gas/config/tc-ip2k.c

   1 /* tc-ip2k.c -- Assembler for the Scenix IP2xxx.
   2    Copyright (C) 2000, 2002, 2003 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
  18    the Free Software Foundation, 59 Temple Place - Suite 330,
  19    Boston, MA 02111-1307, USA.  */
  20
  21 #include <stdio.h>
  22 #include <ctype.h>
  23
  24 #include "as.h"
  25 #include "dwarf2dbg.h"
  26 #include "subsegs.h"
  27 #include "symcat.h"
  28 #include "opcodes/ip2k-desc.h"
  29 #include "opcodes/ip2k-opc.h"
  30 #include "cgen.h"
  31 #include "elf/common.h"
  32 #include "elf/ip2k.h"
  33 #include "libbfd.h"
  34
  35 /* Structure to hold all of the different components describing
  36    an individual instruction.  */
  37 typedef struct
  38 {
  39   const CGEN_INSN *     insn;
  40   const CGEN_INSN *     orig_insn;
  41   CGEN_FIELDS           fields;
  42 #if CGEN_INT_INSN_P
  43   CGEN_INSN_INT         buffer [1];
  44 #define INSN_VALUE(buf) (*(buf))
  45 #else
  46   unsigned char         buffer [CGEN_MAX_INSN_SIZE];
  47 #define INSN_VALUE(buf) (buf)
  48 #endif
  49   char *                addr;
  50   fragS *               frag;
  51   int                   num_fixups;
  52   fixS *                fixups [GAS_CGEN_MAX_FIXUPS];
  53   int                   indices [MAX_OPERAND_INSTANCES];
  54 }
  55 ip2k_insn;
  56
  57 const char comment_chars[]        = ";";
  58 const char line_comment_chars[]   = "#";
  59 const char line_separator_chars[] = "";
  60 const char EXP_CHARS[]            = "eE";
  61 const char FLT_CHARS[]            = "dD";
  62
  63 static void ip2k_elf_section_text (int);
  64 static void ip2k_elf_section_rtn (int);
  65
  66 /* The target specific pseudo-ops which we support.  */
  67 const pseudo_typeS md_pseudo_table[] =
  68 {
  69     { "file",   (void (*) PARAMS ((int))) dwarf2_directive_file, 0 },
  70     { "loc",    dwarf2_directive_loc,   0 },
  71     { "text",   ip2k_elf_section_text,  0 },
  72     { "sect",   ip2k_elf_section_rtn,   0 },
  73     { NULL,     NULL,                   0 }
  74 };
  75
  76 \f
  77
  78 #define OPTION_CPU_IP2022    (OPTION_MD_BASE)
  79 #define OPTION_CPU_IP2022EXT (OPTION_MD_BASE+1)
  80
  81 struct option md_longopts[] =
  82 {
  83   { "mip2022",     no_argument, NULL, OPTION_CPU_IP2022 },
  84   { "mip2022ext",  no_argument, NULL, OPTION_CPU_IP2022EXT },
  85   { NULL,           no_argument, NULL, 0 },
  86 };
  87 size_t md_longopts_size = sizeof (md_longopts);
  88
  89 const char * md_shortopts = "";
  90
  91 /* Flag to detect when switching to code section where insn alignment is
  92    implied.  */
  93 static int force_code_align = 0;
  94
  95 /* Mach selected from command line.  */
  96 int ip2k_mach = 0;
  97 unsigned ip2k_mach_bitmask = 0;
  98
  99 int
 100 md_parse_option (c, arg)
 101     int c ATTRIBUTE_UNUSED;
 102     char * arg ATTRIBUTE_UNUSED;
 103 {
 104   switch (c)
 105     {
 106     case OPTION_CPU_IP2022:
 107       ip2k_mach = bfd_mach_ip2022;
 108       ip2k_mach_bitmask = 1 << MACH_IP2022;
 109       break;
 110
 111     case OPTION_CPU_IP2022EXT:
 112       ip2k_mach = bfd_mach_ip2022ext;
 113       ip2k_mach_bitmask = 1 << MACH_IP2022EXT;
 114       break;
 115
 116     default:
 117       return 0;
 118     }
 119
 120   return 1;
 121 }
 122
 123
 124 void
 125 md_show_usage (stream)
 126     FILE * stream;
 127 {
 128   fprintf (stream, _("IP2K specific command line options:\n"));
 129   fprintf (stream, _("  -mip2022               restrict to IP2022 insns \n"));
 130   fprintf (stream, _("  -mip2022ext            permit extended IP2022 insn\n"));
 131 }
 132
 133 \f
 134 void
 135 md_begin ()
 136 {
 137   /* Initialize the `cgen' interface.  */
 138
 139   /* Set the machine number and endian.  */
 140   gas_cgen_cpu_desc = ip2k_cgen_cpu_open (CGEN_CPU_OPEN_MACHS,
 141                                           ip2k_mach_bitmask,
 142                                           CGEN_CPU_OPEN_ENDIAN,
 143                                           CGEN_ENDIAN_BIG,
 144                                           CGEN_CPU_OPEN_END);
 145   ip2k_cgen_init_asm (gas_cgen_cpu_desc);
 146
 147   /* This is a callback from cgen to gas to parse operands.  */
 148   cgen_set_parse_operand_fn (gas_cgen_cpu_desc, gas_cgen_parse_operand);
 149
 150   /* Set the machine type.  */
 151   bfd_default_set_arch_mach (stdoutput, bfd_arch_ip2k, ip2k_mach);
 152 }
 153
 154
 155 void
 156 md_assemble (str)
 157      char * str;
 158 {
 159   ip2k_insn insn;
 160   char * errmsg;
 161
 162   /* Initialize GAS's cgen interface for a new instruction.  */
 163   gas_cgen_init_parse ();
 164
 165   insn.insn = ip2k_cgen_assemble_insn
 166       (gas_cgen_cpu_desc, str, & insn.fields, insn.buffer, & errmsg);
 167
 168   if (!insn.insn)
 169     {
 170       as_bad ("%s", errmsg);
 171       return;
 172     }
 173
 174   /* Check for special relocation required by SKIP instructions.  */
 175   if (CGEN_INSN_ATTR_VALUE (insn.insn, CGEN_INSN_SKIPA))
 176     /* Unconditional skip has a 1-bit relocation of the current pc, so
 177        that we emit either sb pcl.0 or snb pcl.0 depending on whether
 178        the PCL (pc + 2) >> 1 is odd or even.  */
 179     {
 180       enum cgen_parse_operand_result result_type;
 181       long value;
 182       const char *curpc_plus_2 = ".+2";
 183       const char *err;
 184
 185       err = cgen_parse_address (gas_cgen_cpu_desc, & curpc_plus_2,
 186                                 IP2K_OPERAND_ADDR16CJP,
 187                                 BFD_RELOC_IP2K_PC_SKIP,
 188                                 & result_type, & value);
 189       if (err)
 190         {
 191           as_bad ("%s", err);
 192           return;
 193         }
 194     }
 195
 196   /* Doesn't really matter what we pass for RELAX_P here.  */
 197   gas_cgen_finish_insn (insn.insn, insn.buffer,
 198                         CGEN_FIELDS_BITSIZE (& insn.fields), 1, NULL);
 199 }
 200
 201 valueT
 202 md_section_align (segment, size)
 203      segT   segment;
 204      valueT size;
 205 {
 206   int align = bfd_get_section_alignment (stdoutput, segment);
 207
 208   return ((size + (1 << align) - 1) & (-1 << align));
 209 }
 210
 211
 212 symbolS *
 213 md_undefined_symbol (name)
 214     char * name ATTRIBUTE_UNUSED;
 215 {
 216     return 0;
 217 }
 218 \f
 219 int
 220 md_estimate_size_before_relax (fragP, segment)
 221      fragS * fragP ATTRIBUTE_UNUSED;
 222      segT    segment ATTRIBUTE_UNUSED;
 223 {
 224   as_fatal (_("md_estimate_size_before_relax\n"));
 225   return 1;
 226 }
 227
 228
 229 /* *fragP has been relaxed to its final size, and now needs to have
 230    the bytes inside it modified to conform to the new size.
 231
 232    Called after relaxation is finished.
 233    fragP->fr_type == rs_machine_dependent.
 234    fragP->fr_subtype is the subtype of what the address relaxed to.  */
 235
 236 void
 237 md_convert_frag (abfd, sec, fragP)
 238     bfd   * abfd  ATTRIBUTE_UNUSED;
 239     segT    sec   ATTRIBUTE_UNUSED;
 240     fragS * fragP ATTRIBUTE_UNUSED;
 241 {
 242 }
 243
 244 \f
 245 /* Functions concerning relocs.  */
 246
 247 long
 248 md_pcrel_from (fixP)
 249      fixS *fixP;
 250 {
 251   as_fatal (_("md_pcrel_from\n"));
 252
 253   /* Return the address of the delay slot. */
 254   return fixP->fx_size + fixP->fx_where + fixP->fx_frag->fr_address;
 255 }
 256
 257
 258 /* Return the bfd reloc type for OPERAND of INSN at fixup FIXP.
 259    Returns BFD_RELOC_NONE if no reloc type can be found.
 260    *FIXP may be modified if desired.  */
 261
 262 bfd_reloc_code_real_type
 263 md_cgen_lookup_reloc (insn, operand, fixP)
 264      const CGEN_INSN *    insn     ATTRIBUTE_UNUSED;
 265      const CGEN_OPERAND * operand;
 266      fixS *               fixP     ATTRIBUTE_UNUSED;
 267 {
 268   bfd_reloc_code_real_type result;
 269
 270   result = BFD_RELOC_NONE;
 271
 272   switch (operand->type)
 273     {
 274     case IP2K_OPERAND_FR:
 275     case IP2K_OPERAND_ADDR16L:
 276     case IP2K_OPERAND_ADDR16H:
 277     case IP2K_OPERAND_LIT8:
 278       /* These may have been processed at parse time.  */
 279       if (fixP->fx_cgen.opinfo != 0)
 280         result = fixP->fx_cgen.opinfo;
 281       fixP->fx_no_overflow = 1;
 282       break;
 283
 284     case IP2K_OPERAND_ADDR16CJP:
 285       result = fixP->fx_cgen.opinfo;
 286       if (result == 0 || result == BFD_RELOC_NONE)
 287         result = BFD_RELOC_IP2K_ADDR16CJP;
 288       fixP->fx_no_overflow = 1;
 289       break;
 290
 291     case IP2K_OPERAND_ADDR16P:
 292       result = BFD_RELOC_IP2K_PAGE3;
 293       fixP->fx_no_overflow = 1;
 294       break;
 295
 296     default:
 297       result = BFD_RELOC_NONE;
 298       break;
 299     }
 300
 301   return result;
 302 }
 303
 304
 305 /* Write a value out to the object file, using the appropriate endianness.  */
 306
 307 void
 308 md_number_to_chars (buf, val, n)
 309      char * buf;
 310      valueT val;
 311      int    n;
 312 {
 313   number_to_chars_bigendian (buf, val, n);
 314 }
 315
 316 /* Turn a string in input_line_pointer into a floating point constant of type
 317    type, and store the appropriate bytes in *litP.  The number of LITTLENUMS
 318    emitted is stored in *sizeP .  An error message is returned, or NULL on
 319    OK.  */
 320
 321 /* Equal to MAX_PRECISION in atof-ieee.c  */
 322 #define MAX_LITTLENUMS 6
 323
 324 char *
 325 md_atof (type, litP, sizeP)
 326      char   type;
 327      char * litP;
 328      int *  sizeP;
 329 {
 330   int              prec;
 331   LITTLENUM_TYPE   words [MAX_LITTLENUMS];
 332   LITTLENUM_TYPE  *wordP;
 333   char *           t;
 334   char *           atof_ieee PARAMS ((char *, int, LITTLENUM_TYPE *));
 335
 336   switch (type)
 337     {
 338     case 'f':
 339     case 'F':
 340     case 's':
 341     case 'S':
 342       prec = 2;
 343       break;
 344
 345     case 'd':
 346     case 'D':
 347     case 'r':
 348     case 'R':
 349       prec = 4;
 350       break;
 351
 352    /* FIXME: Some targets allow other format chars for bigger sizes here.  */
 353
 354     default:
 355       * sizeP = 0;
 356       return _("Bad call to md_atof()");
 357     }
 358
 359   t = atof_ieee (input_line_pointer, type, words);
 360   if (t)
 361     input_line_pointer = t;
 362   * sizeP = prec * sizeof (LITTLENUM_TYPE);
 363
 364   /* This loops outputs the LITTLENUMs in REVERSE order; in accord with
 365      the ip2k endianness.  */
 366   for (wordP = words; prec--;)
 367     {
 368       md_number_to_chars (litP, (valueT) (*wordP++), sizeof (LITTLENUM_TYPE));
 369       litP += sizeof (LITTLENUM_TYPE);
 370     }
 371
 372   return 0;
 373 }
 374
 375
 376 /* See whether we need to force a relocation into the output file.
 377    Force most of them, since the linker's bfd relocation engine
 378    understands range limits better than gas' cgen fixup engine.
 379    Consider the case of a fixup intermediate value being larger than
 380    the instruction it will be eventually encoded within.  */
 381
 382 int
 383 ip2k_force_relocation (fix)
 384      fixS * fix;
 385 {
 386   switch (fix->fx_r_type)
 387     {
 388     case BFD_RELOC_IP2K_FR9:
 389     case BFD_RELOC_IP2K_FR_OFFSET:
 390     case BFD_RELOC_IP2K_BANK:
 391     case BFD_RELOC_IP2K_ADDR16CJP:
 392     case BFD_RELOC_IP2K_PAGE3:
 393     case BFD_RELOC_IP2K_LO8DATA:
 394     case BFD_RELOC_IP2K_HI8DATA:
 395     case BFD_RELOC_IP2K_EX8DATA:
 396     case BFD_RELOC_IP2K_LO8INSN:
 397     case BFD_RELOC_IP2K_HI8INSN:
 398     case BFD_RELOC_IP2K_PC_SKIP:
 399     case BFD_RELOC_IP2K_TEXT:
 400       return 1;
 401
 402     case BFD_RELOC_16:
 403       if (fix->fx_subsy && S_IS_DEFINED (fix->fx_subsy)
 404           && fix->fx_addsy && S_IS_DEFINED (fix->fx_addsy)
 405           && (S_GET_SEGMENT (fix->fx_addsy)->flags & SEC_CODE))
 406         {
 407           fix->fx_r_type = BFD_RELOC_IP2K_TEXT;
 408           return 0;
 409         }
 410       break;
 411
 412     default:
 413       break;
 414     }
 415
 416   return generic_force_reloc (fix);
 417 }
 418
 419 void
 420 ip2k_apply_fix3 (fixP, valueP, seg)
 421      fixS *fixP;
 422      valueT *valueP;
 423      segT seg;
 424 {
 425   if (fixP->fx_r_type == BFD_RELOC_IP2K_TEXT
 426       && ! fixP->fx_addsy
 427       && ! fixP->fx_subsy)
 428     {
 429       *valueP = ((int)(*valueP)) / 2;
 430       fixP->fx_r_type = BFD_RELOC_16;
 431     }
 432   else if (fixP->fx_r_type == BFD_RELOC_UNUSED + IP2K_OPERAND_FR)
 433     {
 434       /* Must be careful when we are fixing up an FR.  We could be
 435          fixing up an offset to (SP) or (DP) in which case we don't
 436          want to step on the top 2 bits of the FR operand.  The
 437          gas_cgen_md_apply_fix3 doesn't know any better and overwrites
 438          the entire operand.  We counter this by adding the bits
 439          to the new value.  */
 440       char *where = fixP->fx_frag->fr_literal + fixP->fx_where;
 441
 442       /* Canonical name, since used a lot.  */
 443       CGEN_CPU_DESC cd = gas_cgen_cpu_desc;
 444       CGEN_INSN_INT insn_value
 445         = cgen_get_insn_value (cd, where,
 446                                CGEN_INSN_BITSIZE (fixP->fx_cgen.insn));
 447       /* Preserve (DP) or (SP) specification.  */
 448       *valueP += (insn_value & 0x180);
 449     }
 450
 451   gas_cgen_md_apply_fix3 (fixP, valueP, seg);
 452 }
 453
 454 int
 455 ip2k_elf_section_flags (flags, attr, type)
 456      int flags;
 457      int attr ATTRIBUTE_UNUSED;
 458      int type ATTRIBUTE_UNUSED;
 459 {
 460   /* This is used to detect when the section changes to an executable section.
 461      This function is called by the elf section processing.  When we note an
 462      executable section specifier we set an internal flag to denote when
 463      word alignment should be forced.  */
 464   if (flags & SEC_CODE)
 465     force_code_align = 1;
 466
 467   return flags;
 468 }
 469
 470 static void
 471 ip2k_elf_section_rtn (int i)
 472 {
 473   obj_elf_section(i);
 474
 475   if (force_code_align)
 476     {
 477       /* The s_align_ptwo function expects that we are just after a .align
 478          directive and it will either try and read the align value or stop
 479          if end of line so we must fake it out so it thinks we are at the
 480          end of the line.  */
 481       char *old_input_line_pointer = input_line_pointer;
 482       input_line_pointer = "\n";
 483       s_align_ptwo (1);
 484       force_code_align = 0;
 485       /* Restore.  */
 486       input_line_pointer = old_input_line_pointer;
 487     }
 488 }
 489
 490 static void
 491 ip2k_elf_section_text (int i)
 492 {
 493   char *old_input_line_pointer;
 494   obj_elf_text(i);
 495
 496   /* the s_align_ptwo function expects that we are just after a .align
 497      directive and it will either try and read the align value or stop if
 498      end of line so we must fake it out so it thinks we are at the end of
 499      the line.  */
 500   old_input_line_pointer = input_line_pointer;
 501   input_line_pointer = "\n";
 502   s_align_ptwo (1);
 503   force_code_align = 0;
 504   /* Restore.  */
 505   input_line_pointer = old_input_line_pointer;
 506 }