1 /* tc-avr.c -- Assembler code for the ATMEL AVR
2 
3    Copyright 1999, 2000, 2001, 2002, 2004, 2005, 2006, 2007, 2008
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 3, 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 "as.h"
25 #include "safe-ctype.h"
26 #include "subsegs.h"
27 
28 struct avr_opcodes_s
29 {
30   char *        name;
31   char *        constraints;
32   int           insn_size;		/* In words.  */
33   int           isa;
34   unsigned int  bin_opcode;
35 };
36 
37 #define AVR_INSN(NAME, CONSTR, OPCODE, SIZE, ISA, BIN) \
38 {#NAME, CONSTR, SIZE, ISA, BIN},
39 
40 struct avr_opcodes_s avr_opcodes[] =
41 {
42   #include "opcode/avr.h"
43   {NULL, NULL, 0, 0, 0}
44 };
45 
46 const char comment_chars[] = ";";
47 const char line_comment_chars[] = "#";
48 const char line_separator_chars[] = "$";
49 
50 const char *md_shortopts = "m:";
51 struct mcu_type_s
52 {
53   char *name;
54   int isa;
55   int mach;
56 };
57 
58 /* XXX - devices that don't seem to exist (renamed, replaced with larger
59    ones, or planned but never produced), left here for compatibility.  */
60 
61 static struct mcu_type_s mcu_types[] =
62 {
63   {"avr1",       AVR_ISA_AVR1,    bfd_mach_avr1},
64 /* TODO: insruction set for avr2 architecture should be AVR_ISA_AVR2,
65  but set to AVR_ISA_AVR25 for some following version
66  of GCC (from 4.3) for backward compatibility.  */
67   {"avr2",       AVR_ISA_AVR25,   bfd_mach_avr2},
68   {"avr25",      AVR_ISA_AVR25,   bfd_mach_avr25},
69 /* TODO: insruction set for avr3 architecture should be AVR_ISA_AVR3,
70  but set to AVR_ISA_AVR3_ALL for some following version
71  of GCC (from 4.3) for backward compatibility.  */
72   {"avr3",       AVR_ISA_AVR3_ALL, bfd_mach_avr3},
73   {"avr31",      AVR_ISA_AVR31,   bfd_mach_avr31},
74   {"avr35",      AVR_ISA_AVR35,   bfd_mach_avr35},
75   {"avr4",       AVR_ISA_AVR4,    bfd_mach_avr4},
76 /* TODO: insruction set for avr5 architecture should be AVR_ISA_AVR5,
77  but set to AVR_ISA_AVR51 for some following version
78  of GCC (from 4.3) for backward compatibility.  */
79   {"avr5",       AVR_ISA_AVR51,   bfd_mach_avr5},
80   {"avr51",      AVR_ISA_AVR51,   bfd_mach_avr51},
81   {"avr6",       AVR_ISA_AVR6,    bfd_mach_avr6},
82   {"at90s1200",  AVR_ISA_1200,    bfd_mach_avr1},
83   {"attiny11",   AVR_ISA_AVR1,    bfd_mach_avr1},
84   {"attiny12",   AVR_ISA_AVR1,    bfd_mach_avr1},
85   {"attiny15",   AVR_ISA_AVR1,    bfd_mach_avr1},
86   {"attiny28",   AVR_ISA_AVR1,    bfd_mach_avr1},
87   {"at90s2313",  AVR_ISA_AVR2,    bfd_mach_avr2},
88   {"at90s2323",  AVR_ISA_AVR2,    bfd_mach_avr2},
89   {"at90s2333",  AVR_ISA_AVR2,    bfd_mach_avr2}, /* XXX -> 4433 */
90   {"at90s2343",  AVR_ISA_AVR2,    bfd_mach_avr2},
91   {"attiny22",   AVR_ISA_AVR2,    bfd_mach_avr2}, /* XXX -> 2343 */
92   {"attiny26",   AVR_ISA_2xxe,    bfd_mach_avr2},
93   {"at90s4414",  AVR_ISA_AVR2,    bfd_mach_avr2}, /* XXX -> 8515 */
94   {"at90s4433",  AVR_ISA_AVR2,    bfd_mach_avr2},
95   {"at90s4434",  AVR_ISA_AVR2,    bfd_mach_avr2}, /* XXX -> 8535 */
96   {"at90s8515",  AVR_ISA_AVR2,    bfd_mach_avr2},
97   {"at90c8534",  AVR_ISA_AVR2,    bfd_mach_avr2},
98   {"at90s8535",  AVR_ISA_AVR2,    bfd_mach_avr2},
99   {"attiny13",   AVR_ISA_AVR25,   bfd_mach_avr25},
100   {"attiny13a",  AVR_ISA_AVR25,   bfd_mach_avr25},
101   {"attiny2313", AVR_ISA_AVR25,   bfd_mach_avr25},
102   {"attiny24",   AVR_ISA_AVR25,   bfd_mach_avr25},
103   {"attiny44",   AVR_ISA_AVR25,   bfd_mach_avr25},
104   {"attiny84",   AVR_ISA_AVR25,   bfd_mach_avr25},
105   {"attiny25",   AVR_ISA_AVR25,   bfd_mach_avr25},
106   {"attiny45",   AVR_ISA_AVR25,   bfd_mach_avr25},
107   {"attiny85",   AVR_ISA_AVR25,   bfd_mach_avr25},
108   {"attiny261",  AVR_ISA_AVR25,   bfd_mach_avr25},
109   {"attiny461",  AVR_ISA_AVR25,   bfd_mach_avr25},
110   {"attiny861",  AVR_ISA_AVR25,   bfd_mach_avr25},
111   {"attiny43u",  AVR_ISA_AVR25,   bfd_mach_avr25},
112   {"attiny48",   AVR_ISA_AVR25,   bfd_mach_avr25},
113   {"attiny88",   AVR_ISA_AVR25,   bfd_mach_avr25},
114   {"at86rf401",  AVR_ISA_RF401,   bfd_mach_avr25},
115   {"at43usb355", AVR_ISA_AVR3,    bfd_mach_avr3},
116   {"at76c711",   AVR_ISA_AVR3,    bfd_mach_avr3},
117   {"atmega103",  AVR_ISA_AVR31,   bfd_mach_avr31},
118   {"at43usb320", AVR_ISA_AVR31,   bfd_mach_avr31},
119   {"attiny167",  AVR_ISA_AVR35,   bfd_mach_avr35},
120   {"at90usb82",  AVR_ISA_AVR35,   bfd_mach_avr35},
121   {"at90usb162", AVR_ISA_AVR35,   bfd_mach_avr35},
122   {"atmega8",    AVR_ISA_M8,      bfd_mach_avr4},
123   {"atmega48",   AVR_ISA_AVR4,    bfd_mach_avr4},
124   {"atmega48p",  AVR_ISA_AVR4,    bfd_mach_avr4},
125   {"atmega88",   AVR_ISA_AVR4,    bfd_mach_avr4},
126   {"atmega88p",  AVR_ISA_AVR4,    bfd_mach_avr4},
127   {"atmega8515", AVR_ISA_M8,      bfd_mach_avr4},
128   {"atmega8535", AVR_ISA_M8,      bfd_mach_avr4},
129   {"atmega8hva", AVR_ISA_AVR4,    bfd_mach_avr4},
130   {"at90pwm1",   AVR_ISA_AVR4,    bfd_mach_avr4},
131   {"at90pwm2",   AVR_ISA_AVR4,    bfd_mach_avr4},
132   {"at90pwm2b",  AVR_ISA_AVR4,    bfd_mach_avr4},
133   {"at90pwm3",   AVR_ISA_AVR4,    bfd_mach_avr4},
134   {"at90pwm3b",  AVR_ISA_AVR4,    bfd_mach_avr4},
135   {"atmega16",   AVR_ISA_AVR5,    bfd_mach_avr5},
136   {"atmega161",  AVR_ISA_M161,    bfd_mach_avr5},
137   {"atmega162",  AVR_ISA_AVR5,    bfd_mach_avr5},
138   {"atmega163",  AVR_ISA_M161,    bfd_mach_avr5},
139   {"atmega164p", AVR_ISA_AVR5,    bfd_mach_avr5},
140   {"atmega165",  AVR_ISA_AVR5,    bfd_mach_avr5},
141   {"atmega165p", AVR_ISA_AVR5,    bfd_mach_avr5},
142   {"atmega168",  AVR_ISA_AVR5,    bfd_mach_avr5},
143   {"atmega168p", AVR_ISA_AVR5,    bfd_mach_avr5},
144   {"atmega169",  AVR_ISA_AVR5,    bfd_mach_avr5},
145   {"atmega169p", AVR_ISA_AVR5,    bfd_mach_avr5},
146   {"atmega32",   AVR_ISA_AVR5,    bfd_mach_avr5},
147   {"atmega323",  AVR_ISA_AVR5,    bfd_mach_avr5},
148   {"atmega324p", AVR_ISA_AVR5,    bfd_mach_avr5},
149   {"atmega325",  AVR_ISA_AVR5,    bfd_mach_avr5},
150   {"atmega325p", AVR_ISA_AVR5,    bfd_mach_avr5},
151   {"atmega3250", AVR_ISA_AVR5,    bfd_mach_avr5},
152   {"atmega3250p",AVR_ISA_AVR5,    bfd_mach_avr5},
153   {"atmega328p", AVR_ISA_AVR5,    bfd_mach_avr5},
154   {"atmega329",  AVR_ISA_AVR5,    bfd_mach_avr5},
155   {"atmega329p", AVR_ISA_AVR5,    bfd_mach_avr5},
156   {"atmega3290", AVR_ISA_AVR5,    bfd_mach_avr5},
157   {"atmega3290p",AVR_ISA_AVR5,    bfd_mach_avr5},
158   {"atmega406",  AVR_ISA_AVR5,    bfd_mach_avr5},
159   {"atmega64",   AVR_ISA_AVR5,    bfd_mach_avr5},
160   {"atmega640",  AVR_ISA_AVR5,    bfd_mach_avr5},
161   {"atmega644",  AVR_ISA_AVR5,    bfd_mach_avr5},
162   {"atmega644p", AVR_ISA_AVR5,    bfd_mach_avr5},
163   {"atmega645",  AVR_ISA_AVR5,    bfd_mach_avr5},
164   {"atmega649",  AVR_ISA_AVR5,    bfd_mach_avr5},
165   {"atmega6450", AVR_ISA_AVR5,    bfd_mach_avr5},
166   {"atmega6490", AVR_ISA_AVR5,    bfd_mach_avr5},
167   {"atmega16hva",AVR_ISA_AVR5,    bfd_mach_avr5},
168   {"at90can32" , AVR_ISA_AVR5,    bfd_mach_avr5},
169   {"at90can64" , AVR_ISA_AVR5,    bfd_mach_avr5},
170   {"at90pwm216", AVR_ISA_AVR5,    bfd_mach_avr5},
171   {"at90pwm316", AVR_ISA_AVR5,    bfd_mach_avr5},
172   {"atmega16u4", AVR_ISA_AVR5,    bfd_mach_avr5},
173   {"atmega32c1", AVR_ISA_AVR5,    bfd_mach_avr5},
174   {"atmega32m1", AVR_ISA_AVR5,    bfd_mach_avr5},
175   {"atmega32u4", AVR_ISA_AVR5,    bfd_mach_avr5},
176   {"at90usb646", AVR_ISA_AVR5,    bfd_mach_avr5},
177   {"at90usb647", AVR_ISA_AVR5,    bfd_mach_avr5},
178   {"at94k",      AVR_ISA_94K,     bfd_mach_avr5},
179   {"atmega128",  AVR_ISA_AVR51,   bfd_mach_avr51},
180   {"atmega1280", AVR_ISA_AVR51,   bfd_mach_avr51},
181   {"atmega1281", AVR_ISA_AVR51,   bfd_mach_avr51},
182   {"atmega1284p",AVR_ISA_AVR51,   bfd_mach_avr51},
183   {"at90can128", AVR_ISA_AVR51,   bfd_mach_avr51},
184   {"at90usb1286",AVR_ISA_AVR51,   bfd_mach_avr51},
185   {"at90usb1287",AVR_ISA_AVR51,   bfd_mach_avr51},
186   {"atmega2560", AVR_ISA_AVR6,    bfd_mach_avr6},
187   {"atmega2561", AVR_ISA_AVR6,    bfd_mach_avr6},
188   {NULL, 0, 0}
189 };
190 
191 /* Current MCU type.  */
192 static struct mcu_type_s   default_mcu = {"avr2", AVR_ISA_AVR2, bfd_mach_avr2};
193 static struct mcu_type_s * avr_mcu = & default_mcu;
194 
195 /* AVR target-specific switches.  */
196 struct avr_opt_s
197 {
198   int all_opcodes;  /* -mall-opcodes: accept all known AVR opcodes.  */
199   int no_skip_bug;  /* -mno-skip-bug: no warnings for skipping 2-word insns.  */
200   int no_wrap;      /* -mno-wrap: reject rjmp/rcall with 8K wrap-around.  */
201 };
202 
203 static struct avr_opt_s avr_opt = { 0, 0, 0 };
204 
205 const char EXP_CHARS[] = "eE";
206 const char FLT_CHARS[] = "dD";
207 
208 static void avr_set_arch (int);
209 
210 /* The target specific pseudo-ops which we support.  */
211 const pseudo_typeS md_pseudo_table[] =
212 {
213   {"arch", avr_set_arch,	0},
214   { NULL,	NULL,		0}
215 };
216 
217 #define LDI_IMMEDIATE(x) (((x) & 0xf) | (((x) << 4) & 0xf00))
218 
219 #define EXP_MOD_NAME(i)       exp_mod[i].name
220 #define EXP_MOD_RELOC(i)      exp_mod[i].reloc
221 #define EXP_MOD_NEG_RELOC(i)  exp_mod[i].neg_reloc
222 #define HAVE_PM_P(i)          exp_mod[i].have_pm
223 
224 struct exp_mod_s
225 {
226   char *                    name;
227   bfd_reloc_code_real_type  reloc;
228   bfd_reloc_code_real_type  neg_reloc;
229   int                       have_pm;
230 };
231 
232 static struct exp_mod_s exp_mod[] =
233 {
234   {"hh8",    BFD_RELOC_AVR_HH8_LDI,    BFD_RELOC_AVR_HH8_LDI_NEG,    1},
235   {"pm_hh8", BFD_RELOC_AVR_HH8_LDI_PM, BFD_RELOC_AVR_HH8_LDI_PM_NEG, 0},
236   {"hi8",    BFD_RELOC_AVR_HI8_LDI,    BFD_RELOC_AVR_HI8_LDI_NEG,    1},
237   {"pm_hi8", BFD_RELOC_AVR_HI8_LDI_PM, BFD_RELOC_AVR_HI8_LDI_PM_NEG, 0},
238   {"lo8",    BFD_RELOC_AVR_LO8_LDI,    BFD_RELOC_AVR_LO8_LDI_NEG,    1},
239   {"pm_lo8", BFD_RELOC_AVR_LO8_LDI_PM, BFD_RELOC_AVR_LO8_LDI_PM_NEG, 0},
240   {"hlo8",   BFD_RELOC_AVR_HH8_LDI,    BFD_RELOC_AVR_HH8_LDI_NEG,    0},
241   {"hhi8",   BFD_RELOC_AVR_MS8_LDI,    BFD_RELOC_AVR_MS8_LDI_NEG,    0},
242 };
243 
244 /* A union used to store indicies into the exp_mod[] array
245    in a hash table which expects void * data types.  */
246 typedef union
247 {
248   void * ptr;
249   int    index;
250 } mod_index;
251 
252 /* Opcode hash table.  */
253 static struct hash_control *avr_hash;
254 
255 /* Reloc modifiers hash control (hh8,hi8,lo8,pm_xx).  */
256 static struct hash_control *avr_mod_hash;
257 
258 #define OPTION_MMCU 'm'
259 enum options
260 {
261   OPTION_ALL_OPCODES = OPTION_MD_BASE + 1,
262   OPTION_NO_SKIP_BUG,
263   OPTION_NO_WRAP
264 };
265 
266 struct option md_longopts[] =
267 {
268   { "mmcu",   required_argument, NULL, OPTION_MMCU        },
269   { "mall-opcodes", no_argument, NULL, OPTION_ALL_OPCODES },
270   { "mno-skip-bug", no_argument, NULL, OPTION_NO_SKIP_BUG },
271   { "mno-wrap",     no_argument, NULL, OPTION_NO_WRAP     },
272   { NULL, no_argument, NULL, 0 }
273 };
274 
275 size_t md_longopts_size = sizeof (md_longopts);
276 
277 /* Display nicely formatted list of known MCU names.  */
278 
279 static void
280 show_mcu_list (FILE *stream)
281 {
282   int i, x;
283 
284   fprintf (stream, _("Known MCU names:"));
285   x = 1000;
286 
287   for (i = 0; mcu_types[i].name; i++)
288     {
289       int len = strlen (mcu_types[i].name);
290 
291       x += len + 1;
292 
293       if (x < 75)
294 	fprintf (stream, " %s", mcu_types[i].name);
295       else
296 	{
297 	  fprintf (stream, "\n  %s", mcu_types[i].name);
298 	  x = len + 2;
299 	}
300     }
301 
302   fprintf (stream, "\n");
303 }
304 
305 static inline char *
306 skip_space (char *s)
307 {
308   while (*s == ' ' || *s == '\t')
309     ++s;
310   return s;
311 }
312 
313 /* Extract one word from FROM and copy it to TO.  */
314 
315 static char *
316 extract_word (char *from, char *to, int limit)
317 {
318   char *op_start;
319   char *op_end;
320   int size = 0;
321 
322   /* Drop leading whitespace.  */
323   from = skip_space (from);
324   *to = 0;
325 
326   /* Find the op code end.  */
327   for (op_start = op_end = from; *op_end != 0 && is_part_of_name (*op_end);)
328     {
329       to[size++] = *op_end++;
330       if (size + 1 >= limit)
331 	break;
332     }
333 
334   to[size] = 0;
335   return op_end;
336 }
337 
338 int
339 md_estimate_size_before_relax (fragS *fragp ATTRIBUTE_UNUSED,
340 			       asection *seg ATTRIBUTE_UNUSED)
341 {
342   abort ();
343   return 0;
344 }
345 
346 void
347 md_show_usage (FILE *stream)
348 {
349   fprintf (stream,
350       _("AVR options:\n"
351 	"  -mmcu=[avr-name] select microcontroller variant\n"
352 	"                   [avr-name] can be:\n"
353 	"                   avr1  - classic AVR core without data RAM\n"
354 	"                   avr2  - classic AVR core with up to 8K program memory\n"
355 	"                   avr25 - classic AVR core with up to 8K program memory\n"
356 	"                           plus the MOVW instruction\n"
357 	"                   avr3  - classic AVR core with up to 64K program memory\n"
358 	"                   avr31 - classic AVR core with up to 128K program memory\n"
359 	"                   avr35 - classic AVR core with up to 64K program memory\n"
360 	"                           plus the MOVW instruction\n"
361 	"                   avr4  - enhanced AVR core with up to 8K program memory\n"
362 	"                   avr5  - enhanced AVR core with up to 64K program memory\n"
363 	"                   avr51 - enhanced AVR core with up to 128K program memory\n"
364 	"                   avr6  - enhanced AVR core with up to 256K program memory\n"
365 	"                   or immediate microcontroller name.\n"));
366   fprintf (stream,
367       _("  -mall-opcodes    accept all AVR opcodes, even if not supported by MCU\n"
368 	"  -mno-skip-bug    disable warnings for skipping two-word instructions\n"
369 	"                   (default for avr4, avr5)\n"
370 	"  -mno-wrap        reject rjmp/rcall instructions with 8K wrap-around\n"
371 	"                   (default for avr3, avr5)\n"));
372   show_mcu_list (stream);
373 }
374 
375 static void
376 avr_set_arch (int dummy ATTRIBUTE_UNUSED)
377 {
378   char str[20];
379 
380   input_line_pointer = extract_word (input_line_pointer, str, 20);
381   md_parse_option (OPTION_MMCU, str);
382   bfd_set_arch_mach (stdoutput, TARGET_ARCH, avr_mcu->mach);
383 }
384 
385 int
386 md_parse_option (int c, char *arg)
387 {
388   switch (c)
389     {
390     case OPTION_MMCU:
391       {
392 	int i;
393 	char *s = alloca (strlen (arg) + 1);
394 
395 	{
396 	  char *t = s;
397 	  char *arg1 = arg;
398 
399 	  do
400 	    *t = TOLOWER (*arg1++);
401 	  while (*t++);
402 	}
403 
404 	for (i = 0; mcu_types[i].name; ++i)
405 	  if (strcmp (mcu_types[i].name, s) == 0)
406 	    break;
407 
408 	if (!mcu_types[i].name)
409 	  {
410 	    show_mcu_list (stderr);
411 	    as_fatal (_("unknown MCU: %s\n"), arg);
412 	  }
413 
414 	/* It is OK to redefine mcu type within the same avr[1-5] bfd machine
415 	   type - this for allows passing -mmcu=... via gcc ASM_SPEC as well
416 	   as .arch ... in the asm output at the same time.  */
417 	if (avr_mcu == &default_mcu || avr_mcu->mach == mcu_types[i].mach)
418 	  avr_mcu = &mcu_types[i];
419 	else
420 	  as_fatal (_("redefinition of mcu type `%s' to `%s'"),
421 		    avr_mcu->name, mcu_types[i].name);
422 	return 1;
423       }
424     case OPTION_ALL_OPCODES:
425       avr_opt.all_opcodes = 1;
426       return 1;
427     case OPTION_NO_SKIP_BUG:
428       avr_opt.no_skip_bug = 1;
429       return 1;
430     case OPTION_NO_WRAP:
431       avr_opt.no_wrap = 1;
432       return 1;
433     }
434 
435   return 0;
436 }
437 
438 symbolS *
439 md_undefined_symbol (char *name ATTRIBUTE_UNUSED)
440 {
441   return NULL;
442 }
443 
444 char *
445 md_atof (int type, char *litP, int *sizeP)
446 {
447   return ieee_md_atof (type, litP, sizeP, FALSE);
448 }
449 
450 void
451 md_convert_frag (bfd *abfd ATTRIBUTE_UNUSED,
452 		 asection *sec ATTRIBUTE_UNUSED,
453 		 fragS *fragP ATTRIBUTE_UNUSED)
454 {
455   abort ();
456 }
457 
458 void
459 md_begin (void)
460 {
461   unsigned int i;
462   struct avr_opcodes_s *opcode;
463 
464   avr_hash = hash_new ();
465 
466   /* Insert unique names into hash table.  This hash table then provides a
467      quick index to the first opcode with a particular name in the opcode
468      table.  */
469   for (opcode = avr_opcodes; opcode->name; opcode++)
470     hash_insert (avr_hash, opcode->name, (char *) opcode);
471 
472   avr_mod_hash = hash_new ();
473 
474   for (i = 0; i < ARRAY_SIZE (exp_mod); ++i)
475     {
476       mod_index m;
477 
478       m.index = i + 10;
479       hash_insert (avr_mod_hash, EXP_MOD_NAME (i), m.ptr);
480     }
481 
482   bfd_set_arch_mach (stdoutput, TARGET_ARCH, avr_mcu->mach);
483 }
484 
485 /* Resolve STR as a constant expression and return the result.
486    If result greater than MAX then error.  */
487 
488 static unsigned int
489 avr_get_constant (char *str, int max)
490 {
491   expressionS ex;
492 
493   str = skip_space (str);
494   input_line_pointer = str;
495   expression (& ex);
496 
497   if (ex.X_op != O_constant)
498     as_bad (_("constant value required"));
499 
500   if (ex.X_add_number > max || ex.X_add_number < 0)
501     as_bad (_("number must be positive and less than %d"), max + 1);
502 
503   return ex.X_add_number;
504 }
505 
506 /* Parse for ldd/std offset.  */
507 
508 static void
509 avr_offset_expression (expressionS *exp)
510 {
511   char *str = input_line_pointer;
512   char *tmp;
513   char op[8];
514 
515   tmp = str;
516   str = extract_word (str, op, sizeof (op));
517 
518   input_line_pointer = tmp;
519   expression (exp);
520 
521   /* Warn about expressions that fail to use lo8 ().  */
522   if (exp->X_op == O_constant)
523     {
524       int x = exp->X_add_number;
525 
526       if (x < -255 || x > 255)
527 	as_warn (_("constant out of 8-bit range: %d"), x);
528     }
529 }
530 
531 /* Parse ordinary expression.  */
532 
533 static char *
534 parse_exp (char *s, expressionS *op)
535 {
536   input_line_pointer = s;
537   expression (op);
538   if (op->X_op == O_absent)
539     as_bad (_("missing operand"));
540   return input_line_pointer;
541 }
542 
543 /* Parse special expressions (needed for LDI command):
544    xx8 (address)
545    xx8 (-address)
546    pm_xx8 (address)
547    pm_xx8 (-address)
548    where xx is: hh, hi, lo.  */
549 
550 static bfd_reloc_code_real_type
551 avr_ldi_expression (expressionS *exp)
552 {
553   char *str = input_line_pointer;
554   char *tmp;
555   char op[8];
556   int mod;
557   int linker_stubs_should_be_generated = 0;
558 
559   tmp = str;
560 
561   str = extract_word (str, op, sizeof (op));
562 
563   if (op[0])
564     {
565       mod_index m;
566 
567       m.ptr = hash_find (avr_mod_hash, op);
568       mod = m.index;
569 
570       if (mod)
571 	{
572 	  int closes = 0;
573 
574 	  mod -= 10;
575 	  str = skip_space (str);
576 
577 	  if (*str == '(')
578 	    {
579 	      bfd_reloc_code_real_type  reloc_to_return;
580 	      int neg_p = 0;
581 
582 	      ++str;
583 
584 	      if (strncmp ("pm(", str, 3) == 0
585                   || strncmp ("gs(",str,3) == 0
586                   || strncmp ("-(gs(",str,5) == 0
587 		  || strncmp ("-(pm(", str, 5) == 0)
588 		{
589 		  if (HAVE_PM_P (mod))
590 		    {
591 		      ++mod;
592 		      ++closes;
593 		    }
594 		  else
595 		    as_bad (_("illegal expression"));
596 
597                   if (str[0] == 'g' || str[2] == 'g')
598                     linker_stubs_should_be_generated = 1;
599 
600 		  if (*str == '-')
601 		    {
602 		      neg_p = 1;
603 		      ++closes;
604 		      str += 5;
605 		    }
606 		  else
607 		    str += 3;
608 		}
609 
610 	      if (*str == '-' && *(str + 1) == '(')
611 		{
612 		  neg_p ^= 1;
613 		  ++closes;
614 		  str += 2;
615 		}
616 
617 	      input_line_pointer = str;
618 	      expression (exp);
619 
620 	      do
621 		{
622 		  if (*input_line_pointer != ')')
623 		    {
624 		      as_bad (_("`)' required"));
625 		      break;
626 		    }
627 		  input_line_pointer++;
628 		}
629 	      while (closes--);
630 
631 	      reloc_to_return =
632 		neg_p ? EXP_MOD_NEG_RELOC (mod) : EXP_MOD_RELOC (mod);
633 	      if (linker_stubs_should_be_generated)
634 		{
635 		  switch (reloc_to_return)
636 		    {
637 		    case BFD_RELOC_AVR_LO8_LDI_PM:
638 		      reloc_to_return = BFD_RELOC_AVR_LO8_LDI_GS;
639 		      break;
640 		    case BFD_RELOC_AVR_HI8_LDI_PM:
641 		      reloc_to_return = BFD_RELOC_AVR_HI8_LDI_GS;
642 		      break;
643 
644 		    default:
645 		      /* PR 5523: Do not generate a warning here,
646 			 legitimate code can trigger this case.  */
647 		      break;
648 		    }
649 		}
650 	      return reloc_to_return;
651 	    }
652 	}
653     }
654 
655   input_line_pointer = tmp;
656   expression (exp);
657 
658   /* Warn about expressions that fail to use lo8 ().  */
659   if (exp->X_op == O_constant)
660     {
661       int x = exp->X_add_number;
662 
663       if (x < -255 || x > 255)
664 	as_warn (_("constant out of 8-bit range: %d"), x);
665     }
666 
667   return BFD_RELOC_AVR_LDI;
668 }
669 
670 /* Parse one instruction operand.
671    Return operand bitmask.  Also fixups can be generated.  */
672 
673 static unsigned int
674 avr_operand (struct avr_opcodes_s *opcode,
675 	     int where,
676 	     char *op,
677 	     char **line)
678 {
679   expressionS op_expr;
680   unsigned int op_mask = 0;
681   char *str = skip_space (*line);
682 
683   switch (*op)
684     {
685       /* Any register operand.  */
686     case 'w':
687     case 'd':
688     case 'r':
689     case 'a':
690     case 'v':
691       if (*str == 'r' || *str == 'R')
692 	{
693 	  char r_name[20];
694 
695 	  str = extract_word (str, r_name, sizeof (r_name));
696 	  op_mask = 0xff;
697 	  if (ISDIGIT (r_name[1]))
698 	    {
699 	      if (r_name[2] == '\0')
700 		op_mask = r_name[1] - '0';
701 	      else if (r_name[1] != '0'
702 		       && ISDIGIT (r_name[2])
703 		       && r_name[3] == '\0')
704 		op_mask = (r_name[1] - '0') * 10 + r_name[2] - '0';
705 	    }
706 	}
707       else
708 	{
709 	  op_mask = avr_get_constant (str, 31);
710 	  str = input_line_pointer;
711 	}
712 
713       if (op_mask <= 31)
714 	{
715 	  switch (*op)
716 	    {
717 	    case 'a':
718 	      if (op_mask < 16 || op_mask > 23)
719 		as_bad (_("register r16-r23 required"));
720 	      op_mask -= 16;
721 	      break;
722 
723 	    case 'd':
724 	      if (op_mask < 16)
725 		as_bad (_("register number above 15 required"));
726 	      op_mask -= 16;
727 	      break;
728 
729 	    case 'v':
730 	      if (op_mask & 1)
731 		as_bad (_("even register number required"));
732 	      op_mask >>= 1;
733 	      break;
734 
735 	    case 'w':
736 	      if ((op_mask & 1) || op_mask < 24)
737 		as_bad (_("register r24, r26, r28 or r30 required"));
738 	      op_mask = (op_mask - 24) >> 1;
739 	      break;
740 	    }
741 	  break;
742 	}
743       as_bad (_("register name or number from 0 to 31 required"));
744       break;
745 
746     case 'e':
747       {
748 	char c;
749 
750 	if (*str == '-')
751 	  {
752 	    str = skip_space (str + 1);
753 	    op_mask = 0x1002;
754 	  }
755 	c = TOLOWER (*str);
756 	if (c == 'x')
757 	  op_mask |= 0x100c;
758 	else if (c == 'y')
759 	  op_mask |= 0x8;
760 	else if (c != 'z')
761 	  as_bad (_("pointer register (X, Y or Z) required"));
762 
763 	str = skip_space (str + 1);
764 	if (*str == '+')
765 	  {
766 	    ++str;
767 	    if (op_mask & 2)
768 	      as_bad (_("cannot both predecrement and postincrement"));
769 	    op_mask |= 0x1001;
770 	  }
771 
772 	/* avr1 can do "ld r,Z" and "st Z,r" but no other pointer
773 	   registers, no predecrement, no postincrement.  */
774 	if (!avr_opt.all_opcodes && (op_mask & 0x100F)
775 	    && !(avr_mcu->isa & AVR_ISA_SRAM))
776 	  as_bad (_("addressing mode not supported"));
777       }
778       break;
779 
780     case 'z':
781       if (*str == '-')
782 	as_bad (_("can't predecrement"));
783 
784       if (! (*str == 'z' || *str == 'Z'))
785 	as_bad (_("pointer register Z required"));
786 
787       str = skip_space (str + 1);
788 
789       if (*str == '+')
790 	{
791 	  ++str;
792 	  op_mask |= 1;
793 	}
794 
795       /* attiny26 can do "lpm" and "lpm r,Z" but not "lpm r,Z+".  */
796       if (!avr_opt.all_opcodes
797 	  && (op_mask & 0x0001)
798 	  && !(avr_mcu->isa & AVR_ISA_MOVW))
799 	as_bad (_("postincrement not supported"));
800       break;
801 
802     case 'b':
803       {
804 	char c = TOLOWER (*str++);
805 
806 	if (c == 'y')
807 	  op_mask |= 0x8;
808 	else if (c != 'z')
809 	  as_bad (_("pointer register (Y or Z) required"));
810 	str = skip_space (str);
811 	if (*str++ == '+')
812 	  {
813 	    input_line_pointer = str;
814 	    avr_offset_expression (& op_expr);
815 	    str = input_line_pointer;
816 	    fix_new_exp (frag_now, where, 3,
817 			 &op_expr, FALSE, BFD_RELOC_AVR_6);
818 	  }
819       }
820       break;
821 
822     case 'h':
823       str = parse_exp (str, &op_expr);
824       fix_new_exp (frag_now, where, opcode->insn_size * 2,
825 		   &op_expr, FALSE, BFD_RELOC_AVR_CALL);
826       break;
827 
828     case 'L':
829       str = parse_exp (str, &op_expr);
830       fix_new_exp (frag_now, where, opcode->insn_size * 2,
831 		   &op_expr, TRUE, BFD_RELOC_AVR_13_PCREL);
832       break;
833 
834     case 'l':
835       str = parse_exp (str, &op_expr);
836       fix_new_exp (frag_now, where, opcode->insn_size * 2,
837 		   &op_expr, TRUE, BFD_RELOC_AVR_7_PCREL);
838       break;
839 
840     case 'i':
841       str = parse_exp (str, &op_expr);
842       fix_new_exp (frag_now, where + 2, opcode->insn_size * 2,
843 		   &op_expr, FALSE, BFD_RELOC_16);
844       break;
845 
846     case 'M':
847       {
848 	bfd_reloc_code_real_type r_type;
849 
850 	input_line_pointer = str;
851 	r_type = avr_ldi_expression (&op_expr);
852 	str = input_line_pointer;
853 	fix_new_exp (frag_now, where, 3,
854 		     &op_expr, FALSE, r_type);
855       }
856       break;
857 
858     case 'n':
859       {
860 	unsigned int x;
861 
862 	x = ~avr_get_constant (str, 255);
863 	str = input_line_pointer;
864 	op_mask |= (x & 0xf) | ((x << 4) & 0xf00);
865       }
866       break;
867 
868     case 'K':
869       input_line_pointer = str;
870       avr_offset_expression (& op_expr);
871       str = input_line_pointer;
872       fix_new_exp (frag_now, where, 3,
873 		   & op_expr, FALSE, BFD_RELOC_AVR_6_ADIW);
874       break;
875 
876     case 'S':
877     case 's':
878       {
879 	unsigned int x;
880 
881 	x = avr_get_constant (str, 7);
882 	str = input_line_pointer;
883 	if (*op == 'S')
884 	  x <<= 4;
885 	op_mask |= x;
886       }
887       break;
888 
889     case 'P':
890       {
891 	unsigned int x;
892 
893 	x = avr_get_constant (str, 63);
894 	str = input_line_pointer;
895 	op_mask |= (x & 0xf) | ((x & 0x30) << 5);
896       }
897       break;
898 
899     case 'p':
900       {
901 	unsigned int x;
902 
903 	x = avr_get_constant (str, 31);
904 	str = input_line_pointer;
905 	op_mask |= x << 3;
906       }
907       break;
908 
909     case '?':
910       break;
911 
912     default:
913       as_bad (_("unknown constraint `%c'"), *op);
914     }
915 
916   *line = str;
917   return op_mask;
918 }
919 
920 /* Parse instruction operands.
921    Return binary opcode.  */
922 
923 static unsigned int
924 avr_operands (struct avr_opcodes_s *opcode, char **line)
925 {
926   char *op = opcode->constraints;
927   unsigned int bin = opcode->bin_opcode;
928   char *frag = frag_more (opcode->insn_size * 2);
929   char *str = *line;
930   int where = frag - frag_now->fr_literal;
931   static unsigned int prev = 0;  /* Previous opcode.  */
932 
933   /* Opcode have operands.  */
934   if (*op)
935     {
936       unsigned int reg1 = 0;
937       unsigned int reg2 = 0;
938       int reg1_present = 0;
939       int reg2_present = 0;
940 
941       /* Parse first operand.  */
942       if (REGISTER_P (*op))
943 	reg1_present = 1;
944       reg1 = avr_operand (opcode, where, op, &str);
945       ++op;
946 
947       /* Parse second operand.  */
948       if (*op)
949 	{
950 	  if (*op == ',')
951 	    ++op;
952 
953 	  if (*op == '=')
954 	    {
955 	      reg2 = reg1;
956 	      reg2_present = 1;
957 	    }
958 	  else
959 	    {
960 	      if (REGISTER_P (*op))
961 		reg2_present = 1;
962 
963 	      str = skip_space (str);
964 	      if (*str++ != ',')
965 		as_bad (_("`,' required"));
966 	      str = skip_space (str);
967 
968 	      reg2 = avr_operand (opcode, where, op, &str);
969 	    }
970 
971 	  if (reg1_present && reg2_present)
972 	    reg2 = (reg2 & 0xf) | ((reg2 << 5) & 0x200);
973 	  else if (reg2_present)
974 	    reg2 <<= 4;
975 	}
976       if (reg1_present)
977 	reg1 <<= 4;
978       bin |= reg1 | reg2;
979     }
980 
981   /* Detect undefined combinations (like ld r31,Z+).  */
982   if (!avr_opt.all_opcodes && AVR_UNDEF_P (bin))
983     as_warn (_("undefined combination of operands"));
984 
985   if (opcode->insn_size == 2)
986     {
987       /* Warn if the previous opcode was cpse/sbic/sbis/sbrc/sbrs
988          (AVR core bug, fixed in the newer devices).  */
989       if (!(avr_opt.no_skip_bug ||
990             (avr_mcu->isa & (AVR_ISA_MUL | AVR_ISA_MOVW)))
991 	  && AVR_SKIP_P (prev))
992 	as_warn (_("skipping two-word instruction"));
993 
994       bfd_putl32 ((bfd_vma) bin, frag);
995     }
996   else
997     bfd_putl16 ((bfd_vma) bin, frag);
998 
999   prev = bin;
1000   *line = str;
1001   return bin;
1002 }
1003 
1004 /* GAS will call this function for each section at the end of the assembly,
1005    to permit the CPU backend to adjust the alignment of a section.  */
1006 
1007 valueT
1008 md_section_align (asection *seg, valueT addr)
1009 {
1010   int align = bfd_get_section_alignment (stdoutput, seg);
1011   return ((addr + (1 << align) - 1) & (-1 << align));
1012 }
1013 
1014 /* If you define this macro, it should return the offset between the
1015    address of a PC relative fixup and the position from which the PC
1016    relative adjustment should be made.  On many processors, the base
1017    of a PC relative instruction is the next instruction, so this
1018    macro would return the length of an instruction.  */
1019 
1020 long
1021 md_pcrel_from_section (fixS *fixp, segT sec)
1022 {
1023   if (fixp->fx_addsy != (symbolS *) NULL
1024       && (!S_IS_DEFINED (fixp->fx_addsy)
1025 	  || (S_GET_SEGMENT (fixp->fx_addsy) != sec)))
1026     return 0;
1027 
1028   return fixp->fx_frag->fr_address + fixp->fx_where;
1029 }
1030 
1031 /* GAS will call this for each fixup.  It should store the correct
1032    value in the object file.  */
1033 
1034 void
1035 md_apply_fix (fixS *fixP, valueT * valP, segT seg)
1036 {
1037   unsigned char *where;
1038   unsigned long insn;
1039   long value = *valP;
1040 
1041   if (fixP->fx_addsy == (symbolS *) NULL)
1042     fixP->fx_done = 1;
1043 
1044   else if (fixP->fx_pcrel)
1045     {
1046       segT s = S_GET_SEGMENT (fixP->fx_addsy);
1047 
1048       if (s == seg || s == absolute_section)
1049 	{
1050 	  value += S_GET_VALUE (fixP->fx_addsy);
1051 	  fixP->fx_done = 1;
1052 	}
1053     }
1054 
1055   /* We don't actually support subtracting a symbol.  */
1056   if (fixP->fx_subsy != (symbolS *) NULL)
1057     as_bad_where (fixP->fx_file, fixP->fx_line, _("expression too complex"));
1058 
1059   switch (fixP->fx_r_type)
1060     {
1061     default:
1062       fixP->fx_no_overflow = 1;
1063       break;
1064     case BFD_RELOC_AVR_7_PCREL:
1065     case BFD_RELOC_AVR_13_PCREL:
1066     case BFD_RELOC_32:
1067     case BFD_RELOC_16:
1068     case BFD_RELOC_AVR_CALL:
1069       break;
1070     }
1071 
1072   if (fixP->fx_done)
1073     {
1074       /* Fetch the instruction, insert the fully resolved operand
1075 	 value, and stuff the instruction back again.  */
1076       where = (unsigned char *) fixP->fx_frag->fr_literal + fixP->fx_where;
1077       insn = bfd_getl16 (where);
1078 
1079       switch (fixP->fx_r_type)
1080 	{
1081 	case BFD_RELOC_AVR_7_PCREL:
1082 	  if (value & 1)
1083 	    as_bad_where (fixP->fx_file, fixP->fx_line,
1084 			  _("odd address operand: %ld"), value);
1085 
1086 	  /* Instruction addresses are always right-shifted by 1.  */
1087 	  value >>= 1;
1088 	  --value;			/* Correct PC.  */
1089 
1090 	  if (value < -64 || value > 63)
1091 	    as_bad_where (fixP->fx_file, fixP->fx_line,
1092 			  _("operand out of range: %ld"), value);
1093 	  value = (value << 3) & 0x3f8;
1094 	  bfd_putl16 ((bfd_vma) (value | insn), where);
1095 	  break;
1096 
1097 	case BFD_RELOC_AVR_13_PCREL:
1098 	  if (value & 1)
1099 	    as_bad_where (fixP->fx_file, fixP->fx_line,
1100 			  _("odd address operand: %ld"), value);
1101 
1102 	  /* Instruction addresses are always right-shifted by 1.  */
1103 	  value >>= 1;
1104 	  --value;			/* Correct PC.  */
1105 
1106 	  if (value < -2048 || value > 2047)
1107 	    {
1108 	      /* No wrap for devices with >8K of program memory.  */
1109 	      if ((avr_mcu->isa & AVR_ISA_MEGA) || avr_opt.no_wrap)
1110 		as_bad_where (fixP->fx_file, fixP->fx_line,
1111 			      _("operand out of range: %ld"), value);
1112 	    }
1113 
1114 	  value &= 0xfff;
1115 	  bfd_putl16 ((bfd_vma) (value | insn), where);
1116 	  break;
1117 
1118 	case BFD_RELOC_32:
1119 	  bfd_putl16 ((bfd_vma) value, where);
1120 	  break;
1121 
1122 	case BFD_RELOC_16:
1123 	  bfd_putl16 ((bfd_vma) value, where);
1124 	  break;
1125 
1126 	case BFD_RELOC_AVR_16_PM:
1127 	  bfd_putl16 ((bfd_vma) (value >> 1), where);
1128 	  break;
1129 
1130 	case BFD_RELOC_AVR_LDI:
1131 	  if (value > 255)
1132 	    as_bad_where (fixP->fx_file, fixP->fx_line,
1133 			  _("operand out of range: %ld"), value);
1134 	  bfd_putl16 ((bfd_vma) insn | LDI_IMMEDIATE (value), where);
1135 	  break;
1136 
1137 	case BFD_RELOC_AVR_6:
1138 	  if ((value > 63) || (value < 0))
1139 	    as_bad_where (fixP->fx_file, fixP->fx_line,
1140 			  _("operand out of range: %ld"), value);
1141 	  bfd_putl16 ((bfd_vma) insn | ((value & 7) | ((value & (3 << 3)) << 7) | ((value & (1 << 5)) << 8)), where);
1142 	  break;
1143 
1144 	case BFD_RELOC_AVR_6_ADIW:
1145 	  if ((value > 63) || (value < 0))
1146 	    as_bad_where (fixP->fx_file, fixP->fx_line,
1147 			  _("operand out of range: %ld"), value);
1148 	  bfd_putl16 ((bfd_vma) insn | (value & 0xf) | ((value & 0x30) << 2), where);
1149 	  break;
1150 
1151 	case BFD_RELOC_AVR_LO8_LDI:
1152 	  bfd_putl16 ((bfd_vma) insn | LDI_IMMEDIATE (value), where);
1153 	  break;
1154 
1155 	case BFD_RELOC_AVR_HI8_LDI:
1156 	  bfd_putl16 ((bfd_vma) insn | LDI_IMMEDIATE (value >> 8), where);
1157 	  break;
1158 
1159 	case BFD_RELOC_AVR_MS8_LDI:
1160 	  bfd_putl16 ((bfd_vma) insn | LDI_IMMEDIATE (value >> 24), where);
1161 	  break;
1162 
1163 	case BFD_RELOC_AVR_HH8_LDI:
1164 	  bfd_putl16 ((bfd_vma) insn | LDI_IMMEDIATE (value >> 16), where);
1165 	  break;
1166 
1167 	case BFD_RELOC_AVR_LO8_LDI_NEG:
1168 	  bfd_putl16 ((bfd_vma) insn | LDI_IMMEDIATE (-value), where);
1169 	  break;
1170 
1171 	case BFD_RELOC_AVR_HI8_LDI_NEG:
1172 	  bfd_putl16 ((bfd_vma) insn | LDI_IMMEDIATE (-value >> 8), where);
1173 	  break;
1174 
1175 	case BFD_RELOC_AVR_MS8_LDI_NEG:
1176 	  bfd_putl16 ((bfd_vma) insn | LDI_IMMEDIATE (-value >> 24), where);
1177 	  break;
1178 
1179 	case BFD_RELOC_AVR_HH8_LDI_NEG:
1180 	  bfd_putl16 ((bfd_vma) insn | LDI_IMMEDIATE (-value >> 16), where);
1181 	  break;
1182 
1183 	case BFD_RELOC_AVR_LO8_LDI_PM:
1184 	  bfd_putl16 ((bfd_vma) insn | LDI_IMMEDIATE (value >> 1), where);
1185 	  break;
1186 
1187 	case BFD_RELOC_AVR_HI8_LDI_PM:
1188 	  bfd_putl16 ((bfd_vma) insn | LDI_IMMEDIATE (value >> 9), where);
1189 	  break;
1190 
1191 	case BFD_RELOC_AVR_HH8_LDI_PM:
1192 	  bfd_putl16 ((bfd_vma) insn | LDI_IMMEDIATE (value >> 17), where);
1193 	  break;
1194 
1195 	case BFD_RELOC_AVR_LO8_LDI_PM_NEG:
1196 	  bfd_putl16 ((bfd_vma) insn | LDI_IMMEDIATE (-value >> 1), where);
1197 	  break;
1198 
1199 	case BFD_RELOC_AVR_HI8_LDI_PM_NEG:
1200 	  bfd_putl16 ((bfd_vma) insn | LDI_IMMEDIATE (-value >> 9), where);
1201 	  break;
1202 
1203 	case BFD_RELOC_AVR_HH8_LDI_PM_NEG:
1204 	  bfd_putl16 ((bfd_vma) insn | LDI_IMMEDIATE (-value >> 17), where);
1205 	  break;
1206 
1207 	case BFD_RELOC_AVR_CALL:
1208 	  {
1209 	    unsigned long x;
1210 
1211 	    x = bfd_getl16 (where);
1212 	    if (value & 1)
1213 	      as_bad_where (fixP->fx_file, fixP->fx_line,
1214 			    _("odd address operand: %ld"), value);
1215 	    value >>= 1;
1216 	    x |= ((value & 0x10000) | ((value << 3) & 0x1f00000)) >> 16;
1217 	    bfd_putl16 ((bfd_vma) x, where);
1218 	    bfd_putl16 ((bfd_vma) (value & 0xffff), where + 2);
1219 	  }
1220 	  break;
1221 
1222 	default:
1223 	  as_fatal (_("line %d: unknown relocation type: 0x%x"),
1224 		    fixP->fx_line, fixP->fx_r_type);
1225 	  break;
1226 	}
1227     }
1228   else
1229     {
1230       switch (fixP->fx_r_type)
1231 	{
1232 	case -BFD_RELOC_AVR_HI8_LDI_NEG:
1233 	case -BFD_RELOC_AVR_HI8_LDI:
1234 	case -BFD_RELOC_AVR_LO8_LDI_NEG:
1235 	case -BFD_RELOC_AVR_LO8_LDI:
1236 	  as_bad_where (fixP->fx_file, fixP->fx_line,
1237 			_("only constant expression allowed"));
1238 	  fixP->fx_done = 1;
1239 	  break;
1240 	default:
1241 	  break;
1242 	}
1243     }
1244 }
1245 
1246 /* GAS will call this to generate a reloc, passing the resulting reloc
1247    to `bfd_install_relocation'.  This currently works poorly, as
1248    `bfd_install_relocation' often does the wrong thing, and instances of
1249    `tc_gen_reloc' have been written to work around the problems, which
1250    in turns makes it difficult to fix `bfd_install_relocation'.  */
1251 
1252 /* If while processing a fixup, a reloc really needs to be created
1253    then it is done here.  */
1254 
1255 arelent *
1256 tc_gen_reloc (asection *seg ATTRIBUTE_UNUSED,
1257 	      fixS *fixp)
1258 {
1259   arelent *reloc;
1260 
1261   if (fixp->fx_addsy && fixp->fx_subsy)
1262     {
1263       long value = 0;
1264 
1265       if ((S_GET_SEGMENT (fixp->fx_addsy) != S_GET_SEGMENT (fixp->fx_subsy))
1266           || S_GET_SEGMENT (fixp->fx_addsy) == undefined_section)
1267         {
1268           as_bad_where (fixp->fx_file, fixp->fx_line,
1269               "Difference of symbols in different sections is not supported");
1270           return NULL;
1271         }
1272 
1273       /* We are dealing with two symbols defined in the same section.
1274          Let us fix-up them here.  */
1275       value += S_GET_VALUE (fixp->fx_addsy);
1276       value -= S_GET_VALUE (fixp->fx_subsy);
1277 
1278       /* When fx_addsy and fx_subsy both are zero, md_apply_fix
1279          only takes it's second operands for the fixup value.  */
1280       fixp->fx_addsy = NULL;
1281       fixp->fx_subsy = NULL;
1282       md_apply_fix (fixp, (valueT *) &value, NULL);
1283 
1284       return NULL;
1285     }
1286 
1287   reloc = xmalloc (sizeof (arelent));
1288 
1289   reloc->sym_ptr_ptr = xmalloc (sizeof (asymbol *));
1290   *reloc->sym_ptr_ptr = symbol_get_bfdsym (fixp->fx_addsy);
1291 
1292   reloc->address = fixp->fx_frag->fr_address + fixp->fx_where;
1293   reloc->howto = bfd_reloc_type_lookup (stdoutput, fixp->fx_r_type);
1294   if (reloc->howto == (reloc_howto_type *) NULL)
1295     {
1296       as_bad_where (fixp->fx_file, fixp->fx_line,
1297 		    _("reloc %d not supported by object file format"),
1298 		    (int) fixp->fx_r_type);
1299       return NULL;
1300     }
1301 
1302   if (fixp->fx_r_type == BFD_RELOC_VTABLE_INHERIT
1303       || fixp->fx_r_type == BFD_RELOC_VTABLE_ENTRY)
1304     reloc->address = fixp->fx_offset;
1305 
1306   reloc->addend = fixp->fx_offset;
1307 
1308   return reloc;
1309 }
1310 
1311 void
1312 md_assemble (char *str)
1313 {
1314   struct avr_opcodes_s *opcode;
1315   char op[11];
1316 
1317   str = skip_space (extract_word (str, op, sizeof (op)));
1318 
1319   if (!op[0])
1320     as_bad (_("can't find opcode "));
1321 
1322   opcode = (struct avr_opcodes_s *) hash_find (avr_hash, op);
1323 
1324   if (opcode == NULL)
1325     {
1326       as_bad (_("unknown opcode `%s'"), op);
1327       return;
1328     }
1329 
1330   /* Special case for opcodes with optional operands (lpm, elpm) -
1331      version with operands exists in avr_opcodes[] in the next entry.  */
1332 
1333   if (*str && *opcode->constraints == '?')
1334     ++opcode;
1335 
1336   if (!avr_opt.all_opcodes && (opcode->isa & avr_mcu->isa) != opcode->isa)
1337     as_bad (_("illegal opcode %s for mcu %s"), opcode->name, avr_mcu->name);
1338 
1339   /* We used to set input_line_pointer to the result of get_operands,
1340      but that is wrong.  Our caller assumes we don't change it.  */
1341   {
1342     char *t = input_line_pointer;
1343 
1344     avr_operands (opcode, &str);
1345     if (*skip_space (str))
1346       as_bad (_("garbage at end of line"));
1347     input_line_pointer = t;
1348   }
1349 }
1350 
1351 /* Flag to pass `pm' mode between `avr_parse_cons_expression' and
1352    `avr_cons_fix_new'.  */
1353 static int exp_mod_pm = 0;
1354 
1355 /* Parse special CONS expression: pm (expression)
1356    or alternatively: gs (expression).
1357    These are used for addressing program memory.
1358    Relocation: BFD_RELOC_AVR_16_PM.  */
1359 
1360 void
1361 avr_parse_cons_expression (expressionS *exp, int nbytes)
1362 {
1363   char *tmp;
1364 
1365   exp_mod_pm = 0;
1366 
1367   tmp = input_line_pointer = skip_space (input_line_pointer);
1368 
1369   if (nbytes == 2)
1370     {
1371       char *pm_name1 = "pm";
1372       char *pm_name2 = "gs";
1373       int len = strlen (pm_name1);
1374       /* len must be the same for both pm identifiers.  */
1375 
1376       if (strncasecmp (input_line_pointer, pm_name1, len) == 0
1377           || strncasecmp (input_line_pointer, pm_name2, len) == 0)
1378 	{
1379 	  input_line_pointer = skip_space (input_line_pointer + len);
1380 
1381 	  if (*input_line_pointer == '(')
1382 	    {
1383 	      input_line_pointer = skip_space (input_line_pointer + 1);
1384 	      exp_mod_pm = 1;
1385 	      expression (exp);
1386 
1387 	      if (*input_line_pointer == ')')
1388 		++input_line_pointer;
1389 	      else
1390 		{
1391 		  as_bad (_("`)' required"));
1392 		  exp_mod_pm = 0;
1393 		}
1394 
1395 	      return;
1396 	    }
1397 
1398 	  input_line_pointer = tmp;
1399 	}
1400     }
1401 
1402   expression (exp);
1403 }
1404 
1405 void
1406 avr_cons_fix_new (fragS *frag,
1407 		  int where,
1408 		  int nbytes,
1409 		  expressionS *exp)
1410 {
1411   if (exp_mod_pm == 0)
1412     {
1413       if (nbytes == 2)
1414 	fix_new_exp (frag, where, nbytes, exp, FALSE, BFD_RELOC_16);
1415       else if (nbytes == 4)
1416 	fix_new_exp (frag, where, nbytes, exp, FALSE, BFD_RELOC_32);
1417       else
1418 	as_bad (_("illegal %srelocation size: %d"), "", nbytes);
1419     }
1420   else
1421     {
1422       if (nbytes == 2)
1423 	fix_new_exp (frag, where, nbytes, exp, FALSE, BFD_RELOC_AVR_16_PM);
1424       else
1425 	as_bad (_("illegal %srelocation size: %d"), "`pm' ", nbytes);
1426       exp_mod_pm = 0;
1427     }
1428 }
1429