gas/config/tc-ip2k.c

   1 /* tc-ip2k.c -- Assembler for the Scenix IP2xxx.
   2    Copyright (C) 2000-2021 Free Software Foundation, Inc.
   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 3, 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, 51 Franklin Street - Fifth Floor,
  19    Boston, MA 02110-1301, USA.  */
  20
  21 #include "as.h"
  22 #include "subsegs.h"
  23 #include "symcat.h"
  24 #include "opcodes/ip2k-desc.h"
  25 #include "opcodes/ip2k-opc.h"
  26 #include "cgen.h"
  27 #include "elf/common.h"
  28 #include "elf/ip2k.h"
  29
  30 /* Structure to hold all of the different components describing
  31    an individual instruction.  */
  32 typedef struct
  33 {
  34   const CGEN_INSN *     insn;
  35   const CGEN_INSN *     orig_insn;
  36   CGEN_FIELDS           fields;
  37 #if CGEN_INT_INSN_P
  38   CGEN_INSN_INT         buffer [1];
  39 #define INSN_VALUE(buf) (*(buf))
  40 #else
  41   unsigned char         buffer [CGEN_MAX_INSN_SIZE];
  42 #define INSN_VALUE(buf) (buf)
  43 #endif
  44   char *                addr;
  45   fragS *               frag;
  46   int                   num_fixups;
  47   fixS *                fixups [GAS_CGEN_MAX_FIXUPS];
  48   int                   indices [MAX_OPERAND_INSTANCES];
  49 }
  50 ip2k_insn;
  51
  52 const char comment_chars[]        = ";";
  53 const char line_comment_chars[]   = "#";
  54 const char line_separator_chars[] = "";
  55 const char EXP_CHARS[]            = "eE";
  56 const char FLT_CHARS[]            = "dD";
  57
  58 /* Flag to detect when switching to code section where insn alignment is
  59    implied.  */
  60 static int force_code_align = 0;
  61
  62 /* Mach selected from command line.  */
  63 static int ip2k_mach = 0;
  64 static unsigned ip2k_mach_bitmask = 0;
  65
  66
  67 static void
  68 ip2k_elf_section_rtn (int i)
  69 {
  70   obj_elf_section(i);
  71
  72   if (force_code_align)
  73     {
  74       do_align (1, NULL, 0, 0);
  75       force_code_align = 0;
  76     }
  77 }
  78
  79 static void
  80 ip2k_elf_section_text (int i)
  81 {
  82   obj_elf_text(i);
  83
  84   do_align (1, NULL, 0, 0);
  85   force_code_align = 0;
  86 }
  87
  88 /* The target specific pseudo-ops which we support.  */
  89 const pseudo_typeS md_pseudo_table[] =
  90 {
  91     { "text",   ip2k_elf_section_text,  0 },
  92     { "sect",   ip2k_elf_section_rtn,   0 },
  93     { NULL,     NULL,                   0 }
  94 };
  95
  96 \f
  97
  98 enum options
  99 {
 100   OPTION_CPU_IP2022 = OPTION_MD_BASE,
 101   OPTION_CPU_IP2022EXT
 102 };
 103
 104 struct option md_longopts[] =
 105 {
 106   { "mip2022",     no_argument, NULL, OPTION_CPU_IP2022 },
 107   { "mip2022ext",  no_argument, NULL, OPTION_CPU_IP2022EXT },
 108   { NULL,           no_argument, NULL, 0 },
 109 };
 110 size_t md_longopts_size = sizeof (md_longopts);
 111
 112 const char * md_shortopts = "";
 113
 114 int
 115 md_parse_option (int c ATTRIBUTE_UNUSED, const char * arg ATTRIBUTE_UNUSED)
 116 {
 117   switch (c)
 118     {
 119     case OPTION_CPU_IP2022:
 120       ip2k_mach = bfd_mach_ip2022;
 121       ip2k_mach_bitmask = 1 << MACH_IP2022;
 122       break;
 123
 124     case OPTION_CPU_IP2022EXT:
 125       ip2k_mach = bfd_mach_ip2022ext;
 126       ip2k_mach_bitmask = 1 << MACH_IP2022EXT;
 127       break;
 128
 129     default:
 130       return 0;
 131     }
 132
 133   return 1;
 134 }
 135
 136 void
 137 md_show_usage (FILE * stream)
 138 {
 139   fprintf (stream, _("IP2K specific command line options:\n"));
 140   fprintf (stream, _("  -mip2022               restrict to IP2022 insns \n"));
 141   fprintf (stream, _("  -mip2022ext            permit extended IP2022 insn\n"));
 142 }
 143
 144 \f
 145 void
 146 md_begin (void)
 147 {
 148   /* Initialize the `cgen' interface.  */
 149
 150   /* Set the machine number and endian.  */
 151   gas_cgen_cpu_desc = ip2k_cgen_cpu_open (CGEN_CPU_OPEN_MACHS,
 152                                           ip2k_mach_bitmask,
 153                                           CGEN_CPU_OPEN_ENDIAN,
 154                                           CGEN_ENDIAN_BIG,
 155                                           CGEN_CPU_OPEN_END);
 156   ip2k_cgen_init_asm (gas_cgen_cpu_desc);
 157
 158   /* This is a callback from cgen to gas to parse operands.  */
 159   cgen_set_parse_operand_fn (gas_cgen_cpu_desc, gas_cgen_parse_operand);
 160
 161   /* Set the machine type.  */
 162   bfd_default_set_arch_mach (stdoutput, bfd_arch_ip2k, ip2k_mach);
 163
 164   literal_prefix_dollar_hex = TRUE;
 165 }
 166
 167
 168 void
 169 md_assemble (char * str)
 170 {
 171   ip2k_insn insn;
 172   char * errmsg;
 173
 174   /* Initialize GAS's cgen interface for a new instruction.  */
 175   gas_cgen_init_parse ();
 176
 177   insn.insn = ip2k_cgen_assemble_insn
 178       (gas_cgen_cpu_desc, str, & insn.fields, insn.buffer, & errmsg);
 179
 180   if (!insn.insn)
 181     {
 182       as_bad ("%s", errmsg);
 183       return;
 184     }
 185
 186   /* Check for special relocation required by SKIP instructions.  */
 187   if (CGEN_INSN_ATTR_VALUE (insn.insn, CGEN_INSN_SKIPA))
 188     /* Unconditional skip has a 1-bit relocation of the current pc, so
 189        that we emit either sb pcl.0 or snb pcl.0 depending on whether
 190        the PCL (pc + 2) >> 1 is odd or even.  */
 191     {
 192       enum cgen_parse_operand_result result_type;
 193       bfd_vma value;
 194       const char *curpc_plus_2 = ".+2";
 195       const char *err;
 196
 197       err = cgen_parse_address (gas_cgen_cpu_desc, & curpc_plus_2,
 198                                 IP2K_OPERAND_ADDR16CJP,
 199                                 BFD_RELOC_IP2K_PC_SKIP,
 200                                 & result_type, & value);
 201       if (err)
 202         {
 203           as_bad ("%s", err);
 204           return;
 205         }
 206     }
 207
 208   /* Doesn't really matter what we pass for RELAX_P here.  */
 209   gas_cgen_finish_insn (insn.insn, insn.buffer,
 210                         CGEN_FIELDS_BITSIZE (& insn.fields), 1, NULL);
 211 }
 212
 213 valueT
 214 md_section_align (segT segment, valueT size)
 215 {
 216   int align = bfd_section_alignment (segment);
 217
 218   return ((size + (1 << align) - 1) & -(1 << align));
 219 }
 220
 221
 222 symbolS *
 223 md_undefined_symbol (char * name ATTRIBUTE_UNUSED)
 224 {
 225     return 0;
 226 }
 227 \f
 228 int
 229 md_estimate_size_before_relax (fragS * fragP ATTRIBUTE_UNUSED,
 230                                segT    segment ATTRIBUTE_UNUSED)
 231 {
 232   as_fatal (_("relaxation not supported\n"));
 233   return 1;
 234 }
 235
 236
 237 /* *fragP has been relaxed to its final size, and now needs to have
 238    the bytes inside it modified to conform to the new size.
 239
 240    Called after relaxation is finished.
 241    fragP->fr_type == rs_machine_dependent.
 242    fragP->fr_subtype is the subtype of what the address relaxed to.  */
 243
 244 void
 245 md_convert_frag (bfd   * abfd  ATTRIBUTE_UNUSED,
 246                  segT    sec   ATTRIBUTE_UNUSED,
 247                  fragS * fragP ATTRIBUTE_UNUSED)
 248 {
 249 }
 250
 251 \f
 252 /* Functions concerning relocs.  */
 253
 254 long
 255 md_pcrel_from (fixS *fixP ATTRIBUTE_UNUSED)
 256 {
 257   abort ();
 258 }
 259
 260
 261 /* Return the bfd reloc type for OPERAND of INSN at fixup FIXP.
 262    Returns BFD_RELOC_NONE if no reloc type can be found.
 263    *FIXP may be modified if desired.  */
 264
 265 bfd_reloc_code_real_type
 266 md_cgen_lookup_reloc (const CGEN_INSN *    insn     ATTRIBUTE_UNUSED,
 267                       const CGEN_OPERAND * operand,
 268                       fixS *               fixP     ATTRIBUTE_UNUSED)
 269 {
 270   bfd_reloc_code_real_type result;
 271
 272   result = BFD_RELOC_NONE;
 273
 274   switch (operand->type)
 275     {
 276     case IP2K_OPERAND_FR:
 277     case IP2K_OPERAND_ADDR16L:
 278     case IP2K_OPERAND_ADDR16H:
 279     case IP2K_OPERAND_LIT8:
 280       /* These may have been processed at parse time.  */
 281       if (fixP->fx_cgen.opinfo != 0)
 282         result = fixP->fx_cgen.opinfo;
 283       fixP->fx_no_overflow = 1;
 284       break;
 285
 286     case IP2K_OPERAND_ADDR16CJP:
 287       result = fixP->fx_cgen.opinfo;
 288       if (result == 0 || result == BFD_RELOC_NONE)
 289         result = BFD_RELOC_IP2K_ADDR16CJP;
 290       fixP->fx_no_overflow = 1;
 291       break;
 292
 293     case IP2K_OPERAND_ADDR16P:
 294       result = BFD_RELOC_IP2K_PAGE3;
 295       fixP->fx_no_overflow = 1;
 296       break;
 297
 298     default:
 299       result = BFD_RELOC_NONE;
 300       break;
 301     }
 302
 303   return result;
 304 }
 305
 306
 307 /* Write a value out to the object file, using the appropriate endianness.  */
 308
 309 void
 310 md_number_to_chars (char * buf, valueT val, int n)
 311 {
 312   number_to_chars_bigendian (buf, val, n);
 313 }
 314
 315 const char *
 316 md_atof (int type, char * litP, int *  sizeP)
 317 {
 318   return ieee_md_atof (type, litP, sizeP, TRUE);
 319 }
 320
 321
 322 /* See whether we need to force a relocation into the output file.
 323    Force most of them, since the linker's bfd relocation engine
 324    understands range limits better than gas' cgen fixup engine.
 325    Consider the case of a fixup intermediate value being larger than
 326    the instruction it will be eventually encoded within.  */
 327
 328 int
 329 ip2k_force_relocation (fixS * fix)
 330 {
 331   switch (fix->fx_r_type)
 332     {
 333     case BFD_RELOC_IP2K_FR9:
 334     case BFD_RELOC_IP2K_FR_OFFSET:
 335     case BFD_RELOC_IP2K_BANK:
 336     case BFD_RELOC_IP2K_ADDR16CJP:
 337     case BFD_RELOC_IP2K_PAGE3:
 338     case BFD_RELOC_IP2K_LO8DATA:
 339     case BFD_RELOC_IP2K_HI8DATA:
 340     case BFD_RELOC_IP2K_EX8DATA:
 341     case BFD_RELOC_IP2K_LO8INSN:
 342     case BFD_RELOC_IP2K_HI8INSN:
 343     case BFD_RELOC_IP2K_PC_SKIP:
 344     case BFD_RELOC_IP2K_TEXT:
 345       return 1;
 346
 347     case BFD_RELOC_16:
 348       if (fix->fx_subsy && S_IS_DEFINED (fix->fx_subsy)
 349           && fix->fx_addsy && S_IS_DEFINED (fix->fx_addsy)
 350           && (S_GET_SEGMENT (fix->fx_addsy)->flags & SEC_CODE))
 351         {
 352           fix->fx_r_type = BFD_RELOC_IP2K_TEXT;
 353           return 0;
 354         }
 355       break;
 356
 357     default:
 358       break;
 359     }
 360
 361   return generic_force_reloc (fix);
 362 }
 363
 364 void
 365 ip2k_apply_fix (fixS *fixP, valueT *valueP, segT seg)
 366 {
 367   if (fixP->fx_r_type == BFD_RELOC_IP2K_TEXT
 368       && ! fixP->fx_addsy
 369       && ! fixP->fx_subsy)
 370     {
 371       *valueP = ((int)(* valueP)) / 2;
 372       fixP->fx_r_type = BFD_RELOC_16;
 373     }
 374   else if (fixP->fx_r_type == BFD_RELOC_UNUSED + IP2K_OPERAND_FR)
 375     {
 376       /* Must be careful when we are fixing up an FR.  We could be
 377          fixing up an offset to (SP) or (DP) in which case we don't
 378          want to step on the top 2 bits of the FR operand.  The
 379          gas_cgen_md_apply_fix doesn't know any better and overwrites
 380          the entire operand.  We counter this by adding the bits
 381          to the new value.  */
 382       char *where = fixP->fx_frag->fr_literal + fixP->fx_where;
 383
 384       /* Canonical name, since used a lot.  */
 385       CGEN_CPU_DESC cd = gas_cgen_cpu_desc;
 386       CGEN_INSN_INT insn_value
 387         = cgen_get_insn_value (cd, (unsigned char *) where,
 388                                CGEN_INSN_BITSIZE (fixP->fx_cgen.insn),
 389                                gas_cgen_cpu_desc->insn_endian);
 390       /* Preserve (DP) or (SP) specification.  */
 391       *valueP += (insn_value & 0x180);
 392     }
 393
 394   gas_cgen_md_apply_fix (fixP, valueP, seg);
 395 }
 396
 397 int
 398 ip2k_elf_section_flags (flagword flags,
 399                         bfd_vma attr ATTRIBUTE_UNUSED,
 400                         int type ATTRIBUTE_UNUSED)
 401 {
 402   /* This is used to detect when the section changes to an executable section.
 403      This function is called by the elf section processing.  When we note an
 404      executable section specifier we set an internal flag to denote when
 405      word alignment should be forced.  */
 406   if (flags & SEC_CODE)
 407     force_code_align = 1;
 408
 409   return flags;
 410 }
 411