gas/config/tc-ip2k.c

   1 /* tc-ip2k.c -- Assembler for the Scenix IP2xxx.
   2    Copyright (C) 2000, 2002, 2003, 2005, 2006, 2007, 2009
   3    Free Software Foundation. Inc.
   4
   5    This file is part of GAS, the GNU Assembler.
   6
   7    GAS is free software; you can redistribute it and/or modify
   8    it under the terms of the GNU General Public License as published by
   9    the Free Software Foundation; either version 3, or (at your option)
  10    any later version.
  11
  12    GAS is distributed in the hope that it will be useful,
  13    but WITHOUT ANY WARRANTY; without even the implied warranty of
  14    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15    GNU General Public License for more details.
  16
  17    You should have received a copy of the GNU General Public License
  18    along with GAS; see the file COPYING.  If not, write to
  19    the Free Software Foundation, 51 Franklin Street - Fifth Floor,
  20    Boston, MA 02110-1301, USA.  */
  21
  22 #include "as.h"
  23 #include "subsegs.h"
  24 #include "symcat.h"
  25 #include "opcodes/ip2k-desc.h"
  26 #include "opcodes/ip2k-opc.h"
  27 #include "cgen.h"
  28 #include "elf/common.h"
  29 #include "elf/ip2k.h"
  30 #include "libbfd.h"
  31
  32 /* Structure to hold all of the different components describing
  33    an individual instruction.  */
  34 typedef struct
  35 {
  36   const CGEN_INSN *     insn;
  37   const CGEN_INSN *     orig_insn;
  38   CGEN_FIELDS           fields;
  39 #if CGEN_INT_INSN_P
  40   CGEN_INSN_INT         buffer [1];
  41 #define INSN_VALUE(buf) (*(buf))
  42 #else
  43   unsigned char         buffer [CGEN_MAX_INSN_SIZE];
  44 #define INSN_VALUE(buf) (buf)
  45 #endif
  46   char *                addr;
  47   fragS *               frag;
  48   int                   num_fixups;
  49   fixS *                fixups [GAS_CGEN_MAX_FIXUPS];
  50   int                   indices [MAX_OPERAND_INSTANCES];
  51 }
  52 ip2k_insn;
  53
  54 const char comment_chars[]        = ";";
  55 const char line_comment_chars[]   = "#";
  56 const char line_separator_chars[] = "";
  57 const char EXP_CHARS[]            = "eE";
  58 const char FLT_CHARS[]            = "dD";
  59
  60 /* Flag to detect when switching to code section where insn alignment is
  61    implied.  */
  62 static int force_code_align = 0;
  63
  64 /* Mach selected from command line.  */
  65 static int ip2k_mach = 0;
  66 static unsigned ip2k_mach_bitmask = 0;
  67
  68
  69 static void
  70 ip2k_elf_section_rtn (int i)
  71 {
  72   obj_elf_section(i);
  73
  74   if (force_code_align)
  75     {
  76       /* The s_align_ptwo function expects that we are just after a .align
  77          directive and it will either try and read the align value or stop
  78          if end of line so we must fake it out so it thinks we are at the
  79          end of the line.  */
  80       char *old_input_line_pointer = input_line_pointer;
  81       input_line_pointer = "\n";
  82       s_align_ptwo (1);
  83       force_code_align = 0;
  84       /* Restore.  */
  85       input_line_pointer = old_input_line_pointer;
  86     }
  87 }
  88
  89 static void
  90 ip2k_elf_section_text (int i)
  91 {
  92   char *old_input_line_pointer;
  93   obj_elf_text(i);
  94
  95   /* the s_align_ptwo function expects that we are just after a .align
  96      directive and it will either try and read the align value or stop if
  97      end of line so we must fake it out so it thinks we are at the end of
  98      the line.  */
  99   old_input_line_pointer = input_line_pointer;
 100   input_line_pointer = "\n";
 101   s_align_ptwo (1);
 102   force_code_align = 0;
 103   /* Restore.  */
 104   input_line_pointer = old_input_line_pointer;
 105 }
 106
 107 /* The target specific pseudo-ops which we support.  */
 108 const pseudo_typeS md_pseudo_table[] =
 109 {
 110     { "text",   ip2k_elf_section_text,  0 },
 111     { "sect",   ip2k_elf_section_rtn,   0 },
 112     { NULL,     NULL,                   0 }
 113 };
 114
 115 \f
 116
 117 enum options
 118 {
 119   OPTION_CPU_IP2022 = OPTION_MD_BASE,
 120   OPTION_CPU_IP2022EXT
 121 };
 122
 123 struct option md_longopts[] =
 124 {
 125   { "mip2022",     no_argument, NULL, OPTION_CPU_IP2022 },
 126   { "mip2022ext",  no_argument, NULL, OPTION_CPU_IP2022EXT },
 127   { NULL,           no_argument, NULL, 0 },
 128 };
 129 size_t md_longopts_size = sizeof (md_longopts);
 130
 131 const char * md_shortopts = "";
 132
 133 int
 134 md_parse_option (int c ATTRIBUTE_UNUSED, char * arg ATTRIBUTE_UNUSED)
 135 {
 136   switch (c)
 137     {
 138     case OPTION_CPU_IP2022:
 139       ip2k_mach = bfd_mach_ip2022;
 140       ip2k_mach_bitmask = 1 << MACH_IP2022;
 141       break;
 142
 143     case OPTION_CPU_IP2022EXT:
 144       ip2k_mach = bfd_mach_ip2022ext;
 145       ip2k_mach_bitmask = 1 << MACH_IP2022EXT;
 146       break;
 147
 148     default:
 149       return 0;
 150     }
 151
 152   return 1;
 153 }
 154
 155 void
 156 md_show_usage (FILE * stream)
 157 {
 158   fprintf (stream, _("IP2K specific command line options:\n"));
 159   fprintf (stream, _("  -mip2022               restrict to IP2022 insns \n"));
 160   fprintf (stream, _("  -mip2022ext            permit extended IP2022 insn\n"));
 161 }
 162
 163 \f
 164 void
 165 md_begin (void)
 166 {
 167   /* Initialize the `cgen' interface.  */
 168
 169   /* Set the machine number and endian.  */
 170   gas_cgen_cpu_desc = ip2k_cgen_cpu_open (CGEN_CPU_OPEN_MACHS,
 171                                           ip2k_mach_bitmask,
 172                                           CGEN_CPU_OPEN_ENDIAN,
 173                                           CGEN_ENDIAN_BIG,
 174                                           CGEN_CPU_OPEN_END);
 175   ip2k_cgen_init_asm (gas_cgen_cpu_desc);
 176
 177   /* This is a callback from cgen to gas to parse operands.  */
 178   cgen_set_parse_operand_fn (gas_cgen_cpu_desc, gas_cgen_parse_operand);
 179
 180   /* Set the machine type.  */
 181   bfd_default_set_arch_mach (stdoutput, bfd_arch_ip2k, ip2k_mach);
 182 }
 183
 184
 185 void
 186 md_assemble (char * str)
 187 {
 188   ip2k_insn insn;
 189   char * errmsg;
 190
 191   /* Initialize GAS's cgen interface for a new instruction.  */
 192   gas_cgen_init_parse ();
 193
 194   insn.insn = ip2k_cgen_assemble_insn
 195       (gas_cgen_cpu_desc, str, & insn.fields, insn.buffer, & errmsg);
 196
 197   if (!insn.insn)
 198     {
 199       as_bad ("%s", errmsg);
 200       return;
 201     }
 202
 203   /* Check for special relocation required by SKIP instructions.  */
 204   if (CGEN_INSN_ATTR_VALUE (insn.insn, CGEN_INSN_SKIPA))
 205     /* Unconditional skip has a 1-bit relocation of the current pc, so
 206        that we emit either sb pcl.0 or snb pcl.0 depending on whether
 207        the PCL (pc + 2) >> 1 is odd or even.  */
 208     {
 209       enum cgen_parse_operand_result result_type;
 210       bfd_vma value;
 211       const char *curpc_plus_2 = ".+2";
 212       const char *err;
 213
 214       err = cgen_parse_address (gas_cgen_cpu_desc, & curpc_plus_2,
 215                                 IP2K_OPERAND_ADDR16CJP,
 216                                 BFD_RELOC_IP2K_PC_SKIP,
 217                                 & result_type, & value);
 218       if (err)
 219         {
 220           as_bad ("%s", err);
 221           return;
 222         }
 223     }
 224
 225   /* Doesn't really matter what we pass for RELAX_P here.  */
 226   gas_cgen_finish_insn (insn.insn, insn.buffer,
 227                         CGEN_FIELDS_BITSIZE (& insn.fields), 1, NULL);
 228 }
 229
 230 valueT
 231 md_section_align (segT segment, valueT size)
 232 {
 233   int align = bfd_get_section_alignment (stdoutput, segment);
 234
 235   return ((size + (1 << align) - 1) & (-1 << align));
 236 }
 237
 238
 239 symbolS *
 240 md_undefined_symbol (char * name ATTRIBUTE_UNUSED)
 241 {
 242     return 0;
 243 }
 244 \f
 245 int
 246 md_estimate_size_before_relax (fragS * fragP ATTRIBUTE_UNUSED,
 247                                segT    segment ATTRIBUTE_UNUSED)
 248 {
 249   as_fatal (_("relaxation not supported\n"));
 250   return 1;
 251 }
 252
 253
 254 /* *fragP has been relaxed to its final size, and now needs to have
 255    the bytes inside it modified to conform to the new size.
 256
 257    Called after relaxation is finished.
 258    fragP->fr_type == rs_machine_dependent.
 259    fragP->fr_subtype is the subtype of what the address relaxed to.  */
 260
 261 void
 262 md_convert_frag (bfd   * abfd  ATTRIBUTE_UNUSED,
 263                  segT    sec   ATTRIBUTE_UNUSED,
 264                  fragS * fragP ATTRIBUTE_UNUSED)
 265 {
 266 }
 267
 268 \f
 269 /* Functions concerning relocs.  */
 270
 271 long
 272 md_pcrel_from (fixS *fixP ATTRIBUTE_UNUSED)
 273 {
 274   abort ();
 275 }
 276
 277
 278 /* Return the bfd reloc type for OPERAND of INSN at fixup FIXP.
 279    Returns BFD_RELOC_NONE if no reloc type can be found.
 280    *FIXP may be modified if desired.  */
 281
 282 bfd_reloc_code_real_type
 283 md_cgen_lookup_reloc (const CGEN_INSN *    insn     ATTRIBUTE_UNUSED,
 284                       const CGEN_OPERAND * operand,
 285                       fixS *               fixP     ATTRIBUTE_UNUSED)
 286 {
 287   bfd_reloc_code_real_type result;
 288
 289   result = BFD_RELOC_NONE;
 290
 291   switch (operand->type)
 292     {
 293     case IP2K_OPERAND_FR:
 294     case IP2K_OPERAND_ADDR16L:
 295     case IP2K_OPERAND_ADDR16H:
 296     case IP2K_OPERAND_LIT8:
 297       /* These may have been processed at parse time.  */
 298       if (fixP->fx_cgen.opinfo != 0)
 299         result = fixP->fx_cgen.opinfo;
 300       fixP->fx_no_overflow = 1;
 301       break;
 302
 303     case IP2K_OPERAND_ADDR16CJP:
 304       result = fixP->fx_cgen.opinfo;
 305       if (result == 0 || result == BFD_RELOC_NONE)
 306         result = BFD_RELOC_IP2K_ADDR16CJP;
 307       fixP->fx_no_overflow = 1;
 308       break;
 309
 310     case IP2K_OPERAND_ADDR16P:
 311       result = BFD_RELOC_IP2K_PAGE3;
 312       fixP->fx_no_overflow = 1;
 313       break;
 314
 315     default:
 316       result = BFD_RELOC_NONE;
 317       break;
 318     }
 319
 320   return result;
 321 }
 322
 323
 324 /* Write a value out to the object file, using the appropriate endianness.  */
 325
 326 void
 327 md_number_to_chars (char * buf, valueT val, int n)
 328 {
 329   number_to_chars_bigendian (buf, val, n);
 330 }
 331
 332 char *
 333 md_atof (int type, char * litP, int *  sizeP)
 334 {
 335   return ieee_md_atof (type, litP, sizeP, TRUE);
 336 }
 337
 338
 339 /* See whether we need to force a relocation into the output file.
 340    Force most of them, since the linker's bfd relocation engine
 341    understands range limits better than gas' cgen fixup engine.
 342    Consider the case of a fixup intermediate value being larger than
 343    the instruction it will be eventually encoded within.  */
 344
 345 int
 346 ip2k_force_relocation (fixS * fix)
 347 {
 348   switch (fix->fx_r_type)
 349     {
 350     case BFD_RELOC_IP2K_FR9:
 351     case BFD_RELOC_IP2K_FR_OFFSET:
 352     case BFD_RELOC_IP2K_BANK:
 353     case BFD_RELOC_IP2K_ADDR16CJP:
 354     case BFD_RELOC_IP2K_PAGE3:
 355     case BFD_RELOC_IP2K_LO8DATA:
 356     case BFD_RELOC_IP2K_HI8DATA:
 357     case BFD_RELOC_IP2K_EX8DATA:
 358     case BFD_RELOC_IP2K_LO8INSN:
 359     case BFD_RELOC_IP2K_HI8INSN:
 360     case BFD_RELOC_IP2K_PC_SKIP:
 361     case BFD_RELOC_IP2K_TEXT:
 362       return 1;
 363
 364     case BFD_RELOC_16:
 365       if (fix->fx_subsy && S_IS_DEFINED (fix->fx_subsy)
 366           && fix->fx_addsy && S_IS_DEFINED (fix->fx_addsy)
 367           && (S_GET_SEGMENT (fix->fx_addsy)->flags & SEC_CODE))
 368         {
 369           fix->fx_r_type = BFD_RELOC_IP2K_TEXT;
 370           return 0;
 371         }
 372       break;
 373
 374     default:
 375       break;
 376     }
 377
 378   return generic_force_reloc (fix);
 379 }
 380
 381 void
 382 ip2k_apply_fix (fixS *fixP, valueT *valueP, segT seg)
 383 {
 384   if (fixP->fx_r_type == BFD_RELOC_IP2K_TEXT
 385       && ! fixP->fx_addsy
 386       && ! fixP->fx_subsy)
 387     {
 388       *valueP = ((int)(* valueP)) / 2;
 389       fixP->fx_r_type = BFD_RELOC_16;
 390     }
 391   else if (fixP->fx_r_type == BFD_RELOC_UNUSED + IP2K_OPERAND_FR)
 392     {
 393       /* Must be careful when we are fixing up an FR.  We could be
 394          fixing up an offset to (SP) or (DP) in which case we don't
 395          want to step on the top 2 bits of the FR operand.  The
 396          gas_cgen_md_apply_fix doesn't know any better and overwrites
 397          the entire operand.  We counter this by adding the bits
 398          to the new value.  */
 399       char *where = fixP->fx_frag->fr_literal + fixP->fx_where;
 400
 401       /* Canonical name, since used a lot.  */
 402       CGEN_CPU_DESC cd = gas_cgen_cpu_desc;
 403       CGEN_INSN_INT insn_value
 404         = cgen_get_insn_value (cd, (unsigned char *) where,
 405                                CGEN_INSN_BITSIZE (fixP->fx_cgen.insn));
 406       /* Preserve (DP) or (SP) specification.  */
 407       *valueP += (insn_value & 0x180);
 408     }
 409
 410   gas_cgen_md_apply_fix (fixP, valueP, seg);
 411 }
 412
 413 int
 414 ip2k_elf_section_flags (flagword flags,
 415                         bfd_vma attr ATTRIBUTE_UNUSED,
 416                         int type ATTRIBUTE_UNUSED)
 417 {
 418   /* This is used to detect when the section changes to an executable section.
 419      This function is called by the elf section processing.  When we note an
 420      executable section specifier we set an internal flag to denote when
 421      word alignment should be forced.  */
 422   if (flags & SEC_CODE)
 423     force_code_align = 1;
 424
 425   return flags;
 426 }
 427