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Commit | Line | Data |
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3916d6d8 | 1 | /* Support routines for the various generation passes. |
d9221e01 | 2 | Copyright (C) 2000, 2001, 2002, 2003, 2004 |
3d7aafde | 3 | Free Software Foundation, Inc. |
c88c0d42 | 4 | |
1322177d | 5 | This file is part of GCC. |
c88c0d42 | 6 | |
1322177d LB |
7 | GCC is free software; you can redistribute it and/or modify it |
8 | under the terms of the GNU General Public License as published by | |
c88c0d42 CP |
9 | the Free Software Foundation; either version 2, or (at your option) |
10 | any later version. | |
11 | ||
1322177d LB |
12 | GCC is distributed in the hope that it will be useful, but WITHOUT |
13 | ANY WARRANTY; without even the implied warranty of MERCHANTABILITY | |
14 | or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public | |
15 | License for more details. | |
c88c0d42 CP |
16 | |
17 | You should have received a copy of the GNU General Public License | |
1322177d LB |
18 | along with GCC; see the file COPYING. If not, write to the Free |
19 | Software Foundation, 59 Temple Place - Suite 330, Boston, MA | |
20 | 02111-1307, USA. */ | |
c88c0d42 | 21 | |
4977bab6 | 22 | #include "bconfig.h" |
c88c0d42 | 23 | #include "system.h" |
4977bab6 ZW |
24 | #include "coretypes.h" |
25 | #include "tm.h" | |
c88c0d42 | 26 | #include "rtl.h" |
3916d6d8 | 27 | #include "obstack.h" |
c88c0d42 | 28 | #include "errors.h" |
2199e5fa | 29 | #include "hashtab.h" |
c88c0d42 CP |
30 | #include "gensupport.h" |
31 | ||
3916d6d8 | 32 | |
c8cf201f RK |
33 | /* In case some macros used by files we include need it, define this here. */ |
34 | int target_flags; | |
35 | ||
2199e5fa ZW |
36 | int insn_elision = 1; |
37 | ||
3916d6d8 RH |
38 | static struct obstack obstack; |
39 | struct obstack *rtl_obstack = &obstack; | |
40 | ||
c88c0d42 | 41 | static int sequence_num; |
3262c1f5 RH |
42 | static int errors; |
43 | ||
44 | static int predicable_default; | |
45 | static const char *predicable_true; | |
46 | static const char *predicable_false; | |
47 | ||
2199e5fa ZW |
48 | static htab_t condition_table; |
49 | ||
04d8aa70 AM |
50 | static char *base_dir = NULL; |
51 | ||
3262c1f5 RH |
52 | /* We initially queue all patterns, process the define_insn and |
53 | define_cond_exec patterns, then return them one at a time. */ | |
c88c0d42 | 54 | |
3262c1f5 RH |
55 | struct queue_elem |
56 | { | |
57 | rtx data; | |
821e35ba | 58 | const char *filename; |
3262c1f5 RH |
59 | int lineno; |
60 | struct queue_elem *next; | |
a406f566 MM |
61 | /* In a DEFINE_INSN that came from a DEFINE_INSN_AND_SPLIT, SPLIT |
62 | points to the generated DEFINE_SPLIT. */ | |
63 | struct queue_elem *split; | |
c88c0d42 CP |
64 | }; |
65 | ||
3262c1f5 RH |
66 | static struct queue_elem *define_attr_queue; |
67 | static struct queue_elem **define_attr_tail = &define_attr_queue; | |
68 | static struct queue_elem *define_insn_queue; | |
69 | static struct queue_elem **define_insn_tail = &define_insn_queue; | |
70 | static struct queue_elem *define_cond_exec_queue; | |
71 | static struct queue_elem **define_cond_exec_tail = &define_cond_exec_queue; | |
72 | static struct queue_elem *other_queue; | |
73 | static struct queue_elem **other_tail = &other_queue; | |
c88c0d42 | 74 | |
a406f566 MM |
75 | static struct queue_elem *queue_pattern (rtx, struct queue_elem ***, |
76 | const char *, int); | |
04d8aa70 AM |
77 | |
78 | /* Current maximum length of directory names in the search path | |
79 | for include files. (Altered as we get more of them.) */ | |
80 | ||
81 | size_t max_include_len; | |
82 | ||
83 | struct file_name_list | |
84 | { | |
85 | struct file_name_list *next; | |
86 | const char *fname; | |
87 | }; | |
88 | ||
4ec59de2 | 89 | struct file_name_list *first_dir_md_include = 0; /* First dir to search */ |
04d8aa70 AM |
90 | /* First dir to search for <file> */ |
91 | struct file_name_list *first_bracket_include = 0; | |
4ec59de2 | 92 | struct file_name_list *last_dir_md_include = 0; /* Last in chain */ |
04d8aa70 | 93 | |
3d7aafde AJ |
94 | static void remove_constraints (rtx); |
95 | static void process_rtx (rtx, int); | |
96 | ||
97 | static int is_predicable (struct queue_elem *); | |
98 | static void identify_predicable_attribute (void); | |
99 | static int n_alternatives (const char *); | |
100 | static void collect_insn_data (rtx, int *, int *); | |
101 | static rtx alter_predicate_for_insn (rtx, int, int, int); | |
102 | static const char *alter_test_for_insn (struct queue_elem *, | |
103 | struct queue_elem *); | |
104 | static char *shift_output_template (char *, const char *, int); | |
105 | static const char *alter_output_for_insn (struct queue_elem *, | |
106 | struct queue_elem *, | |
107 | int, int); | |
108 | static void process_one_cond_exec (struct queue_elem *); | |
109 | static void process_define_cond_exec (void); | |
110 | static void process_include (rtx, int); | |
111 | static char *save_string (const char *, int); | |
3916d6d8 RH |
112 | \f |
113 | void | |
e34d07f2 | 114 | message_with_line (int lineno, const char *msg, ...) |
3916d6d8 | 115 | { |
e34d07f2 | 116 | va_list ap; |
3d7aafde | 117 | |
e34d07f2 | 118 | va_start (ap, msg); |
36244024 | 119 | |
3916d6d8 RH |
120 | fprintf (stderr, "%s:%d: ", read_rtx_filename, lineno); |
121 | vfprintf (stderr, msg, ap); | |
122 | fputc ('\n', stderr); | |
123 | ||
e34d07f2 | 124 | va_end (ap); |
3916d6d8 | 125 | } |
10b76d73 RK |
126 | |
127 | /* Make a version of gen_rtx_CONST_INT so that GEN_INT can be used in | |
128 | the gensupport programs. */ | |
129 | ||
130 | rtx | |
e18476eb | 131 | gen_rtx_CONST_INT (enum machine_mode ARG_UNUSED (mode), |
3d7aafde | 132 | HOST_WIDE_INT arg) |
10b76d73 RK |
133 | { |
134 | rtx rt = rtx_alloc (CONST_INT); | |
135 | ||
136 | XWINT (rt, 0) = arg; | |
137 | return rt; | |
138 | } | |
3916d6d8 | 139 | \f |
a406f566 MM |
140 | /* Queue PATTERN on LIST_TAIL. Return the address of the new queue |
141 | element. */ | |
3262c1f5 | 142 | |
a406f566 | 143 | static struct queue_elem * |
3d7aafde AJ |
144 | queue_pattern (rtx pattern, struct queue_elem ***list_tail, |
145 | const char *filename, int lineno) | |
3262c1f5 | 146 | { |
703ad42b | 147 | struct queue_elem *e = xmalloc (sizeof (*e)); |
3262c1f5 | 148 | e->data = pattern; |
821e35ba | 149 | e->filename = filename; |
3262c1f5 RH |
150 | e->lineno = lineno; |
151 | e->next = NULL; | |
a406f566 | 152 | e->split = NULL; |
3262c1f5 RH |
153 | **list_tail = e; |
154 | *list_tail = &e->next; | |
a406f566 | 155 | return e; |
3262c1f5 RH |
156 | } |
157 | ||
c88c0d42 CP |
158 | /* Recursively remove constraints from an rtx. */ |
159 | ||
160 | static void | |
3d7aafde | 161 | remove_constraints (rtx part) |
c88c0d42 | 162 | { |
b3694847 SS |
163 | int i, j; |
164 | const char *format_ptr; | |
c88c0d42 CP |
165 | |
166 | if (part == 0) | |
167 | return; | |
168 | ||
169 | if (GET_CODE (part) == MATCH_OPERAND) | |
170 | XSTR (part, 2) = ""; | |
171 | else if (GET_CODE (part) == MATCH_SCRATCH) | |
172 | XSTR (part, 1) = ""; | |
173 | ||
174 | format_ptr = GET_RTX_FORMAT (GET_CODE (part)); | |
175 | ||
176 | for (i = 0; i < GET_RTX_LENGTH (GET_CODE (part)); i++) | |
177 | switch (*format_ptr++) | |
178 | { | |
179 | case 'e': | |
180 | case 'u': | |
181 | remove_constraints (XEXP (part, i)); | |
182 | break; | |
183 | case 'E': | |
184 | if (XVEC (part, i) != NULL) | |
185 | for (j = 0; j < XVECLEN (part, i); j++) | |
186 | remove_constraints (XVECEXP (part, i, j)); | |
187 | break; | |
188 | } | |
189 | } | |
190 | ||
3d7aafde | 191 | /* Process an include file assuming that it lives in gcc/config/{target}/ |
80815706 | 192 | if the include looks like (include "file"). */ |
174cc7d1 RH |
193 | |
194 | static void | |
3d7aafde | 195 | process_include (rtx desc, int lineno) |
04d8aa70 AM |
196 | { |
197 | const char *filename = XSTR (desc, 0); | |
174cc7d1 RH |
198 | const char *old_filename; |
199 | int old_lineno; | |
200 | char *pathname; | |
04d8aa70 | 201 | FILE *input_file; |
04d8aa70 | 202 | |
174cc7d1 | 203 | /* If specified file name is absolute, skip the include stack. */ |
3dce1408 | 204 | if (! IS_ABSOLUTE_PATH (filename)) |
04d8aa70 | 205 | { |
174cc7d1 RH |
206 | struct file_name_list *stackp; |
207 | ||
208 | /* Search directory path, trying to open the file. */ | |
209 | for (stackp = first_dir_md_include; stackp; stackp = stackp->next) | |
04d8aa70 | 210 | { |
174cc7d1 RH |
211 | static const char sep[2] = { DIR_SEPARATOR, '\0' }; |
212 | ||
213 | pathname = concat (stackp->fname, sep, filename, NULL); | |
214 | input_file = fopen (pathname, "r"); | |
3d7aafde | 215 | if (input_file != NULL) |
174cc7d1 RH |
216 | goto success; |
217 | free (pathname); | |
04d8aa70 AM |
218 | } |
219 | } | |
04d8aa70 | 220 | |
174cc7d1 RH |
221 | if (base_dir) |
222 | pathname = concat (base_dir, filename, NULL); | |
223 | else | |
224 | pathname = xstrdup (filename); | |
225 | input_file = fopen (pathname, "r"); | |
226 | if (input_file == NULL) | |
227 | { | |
228 | free (pathname); | |
229 | message_with_line (lineno, "include file `%s' not found", filename); | |
230 | errors = 1; | |
231 | return; | |
232 | } | |
233 | success: | |
04d8aa70 | 234 | |
174cc7d1 RH |
235 | /* Save old cursor; setup new for the new file. Note that "lineno" the |
236 | argument to this function is the beginning of the include statement, | |
237 | while read_rtx_lineno has already been advanced. */ | |
238 | old_filename = read_rtx_filename; | |
239 | old_lineno = read_rtx_lineno; | |
240 | read_rtx_filename = pathname; | |
241 | read_rtx_lineno = 1; | |
04d8aa70 | 242 | |
174cc7d1 RH |
243 | /* Read the entire file. */ |
244 | while (1) | |
245 | { | |
246 | rtx desc; | |
247 | int c; | |
04d8aa70 | 248 | |
174cc7d1 RH |
249 | c = read_skip_spaces (input_file); |
250 | if (c == EOF) | |
251 | break; | |
04d8aa70 | 252 | |
174cc7d1 RH |
253 | ungetc (c, input_file); |
254 | lineno = read_rtx_lineno; | |
255 | desc = read_rtx (input_file); | |
256 | process_rtx (desc, lineno); | |
04d8aa70 AM |
257 | } |
258 | ||
821e35ba RH |
259 | /* Do not free pathname. It is attached to the various rtx queue |
260 | elements. */ | |
261 | ||
174cc7d1 RH |
262 | read_rtx_filename = old_filename; |
263 | read_rtx_lineno = old_lineno; | |
04d8aa70 | 264 | |
174cc7d1 | 265 | fclose (input_file); |
04d8aa70 AM |
266 | } |
267 | ||
d91edf86 | 268 | /* Process a top level rtx in some way, queuing as appropriate. */ |
c88c0d42 CP |
269 | |
270 | static void | |
3d7aafde | 271 | process_rtx (rtx desc, int lineno) |
3262c1f5 RH |
272 | { |
273 | switch (GET_CODE (desc)) | |
274 | { | |
275 | case DEFINE_INSN: | |
821e35ba | 276 | queue_pattern (desc, &define_insn_tail, read_rtx_filename, lineno); |
3262c1f5 RH |
277 | break; |
278 | ||
279 | case DEFINE_COND_EXEC: | |
821e35ba | 280 | queue_pattern (desc, &define_cond_exec_tail, read_rtx_filename, lineno); |
3262c1f5 RH |
281 | break; |
282 | ||
283 | case DEFINE_ATTR: | |
821e35ba | 284 | queue_pattern (desc, &define_attr_tail, read_rtx_filename, lineno); |
3262c1f5 RH |
285 | break; |
286 | ||
04d8aa70 | 287 | case INCLUDE: |
174cc7d1 | 288 | process_include (desc, lineno); |
04d8aa70 AM |
289 | break; |
290 | ||
3262c1f5 RH |
291 | case DEFINE_INSN_AND_SPLIT: |
292 | { | |
293 | const char *split_cond; | |
20217ac1 KG |
294 | rtx split; |
295 | rtvec attr; | |
de4bfbcb | 296 | int i; |
a406f566 MM |
297 | struct queue_elem *insn_elem; |
298 | struct queue_elem *split_elem; | |
3262c1f5 | 299 | |
dc297297 | 300 | /* Create a split with values from the insn_and_split. */ |
3262c1f5 | 301 | split = rtx_alloc (DEFINE_SPLIT); |
de4bfbcb RH |
302 | |
303 | i = XVECLEN (desc, 1); | |
fbd40359 | 304 | XVEC (split, 0) = rtvec_alloc (i); |
de4bfbcb RH |
305 | while (--i >= 0) |
306 | { | |
307 | XVECEXP (split, 0, i) = copy_rtx (XVECEXP (desc, 1, i)); | |
308 | remove_constraints (XVECEXP (split, 0, i)); | |
309 | } | |
3262c1f5 RH |
310 | |
311 | /* If the split condition starts with "&&", append it to the | |
312 | insn condition to create the new split condition. */ | |
313 | split_cond = XSTR (desc, 4); | |
314 | if (split_cond[0] == '&' && split_cond[1] == '&') | |
1dcd444b | 315 | split_cond = concat (XSTR (desc, 2), split_cond, NULL); |
3262c1f5 RH |
316 | XSTR (split, 1) = split_cond; |
317 | XVEC (split, 2) = XVEC (desc, 5); | |
318 | XSTR (split, 3) = XSTR (desc, 6); | |
319 | ||
320 | /* Fix up the DEFINE_INSN. */ | |
ee138cf8 | 321 | attr = XVEC (desc, 7); |
3262c1f5 | 322 | PUT_CODE (desc, DEFINE_INSN); |
ee138cf8 | 323 | XVEC (desc, 4) = attr; |
3262c1f5 RH |
324 | |
325 | /* Queue them. */ | |
a406f566 MM |
326 | insn_elem |
327 | = queue_pattern (desc, &define_insn_tail, read_rtx_filename, | |
328 | lineno); | |
329 | split_elem | |
330 | = queue_pattern (split, &other_tail, read_rtx_filename, lineno); | |
331 | insn_elem->split = split_elem; | |
3262c1f5 RH |
332 | break; |
333 | } | |
334 | ||
335 | default: | |
821e35ba | 336 | queue_pattern (desc, &other_tail, read_rtx_filename, lineno); |
3262c1f5 | 337 | break; |
c88c0d42 CP |
338 | } |
339 | } | |
3916d6d8 | 340 | \f |
3262c1f5 RH |
341 | /* Return true if attribute PREDICABLE is true for ELEM, which holds |
342 | a DEFINE_INSN. */ | |
343 | ||
344 | static int | |
3d7aafde | 345 | is_predicable (struct queue_elem *elem) |
3262c1f5 RH |
346 | { |
347 | rtvec vec = XVEC (elem->data, 4); | |
348 | const char *value; | |
349 | int i; | |
350 | ||
351 | if (! vec) | |
352 | return predicable_default; | |
353 | ||
354 | for (i = GET_NUM_ELEM (vec) - 1; i >= 0; --i) | |
355 | { | |
356 | rtx sub = RTVEC_ELT (vec, i); | |
357 | switch (GET_CODE (sub)) | |
358 | { | |
359 | case SET_ATTR: | |
360 | if (strcmp (XSTR (sub, 0), "predicable") == 0) | |
361 | { | |
362 | value = XSTR (sub, 1); | |
363 | goto found; | |
364 | } | |
365 | break; | |
366 | ||
367 | case SET_ATTR_ALTERNATIVE: | |
368 | if (strcmp (XSTR (sub, 0), "predicable") == 0) | |
369 | { | |
370 | message_with_line (elem->lineno, | |
371 | "multiple alternatives for `predicable'"); | |
372 | errors = 1; | |
373 | return 0; | |
374 | } | |
375 | break; | |
376 | ||
377 | case SET: | |
378 | if (GET_CODE (SET_DEST (sub)) != ATTR | |
379 | || strcmp (XSTR (SET_DEST (sub), 0), "predicable") != 0) | |
380 | break; | |
381 | sub = SET_SRC (sub); | |
382 | if (GET_CODE (sub) == CONST_STRING) | |
383 | { | |
384 | value = XSTR (sub, 0); | |
385 | goto found; | |
386 | } | |
387 | ||
388 | /* ??? It would be possible to handle this if we really tried. | |
389 | It's not easy though, and I'm not going to bother until it | |
390 | really proves necessary. */ | |
391 | message_with_line (elem->lineno, | |
392 | "non-constant value for `predicable'"); | |
393 | errors = 1; | |
394 | return 0; | |
395 | ||
396 | default: | |
397 | abort (); | |
398 | } | |
399 | } | |
400 | ||
401 | return predicable_default; | |
402 | ||
403 | found: | |
404 | /* Verify that predicability does not vary on the alternative. */ | |
405 | /* ??? It should be possible to handle this by simply eliminating | |
406 | the non-predicable alternatives from the insn. FRV would like | |
407 | to do this. Delay this until we've got the basics solid. */ | |
408 | if (strchr (value, ',') != NULL) | |
409 | { | |
410 | message_with_line (elem->lineno, | |
411 | "multiple alternatives for `predicable'"); | |
412 | errors = 1; | |
413 | return 0; | |
414 | } | |
415 | ||
416 | /* Find out which value we're looking at. */ | |
417 | if (strcmp (value, predicable_true) == 0) | |
418 | return 1; | |
419 | if (strcmp (value, predicable_false) == 0) | |
420 | return 0; | |
421 | ||
422 | message_with_line (elem->lineno, | |
1f978f5f | 423 | "unknown value `%s' for `predicable' attribute", |
3262c1f5 RH |
424 | value); |
425 | errors = 1; | |
426 | return 0; | |
427 | } | |
428 | ||
429 | /* Examine the attribute "predicable"; discover its boolean values | |
430 | and its default. */ | |
431 | ||
432 | static void | |
3d7aafde | 433 | identify_predicable_attribute (void) |
3262c1f5 RH |
434 | { |
435 | struct queue_elem *elem; | |
d6edb99e | 436 | char *p_true, *p_false; |
3262c1f5 | 437 | const char *value; |
3262c1f5 RH |
438 | |
439 | /* Look for the DEFINE_ATTR for `predicable', which must exist. */ | |
440 | for (elem = define_attr_queue; elem ; elem = elem->next) | |
441 | if (strcmp (XSTR (elem->data, 0), "predicable") == 0) | |
442 | goto found; | |
443 | ||
444 | message_with_line (define_cond_exec_queue->lineno, | |
1f978f5f | 445 | "attribute `predicable' not defined"); |
3262c1f5 RH |
446 | errors = 1; |
447 | return; | |
448 | ||
449 | found: | |
450 | value = XSTR (elem->data, 1); | |
1dcd444b | 451 | p_false = xstrdup (value); |
d6edb99e ZW |
452 | p_true = strchr (p_false, ','); |
453 | if (p_true == NULL || strchr (++p_true, ',') != NULL) | |
3262c1f5 RH |
454 | { |
455 | message_with_line (elem->lineno, | |
1f978f5f | 456 | "attribute `predicable' is not a boolean"); |
3262c1f5 RH |
457 | errors = 1; |
458 | return; | |
459 | } | |
d6edb99e | 460 | p_true[-1] = '\0'; |
3262c1f5 | 461 | |
d6edb99e ZW |
462 | predicable_true = p_true; |
463 | predicable_false = p_false; | |
3262c1f5 RH |
464 | |
465 | switch (GET_CODE (XEXP (elem->data, 2))) | |
466 | { | |
467 | case CONST_STRING: | |
468 | value = XSTR (XEXP (elem->data, 2), 0); | |
469 | break; | |
470 | ||
471 | case CONST: | |
472 | message_with_line (elem->lineno, | |
1f978f5f | 473 | "attribute `predicable' cannot be const"); |
3262c1f5 RH |
474 | errors = 1; |
475 | return; | |
476 | ||
477 | default: | |
478 | message_with_line (elem->lineno, | |
1f978f5f | 479 | "attribute `predicable' must have a constant default"); |
3262c1f5 RH |
480 | errors = 1; |
481 | return; | |
482 | } | |
483 | ||
d6edb99e | 484 | if (strcmp (value, p_true) == 0) |
3262c1f5 | 485 | predicable_default = 1; |
d6edb99e | 486 | else if (strcmp (value, p_false) == 0) |
3262c1f5 RH |
487 | predicable_default = 0; |
488 | else | |
489 | { | |
490 | message_with_line (elem->lineno, | |
1f978f5f | 491 | "unknown value `%s' for `predicable' attribute", |
3262c1f5 RH |
492 | value); |
493 | errors = 1; | |
494 | } | |
495 | } | |
496 | ||
497 | /* Return the number of alternatives in constraint S. */ | |
498 | ||
499 | static int | |
3d7aafde | 500 | n_alternatives (const char *s) |
3262c1f5 RH |
501 | { |
502 | int n = 1; | |
503 | ||
504 | if (s) | |
505 | while (*s) | |
506 | n += (*s++ == ','); | |
507 | ||
508 | return n; | |
509 | } | |
510 | ||
511 | /* Determine how many alternatives there are in INSN, and how many | |
512 | operands. */ | |
513 | ||
514 | static void | |
3d7aafde | 515 | collect_insn_data (rtx pattern, int *palt, int *pmax) |
3262c1f5 RH |
516 | { |
517 | const char *fmt; | |
518 | enum rtx_code code; | |
519 | int i, j, len; | |
520 | ||
521 | code = GET_CODE (pattern); | |
522 | switch (code) | |
523 | { | |
524 | case MATCH_OPERAND: | |
892ecf92 RH |
525 | i = n_alternatives (XSTR (pattern, 2)); |
526 | *palt = (i > *palt ? i : *palt); | |
5d3cc252 | 527 | /* Fall through. */ |
3262c1f5 RH |
528 | |
529 | case MATCH_OPERATOR: | |
530 | case MATCH_SCRATCH: | |
531 | case MATCH_PARALLEL: | |
3262c1f5 RH |
532 | i = XINT (pattern, 0); |
533 | if (i > *pmax) | |
534 | *pmax = i; | |
535 | break; | |
536 | ||
537 | default: | |
538 | break; | |
539 | } | |
540 | ||
541 | fmt = GET_RTX_FORMAT (code); | |
542 | len = GET_RTX_LENGTH (code); | |
543 | for (i = 0; i < len; i++) | |
544 | { | |
545 | switch (fmt[i]) | |
546 | { | |
547 | case 'e': case 'u': | |
548 | collect_insn_data (XEXP (pattern, i), palt, pmax); | |
549 | break; | |
550 | ||
551 | case 'V': | |
552 | if (XVEC (pattern, i) == NULL) | |
553 | break; | |
5d3cc252 | 554 | /* Fall through. */ |
3262c1f5 RH |
555 | case 'E': |
556 | for (j = XVECLEN (pattern, i) - 1; j >= 0; --j) | |
557 | collect_insn_data (XVECEXP (pattern, i, j), palt, pmax); | |
558 | break; | |
559 | ||
3b324340 | 560 | case 'i': case 'w': case '0': case 's': case 'S': case 'T': |
3262c1f5 RH |
561 | break; |
562 | ||
563 | default: | |
564 | abort (); | |
565 | } | |
566 | } | |
567 | } | |
568 | ||
569 | static rtx | |
3d7aafde | 570 | alter_predicate_for_insn (rtx pattern, int alt, int max_op, int lineno) |
3262c1f5 RH |
571 | { |
572 | const char *fmt; | |
573 | enum rtx_code code; | |
574 | int i, j, len; | |
575 | ||
576 | code = GET_CODE (pattern); | |
577 | switch (code) | |
578 | { | |
579 | case MATCH_OPERAND: | |
580 | { | |
581 | const char *c = XSTR (pattern, 2); | |
582 | ||
583 | if (n_alternatives (c) != 1) | |
584 | { | |
585 | message_with_line (lineno, | |
1f978f5f | 586 | "too many alternatives for operand %d", |
3262c1f5 RH |
587 | XINT (pattern, 0)); |
588 | errors = 1; | |
589 | return NULL; | |
590 | } | |
591 | ||
592 | /* Replicate C as needed to fill out ALT alternatives. */ | |
593 | if (c && *c && alt > 1) | |
594 | { | |
595 | size_t c_len = strlen (c); | |
596 | size_t len = alt * (c_len + 1); | |
703ad42b | 597 | char *new_c = xmalloc (len); |
3262c1f5 RH |
598 | |
599 | memcpy (new_c, c, c_len); | |
600 | for (i = 1; i < alt; ++i) | |
601 | { | |
602 | new_c[i * (c_len + 1) - 1] = ','; | |
603 | memcpy (&new_c[i * (c_len + 1)], c, c_len); | |
604 | } | |
605 | new_c[len - 1] = '\0'; | |
606 | XSTR (pattern, 2) = new_c; | |
607 | } | |
608 | } | |
5d3cc252 | 609 | /* Fall through. */ |
3262c1f5 RH |
610 | |
611 | case MATCH_OPERATOR: | |
612 | case MATCH_SCRATCH: | |
613 | case MATCH_PARALLEL: | |
3262c1f5 RH |
614 | XINT (pattern, 0) += max_op; |
615 | break; | |
616 | ||
617 | default: | |
618 | break; | |
619 | } | |
620 | ||
621 | fmt = GET_RTX_FORMAT (code); | |
622 | len = GET_RTX_LENGTH (code); | |
623 | for (i = 0; i < len; i++) | |
624 | { | |
625 | rtx r; | |
626 | ||
627 | switch (fmt[i]) | |
628 | { | |
629 | case 'e': case 'u': | |
630 | r = alter_predicate_for_insn (XEXP (pattern, i), alt, | |
631 | max_op, lineno); | |
632 | if (r == NULL) | |
633 | return r; | |
634 | break; | |
635 | ||
636 | case 'E': | |
637 | for (j = XVECLEN (pattern, i) - 1; j >= 0; --j) | |
638 | { | |
639 | r = alter_predicate_for_insn (XVECEXP (pattern, i, j), | |
640 | alt, max_op, lineno); | |
641 | if (r == NULL) | |
642 | return r; | |
643 | } | |
644 | break; | |
645 | ||
646 | case 'i': case 'w': case '0': case 's': | |
647 | break; | |
648 | ||
649 | default: | |
650 | abort (); | |
651 | } | |
652 | } | |
653 | ||
654 | return pattern; | |
655 | } | |
656 | ||
657 | static const char * | |
3d7aafde AJ |
658 | alter_test_for_insn (struct queue_elem *ce_elem, |
659 | struct queue_elem *insn_elem) | |
3262c1f5 RH |
660 | { |
661 | const char *ce_test, *insn_test; | |
3262c1f5 RH |
662 | |
663 | ce_test = XSTR (ce_elem->data, 1); | |
664 | insn_test = XSTR (insn_elem->data, 2); | |
665 | if (!ce_test || *ce_test == '\0') | |
666 | return insn_test; | |
667 | if (!insn_test || *insn_test == '\0') | |
668 | return ce_test; | |
669 | ||
1dcd444b | 670 | return concat ("(", ce_test, ") && (", insn_test, ")", NULL); |
3262c1f5 RH |
671 | } |
672 | ||
673 | /* Adjust all of the operand numbers in OLD to match the shift they'll | |
674 | get from an operand displacement of DISP. Return a pointer after the | |
675 | adjusted string. */ | |
676 | ||
677 | static char * | |
3d7aafde | 678 | shift_output_template (char *new, const char *old, int disp) |
3262c1f5 RH |
679 | { |
680 | while (*old) | |
681 | { | |
682 | char c = *old++; | |
683 | *new++ = c; | |
684 | if (c == '%') | |
685 | { | |
686 | c = *old++; | |
687 | if (ISDIGIT ((unsigned char) c)) | |
688 | c += disp; | |
0df6c2c7 | 689 | else if (ISALPHA (c)) |
3262c1f5 RH |
690 | { |
691 | *new++ = c; | |
692 | c = *old++ + disp; | |
693 | } | |
694 | *new++ = c; | |
695 | } | |
696 | } | |
697 | ||
698 | return new; | |
699 | } | |
700 | ||
701 | static const char * | |
3d7aafde AJ |
702 | alter_output_for_insn (struct queue_elem *ce_elem, |
703 | struct queue_elem *insn_elem, | |
704 | int alt, int max_op) | |
3262c1f5 RH |
705 | { |
706 | const char *ce_out, *insn_out; | |
707 | char *new, *p; | |
708 | size_t len, ce_len, insn_len; | |
709 | ||
710 | /* ??? Could coordinate with genoutput to not duplicate code here. */ | |
711 | ||
712 | ce_out = XSTR (ce_elem->data, 2); | |
66621f9e | 713 | insn_out = XTMPL (insn_elem->data, 3); |
3262c1f5 RH |
714 | if (!ce_out || *ce_out == '\0') |
715 | return insn_out; | |
716 | ||
717 | ce_len = strlen (ce_out); | |
718 | insn_len = strlen (insn_out); | |
719 | ||
720 | if (*insn_out == '*') | |
721 | /* You must take care of the predicate yourself. */ | |
722 | return insn_out; | |
723 | ||
724 | if (*insn_out == '@') | |
725 | { | |
726 | len = (ce_len + 1) * alt + insn_len + 1; | |
727 | p = new = xmalloc (len); | |
728 | ||
729 | do | |
730 | { | |
731 | do | |
732 | *p++ = *insn_out++; | |
733 | while (ISSPACE ((unsigned char) *insn_out)); | |
734 | ||
735 | if (*insn_out != '#') | |
736 | { | |
737 | p = shift_output_template (p, ce_out, max_op); | |
738 | *p++ = ' '; | |
739 | } | |
740 | ||
741 | do | |
742 | *p++ = *insn_out++; | |
743 | while (*insn_out && *insn_out != '\n'); | |
744 | } | |
745 | while (*insn_out); | |
746 | *p = '\0'; | |
747 | } | |
748 | else | |
749 | { | |
750 | len = ce_len + 1 + insn_len + 1; | |
751 | new = xmalloc (len); | |
752 | ||
753 | p = shift_output_template (new, ce_out, max_op); | |
754 | *p++ = ' '; | |
755 | memcpy (p, insn_out, insn_len + 1); | |
756 | } | |
757 | ||
758 | return new; | |
759 | } | |
760 | ||
761 | /* Replicate insns as appropriate for the given DEFINE_COND_EXEC. */ | |
762 | ||
763 | static void | |
3d7aafde | 764 | process_one_cond_exec (struct queue_elem *ce_elem) |
3262c1f5 RH |
765 | { |
766 | struct queue_elem *insn_elem; | |
767 | for (insn_elem = define_insn_queue; insn_elem ; insn_elem = insn_elem->next) | |
768 | { | |
769 | int alternatives, max_operand; | |
a406f566 MM |
770 | rtx pred, insn, pattern, split; |
771 | int i; | |
3262c1f5 RH |
772 | |
773 | if (! is_predicable (insn_elem)) | |
774 | continue; | |
775 | ||
776 | alternatives = 1; | |
777 | max_operand = -1; | |
778 | collect_insn_data (insn_elem->data, &alternatives, &max_operand); | |
779 | max_operand += 1; | |
780 | ||
781 | if (XVECLEN (ce_elem->data, 0) != 1) | |
782 | { | |
783 | message_with_line (ce_elem->lineno, | |
784 | "too many patterns in predicate"); | |
785 | errors = 1; | |
786 | return; | |
787 | } | |
788 | ||
789 | pred = copy_rtx (XVECEXP (ce_elem->data, 0, 0)); | |
790 | pred = alter_predicate_for_insn (pred, alternatives, max_operand, | |
791 | ce_elem->lineno); | |
792 | if (pred == NULL) | |
793 | return; | |
794 | ||
795 | /* Construct a new pattern for the new insn. */ | |
796 | insn = copy_rtx (insn_elem->data); | |
797 | XSTR (insn, 0) = ""; | |
798 | pattern = rtx_alloc (COND_EXEC); | |
799 | XEXP (pattern, 0) = pred; | |
800 | if (XVECLEN (insn, 1) == 1) | |
801 | { | |
802 | XEXP (pattern, 1) = XVECEXP (insn, 1, 0); | |
803 | XVECEXP (insn, 1, 0) = pattern; | |
804 | PUT_NUM_ELEM (XVEC (insn, 1), 1); | |
805 | } | |
806 | else | |
807 | { | |
808 | XEXP (pattern, 1) = rtx_alloc (PARALLEL); | |
809 | XVEC (XEXP (pattern, 1), 0) = XVEC (insn, 1); | |
810 | XVEC (insn, 1) = rtvec_alloc (1); | |
811 | XVECEXP (insn, 1, 0) = pattern; | |
812 | } | |
813 | ||
814 | XSTR (insn, 2) = alter_test_for_insn (ce_elem, insn_elem); | |
66621f9e | 815 | XTMPL (insn, 3) = alter_output_for_insn (ce_elem, insn_elem, |
3262c1f5 RH |
816 | alternatives, max_operand); |
817 | ||
818 | /* ??? Set `predicable' to false. Not crucial since it's really | |
819 | only used here, and we won't reprocess this new pattern. */ | |
820 | ||
821 | /* Put the new pattern on the `other' list so that it | |
822 | (a) is not reprocessed by other define_cond_exec patterns | |
823 | (b) appears after all normal define_insn patterns. | |
824 | ||
825 | ??? B is debatable. If one has normal insns that match | |
826 | cond_exec patterns, they will be preferred over these | |
827 | generated patterns. Whether this matters in practice, or if | |
828 | it's a good thing, or whether we should thread these new | |
829 | patterns into the define_insn chain just after their generator | |
830 | is something we'll have to experiment with. */ | |
831 | ||
821e35ba RH |
832 | queue_pattern (insn, &other_tail, insn_elem->filename, |
833 | insn_elem->lineno); | |
a406f566 MM |
834 | |
835 | if (!insn_elem->split) | |
836 | continue; | |
837 | ||
838 | /* If the original insn came from a define_insn_and_split, | |
9cf737f8 | 839 | generate a new split to handle the predicated insn. */ |
a406f566 MM |
840 | split = copy_rtx (insn_elem->split->data); |
841 | /* Predicate the pattern matched by the split. */ | |
842 | pattern = rtx_alloc (COND_EXEC); | |
843 | XEXP (pattern, 0) = pred; | |
844 | if (XVECLEN (split, 0) == 1) | |
845 | { | |
846 | XEXP (pattern, 1) = XVECEXP (split, 0, 0); | |
847 | XVECEXP (split, 0, 0) = pattern; | |
848 | PUT_NUM_ELEM (XVEC (split, 0), 1); | |
849 | } | |
850 | else | |
851 | { | |
852 | XEXP (pattern, 1) = rtx_alloc (PARALLEL); | |
853 | XVEC (XEXP (pattern, 1), 0) = XVEC (split, 0); | |
854 | XVEC (split, 0) = rtvec_alloc (1); | |
855 | XVECEXP (split, 0, 0) = pattern; | |
856 | } | |
857 | /* Predicate all of the insns generated by the split. */ | |
858 | for (i = 0; i < XVECLEN (split, 2); i++) | |
859 | { | |
860 | pattern = rtx_alloc (COND_EXEC); | |
861 | XEXP (pattern, 0) = pred; | |
862 | XEXP (pattern, 1) = XVECEXP (split, 2, i); | |
863 | XVECEXP (split, 2, i) = pattern; | |
864 | } | |
865 | /* Add the new split to the queue. */ | |
866 | queue_pattern (split, &other_tail, read_rtx_filename, | |
867 | insn_elem->split->lineno); | |
3262c1f5 RH |
868 | } |
869 | } | |
870 | ||
871 | /* If we have any DEFINE_COND_EXEC patterns, expand the DEFINE_INSN | |
872 | patterns appropriately. */ | |
873 | ||
874 | static void | |
3d7aafde | 875 | process_define_cond_exec (void) |
3262c1f5 RH |
876 | { |
877 | struct queue_elem *elem; | |
878 | ||
879 | identify_predicable_attribute (); | |
880 | if (errors) | |
881 | return; | |
882 | ||
883 | for (elem = define_cond_exec_queue; elem ; elem = elem->next) | |
884 | process_one_cond_exec (elem); | |
885 | } | |
04d8aa70 AM |
886 | |
887 | static char * | |
3d7aafde | 888 | save_string (const char *s, int len) |
04d8aa70 | 889 | { |
49a27995 | 890 | char *result = xmalloc (len + 1); |
04d8aa70 AM |
891 | |
892 | memcpy (result, s, len); | |
893 | result[len] = 0; | |
894 | return result; | |
895 | } | |
896 | ||
897 | \f | |
898 | /* The entry point for initializing the reader. */ | |
899 | ||
900 | int | |
3d7aafde | 901 | init_md_reader_args (int argc, char **argv) |
04d8aa70 AM |
902 | { |
903 | int i; | |
904 | const char *in_fname; | |
905 | ||
906 | max_include_len = 0; | |
907 | in_fname = NULL; | |
908 | for (i = 1; i < argc; i++) | |
909 | { | |
910 | if (argv[i][0] != '-') | |
911 | { | |
912 | if (in_fname == NULL) | |
913 | in_fname = argv[i]; | |
914 | } | |
915 | else | |
916 | { | |
917 | int c = argv[i][1]; | |
918 | switch (c) | |
919 | { | |
920 | case 'I': /* Add directory to path for includes. */ | |
921 | { | |
922 | struct file_name_list *dirtmp; | |
923 | ||
703ad42b | 924 | dirtmp = xmalloc (sizeof (struct file_name_list)); |
04d8aa70 | 925 | dirtmp->next = 0; /* New one goes on the end */ |
4ec59de2 MH |
926 | if (first_dir_md_include == 0) |
927 | first_dir_md_include = dirtmp; | |
04d8aa70 | 928 | else |
4ec59de2 MH |
929 | last_dir_md_include->next = dirtmp; |
930 | last_dir_md_include = dirtmp; /* Tail follows the last one */ | |
04d8aa70 AM |
931 | if (argv[i][1] == 'I' && argv[i][2] != 0) |
932 | dirtmp->fname = argv[i] + 2; | |
933 | else if (i + 1 == argc) | |
1f978f5f | 934 | fatal ("directory name missing after -I option"); |
04d8aa70 AM |
935 | else |
936 | dirtmp->fname = argv[++i]; | |
937 | if (strlen (dirtmp->fname) > max_include_len) | |
938 | max_include_len = strlen (dirtmp->fname); | |
939 | } | |
940 | break; | |
941 | default: | |
1f978f5f | 942 | fatal ("invalid option `%s'", argv[i]); |
04d8aa70 AM |
943 | |
944 | } | |
945 | } | |
946 | } | |
947 | return init_md_reader (in_fname); | |
948 | } | |
3262c1f5 | 949 | \f |
c88c0d42 CP |
950 | /* The entry point for initializing the reader. */ |
951 | ||
3262c1f5 | 952 | int |
3d7aafde | 953 | init_md_reader (const char *filename) |
c88c0d42 | 954 | { |
3262c1f5 RH |
955 | FILE *input_file; |
956 | int c; | |
2199e5fa | 957 | size_t i; |
04d8aa70 AM |
958 | char *lastsl; |
959 | ||
4ec59de2 | 960 | lastsl = strrchr (filename, '/'); |
3d7aafde | 961 | if (lastsl != NULL) |
4ec59de2 | 962 | base_dir = save_string (filename, lastsl - filename + 1 ); |
3262c1f5 | 963 | |
3916d6d8 | 964 | read_rtx_filename = filename; |
c88c0d42 | 965 | input_file = fopen (filename, "r"); |
c88c0d42 CP |
966 | if (input_file == 0) |
967 | { | |
968 | perror (filename); | |
969 | return FATAL_EXIT_CODE; | |
970 | } | |
971 | ||
2199e5fa ZW |
972 | /* Initialize the table of insn conditions. */ |
973 | condition_table = htab_create (n_insn_conditions, | |
974 | hash_c_test, cmp_c_test, NULL); | |
975 | ||
976 | for (i = 0; i < n_insn_conditions; i++) | |
fad205ff KG |
977 | *(htab_find_slot (condition_table, &insn_conditions[i], INSERT)) |
978 | = (void *) &insn_conditions[i]; | |
2199e5fa | 979 | |
3916d6d8 | 980 | obstack_init (rtl_obstack); |
3262c1f5 | 981 | errors = 0; |
c88c0d42 | 982 | sequence_num = 0; |
c88c0d42 | 983 | |
3262c1f5 RH |
984 | /* Read the entire file. */ |
985 | while (1) | |
c88c0d42 | 986 | { |
3262c1f5 RH |
987 | rtx desc; |
988 | int lineno; | |
989 | ||
c88c0d42 CP |
990 | c = read_skip_spaces (input_file); |
991 | if (c == EOF) | |
04d8aa70 | 992 | break; |
c88c0d42 CP |
993 | |
994 | ungetc (c, input_file); | |
3262c1f5 | 995 | lineno = read_rtx_lineno; |
c88c0d42 | 996 | desc = read_rtx (input_file); |
3262c1f5 | 997 | process_rtx (desc, lineno); |
c88c0d42 | 998 | } |
3262c1f5 RH |
999 | fclose (input_file); |
1000 | ||
1001 | /* Process define_cond_exec patterns. */ | |
1002 | if (define_cond_exec_queue != NULL) | |
1003 | process_define_cond_exec (); | |
1004 | ||
1005 | return errors ? FATAL_EXIT_CODE : SUCCESS_EXIT_CODE; | |
1006 | } | |
1007 | ||
1008 | /* The entry point for reading a single rtx from an md file. */ | |
1009 | ||
1010 | rtx | |
3d7aafde | 1011 | read_md_rtx (int *lineno, int *seqnr) |
3262c1f5 RH |
1012 | { |
1013 | struct queue_elem **queue, *elem; | |
1014 | rtx desc; | |
1015 | ||
2199e5fa ZW |
1016 | discard: |
1017 | ||
3262c1f5 RH |
1018 | /* Read all patterns from a given queue before moving on to the next. */ |
1019 | if (define_attr_queue != NULL) | |
1020 | queue = &define_attr_queue; | |
1021 | else if (define_insn_queue != NULL) | |
1022 | queue = &define_insn_queue; | |
1023 | else if (other_queue != NULL) | |
1024 | queue = &other_queue; | |
1025 | else | |
1026 | return NULL_RTX; | |
1027 | ||
1028 | elem = *queue; | |
1029 | *queue = elem->next; | |
1030 | desc = elem->data; | |
821e35ba | 1031 | read_rtx_filename = elem->filename; |
3262c1f5 | 1032 | *lineno = elem->lineno; |
c88c0d42 | 1033 | *seqnr = sequence_num; |
3262c1f5 RH |
1034 | |
1035 | free (elem); | |
1036 | ||
2199e5fa ZW |
1037 | /* Discard insn patterns which we know can never match (because |
1038 | their C test is provably always false). If insn_elision is | |
1039 | false, our caller needs to see all the patterns. Note that the | |
1040 | elided patterns are never counted by the sequence numbering; it | |
1041 | it is the caller's responsibility, when insn_elision is false, not | |
1042 | to use elided pattern numbers for anything. */ | |
c88c0d42 CP |
1043 | switch (GET_CODE (desc)) |
1044 | { | |
3262c1f5 RH |
1045 | case DEFINE_INSN: |
1046 | case DEFINE_EXPAND: | |
2199e5fa ZW |
1047 | if (maybe_eval_c_test (XSTR (desc, 2)) != 0) |
1048 | sequence_num++; | |
1049 | else if (insn_elision) | |
1050 | goto discard; | |
1051 | break; | |
1052 | ||
3262c1f5 RH |
1053 | case DEFINE_SPLIT: |
1054 | case DEFINE_PEEPHOLE: | |
1055 | case DEFINE_PEEPHOLE2: | |
2199e5fa ZW |
1056 | if (maybe_eval_c_test (XSTR (desc, 1)) != 0) |
1057 | sequence_num++; | |
1058 | else if (insn_elision) | |
1059 | goto discard; | |
3262c1f5 RH |
1060 | break; |
1061 | ||
1062 | default: | |
1063 | break; | |
c88c0d42 CP |
1064 | } |
1065 | ||
1066 | return desc; | |
1067 | } | |
9a5834ae | 1068 | |
2199e5fa ZW |
1069 | /* Helper functions for insn elision. */ |
1070 | ||
1071 | /* Compute a hash function of a c_test structure, which is keyed | |
1072 | by its ->expr field. */ | |
1073 | hashval_t | |
3d7aafde | 1074 | hash_c_test (const void *x) |
2199e5fa ZW |
1075 | { |
1076 | const struct c_test *a = (const struct c_test *) x; | |
1077 | const unsigned char *base, *s = (const unsigned char *) a->expr; | |
1078 | hashval_t hash; | |
1079 | unsigned char c; | |
1080 | unsigned int len; | |
1081 | ||
1082 | base = s; | |
1083 | hash = 0; | |
1084 | ||
1085 | while ((c = *s++) != '\0') | |
1086 | { | |
1087 | hash += c + (c << 17); | |
1088 | hash ^= hash >> 2; | |
1089 | } | |
1090 | ||
1091 | len = s - base; | |
1092 | hash += len + (len << 17); | |
1093 | hash ^= hash >> 2; | |
1094 | ||
1095 | return hash; | |
1096 | } | |
1097 | ||
1098 | /* Compare two c_test expression structures. */ | |
1099 | int | |
3d7aafde | 1100 | cmp_c_test (const void *x, const void *y) |
2199e5fa ZW |
1101 | { |
1102 | const struct c_test *a = (const struct c_test *) x; | |
1103 | const struct c_test *b = (const struct c_test *) y; | |
1104 | ||
1105 | return !strcmp (a->expr, b->expr); | |
1106 | } | |
1107 | ||
1108 | /* Given a string representing a C test expression, look it up in the | |
1109 | condition_table and report whether or not its value is known | |
1110 | at compile time. Returns a tristate: 1 for known true, 0 for | |
1111 | known false, -1 for unknown. */ | |
1112 | int | |
3d7aafde | 1113 | maybe_eval_c_test (const char *expr) |
2199e5fa ZW |
1114 | { |
1115 | const struct c_test *test; | |
1116 | struct c_test dummy; | |
1117 | ||
1118 | if (expr[0] == 0) | |
1119 | return 1; | |
1120 | ||
1121 | if (insn_elision_unavailable) | |
1122 | return -1; | |
1123 | ||
1124 | dummy.expr = expr; | |
703ad42b | 1125 | test = htab_find (condition_table, &dummy); |
2199e5fa ZW |
1126 | if (!test) |
1127 | abort (); | |
1128 | ||
1129 | return test->value; | |
1130 | } | |
1131 | ||
9a5834ae ZW |
1132 | /* Given a string, return the number of comma-separated elements in it. |
1133 | Return 0 for the null string. */ | |
1134 | int | |
3d7aafde | 1135 | n_comma_elts (const char *s) |
9a5834ae ZW |
1136 | { |
1137 | int n; | |
1138 | ||
1139 | if (*s == '\0') | |
1140 | return 0; | |
1141 | ||
1142 | for (n = 1; *s; s++) | |
1143 | if (*s == ',') | |
1144 | n++; | |
1145 | ||
1146 | return n; | |
1147 | } | |
1148 | ||
1149 | /* Given a pointer to a (char *), return a pointer to the beginning of the | |
1150 | next comma-separated element in the string. Advance the pointer given | |
1151 | to the end of that element. Return NULL if at end of string. Caller | |
1152 | is responsible for copying the string if necessary. White space between | |
1153 | a comma and an element is ignored. */ | |
1154 | ||
1155 | const char * | |
3d7aafde | 1156 | scan_comma_elt (const char **pstr) |
9a5834ae ZW |
1157 | { |
1158 | const char *start; | |
1159 | const char *p = *pstr; | |
1160 | ||
1161 | if (*p == ',') | |
1162 | p++; | |
1163 | while (ISSPACE(*p)) | |
1164 | p++; | |
1165 | ||
1166 | if (*p == '\0') | |
1167 | return NULL; | |
1168 | ||
1169 | start = p; | |
1170 | ||
1171 | while (*p != ',' && *p != '\0') | |
1172 | p++; | |
1173 | ||
1174 | *pstr = p; | |
1175 | return start; | |
1176 | } |