #define TC_GENERIC_RELAX_TABLE md_relax_table
 395
 396
 397 extern int flag_16bit_code;
 398
 399 #define md_do_align(n, fill, len, max, around)                          \
 400 if ((n) && !need_pass_2                                                 \
 401     && (!(fill) || ((char)*(fill) == (char)0x90 && (len) == 1))         \
 402     && now_seg != data_section && now_seg != bss_section)               \
 403   {                                                                     \
 404     char *p;                                                            \
 405     p = frag_var (rs_align_code, 15, 1, (relax_substateT) max,          \
 406                   (symbolS *) 0, (offsetT) (n), (char *) 0);            \
 407     *p = 0x90;                                                          \
 408     goto around;                                                        \
 409   }
 410
 411 extern void i386_align_code PARAMS ((fragS *, int));
 412
 413 #define HANDLE_ALIGN(fragP)                                             \
 414 if (fragP->fr_type == rs_align_code)                                    \
 415   i386_align_code (fragP, (fragP->fr_next->fr_address                   \
 416                            - fragP->fr_address                          \
 417                            - fragP->fr_fix));
 418
 419 /* call md_apply_fix3 with segment instead of md_apply_fix */
 420 #define MD_APPLY_FIX3
 421
 422 void i386_print_statistics PARAMS ((FILE *));
 423 #define tc_print_statistics i386_print_statistics
 424
 425 #define md_number_to_chars number_to_chars_littleendian
 426
 427 #ifdef SCO_ELF
 428 #define tc_init_after_args() sco_id ()
 429 extern void sco_id PARAMS ((void));
 430 #endif
 431
 432 /* end of tc-i386.h */