gas/config/tc-avr.c

   1 /* tc-avr.c -- Assembler code for the ATMEL AVR
   2
   3    Copyright 1999, 2000, 2001, 2002, 2004, 2005
   4    Free Software Foundation, Inc.
   5    Contributed by Denis Chertykov <denisc@overta.ru>
   6
   7    This file is part of GAS, the GNU Assembler.
   8
   9    GAS is free software; you can redistribute it and/or modify
  10    it under the terms of the GNU General Public License as published by
  11    the Free Software Foundation; either version 2, or (at your option)
  12    any later version.
  13
  14    GAS is distributed in the hope that it will be useful,
  15    but WITHOUT ANY WARRANTY; without even the implied warranty of
  16    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  17    GNU General Public License for more details.
  18
  19    You should have received a copy of the GNU General Public License
  20    along with GAS; see the file COPYING.  If not, write to
  21    the Free Software Foundation, 51 Franklin Street - Fifth Floor,
  22    Boston, MA 02110-1301, USA.  */
  23
  24 #include <stdio.h>
  25 #include "as.h"
  26 #include "safe-ctype.h"
  27 #include "subsegs.h"
  28
  29 struct avr_opcodes_s
  30 {
  31   char *name;
  32   char *constraints;
  33   int insn_size;                /* In words.  */
  34   int isa;
  35   unsigned int bin_opcode;
  36 };
  37
  38 #define AVR_INSN(NAME, CONSTR, OPCODE, SIZE, ISA, BIN) \
  39 {#NAME, CONSTR, SIZE, ISA, BIN},
  40
  41 struct avr_opcodes_s avr_opcodes[] =
  42 {
  43   #include "opcode/avr.h"
  44   {NULL, NULL, 0, 0, 0}
  45 };
  46
  47 const char comment_chars[] = ";";
  48 const char line_comment_chars[] = "#";
  49 const char line_separator_chars[] = "$";
  50
  51 const char *md_shortopts = "m:";
  52 struct mcu_type_s
  53 {
  54   char *name;
  55   int isa;
  56   int mach;
  57 };
  58
  59 /* XXX - devices that don't seem to exist (renamed, replaced with larger
  60    ones, or planned but never produced), left here for compatibility.
  61    TODO: hide them in show_mcu_list output?  */
  62
  63 static struct mcu_type_s mcu_types[] =
  64 {
  65   {"avr1",      AVR_ISA_TINY1,    bfd_mach_avr1},
  66   {"avr2",      AVR_ISA_TINY2,    bfd_mach_avr2},
  67   {"avr3",      AVR_ISA_M103,     bfd_mach_avr3},
  68   {"avr4",      AVR_ISA_M8,       bfd_mach_avr4},
  69   {"avr5",      AVR_ISA_ALL,      bfd_mach_avr5},
  70   {"at90s1200", AVR_ISA_1200,     bfd_mach_avr1},
  71   {"attiny10",  AVR_ISA_TINY1,    bfd_mach_avr1}, /* XXX -> tn11 */
  72   {"attiny11",  AVR_ISA_TINY1,    bfd_mach_avr1},
  73   {"attiny12",  AVR_ISA_TINY1,    bfd_mach_avr1},
  74   {"attiny15",  AVR_ISA_TINY1,    bfd_mach_avr1},
  75   {"attiny28",  AVR_ISA_TINY1,    bfd_mach_avr1},
  76   {"at90s2313", AVR_ISA_2xxx,     bfd_mach_avr2},
  77   {"at90s2323", AVR_ISA_2xxx,     bfd_mach_avr2},
  78   {"at90s2333", AVR_ISA_2xxx,     bfd_mach_avr2}, /* XXX -> 4433 */
  79   {"at90s2343", AVR_ISA_2xxx,     bfd_mach_avr2},
  80   {"attiny22",  AVR_ISA_2xxx,     bfd_mach_avr2}, /* XXX -> 2343 */
  81   {"attiny26",  AVR_ISA_2xxx,     bfd_mach_avr2},
  82   {"at90s4433", AVR_ISA_2xxx,     bfd_mach_avr2},
  83   {"at90s4414", AVR_ISA_2xxx,     bfd_mach_avr2}, /* XXX -> 8515 */
  84   {"at90s4434", AVR_ISA_2xxx,     bfd_mach_avr2}, /* XXX -> 8535 */
  85   {"at90s8515", AVR_ISA_2xxx,     bfd_mach_avr2},
  86   {"at90s8535", AVR_ISA_2xxx,     bfd_mach_avr2},
  87   {"at90c8534", AVR_ISA_2xxx,     bfd_mach_avr2},
  88   {"at86rf401", AVR_ISA_2xxx,     bfd_mach_avr2},
  89   {"attiny13",  AVR_ISA_TINY2,    bfd_mach_avr2},
  90   {"attiny2313",AVR_ISA_TINY2,    bfd_mach_avr2},
  91   {"atmega603", AVR_ISA_M603,     bfd_mach_avr3}, /* XXX -> m103 */
  92   {"atmega103", AVR_ISA_M103,     bfd_mach_avr3},
  93   {"at43usb320",AVR_ISA_M103,     bfd_mach_avr3},
  94   {"at43usb355",AVR_ISA_M603,     bfd_mach_avr3},
  95   {"at76c711",  AVR_ISA_M603,     bfd_mach_avr3},
  96   {"atmega48",  AVR_ISA_M8,       bfd_mach_avr4},
  97   {"atmega8",   AVR_ISA_M8,       bfd_mach_avr4},
  98   {"atmega83",  AVR_ISA_M8,       bfd_mach_avr4}, /* XXX -> m8535 */
  99   {"atmega85",  AVR_ISA_M8,       bfd_mach_avr4}, /* XXX -> m8 */
 100   {"atmega88",  AVR_ISA_M8,       bfd_mach_avr4},
 101   {"atmega8515",AVR_ISA_M8,       bfd_mach_avr4},
 102   {"atmega8535",AVR_ISA_M8,       bfd_mach_avr4},
 103   {"atmega16",  AVR_ISA_M323,     bfd_mach_avr5},
 104   {"atmega161", AVR_ISA_M161,     bfd_mach_avr5},
 105   {"atmega162", AVR_ISA_M323,     bfd_mach_avr5},
 106   {"atmega163", AVR_ISA_M161,     bfd_mach_avr5},
 107   {"atmega165", AVR_ISA_M323,     bfd_mach_avr5},
 108   {"atmega168", AVR_ISA_M323,     bfd_mach_avr5},
 109   {"atmega169", AVR_ISA_M323,     bfd_mach_avr5},
 110   {"atmega32",  AVR_ISA_M323,     bfd_mach_avr5},
 111   {"atmega323", AVR_ISA_M323,     bfd_mach_avr5},
 112   {"atmega325", AVR_ISA_M323,     bfd_mach_avr5},
 113   {"atmega3250",AVR_ISA_M323,     bfd_mach_avr5},
 114   {"atmega64",  AVR_ISA_M323,     bfd_mach_avr5},
 115   {"atmega128", AVR_ISA_M128,     bfd_mach_avr5},
 116   {"atmega645", AVR_ISA_M323,     bfd_mach_avr5},
 117   {"atmega6450",AVR_ISA_M323,     bfd_mach_avr5},
 118   {"at90can128",AVR_ISA_M128,     bfd_mach_avr5},
 119   {"at94k",     AVR_ISA_94K,      bfd_mach_avr5},
 120   {NULL, 0, 0}
 121 };
 122
 123 /* Current MCU type.  */
 124 static struct mcu_type_s default_mcu = {"avr2", AVR_ISA_2xxx,bfd_mach_avr2};
 125 static struct mcu_type_s *avr_mcu = &default_mcu;
 126
 127 /* AVR target-specific switches.  */
 128 struct avr_opt_s
 129 {
 130   int all_opcodes;  /* -mall-opcodes: accept all known AVR opcodes  */
 131   int no_skip_bug;  /* -mno-skip-bug: no warnings for skipping 2-word insns  */
 132   int no_wrap;      /* -mno-wrap: reject rjmp/rcall with 8K wrap-around  */
 133 };
 134
 135 static struct avr_opt_s avr_opt = { 0, 0, 0 };
 136
 137 const char EXP_CHARS[] = "eE";
 138 const char FLT_CHARS[] = "dD";
 139 static void avr_set_arch (int dummy);
 140
 141 /* The target specific pseudo-ops which we support.  */
 142 const pseudo_typeS md_pseudo_table[] =
 143 {
 144   {"arch", avr_set_arch,        0},
 145   { NULL,       NULL,           0}
 146 };
 147
 148 #define LDI_IMMEDIATE(x) (((x) & 0xf) | (((x) << 4) & 0xf00))
 149
 150 static void show_mcu_list PARAMS ((FILE *));
 151 static char *skip_space PARAMS ((char *));
 152 static char *extract_word PARAMS ((char *, char *, int));
 153 static unsigned int avr_operand PARAMS ((struct avr_opcodes_s *,
 154                                          int, char *, char **));
 155 static unsigned int avr_operands PARAMS ((struct avr_opcodes_s *, char **));
 156 static unsigned int avr_get_constant PARAMS ((char *, int));
 157 static char *parse_exp PARAMS ((char *, expressionS *));
 158 static bfd_reloc_code_real_type avr_ldi_expression PARAMS ((expressionS *));
 159
 160 #define EXP_MOD_NAME(i) exp_mod[i].name
 161 #define EXP_MOD_RELOC(i) exp_mod[i].reloc
 162 #define EXP_MOD_NEG_RELOC(i) exp_mod[i].neg_reloc
 163 #define HAVE_PM_P(i) exp_mod[i].have_pm
 164
 165 struct exp_mod_s
 166 {
 167   char *name;
 168   bfd_reloc_code_real_type reloc;
 169   bfd_reloc_code_real_type neg_reloc;
 170   int have_pm;
 171 };
 172
 173 static struct exp_mod_s exp_mod[] =
 174 {
 175   {"hh8",    BFD_RELOC_AVR_HH8_LDI,    BFD_RELOC_AVR_HH8_LDI_NEG,    1},
 176   {"pm_hh8", BFD_RELOC_AVR_HH8_LDI_PM, BFD_RELOC_AVR_HH8_LDI_PM_NEG, 0},
 177   {"hi8",    BFD_RELOC_AVR_HI8_LDI,    BFD_RELOC_AVR_HI8_LDI_NEG,    1},
 178   {"pm_hi8", BFD_RELOC_AVR_HI8_LDI_PM, BFD_RELOC_AVR_HI8_LDI_PM_NEG, 0},
 179   {"lo8",    BFD_RELOC_AVR_LO8_LDI,    BFD_RELOC_AVR_LO8_LDI_NEG,    1},
 180   {"pm_lo8", BFD_RELOC_AVR_LO8_LDI_PM, BFD_RELOC_AVR_LO8_LDI_PM_NEG, 0},
 181   {"hlo8",   -BFD_RELOC_AVR_LO8_LDI,   -BFD_RELOC_AVR_LO8_LDI_NEG,   0},
 182   {"hhi8",   -BFD_RELOC_AVR_HI8_LDI,   -BFD_RELOC_AVR_HI8_LDI_NEG,   0},
 183 };
 184
 185 /* Opcode hash table.  */
 186 static struct hash_control *avr_hash;
 187
 188 /* Reloc modifiers hash control (hh8,hi8,lo8,pm_xx).  */
 189 static struct hash_control *avr_mod_hash;
 190
 191 #define OPTION_MMCU 'm'
 192 #define OPTION_ALL_OPCODES (OPTION_MD_BASE + 1)
 193 #define OPTION_NO_SKIP_BUG (OPTION_MD_BASE + 2)
 194 #define OPTION_NO_WRAP     (OPTION_MD_BASE + 3)
 195
 196 struct option md_longopts[] =
 197 {
 198   { "mmcu",   required_argument, NULL, OPTION_MMCU        },
 199   { "mall-opcodes", no_argument, NULL, OPTION_ALL_OPCODES },
 200   { "mno-skip-bug", no_argument, NULL, OPTION_NO_SKIP_BUG },
 201   { "mno-wrap",     no_argument, NULL, OPTION_NO_WRAP     },
 202   { NULL, no_argument, NULL, 0 }
 203 };
 204
 205 size_t md_longopts_size = sizeof (md_longopts);
 206
 207 /* Display nicely formatted list of known MCU names.  */
 208
 209 static void
 210 show_mcu_list (stream)
 211      FILE *stream;
 212 {
 213   int i, x;
 214
 215   fprintf (stream, _("Known MCU names:"));
 216   x = 1000;
 217
 218   for (i = 0; mcu_types[i].name; i++)
 219     {
 220       int len = strlen (mcu_types[i].name);
 221
 222       x += len + 1;
 223
 224       if (x < 75)
 225         fprintf (stream, " %s", mcu_types[i].name);
 226       else
 227         {
 228           fprintf (stream, "\n  %s", mcu_types[i].name);
 229           x = len + 2;
 230         }
 231     }
 232
 233   fprintf (stream, "\n");
 234 }
 235
 236 static inline char *
 237 skip_space (s)
 238      char *s;
 239 {
 240   while (*s == ' ' || *s == '\t')
 241     ++s;
 242   return s;
 243 }
 244
 245 /* Extract one word from FROM and copy it to TO.  */
 246
 247 static char *
 248 extract_word (char *from, char *to, int limit)
 249 {
 250   char *op_start;
 251   char *op_end;
 252   int size = 0;
 253
 254   /* Drop leading whitespace.  */
 255   from = skip_space (from);
 256   *to = 0;
 257
 258   /* Find the op code end.  */
 259   for (op_start = op_end = from; *op_end != 0 && is_part_of_name (*op_end);)
 260     {
 261       to[size++] = *op_end++;
 262       if (size + 1 >= limit)
 263         break;
 264     }
 265
 266   to[size] = 0;
 267   return op_end;
 268 }
 269
 270 int
 271 md_estimate_size_before_relax (fragp, seg)
 272      fragS *fragp ATTRIBUTE_UNUSED;
 273      asection *seg ATTRIBUTE_UNUSED;
 274 {
 275   abort ();
 276   return 0;
 277 }
 278
 279 void
 280 md_show_usage (stream)
 281      FILE *stream;
 282 {
 283   fprintf (stream,
 284       _("AVR options:\n"
 285         "  -mmcu=[avr-name] select microcontroller variant\n"
 286         "                   [avr-name] can be:\n"
 287         "                   avr1 - AT90S1200, ATtiny1x, ATtiny28\n"
 288         "                   avr2 - AT90S2xxx, AT90S4xxx, AT90S8xxx, ATtiny22\n"
 289         "                   avr3 - ATmega103, ATmega603\n"
 290         "                   avr4 - ATmega83, ATmega85\n"
 291         "                   avr5 - ATmega161, ATmega163, ATmega32, AT94K\n"
 292         "                   or immediate microcontroller name.\n"));
 293   fprintf (stream,
 294       _("  -mall-opcodes    accept all AVR opcodes, even if not supported by MCU\n"
 295         "  -mno-skip-bug    disable warnings for skipping two-word instructions\n"
 296         "                   (default for avr4, avr5)\n"
 297         "  -mno-wrap        reject rjmp/rcall instructions with 8K wrap-around\n"
 298         "                   (default for avr3, avr5)\n"));
 299   show_mcu_list (stream);
 300 }
 301
 302 static void
 303 avr_set_arch (dummy)
 304      int dummy ATTRIBUTE_UNUSED;
 305 {
 306   char *str;
 307
 308   str = (char *) alloca (20);
 309   input_line_pointer = extract_word (input_line_pointer, str, 20);
 310   md_parse_option (OPTION_MMCU, str);
 311   bfd_set_arch_mach (stdoutput, TARGET_ARCH, avr_mcu->mach);
 312 }
 313
 314 int
 315 md_parse_option (c, arg)
 316      int c;
 317      char *arg;
 318 {
 319   switch (c)
 320     {
 321     case OPTION_MMCU:
 322       {
 323         int i;
 324         char *s = alloca (strlen (arg) + 1);
 325
 326         {
 327           char *t = s;
 328           char *arg1 = arg;
 329
 330           do
 331             *t = TOLOWER (*arg1++);
 332           while (*t++);
 333         }
 334
 335         for (i = 0; mcu_types[i].name; ++i)
 336           if (strcmp (mcu_types[i].name, s) == 0)
 337             break;
 338
 339         if (!mcu_types[i].name)
 340           {
 341             show_mcu_list (stderr);
 342             as_fatal (_("unknown MCU: %s\n"), arg);
 343           }
 344
 345         /* It is OK to redefine mcu type within the same avr[1-5] bfd machine
 346            type - this for allows passing -mmcu=... via gcc ASM_SPEC as well
 347            as .arch ... in the asm output at the same time.  */
 348         if (avr_mcu == &default_mcu || avr_mcu->mach == mcu_types[i].mach)
 349           avr_mcu = &mcu_types[i];
 350         else
 351           as_fatal (_("redefinition of mcu type `%s' to `%s'"),
 352                     avr_mcu->name, mcu_types[i].name);
 353         return 1;
 354       }
 355     case OPTION_ALL_OPCODES:
 356       avr_opt.all_opcodes = 1;
 357       return 1;
 358     case OPTION_NO_SKIP_BUG:
 359       avr_opt.no_skip_bug = 1;
 360       return 1;
 361     case OPTION_NO_WRAP:
 362       avr_opt.no_wrap = 1;
 363       return 1;
 364     }
 365
 366   return 0;
 367 }
 368
 369 symbolS *
 370 md_undefined_symbol (name)
 371      char *name ATTRIBUTE_UNUSED;
 372 {
 373   return 0;
 374 }
 375
 376 /* Turn a string in input_line_pointer into a floating point constant
 377    of type TYPE, and store the appropriate bytes in *LITP.  The number
 378    of LITTLENUMS emitted is stored in *SIZEP.  An error message is
 379    returned, or NULL on OK.  */
 380
 381 char *
 382 md_atof (type, litP, sizeP)
 383      int type;
 384      char *litP;
 385      int *sizeP;
 386 {
 387   int prec;
 388   LITTLENUM_TYPE words[4];
 389   LITTLENUM_TYPE *wordP;
 390   char *t;
 391
 392   switch (type)
 393     {
 394     case 'f':
 395       prec = 2;
 396       break;
 397     case 'd':
 398       prec = 4;
 399       break;
 400     default:
 401       *sizeP = 0;
 402       return _("bad call to md_atof");
 403     }
 404
 405   t = atof_ieee (input_line_pointer, type, words);
 406   if (t)
 407     input_line_pointer = t;
 408
 409   *sizeP = prec * sizeof (LITTLENUM_TYPE);
 410
 411   /* This loop outputs the LITTLENUMs in REVERSE order.  */
 412   for (wordP = words + prec - 1; prec--;)
 413     {
 414       md_number_to_chars (litP, (valueT) (*wordP--), sizeof (LITTLENUM_TYPE));
 415       litP += sizeof (LITTLENUM_TYPE);
 416     }
 417
 418   return NULL;
 419 }
 420
 421 void
 422 md_convert_frag (abfd, sec, fragP)
 423      bfd *abfd ATTRIBUTE_UNUSED;
 424      asection *sec ATTRIBUTE_UNUSED;
 425      fragS *fragP ATTRIBUTE_UNUSED;
 426 {
 427   abort ();
 428 }
 429
 430 void
 431 md_begin ()
 432 {
 433   unsigned int i;
 434   struct avr_opcodes_s *opcode;
 435   avr_hash = hash_new ();
 436
 437   /* Insert unique names into hash table.  This hash table then provides a
 438      quick index to the first opcode with a particular name in the opcode
 439      table.  */
 440   for (opcode = avr_opcodes; opcode->name; opcode++)
 441     hash_insert (avr_hash, opcode->name, (char *) opcode);
 442
 443   avr_mod_hash = hash_new ();
 444
 445   for (i = 0; i < sizeof (exp_mod) / sizeof (exp_mod[0]); ++i)
 446     hash_insert (avr_mod_hash, EXP_MOD_NAME (i), (void *) (i + 10));
 447
 448   bfd_set_arch_mach (stdoutput, TARGET_ARCH, avr_mcu->mach);
 449 }
 450
 451 /* Resolve STR as a constant expression and return the result.
 452    If result greater than MAX then error.  */
 453
 454 static unsigned int
 455 avr_get_constant (str, max)
 456      char *str;
 457      int max;
 458 {
 459   expressionS ex;
 460   str = skip_space (str);
 461   input_line_pointer = str;
 462   expression (&ex);
 463
 464   if (ex.X_op != O_constant)
 465     as_bad (_("constant value required"));
 466
 467   if (ex.X_add_number > max || ex.X_add_number < 0)
 468     as_bad (_("number must be less than %d"), max + 1);
 469
 470   return ex.X_add_number;
 471 }
 472
 473 /* Parse instruction operands.
 474    Return binary opcode.  */
 475
 476 static unsigned int
 477 avr_operands (opcode, line)
 478      struct avr_opcodes_s *opcode;
 479      char **line;
 480 {
 481   char *op = opcode->constraints;
 482   unsigned int bin = opcode->bin_opcode;
 483   char *frag = frag_more (opcode->insn_size * 2);
 484   char *str = *line;
 485   int where = frag - frag_now->fr_literal;
 486   static unsigned int prev = 0;  /* Previous opcode.  */
 487
 488   /* Opcode have operands.  */
 489   if (*op)
 490     {
 491       unsigned int reg1 = 0;
 492       unsigned int reg2 = 0;
 493       int reg1_present = 0;
 494       int reg2_present = 0;
 495
 496       /* Parse first operand.  */
 497       if (REGISTER_P (*op))
 498         reg1_present = 1;
 499       reg1 = avr_operand (opcode, where, op, &str);
 500       ++op;
 501
 502       /* Parse second operand.  */
 503       if (*op)
 504         {
 505           if (*op == ',')
 506             ++op;
 507
 508           if (*op == '=')
 509             {
 510               reg2 = reg1;
 511               reg2_present = 1;
 512             }
 513           else
 514             {
 515               if (REGISTER_P (*op))
 516                 reg2_present = 1;
 517
 518               str = skip_space (str);
 519               if (*str++ != ',')
 520                 as_bad (_("`,' required"));
 521               str = skip_space (str);
 522
 523               reg2 = avr_operand (opcode, where, op, &str);
 524
 525             }
 526
 527           if (reg1_present && reg2_present)
 528             reg2 = (reg2 & 0xf) | ((reg2 << 5) & 0x200);
 529           else if (reg2_present)
 530             reg2 <<= 4;
 531         }
 532       if (reg1_present)
 533         reg1 <<= 4;
 534       bin |= reg1 | reg2;
 535     }
 536
 537   /* Detect undefined combinations (like ld r31,Z+).  */
 538   if (!avr_opt.all_opcodes && AVR_UNDEF_P (bin))
 539     as_warn (_("undefined combination of operands"));
 540
 541   if (opcode->insn_size == 2)
 542     {
 543       /* Warn if the previous opcode was cpse/sbic/sbis/sbrc/sbrs
 544          (AVR core bug, fixed in the newer devices).  */
 545
 546       if (!(avr_opt.no_skip_bug ||
 547             (avr_mcu->isa & (AVR_ISA_MUL | AVR_ISA_MOVW)))
 548           && AVR_SKIP_P (prev))
 549         as_warn (_("skipping two-word instruction"));
 550
 551       bfd_putl32 ((bfd_vma) bin, frag);
 552     }
 553   else
 554     bfd_putl16 ((bfd_vma) bin, frag);
 555
 556   prev = bin;
 557   *line = str;
 558   return bin;
 559 }
 560
 561 /* Parse for ldd/std offset */
 562
 563 static void
 564 avr_offset_expression (expressionS *exp)
 565 {
 566   char *str = input_line_pointer;
 567   char *tmp;
 568   char op[8];
 569
 570   tmp = str;
 571   str = extract_word (str, op, sizeof (op));
 572
 573   input_line_pointer = tmp;
 574   expression (exp);
 575
 576   /* Warn about expressions that fail to use lo8 ().  */
 577   if (exp->X_op == O_constant)
 578     {
 579       int x = exp->X_add_number;
 580
 581       if (x < -255 || x > 255)
 582         as_warn (_("constant out of 8-bit range: %d"), x);
 583     }
 584 }
 585
 586 /* Parse one instruction operand.
 587    Return operand bitmask.  Also fixups can be generated.  */
 588
 589 static unsigned int
 590 avr_operand (opcode, where, op, line)
 591      struct avr_opcodes_s *opcode;
 592      int where;
 593      char *op;
 594      char **line;
 595 {
 596   expressionS op_expr;
 597   unsigned int op_mask = 0;
 598   char *str = skip_space (*line);
 599
 600   switch (*op)
 601     {
 602       /* Any register operand.  */
 603     case 'w':
 604     case 'd':
 605     case 'r':
 606     case 'a':
 607     case 'v':
 608       if (*str == 'r' || *str == 'R')
 609         {
 610           char r_name[20];
 611
 612           str = extract_word (str, r_name, sizeof (r_name));
 613           op_mask = 0xff;
 614           if (ISDIGIT (r_name[1]))
 615             {
 616               if (r_name[2] == '\0')
 617                 op_mask = r_name[1] - '0';
 618               else if (r_name[1] != '0'
 619                        && ISDIGIT (r_name[2])
 620                        && r_name[3] == '\0')
 621                 op_mask = (r_name[1] - '0') * 10 + r_name[2] - '0';
 622             }
 623         }
 624       else
 625         {
 626           op_mask = avr_get_constant (str, 31);
 627           str = input_line_pointer;
 628         }
 629
 630       if (op_mask <= 31)
 631         {
 632           switch (*op)
 633             {
 634             case 'a':
 635               if (op_mask < 16 || op_mask > 23)
 636                 as_bad (_("register r16-r23 required"));
 637               op_mask -= 16;
 638               break;
 639
 640             case 'd':
 641               if (op_mask < 16)
 642                 as_bad (_("register number above 15 required"));
 643               op_mask -= 16;
 644               break;
 645
 646             case 'v':
 647               if (op_mask & 1)
 648                 as_bad (_("even register number required"));
 649               op_mask >>= 1;
 650               break;
 651
 652             case 'w':
 653               if ((op_mask & 1) || op_mask < 24)
 654                 as_bad (_("register r24, r26, r28 or r30 required"));
 655               op_mask = (op_mask - 24) >> 1;
 656               break;
 657             }
 658           break;
 659         }
 660       as_bad (_("register name or number from 0 to 31 required"));
 661       break;
 662
 663     case 'e':
 664       {
 665         char c;
 666
 667         if (*str == '-')
 668           {
 669             str = skip_space (str + 1);
 670             op_mask = 0x1002;
 671           }
 672         c = TOLOWER (*str);
 673         if (c == 'x')
 674           op_mask |= 0x100c;
 675         else if (c == 'y')
 676           op_mask |= 0x8;
 677         else if (c != 'z')
 678           as_bad (_("pointer register (X, Y or Z) required"));
 679
 680         str = skip_space (str + 1);
 681         if (*str == '+')
 682           {
 683             ++str;
 684             if (op_mask & 2)
 685               as_bad (_("cannot both predecrement and postincrement"));
 686             op_mask |= 0x1001;
 687           }
 688
 689         /* avr1 can do "ld r,Z" and "st Z,r" but no other pointer
 690            registers, no predecrement, no postincrement.  */
 691         if (!avr_opt.all_opcodes && (op_mask & 0x100F)
 692             && !(avr_mcu->isa & AVR_ISA_SRAM))
 693           as_bad (_("addressing mode not supported"));
 694       }
 695       break;
 696
 697     case 'z':
 698       if (*str == '-')
 699         as_bad (_("can't predecrement"));
 700
 701       if (! (*str == 'z' || *str == 'Z'))
 702         as_bad (_("pointer register Z required"));
 703
 704       str = skip_space (str + 1);
 705
 706       if (*str == '+')
 707         {
 708           ++str;
 709           op_mask |= 1;
 710         }
 711       break;
 712
 713     case 'b':
 714       {
 715         char c = TOLOWER (*str++);
 716
 717         if (c == 'y')
 718           op_mask |= 0x8;
 719         else if (c != 'z')
 720           as_bad (_("pointer register (Y or Z) required"));
 721         str = skip_space (str);
 722         if (*str++ == '+')
 723           {
 724             input_line_pointer = str;
 725             avr_offset_expression (& op_expr);
 726             str = input_line_pointer;
 727             fix_new_exp (frag_now, where, 3,
 728                          &op_expr, FALSE, BFD_RELOC_AVR_6);
 729           }
 730       }
 731       break;
 732
 733     case 'h':
 734       str = parse_exp (str, &op_expr);
 735       fix_new_exp (frag_now, where, opcode->insn_size * 2,
 736                    &op_expr, FALSE, BFD_RELOC_AVR_CALL);
 737       break;
 738
 739     case 'L':
 740       str = parse_exp (str, &op_expr);
 741       fix_new_exp (frag_now, where, opcode->insn_size * 2,
 742                    &op_expr, TRUE, BFD_RELOC_AVR_13_PCREL);
 743       break;
 744
 745     case 'l':
 746       str = parse_exp (str, &op_expr);
 747       fix_new_exp (frag_now, where, opcode->insn_size * 2,
 748                    &op_expr, TRUE, BFD_RELOC_AVR_7_PCREL);
 749       break;
 750
 751     case 'i':
 752       str = parse_exp (str, &op_expr);
 753       fix_new_exp (frag_now, where + 2, opcode->insn_size * 2,
 754                    &op_expr, FALSE, BFD_RELOC_16);
 755       break;
 756
 757     case 'M':
 758       {
 759         bfd_reloc_code_real_type r_type;
 760
 761         input_line_pointer = str;
 762         r_type = avr_ldi_expression (&op_expr);
 763         str = input_line_pointer;
 764         fix_new_exp (frag_now, where, 3,
 765                      &op_expr, FALSE, r_type);
 766       }
 767       break;
 768
 769     case 'n':
 770       {
 771         unsigned int x;
 772
 773         x = ~avr_get_constant (str, 255);
 774         str = input_line_pointer;
 775         op_mask |= (x & 0xf) | ((x << 4) & 0xf00);
 776       }
 777       break;
 778
 779     case 'K':
 780       input_line_pointer = str;
 781       avr_offset_expression (& op_expr);
 782       str = input_line_pointer;
 783       fix_new_exp (frag_now, where, 3,
 784                    & op_expr, FALSE, BFD_RELOC_AVR_6_ADIW);
 785       break;
 786
 787     case 'S':
 788     case 's':
 789       {
 790         unsigned int x;
 791
 792         x = avr_get_constant (str, 7);
 793         str = input_line_pointer;
 794         if (*op == 'S')
 795           x <<= 4;
 796         op_mask |= x;
 797       }
 798       break;
 799
 800     case 'P':
 801       {
 802         unsigned int x;
 803
 804         x = avr_get_constant (str, 63);
 805         str = input_line_pointer;
 806         op_mask |= (x & 0xf) | ((x & 0x30) << 5);
 807       }
 808       break;
 809
 810     case 'p':
 811       {
 812         unsigned int x;
 813
 814         x = avr_get_constant (str, 31);
 815         str = input_line_pointer;
 816         op_mask |= x << 3;
 817       }
 818       break;
 819
 820     case '?':
 821       break;
 822
 823     default:
 824       as_bad (_("unknown constraint `%c'"), *op);
 825     }
 826
 827   *line = str;
 828   return op_mask;
 829 }
 830
 831 /* GAS will call this function for each section at the end of the assembly,
 832    to permit the CPU backend to adjust the alignment of a section.  */
 833
 834 valueT
 835 md_section_align (seg, addr)
 836      asection *seg;
 837      valueT addr;
 838 {
 839   int align = bfd_get_section_alignment (stdoutput, seg);
 840   return ((addr + (1 << align) - 1) & (-1 << align));
 841 }
 842
 843 /* If you define this macro, it should return the offset between the
 844    address of a PC relative fixup and the position from which the PC
 845    relative adjustment should be made.  On many processors, the base
 846    of a PC relative instruction is the next instruction, so this
 847    macro would return the length of an instruction.  */
 848
 849 long
 850 md_pcrel_from_section (fixp, sec)
 851      fixS *fixp;
 852      segT sec;
 853 {
 854   if (fixp->fx_addsy != (symbolS *) NULL
 855       && (!S_IS_DEFINED (fixp->fx_addsy)
 856           || (S_GET_SEGMENT (fixp->fx_addsy) != sec)))
 857     return 0;
 858
 859   return fixp->fx_frag->fr_address + fixp->fx_where;
 860 }
 861
 862 /* GAS will call this for each fixup.  It should store the correct
 863    value in the object file.  */
 864
 865 void
 866 md_apply_fix (fixP, valP, seg)
 867      fixS *fixP;
 868      valueT * valP;
 869      segT seg;
 870 {
 871   unsigned char *where;
 872   unsigned long insn;
 873   long value = *valP;
 874
 875   if (fixP->fx_addsy == (symbolS *) NULL)
 876     fixP->fx_done = 1;
 877
 878   else if (fixP->fx_pcrel)
 879     {
 880       segT s = S_GET_SEGMENT (fixP->fx_addsy);
 881
 882       if (s == seg || s == absolute_section)
 883         {
 884           value += S_GET_VALUE (fixP->fx_addsy);
 885           fixP->fx_done = 1;
 886         }
 887     }
 888
 889   /* We don't actually support subtracting a symbol.  */
 890   if (fixP->fx_subsy != (symbolS *) NULL)
 891     as_bad_where (fixP->fx_file, fixP->fx_line, _("expression too complex"));
 892
 893   switch (fixP->fx_r_type)
 894     {
 895     default:
 896       fixP->fx_no_overflow = 1;
 897       break;
 898     case BFD_RELOC_AVR_7_PCREL:
 899     case BFD_RELOC_AVR_13_PCREL:
 900     case BFD_RELOC_32:
 901     case BFD_RELOC_16:
 902     case BFD_RELOC_AVR_CALL:
 903       break;
 904     }
 905
 906   if (fixP->fx_done)
 907     {
 908       /* Fetch the instruction, insert the fully resolved operand
 909          value, and stuff the instruction back again.  */
 910       where = (unsigned char *) fixP->fx_frag->fr_literal + fixP->fx_where;
 911       insn = bfd_getl16 (where);
 912
 913       switch (fixP->fx_r_type)
 914         {
 915         case BFD_RELOC_AVR_7_PCREL:
 916           if (value & 1)
 917             as_bad_where (fixP->fx_file, fixP->fx_line,
 918                           _("odd address operand: %ld"), value);
 919
 920           /* Instruction addresses are always right-shifted by 1.  */
 921           value >>= 1;
 922           --value;                      /* Correct PC.  */
 923
 924           if (value < -64 || value > 63)
 925             as_bad_where (fixP->fx_file, fixP->fx_line,
 926                           _("operand out of range: %ld"), value);
 927           value = (value << 3) & 0x3f8;
 928           bfd_putl16 ((bfd_vma) (value | insn), where);
 929           break;
 930
 931         case BFD_RELOC_AVR_13_PCREL:
 932           if (value & 1)
 933             as_bad_where (fixP->fx_file, fixP->fx_line,
 934                           _("odd address operand: %ld"), value);
 935
 936           /* Instruction addresses are always right-shifted by 1.  */
 937           value >>= 1;
 938           --value;                      /* Correct PC.  */
 939
 940           if (value < -2048 || value > 2047)
 941             {
 942               /* No wrap for devices with >8K of program memory.  */
 943               if ((avr_mcu->isa & AVR_ISA_MEGA) || avr_opt.no_wrap)
 944                 as_bad_where (fixP->fx_file, fixP->fx_line,
 945                               _("operand out of range: %ld"), value);
 946             }
 947
 948           value &= 0xfff;
 949           bfd_putl16 ((bfd_vma) (value | insn), where);
 950           break;
 951
 952         case BFD_RELOC_32:
 953           bfd_putl16 ((bfd_vma) value, where);
 954           break;
 955
 956         case BFD_RELOC_16:
 957           bfd_putl16 ((bfd_vma) value, where);
 958           break;
 959
 960         case BFD_RELOC_AVR_16_PM:
 961           bfd_putl16 ((bfd_vma) (value >> 1), where);
 962           break;
 963
 964         case BFD_RELOC_AVR_LDI:
 965           if (value > 255)
 966             as_bad_where (fixP->fx_file, fixP->fx_line,
 967                           _("operand out of range: %ld"), value);
 968           bfd_putl16 ((bfd_vma) insn | LDI_IMMEDIATE (value), where);
 969           break;
 970
 971         case BFD_RELOC_AVR_6:
 972           if ((value > 63) || (value < 0))
 973             as_bad_where (fixP->fx_file, fixP->fx_line,
 974                           _("operand out of range: %ld"), value);
 975           bfd_putl16 ((bfd_vma) insn | ((value & 7) | ((value & (3 << 3)) << 7) | ((value & (1 << 5)) << 8)), where);
 976           break;
 977
 978         case BFD_RELOC_AVR_6_ADIW:
 979           if ((value > 63) || (value < 0))
 980             as_bad_where (fixP->fx_file, fixP->fx_line,
 981                           _("operand out of range: %ld"), value);
 982           bfd_putl16 ((bfd_vma) insn | (value & 0xf) | ((value & 0x30) << 2), where);
 983           break;
 984
 985         case BFD_RELOC_AVR_LO8_LDI:
 986           bfd_putl16 ((bfd_vma) insn | LDI_IMMEDIATE (value), where);
 987           break;
 988
 989         case -BFD_RELOC_AVR_LO8_LDI:
 990           bfd_putl16 ((bfd_vma) insn | LDI_IMMEDIATE (value >> 16), where);
 991           break;
 992
 993         case BFD_RELOC_AVR_HI8_LDI:
 994           bfd_putl16 ((bfd_vma) insn | LDI_IMMEDIATE (value >> 8), where);
 995           break;
 996
 997         case -BFD_RELOC_AVR_HI8_LDI:
 998           bfd_putl16 ((bfd_vma) insn | LDI_IMMEDIATE (value >> 24), where);
 999           break;
1000
1001         case BFD_RELOC_AVR_HH8_LDI:
1002           bfd_putl16 ((bfd_vma) insn | LDI_IMMEDIATE (value >> 16), where);
1003           break;
1004
1005         case BFD_RELOC_AVR_LO8_LDI_NEG:
1006           bfd_putl16 ((bfd_vma) insn | LDI_IMMEDIATE (-value), where);
1007           break;
1008
1009         case -BFD_RELOC_AVR_LO8_LDI_NEG:
1010           bfd_putl16 ((bfd_vma) insn | LDI_IMMEDIATE (-value >> 16), where);
1011           break;
1012
1013         case BFD_RELOC_AVR_HI8_LDI_NEG:
1014           bfd_putl16 ((bfd_vma) insn | LDI_IMMEDIATE (-value >> 8), where);
1015           break;
1016
1017         case -BFD_RELOC_AVR_HI8_LDI_NEG:
1018           bfd_putl16 ((bfd_vma) insn | LDI_IMMEDIATE (-value >> 24), where);
1019           break;
1020
1021         case BFD_RELOC_AVR_HH8_LDI_NEG:
1022           bfd_putl16 ((bfd_vma) insn | LDI_IMMEDIATE (-value >> 16), where);
1023           break;
1024
1025         case BFD_RELOC_AVR_LO8_LDI_PM:
1026           bfd_putl16 ((bfd_vma) insn | LDI_IMMEDIATE (value >> 1), where);
1027           break;
1028
1029         case BFD_RELOC_AVR_HI8_LDI_PM:
1030           bfd_putl16 ((bfd_vma) insn | LDI_IMMEDIATE (value >> 9), where);
1031           break;
1032
1033         case BFD_RELOC_AVR_HH8_LDI_PM:
1034           bfd_putl16 ((bfd_vma) insn | LDI_IMMEDIATE (value >> 17), where);
1035           break;
1036
1037         case BFD_RELOC_AVR_LO8_LDI_PM_NEG:
1038           bfd_putl16 ((bfd_vma) insn | LDI_IMMEDIATE (-value >> 1), where);
1039           break;
1040
1041         case BFD_RELOC_AVR_HI8_LDI_PM_NEG:
1042           bfd_putl16 ((bfd_vma) insn | LDI_IMMEDIATE (-value >> 9), where);
1043           break;
1044
1045         case BFD_RELOC_AVR_HH8_LDI_PM_NEG:
1046           bfd_putl16 ((bfd_vma) insn | LDI_IMMEDIATE (-value >> 17), where);
1047           break;
1048
1049         case BFD_RELOC_AVR_CALL:
1050           {
1051             unsigned long x;
1052
1053             x = bfd_getl16 (where);
1054             if (value & 1)
1055               as_bad_where (fixP->fx_file, fixP->fx_line,
1056                             _("odd address operand: %ld"), value);
1057             value >>= 1;
1058             x |= ((value & 0x10000) | ((value << 3) & 0x1f00000)) >> 16;
1059             bfd_putl16 ((bfd_vma) x, where);
1060             bfd_putl16 ((bfd_vma) (value & 0xffff), where + 2);
1061           }
1062           break;
1063
1064         default:
1065           as_fatal (_("line %d: unknown relocation type: 0x%x"),
1066                     fixP->fx_line, fixP->fx_r_type);
1067           break;
1068         }
1069     }
1070   else
1071     {
1072       switch (fixP->fx_r_type)
1073         {
1074         case -BFD_RELOC_AVR_HI8_LDI_NEG:
1075         case -BFD_RELOC_AVR_HI8_LDI:
1076         case -BFD_RELOC_AVR_LO8_LDI_NEG:
1077         case -BFD_RELOC_AVR_LO8_LDI:
1078           as_bad_where (fixP->fx_file, fixP->fx_line,
1079                         _("only constant expression allowed"));
1080           fixP->fx_done = 1;
1081           break;
1082         default:
1083           break;
1084         }
1085     }
1086 }
1087
1088 /* GAS will call this to generate a reloc, passing the resulting reloc
1089    to `bfd_install_relocation'.  This currently works poorly, as
1090    `bfd_install_relocation' often does the wrong thing, and instances of
1091    `tc_gen_reloc' have been written to work around the problems, which
1092    in turns makes it difficult to fix `bfd_install_relocation'.  */
1093
1094 /* If while processing a fixup, a reloc really needs to be created
1095    then it is done here.  */
1096
1097 arelent *
1098 tc_gen_reloc (seg, fixp)
1099      asection *seg ATTRIBUTE_UNUSED;
1100      fixS *fixp;
1101 {
1102   arelent *reloc;
1103
1104   reloc = (arelent *) xmalloc (sizeof (arelent));
1105
1106   reloc->sym_ptr_ptr = (asymbol **) xmalloc (sizeof (asymbol *));
1107   *reloc->sym_ptr_ptr = symbol_get_bfdsym (fixp->fx_addsy);
1108
1109   reloc->address = fixp->fx_frag->fr_address + fixp->fx_where;
1110   reloc->howto = bfd_reloc_type_lookup (stdoutput, fixp->fx_r_type);
1111   if (reloc->howto == (reloc_howto_type *) NULL)
1112     {
1113       as_bad_where (fixp->fx_file, fixp->fx_line,
1114                     _("reloc %d not supported by object file format"),
1115                     (int) fixp->fx_r_type);
1116       return NULL;
1117     }
1118
1119   if (fixp->fx_r_type == BFD_RELOC_VTABLE_INHERIT
1120       || fixp->fx_r_type == BFD_RELOC_VTABLE_ENTRY)
1121     reloc->address = fixp->fx_offset;
1122
1123   reloc->addend = fixp->fx_offset;
1124
1125   return reloc;
1126 }
1127
1128 void
1129 md_assemble (str)
1130      char *str;
1131 {
1132   struct avr_opcodes_s *opcode;
1133   char op[11];
1134
1135   str = skip_space (extract_word (str, op, sizeof (op)));
1136
1137   if (!op[0])
1138     as_bad (_("can't find opcode "));
1139
1140   opcode = (struct avr_opcodes_s *) hash_find (avr_hash, op);
1141
1142   if (opcode == NULL)
1143     {
1144       as_bad (_("unknown opcode `%s'"), op);
1145       return;
1146     }
1147
1148   /* Special case for opcodes with optional operands (lpm, elpm) -
1149      version with operands exists in avr_opcodes[] in the next entry.  */
1150
1151   if (*str && *opcode->constraints == '?')
1152     ++opcode;
1153
1154   if (!avr_opt.all_opcodes && (opcode->isa & avr_mcu->isa) != opcode->isa)
1155     as_bad (_("illegal opcode %s for mcu %s"), opcode->name, avr_mcu->name);
1156
1157   /* We used to set input_line_pointer to the result of get_operands,
1158      but that is wrong.  Our caller assumes we don't change it.  */
1159   {
1160     char *t = input_line_pointer;
1161     avr_operands (opcode, &str);
1162     if (*skip_space (str))
1163       as_bad (_("garbage at end of line"));
1164     input_line_pointer = t;
1165   }
1166 }
1167
1168 /* Parse ordinary expression.  */
1169
1170 static char *
1171 parse_exp (s, op)
1172      char *s;
1173      expressionS *op;
1174 {
1175   input_line_pointer = s;
1176   expression (op);
1177   if (op->X_op == O_absent)
1178     as_bad (_("missing operand"));
1179   return input_line_pointer;
1180 }
1181
1182 /* Parse special expressions (needed for LDI command):
1183    xx8 (address)
1184    xx8 (-address)
1185    pm_xx8 (address)
1186    pm_xx8 (-address)
1187    where xx is: hh, hi, lo.  */
1188
1189 static bfd_reloc_code_real_type
1190 avr_ldi_expression (exp)
1191      expressionS *exp;
1192 {
1193   char *str = input_line_pointer;
1194   char *tmp;
1195   char op[8];
1196   int mod;
1197   tmp = str;
1198
1199   str = extract_word (str, op, sizeof (op));
1200
1201   if (op[0])
1202     {
1203       mod = (int) hash_find (avr_mod_hash, op);
1204
1205       if (mod)
1206         {
1207           int closes = 0;
1208
1209           mod -= 10;
1210           str = skip_space (str);
1211
1212           if (*str == '(')
1213             {
1214               int neg_p = 0;
1215
1216               ++str;
1217
1218               if (strncmp ("pm(", str, 3) == 0
1219                   || strncmp ("-(pm(", str, 5) == 0)
1220                 {
1221                   if (HAVE_PM_P (mod))
1222                     {
1223                       ++mod;
1224                       ++closes;
1225                     }
1226                   else
1227                     as_bad (_("illegal expression"));
1228
1229                   if (*str == '-')
1230                     {
1231                       neg_p = 1;
1232                       ++closes;
1233                       str += 5;
1234                     }
1235                   else
1236                     str += 3;
1237                 }
1238
1239               if (*str == '-' && *(str + 1) == '(')
1240                 {
1241                   neg_p ^= 1;
1242                   ++closes;
1243                   str += 2;
1244                 }
1245
1246               input_line_pointer = str;
1247               expression (exp);
1248
1249               do
1250                 {
1251                   if (*input_line_pointer != ')')
1252                     {
1253                       as_bad (_("`)' required"));
1254                       break;
1255                     }
1256                   input_line_pointer++;
1257                 }
1258               while (closes--);
1259
1260               return neg_p ? EXP_MOD_NEG_RELOC (mod) : EXP_MOD_RELOC (mod);
1261             }
1262         }
1263     }
1264
1265   input_line_pointer = tmp;
1266   expression (exp);
1267
1268   /* Warn about expressions that fail to use lo8 ().  */
1269   if (exp->X_op == O_constant)
1270     {
1271       int x = exp->X_add_number;
1272       if (x < -255 || x > 255)
1273         as_warn (_("constant out of 8-bit range: %d"), x);
1274     }
1275
1276   return BFD_RELOC_AVR_LDI;
1277 }
1278
1279 /* Flag to pass `pm' mode between `avr_parse_cons_expression' and
1280    `avr_cons_fix_new'.  */
1281 static int exp_mod_pm = 0;
1282
1283 /* Parse special CONS expression: pm (expression)
1284    which is used for addressing to a program memory.
1285    Relocation: BFD_RELOC_AVR_16_PM.  */
1286
1287 void
1288 avr_parse_cons_expression (exp, nbytes)
1289      expressionS *exp;
1290      int nbytes;
1291 {
1292   char *tmp;
1293
1294   exp_mod_pm = 0;
1295
1296   tmp = input_line_pointer = skip_space (input_line_pointer);
1297
1298   if (nbytes == 2)
1299     {
1300       char *pm_name = "pm";
1301       int len = strlen (pm_name);
1302
1303       if (strncasecmp (input_line_pointer, pm_name, len) == 0)
1304         {
1305           input_line_pointer = skip_space (input_line_pointer + len);
1306
1307           if (*input_line_pointer == '(')
1308             {
1309               input_line_pointer = skip_space (input_line_pointer + 1);
1310               exp_mod_pm = 1;
1311               expression (exp);
1312
1313               if (*input_line_pointer == ')')
1314                 ++input_line_pointer;
1315               else
1316                 {
1317                   as_bad (_("`)' required"));
1318                   exp_mod_pm = 0;
1319                 }
1320
1321               return;
1322             }
1323
1324           input_line_pointer = tmp;
1325         }
1326     }
1327
1328   expression (exp);
1329 }
1330
1331 void
1332 avr_cons_fix_new (frag, where, nbytes, exp)
1333      fragS *frag;
1334      int where;
1335      int nbytes;
1336      expressionS *exp;
1337 {
1338   if (exp_mod_pm == 0)
1339     {
1340       if (nbytes == 2)
1341         fix_new_exp (frag, where, nbytes, exp, FALSE, BFD_RELOC_16);
1342       else if (nbytes == 4)
1343         fix_new_exp (frag, where, nbytes, exp, FALSE, BFD_RELOC_32);
1344       else
1345         as_bad (_("illegal %srelocation size: %d"), "", nbytes);
1346     }
1347   else
1348     {
1349       if (nbytes == 2)
1350         fix_new_exp (frag, where, nbytes, exp, FALSE, BFD_RELOC_AVR_16_PM);
1351       else
1352         as_bad (_("illegal %srelocation size: %d"), "`pm' ", nbytes);
1353       exp_mod_pm = 0;
1354     }
1355 }