gas/config/tc-ip2k.c

   1 /* tc-ip2k.c -- Assembler for the Scenix IP2xxx.
   2    Copyright (C) 2000-2017 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
 165
 166 void
 167 md_assemble (char * str)
 168 {
 169   ip2k_insn insn;
 170   char * errmsg;
 171
 172   /* Initialize GAS's cgen interface for a new instruction.  */
 173   gas_cgen_init_parse ();
 174
 175   insn.insn = ip2k_cgen_assemble_insn
 176       (gas_cgen_cpu_desc, str, & insn.fields, insn.buffer, & errmsg);
 177
 178   if (!insn.insn)
 179     {
 180       as_bad ("%s", errmsg);
 181       return;
 182     }
 183
 184   /* Check for special relocation required by SKIP instructions.  */
 185   if (CGEN_INSN_ATTR_VALUE (insn.insn, CGEN_INSN_SKIPA))
 186     /* Unconditional skip has a 1-bit relocation of the current pc, so
 187        that we emit either sb pcl.0 or snb pcl.0 depending on whether
 188        the PCL (pc + 2) >> 1 is odd or even.  */
 189     {
 190       enum cgen_parse_operand_result result_type;
 191       bfd_vma value;
 192       const char *curpc_plus_2 = ".+2";
 193       const char *err;
 194
 195       err = cgen_parse_address (gas_cgen_cpu_desc, & curpc_plus_2,
 196                                 IP2K_OPERAND_ADDR16CJP,
 197                                 BFD_RELOC_IP2K_PC_SKIP,
 198                                 & result_type, & value);
 199       if (err)
 200         {
 201           as_bad ("%s", err);
 202           return;
 203         }
 204     }
 205
 206   /* Doesn't really matter what we pass for RELAX_P here.  */
 207   gas_cgen_finish_insn (insn.insn, insn.buffer,
 208                         CGEN_FIELDS_BITSIZE (& insn.fields), 1, NULL);
 209 }
 210
 211 valueT
 212 md_section_align (segT segment, valueT size)
 213 {
 214   int align = bfd_get_section_alignment (stdoutput, segment);
 215
 216   return ((size + (1 << align) - 1) & -(1 << align));
 217 }
 218
 219
 220 symbolS *
 221 md_undefined_symbol (char * name ATTRIBUTE_UNUSED)
 222 {
 223     return 0;
 224 }
 225 \f
 226 int
 227 md_estimate_size_before_relax (fragS * fragP ATTRIBUTE_UNUSED,
 228                                segT    segment ATTRIBUTE_UNUSED)
 229 {
 230   as_fatal (_("relaxation not supported\n"));
 231   return 1;
 232 }
 233
 234
 235 /* *fragP has been relaxed to its final size, and now needs to have
 236    the bytes inside it modified to conform to the new size.
 237
 238    Called after relaxation is finished.
 239    fragP->fr_type == rs_machine_dependent.
 240    fragP->fr_subtype is the subtype of what the address relaxed to.  */
 241
 242 void
 243 md_convert_frag (bfd   * abfd  ATTRIBUTE_UNUSED,
 244                  segT    sec   ATTRIBUTE_UNUSED,
 245                  fragS * fragP ATTRIBUTE_UNUSED)
 246 {
 247 }
 248
 249 \f
 250 /* Functions concerning relocs.  */
 251
 252 long
 253 md_pcrel_from (fixS *fixP ATTRIBUTE_UNUSED)
 254 {
 255   abort ();
 256 }
 257
 258
 259 /* Return the bfd reloc type for OPERAND of INSN at fixup FIXP.
 260    Returns BFD_RELOC_NONE if no reloc type can be found.
 261    *FIXP may be modified if desired.  */
 262
 263 bfd_reloc_code_real_type
 264 md_cgen_lookup_reloc (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 (char * buf, valueT val, int n)
 309 {
 310   number_to_chars_bigendian (buf, val, n);
 311 }
 312
 313 const char *
 314 md_atof (int type, char * litP, int *  sizeP)
 315 {
 316   return ieee_md_atof (type, litP, sizeP, TRUE);
 317 }
 318
 319
 320 /* See whether we need to force a relocation into the output file.
 321    Force most of them, since the linker's bfd relocation engine
 322    understands range limits better than gas' cgen fixup engine.
 323    Consider the case of a fixup intermediate value being larger than
 324    the instruction it will be eventually encoded within.  */
 325
 326 int
 327 ip2k_force_relocation (fixS * fix)
 328 {
 329   switch (fix->fx_r_type)
 330     {
 331     case BFD_RELOC_IP2K_FR9:
 332     case BFD_RELOC_IP2K_FR_OFFSET:
 333     case BFD_RELOC_IP2K_BANK:
 334     case BFD_RELOC_IP2K_ADDR16CJP:
 335     case BFD_RELOC_IP2K_PAGE3:
 336     case BFD_RELOC_IP2K_LO8DATA:
 337     case BFD_RELOC_IP2K_HI8DATA:
 338     case BFD_RELOC_IP2K_EX8DATA:
 339     case BFD_RELOC_IP2K_LO8INSN:
 340     case BFD_RELOC_IP2K_HI8INSN:
 341     case BFD_RELOC_IP2K_PC_SKIP:
 342     case BFD_RELOC_IP2K_TEXT:
 343       return 1;
 344
 345     case BFD_RELOC_16:
 346       if (fix->fx_subsy && S_IS_DEFINED (fix->fx_subsy)
 347           && fix->fx_addsy && S_IS_DEFINED (fix->fx_addsy)
 348           && (S_GET_SEGMENT (fix->fx_addsy)->flags & SEC_CODE))
 349         {
 350           fix->fx_r_type = BFD_RELOC_IP2K_TEXT;
 351           return 0;
 352         }
 353       break;
 354
 355     default:
 356       break;
 357     }
 358
 359   return generic_force_reloc (fix);
 360 }
 361
 362 void
 363 ip2k_apply_fix (fixS *fixP, valueT *valueP, segT seg)
 364 {
 365   if (fixP->fx_r_type == BFD_RELOC_IP2K_TEXT
 366       && ! fixP->fx_addsy
 367       && ! fixP->fx_subsy)
 368     {
 369       *valueP = ((int)(* valueP)) / 2;
 370       fixP->fx_r_type = BFD_RELOC_16;
 371     }
 372   else if (fixP->fx_r_type == BFD_RELOC_UNUSED + IP2K_OPERAND_FR)
 373     {
 374       /* Must be careful when we are fixing up an FR.  We could be
 375          fixing up an offset to (SP) or (DP) in which case we don't
 376          want to step on the top 2 bits of the FR operand.  The
 377          gas_cgen_md_apply_fix doesn't know any better and overwrites
 378          the entire operand.  We counter this by adding the bits
 379          to the new value.  */
 380       char *where = fixP->fx_frag->fr_literal + fixP->fx_where;
 381
 382       /* Canonical name, since used a lot.  */
 383       CGEN_CPU_DESC cd = gas_cgen_cpu_desc;
 384       CGEN_INSN_INT insn_value
 385         = cgen_get_insn_value (cd, (unsigned char *) where,
 386                                CGEN_INSN_BITSIZE (fixP->fx_cgen.insn));
 387       /* Preserve (DP) or (SP) specification.  */
 388       *valueP += (insn_value & 0x180);
 389     }
 390
 391   gas_cgen_md_apply_fix (fixP, valueP, seg);
 392 }
 393
 394 int
 395 ip2k_elf_section_flags (flagword flags,
 396                         bfd_vma attr ATTRIBUTE_UNUSED,
 397                         int type ATTRIBUTE_UNUSED)
 398 {
 399   /* This is used to detect when the section changes to an executable section.
 400      This function is called by the elf section processing.  When we note an
 401      executable section specifier we set an internal flag to denote when
 402      word alignment should be forced.  */
 403   if (flags & SEC_CODE)
 404     force_code_align = 1;
 405
 406   return flags;
 407 }
 408