gas/config/tc-xstormy16.c

   1 /* tc-xstormy16.c -- Assembler for the Sanyo XSTORMY16.
   2    Copyright (C) 2000-2022 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/xstormy16-desc.h"
  25 #include "opcodes/xstormy16-opc.h"
  26 #include "cgen.h"
  27
  28 /* Structure to hold all of the different components describing
  29    an individual instruction.  */
  30 typedef struct
  31 {
  32   const CGEN_INSN *     insn;
  33   const CGEN_INSN *     orig_insn;
  34   CGEN_FIELDS           fields;
  35 #if CGEN_INT_INSN_P
  36   CGEN_INSN_INT         buffer [1];
  37 #define INSN_VALUE(buf) (*(buf))
  38 #else
  39   unsigned char         buffer [CGEN_MAX_INSN_SIZE];
  40 #define INSN_VALUE(buf) (buf)
  41 #endif
  42   char *                addr;
  43   fragS *               frag;
  44   int                   num_fixups;
  45   fixS *                fixups [GAS_CGEN_MAX_FIXUPS];
  46   int                   indices [MAX_OPERAND_INSTANCES];
  47 }
  48 xstormy16_insn;
  49
  50 const char comment_chars[]        = ";";
  51 const char line_comment_chars[]   = "#";
  52 const char line_separator_chars[] = "|";
  53 const char EXP_CHARS[]            = "eE";
  54 const char FLT_CHARS[]            = "dD";
  55
  56 #define O_fptr_symbol   (O_max + 1)
  57 \f
  58 #define XSTORMY16_SHORTOPTS ""
  59 const char * md_shortopts = XSTORMY16_SHORTOPTS;
  60
  61 struct option md_longopts[] =
  62 {
  63   {NULL, no_argument, NULL, 0}
  64 };
  65 size_t md_longopts_size = sizeof (md_longopts);
  66
  67 int
  68 md_parse_option (int    c ATTRIBUTE_UNUSED,
  69                  const char * arg ATTRIBUTE_UNUSED)
  70 {
  71   return 0;
  72 }
  73
  74 void
  75 md_show_usage (FILE * stream)
  76 {
  77   fprintf (stream, _(" XSTORMY16 specific command line options:\n"));
  78 }
  79
  80 /* The target specific pseudo-ops which we support.  */
  81 const pseudo_typeS md_pseudo_table[] =
  82 {
  83   { "word",     cons,           4 },
  84   { NULL,       NULL,           0 }
  85 };
  86
  87 \f
  88 void
  89 md_begin (void)
  90 {
  91   /* Initialize the `cgen' interface.  */
  92
  93   /* Set the machine number and endian.  */
  94   gas_cgen_cpu_desc = xstormy16_cgen_cpu_open (CGEN_CPU_OPEN_MACHS, 0,
  95                                           CGEN_CPU_OPEN_ENDIAN,
  96                                           CGEN_ENDIAN_LITTLE,
  97                                           CGEN_CPU_OPEN_END);
  98   xstormy16_cgen_init_asm (gas_cgen_cpu_desc);
  99
 100   /* This is a callback from cgen to gas to parse operands.  */
 101   cgen_set_parse_operand_fn (gas_cgen_cpu_desc, gas_cgen_parse_operand);
 102 }
 103
 104 static bool skipping_fptr = false;
 105
 106 void
 107 md_assemble (char * str)
 108 {
 109   xstormy16_insn insn;
 110   char *    errmsg;
 111
 112   /* Make sure that if we had an erroneous input line which triggered
 113      the skipping_fptr boolean that it does not affect following lines.  */
 114   skipping_fptr = false;
 115
 116   /* Initialize GAS's cgen interface for a new instruction.  */
 117   gas_cgen_init_parse ();
 118
 119   insn.insn = xstormy16_cgen_assemble_insn
 120     (gas_cgen_cpu_desc, str, & insn.fields, insn.buffer, & errmsg);
 121
 122   if (!insn.insn)
 123     {
 124       as_bad ("%s", errmsg);
 125       return;
 126     }
 127
 128   /* Doesn't really matter what we pass for RELAX_P here.  */
 129   gas_cgen_finish_insn (insn.insn, insn.buffer,
 130                         CGEN_FIELDS_BITSIZE (& insn.fields), 0, NULL);
 131 }
 132
 133 void
 134 md_operand (expressionS * e)
 135 {
 136   if (*input_line_pointer != '@')
 137     return;
 138
 139   if (startswith (input_line_pointer + 1, "fptr"))
 140     {
 141       input_line_pointer += 5;
 142       SKIP_WHITESPACE ();
 143       if (*input_line_pointer != '(')
 144         {
 145           as_bad (_("Expected '('"));
 146           goto err;
 147         }
 148       input_line_pointer++;
 149
 150       expression (e);
 151
 152       if (*input_line_pointer != ')')
 153         {
 154           as_bad (_("Missing ')'"));
 155           goto err;
 156         }
 157       input_line_pointer++;
 158       SKIP_WHITESPACE ();
 159
 160       if (e->X_op != O_symbol)
 161         as_bad (_("Not a symbolic expression"));
 162       else if (* input_line_pointer == '-')
 163         /* We are computing the difference of two function pointers
 164            like this:
 165
 166             .hword  @fptr (foo) - @fptr (bar)
 167
 168           In this situation we do not want to generate O_fptr_symbol
 169           operands because the result is an absolute value, not a
 170           function pointer.
 171
 172           We need to make the check here, rather than when the fixup
 173           is generated as the function names (foo & bar in the above
 174           example) might be local symbols and we want the expression
 175           to be evaluated now.  This kind of thing can happen when
 176           gcc is generating computed gotos.  */
 177         skipping_fptr = true;
 178       else if (skipping_fptr)
 179         skipping_fptr = false;
 180       else
 181         e->X_op = O_fptr_symbol;
 182     }
 183
 184   return;
 185  err:
 186   ignore_rest_of_line ();
 187 }
 188
 189 /* Called while parsing data to create a fixup.
 190    Create BFD_RELOC_XSTORMY16_FPTR16 relocations.  */
 191
 192 void
 193 xstormy16_cons_fix_new (fragS *f,
 194                         int where,
 195                         int nbytes,
 196                         expressionS *exp,
 197                         bfd_reloc_code_real_type code)
 198 {
 199   if (exp->X_op == O_fptr_symbol)
 200     {
 201       switch (nbytes)
 202         {
 203         case 4:
 204           /* This can happen when gcc is generating debug output.
 205              For example it can create a stab with the address of
 206              a function:
 207
 208                 .stabs  "foo:F(0,21)",36,0,0,@fptr(foo)
 209
 210              Since this does not involve switching code pages, we
 211              just allow the reloc to be generated without any
 212              @fptr behaviour.  */
 213           exp->X_op = O_symbol;
 214           code = BFD_RELOC_32;
 215           break;
 216
 217         case 2:
 218           exp->X_op = O_symbol;
 219           code = BFD_RELOC_XSTORMY16_FPTR16;
 220           break;
 221
 222         default:
 223           as_bad (_("unsupported fptr fixup size %d"), nbytes);
 224           return;
 225         }
 226     }
 227   else if (nbytes == 1)
 228     code = BFD_RELOC_8;
 229   else if (nbytes == 2)
 230     code = BFD_RELOC_16;
 231   else if (nbytes == 4)
 232     code = BFD_RELOC_32;
 233   else
 234     {
 235       as_bad (_("unsupported fixup size %d"), nbytes);
 236       return;
 237     }
 238
 239   fix_new_exp (f, where, nbytes, exp, 0, code);
 240 }
 241
 242 /* Called while parsing an instruction to create a fixup.
 243    Create BFD_RELOC_XSTORMY16_FPTR16 relocations.  */
 244
 245 fixS *
 246 xstormy16_cgen_record_fixup_exp (fragS *              frag,
 247                                  int                  where,
 248                                  const CGEN_INSN *    insn,
 249                                  int                  length,
 250                                  const CGEN_OPERAND * operand,
 251                                  int                  opinfo,
 252                                  expressionS *        exp)
 253 {
 254   fixS *fixP;
 255   operatorT op = exp->X_op;
 256
 257   if (op == O_fptr_symbol)
 258     exp->X_op = O_symbol;
 259
 260   fixP = gas_cgen_record_fixup_exp (frag, where, insn, length,
 261                                     operand, opinfo, exp);
 262
 263   if (op == O_fptr_symbol)
 264     {
 265       if (operand->type != XSTORMY16_OPERAND_IMM16)
 266         as_bad (_("unsupported fptr fixup"));
 267       else
 268         {
 269           fixP->fx_r_type = BFD_RELOC_XSTORMY16_FPTR16;
 270           fixP->fx_where += 2;
 271         }
 272     }
 273
 274   return fixP;
 275 }
 276
 277 valueT
 278 md_section_align (segT segment, valueT size)
 279 {
 280   int align = bfd_section_alignment (segment);
 281
 282   return ((size + (1 << align) - 1) & -(1 << align));
 283 }
 284
 285 symbolS *
 286 md_undefined_symbol (char * name ATTRIBUTE_UNUSED)
 287 {
 288   return 0;
 289 }
 290 \f
 291 /* Return an initial guess of the length by which a fragment must grow to
 292    hold a branch to reach its destination.
 293    Also updates fr_type/fr_subtype as necessary.
 294
 295    Called just before doing relaxation.
 296    Any symbol that is now undefined will not become defined.
 297    The guess for fr_var is ACTUALLY the growth beyond fr_fix.
 298    Whatever we do to grow fr_fix or fr_var contributes to our returned value.
 299    Although it may not be explicit in the frag, pretend fr_var starts with a
 300    0 value.  */
 301
 302 int
 303 md_estimate_size_before_relax (fragS * fragP ATTRIBUTE_UNUSED,
 304                                segT    segment ATTRIBUTE_UNUSED)
 305 {
 306   /* No assembler relaxation is defined (or necessary) for this port.  */
 307   abort ();
 308 }
 309
 310 /* *fragP has been relaxed to its final size, and now needs to have
 311    the bytes inside it modified to conform to the new size.
 312
 313    Called after relaxation is finished.
 314    fragP->fr_type == rs_machine_dependent.
 315    fragP->fr_subtype is the subtype of what the address relaxed to.  */
 316
 317 void
 318 md_convert_frag (bfd *   abfd ATTRIBUTE_UNUSED,
 319                  segT    sec ATTRIBUTE_UNUSED,
 320                  fragS * fragP ATTRIBUTE_UNUSED)
 321 {
 322   /* No assembler relaxation is defined (or necessary) for this port.  */
 323   abort ();
 324 }
 325 \f
 326 /* Functions concerning relocs.  */
 327
 328 /* The location from which a PC relative jump should be calculated,
 329    given a PC relative reloc.  */
 330
 331 long
 332 md_pcrel_from_section (fixS * fixP, segT sec)
 333 {
 334   if ((fixP->fx_addsy != (symbolS *) NULL
 335        && (! S_IS_DEFINED (fixP->fx_addsy)
 336            || S_GET_SEGMENT (fixP->fx_addsy) != sec))
 337       || xstormy16_force_relocation (fixP))
 338     /* The symbol is undefined,
 339        or it is defined but not in this section,
 340        or the relocation will be relative to this symbol not the section symbol.
 341        Let the linker figure it out.  */
 342     return 0;
 343
 344   return fixP->fx_frag->fr_address + fixP->fx_where;
 345 }
 346
 347 /* Return the bfd reloc type for OPERAND of INSN at fixup FIXP.
 348    Returns BFD_RELOC_NONE if no reloc type can be found.
 349    *FIXP may be modified if desired.  */
 350
 351 bfd_reloc_code_real_type
 352 md_cgen_lookup_reloc (const CGEN_INSN *    insn ATTRIBUTE_UNUSED,
 353                       const CGEN_OPERAND * operand,
 354                       fixS *               fixP)
 355 {
 356   switch (operand->type)
 357     {
 358     case XSTORMY16_OPERAND_IMM2:
 359     case XSTORMY16_OPERAND_IMM3:
 360     case XSTORMY16_OPERAND_IMM3B:
 361     case XSTORMY16_OPERAND_IMM4:
 362     case XSTORMY16_OPERAND_HMEM8:
 363       return BFD_RELOC_NONE;
 364
 365     case XSTORMY16_OPERAND_IMM12:
 366       fixP->fx_where += 2;
 367       return BFD_RELOC_XSTORMY16_12;
 368
 369     case XSTORMY16_OPERAND_IMM8:
 370     case XSTORMY16_OPERAND_LMEM8:
 371       return fixP->fx_pcrel ? BFD_RELOC_8_PCREL : BFD_RELOC_8;
 372
 373     case XSTORMY16_OPERAND_IMM16:
 374       /* This might have been processed at parse time.  */
 375       fixP->fx_where += 2;
 376       if (fixP->fx_cgen.opinfo && fixP->fx_cgen.opinfo != BFD_RELOC_NONE)
 377         return fixP->fx_cgen.opinfo;
 378       return fixP->fx_pcrel ? BFD_RELOC_16_PCREL : BFD_RELOC_16;
 379
 380     case XSTORMY16_OPERAND_ABS24:
 381       return BFD_RELOC_XSTORMY16_24;
 382
 383     case XSTORMY16_OPERAND_REL8_4:
 384       fixP->fx_addnumber -= 2;
 385       /* Fall through.  */
 386     case XSTORMY16_OPERAND_REL8_2:
 387       fixP->fx_addnumber -= 2;
 388       fixP->fx_pcrel = 1;
 389       return BFD_RELOC_8_PCREL;
 390
 391     case XSTORMY16_OPERAND_REL12:
 392       fixP->fx_where += 2;
 393       /* Fall through.  */
 394     case XSTORMY16_OPERAND_REL12A:
 395       fixP->fx_addnumber -= 2;
 396       fixP->fx_pcrel = 1;
 397       return BFD_RELOC_XSTORMY16_REL_12;
 398
 399     default : /* avoid -Wall warning */
 400       abort ();
 401     }
 402 }
 403
 404 /* See whether we need to force a relocation into the output file.
 405    This is used to force out switch and PC relative relocations when
 406    relaxing.  */
 407
 408 int
 409 xstormy16_force_relocation (fixS * fix)
 410 {
 411   if (fix->fx_r_type == BFD_RELOC_XSTORMY16_FPTR16)
 412     return 1;
 413
 414   return generic_force_reloc (fix);
 415 }
 416
 417 /* Return true if a relocation against a symbol may be replaced with
 418    a relocation against section+offset.  */
 419
 420 bool
 421 xstormy16_fix_adjustable (fixS * fixP)
 422 {
 423   /* We need the symbol name for the VTABLE entries.  */
 424   if (fixP->fx_r_type == BFD_RELOC_VTABLE_INHERIT
 425       || fixP->fx_r_type == BFD_RELOC_VTABLE_ENTRY)
 426     return false;
 427
 428   if (fixP->fx_r_type == BFD_RELOC_XSTORMY16_FPTR16)
 429     return false;
 430
 431   return true;
 432 }
 433
 434 /* This is a copy of gas_cgen_md_apply_fix, with some enhancements to
 435    do various things that would not be valid for all ports.  */
 436
 437 void
 438 xstormy16_md_apply_fix (fixS *   fixP,
 439                          valueT * valueP,
 440                          segT     seg ATTRIBUTE_UNUSED)
 441 {
 442   char *where = fixP->fx_frag->fr_literal + fixP->fx_where;
 443   valueT value = *valueP;
 444   /* Canonical name, since used a lot.  */
 445   CGEN_CPU_DESC cd = gas_cgen_cpu_desc;
 446
 447   /* md_cgen_lookup_reloc() will adjust this to compensate for where
 448      in the opcode the relocation happens, for pcrel relocations.  We
 449      have no other way of keeping track of what this offset needs to
 450      be.  */
 451   fixP->fx_addnumber = 0;
 452
 453   /* This port has pc-relative relocs and DIFF_EXPR_OK defined, so
 454      it must deal with turning a BFD_RELOC_{8,16,32,64} into a
 455      BFD_RELOC_*_PCREL for the case of
 456
 457         .word something-.  */
 458   if (fixP->fx_pcrel)
 459     switch (fixP->fx_r_type)
 460       {
 461       case BFD_RELOC_8:
 462         fixP->fx_r_type = BFD_RELOC_8_PCREL;
 463         break;
 464       case BFD_RELOC_16:
 465         fixP->fx_r_type = BFD_RELOC_16_PCREL;
 466         break;
 467       case BFD_RELOC_32:
 468         fixP->fx_r_type = BFD_RELOC_32_PCREL;
 469         break;
 470       case BFD_RELOC_64:
 471         fixP->fx_r_type = BFD_RELOC_64_PCREL;
 472         break;
 473       default:
 474         break;
 475       }
 476
 477   if (fixP->fx_addsy == (symbolS *) NULL)
 478     fixP->fx_done = 1;
 479
 480   /* We don't actually support subtracting a symbol.  */
 481   if (fixP->fx_subsy != (symbolS *) NULL)
 482     as_bad_subtract (fixP);
 483
 484   if ((int) fixP->fx_r_type >= (int) BFD_RELOC_UNUSED)
 485     {
 486       int opindex = (int) fixP->fx_r_type - (int) BFD_RELOC_UNUSED;
 487       const CGEN_OPERAND *operand = cgen_operand_lookup_by_num (cd, opindex);
 488       const char *errmsg;
 489       bfd_reloc_code_real_type reloc_type;
 490       const CGEN_INSN *insn = fixP->fx_cgen.insn;
 491
 492       /* If the reloc has been fully resolved finish the operand here.  */
 493       /* FIXME: This duplicates the capabilities of code in BFD.  */
 494       if (fixP->fx_done)
 495         {
 496           CGEN_FIELDS *fields = xmalloc (CGEN_CPU_SIZEOF_FIELDS (cd));
 497
 498           CGEN_CPU_SET_FIELDS_BITSIZE (cd) (fields, CGEN_INSN_BITSIZE (insn));
 499           CGEN_CPU_SET_VMA_OPERAND (cd) (cd, opindex, fields, (bfd_vma) value);
 500
 501 #if CGEN_INT_INSN_P
 502           {
 503             CGEN_INSN_INT insn_value =
 504               cgen_get_insn_value (cd, (unsigned char *) where,
 505                                    CGEN_INSN_BITSIZE (insn),
 506                                    gas_cgen_cpu_desc->insn_endian);
 507
 508             /* ??? 0 is passed for `pc'.  */
 509             errmsg = CGEN_CPU_INSERT_OPERAND (cd) (cd, opindex, fields,
 510                                                    &insn_value, (bfd_vma) 0);
 511             cgen_put_insn_value (cd, (unsigned char *) where,
 512                                  CGEN_INSN_BITSIZE (insn), insn_value,
 513                                  gas_cgen_cpu_desc->insn_endian);
 514           }
 515 #else
 516           /* ??? 0 is passed for `pc'.  */
 517           errmsg = CGEN_CPU_INSERT_OPERAND (cd) (cd, opindex, fields,
 518                                                  (unsigned char *) where,
 519                                                  (bfd_vma) 0);
 520 #endif
 521           if (errmsg)
 522             as_bad_where (fixP->fx_file, fixP->fx_line, "%s", errmsg);
 523
 524           free (fields);
 525         }
 526
 527       if (fixP->fx_done)
 528         return;
 529
 530       /* The operand isn't fully resolved.  Determine a BFD reloc value
 531          based on the operand information and leave it to
 532          bfd_install_relocation.  Note that this doesn't work when
 533          !partial_inplace.  */
 534
 535       reloc_type = md_cgen_lookup_reloc (insn, operand, fixP);
 536       if (reloc_type != BFD_RELOC_NONE)
 537         fixP->fx_r_type = reloc_type;
 538       else
 539         {
 540           as_bad_where (fixP->fx_file, fixP->fx_line,
 541                         _("unresolved expression that must be resolved"));
 542           fixP->fx_done = 1;
 543           return;
 544         }
 545     }
 546   else if (fixP->fx_done)
 547     {
 548       /* We're finished with this fixup.  Install it because
 549          bfd_install_relocation won't be called to do it.  */
 550       switch (fixP->fx_r_type)
 551         {
 552         case BFD_RELOC_8:
 553           md_number_to_chars (where, value, 1);
 554           break;
 555         case BFD_RELOC_16:
 556           md_number_to_chars (where, value, 2);
 557           break;
 558         case BFD_RELOC_32:
 559           md_number_to_chars (where, value, 4);
 560           break;
 561         case BFD_RELOC_64:
 562           md_number_to_chars (where, value, 8);
 563           break;
 564         default:
 565           as_bad_where (fixP->fx_file, fixP->fx_line,
 566                         _("internal error: can't install fix for reloc type %d (`%s')"),
 567                         fixP->fx_r_type, bfd_get_reloc_code_name (fixP->fx_r_type));
 568           break;
 569         }
 570     }
 571   else
 572     {
 573       /* bfd_install_relocation will be called to finish things up.  */
 574     }
 575
 576   /* This is a RELA port.  Thus, it does not need to store a
 577      value if it is going to make a reloc.  What's more, when
 578      assembling a line like
 579
 580      .byte global-0x7f00
 581
 582      we'll get a spurious error message if we try to stuff 0x7f00 into
 583      the byte.  */
 584   if (! fixP->fx_done)
 585     *valueP = 0;
 586
 587   /* Tuck `value' away for use by tc_gen_reloc.
 588      See the comment describing fx_addnumber in write.h.
 589      This field is misnamed (or misused :-).  */
 590   fixP->fx_addnumber += value;
 591 }
 592
 593 \f
 594 /* Write a value out to the object file, using the appropriate endianness.  */
 595
 596 void
 597 md_number_to_chars (char * buf, valueT val, int n)
 598 {
 599   number_to_chars_littleendian (buf, val, n);
 600 }
 601
 602 const char *
 603 md_atof (int type, char * litP, int * sizeP)
 604 {
 605   return ieee_md_atof (type, litP, sizeP, false);
 606 }