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6de9cd9a | 1 | /* Dependency analysis |
818ab71a | 2 | Copyright (C) 2000-2016 Free Software Foundation, Inc. |
6de9cd9a DN |
3 | Contributed by Paul Brook <paul@nowt.org> |
4 | ||
9fc4d79b | 5 | This file is part of GCC. |
6de9cd9a | 6 | |
9fc4d79b TS |
7 | GCC is free software; you can redistribute it and/or modify it under |
8 | the terms of the GNU General Public License as published by the Free | |
d234d788 | 9 | Software Foundation; either version 3, or (at your option) any later |
9fc4d79b | 10 | version. |
6de9cd9a | 11 | |
9fc4d79b TS |
12 | GCC is distributed in the hope that it will be useful, but WITHOUT ANY |
13 | WARRANTY; without even the implied warranty of MERCHANTABILITY or | |
14 | FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License | |
15 | for more details. | |
6de9cd9a DN |
16 | |
17 | You should have received a copy of the GNU General Public License | |
d234d788 NC |
18 | along with GCC; see the file COPYING3. If not see |
19 | <http://www.gnu.org/licenses/>. */ | |
6de9cd9a DN |
20 | |
21 | /* dependency.c -- Expression dependency analysis code. */ | |
22 | /* There's probably quite a bit of duplication in this file. We currently | |
23 | have different dependency checking functions for different types | |
24 | if dependencies. Ideally these would probably be merged. */ | |
f8ec0561 | 25 | |
6de9cd9a | 26 | #include "config.h" |
7274feea | 27 | #include "system.h" |
953bee7c | 28 | #include "coretypes.h" |
6de9cd9a DN |
29 | #include "gfortran.h" |
30 | #include "dependency.h" | |
b7e75771 | 31 | #include "constructor.h" |
32af57e2 | 32 | #include "arith.h" |
6de9cd9a DN |
33 | |
34 | /* static declarations */ | |
35 | /* Enums */ | |
36 | enum range {LHS, RHS, MID}; | |
37 | ||
38 | /* Dependency types. These must be in reverse order of priority. */ | |
a79683d5 | 39 | enum gfc_dependency |
6de9cd9a DN |
40 | { |
41 | GFC_DEP_ERROR, | |
42 | GFC_DEP_EQUAL, /* Identical Ranges. */ | |
3d03ead0 PT |
43 | GFC_DEP_FORWARD, /* e.g., a(1:3) = a(2:4). */ |
44 | GFC_DEP_BACKWARD, /* e.g. a(2:4) = a(1:3). */ | |
6de9cd9a DN |
45 | GFC_DEP_OVERLAP, /* May overlap in some other way. */ |
46 | GFC_DEP_NODEP /* Distinct ranges. */ | |
a79683d5 | 47 | }; |
6de9cd9a DN |
48 | |
49 | /* Macros */ | |
50 | #define IS_ARRAY_EXPLICIT(as) ((as->type == AS_EXPLICIT ? 1 : 0)) | |
51 | ||
071bdb5f TK |
52 | /* Forward declarations */ |
53 | ||
54 | static gfc_dependency check_section_vs_section (gfc_array_ref *, | |
55 | gfc_array_ref *, int); | |
6de9cd9a DN |
56 | |
57 | /* Returns 1 if the expr is an integer constant value 1, 0 if it is not or | |
58 | def if the value could not be determined. */ | |
59 | ||
60 | int | |
636dff67 | 61 | gfc_expr_is_one (gfc_expr *expr, int def) |
6de9cd9a | 62 | { |
6e45f57b | 63 | gcc_assert (expr != NULL); |
6de9cd9a DN |
64 | |
65 | if (expr->expr_type != EXPR_CONSTANT) | |
66 | return def; | |
67 | ||
68 | if (expr->ts.type != BT_INTEGER) | |
69 | return def; | |
70 | ||
71 | return mpz_cmp_si (expr->value.integer, 1) == 0; | |
72 | } | |
73 | ||
071bdb5f TK |
74 | /* Check if two array references are known to be identical. Calls |
75 | gfc_dep_compare_expr if necessary for comparing array indices. */ | |
76 | ||
77 | static bool | |
78 | identical_array_ref (gfc_array_ref *a1, gfc_array_ref *a2) | |
79 | { | |
80 | int i; | |
81 | ||
82 | if (a1->type == AR_FULL && a2->type == AR_FULL) | |
83 | return true; | |
84 | ||
85 | if (a1->type == AR_SECTION && a2->type == AR_SECTION) | |
86 | { | |
87 | gcc_assert (a1->dimen == a2->dimen); | |
88 | ||
89 | for ( i = 0; i < a1->dimen; i++) | |
90 | { | |
91 | /* TODO: Currently, we punt on an integer array as an index. */ | |
92 | if (a1->dimen_type[i] != DIMEN_RANGE | |
93 | || a2->dimen_type[i] != DIMEN_RANGE) | |
94 | return false; | |
95 | ||
96 | if (check_section_vs_section (a1, a2, i) != GFC_DEP_EQUAL) | |
97 | return false; | |
98 | } | |
99 | return true; | |
100 | } | |
101 | ||
102 | if (a1->type == AR_ELEMENT && a2->type == AR_ELEMENT) | |
103 | { | |
96ad5df6 SK |
104 | if (a1->dimen != a2->dimen) |
105 | gfc_internal_error ("identical_array_ref(): inconsistent dimensions"); | |
106 | ||
071bdb5f TK |
107 | for (i = 0; i < a1->dimen; i++) |
108 | { | |
109 | if (gfc_dep_compare_expr (a1->start[i], a2->start[i]) != 0) | |
110 | return false; | |
111 | } | |
112 | return true; | |
113 | } | |
114 | return false; | |
115 | } | |
116 | ||
117 | ||
118 | ||
119 | /* Return true for identical variables, checking for references if | |
120 | necessary. Calls identical_array_ref for checking array sections. */ | |
121 | ||
99fc1b90 JW |
122 | static bool |
123 | are_identical_variables (gfc_expr *e1, gfc_expr *e2) | |
071bdb5f TK |
124 | { |
125 | gfc_ref *r1, *r2; | |
126 | ||
2240d1cf JW |
127 | if (e1->symtree->n.sym->attr.dummy && e2->symtree->n.sym->attr.dummy) |
128 | { | |
129 | /* Dummy arguments: Only check for equal names. */ | |
130 | if (e1->symtree->n.sym->name != e2->symtree->n.sym->name) | |
131 | return false; | |
132 | } | |
133 | else | |
134 | { | |
135 | /* Check for equal symbols. */ | |
136 | if (e1->symtree->n.sym != e2->symtree->n.sym) | |
137 | return false; | |
138 | } | |
071bdb5f | 139 | |
32af57e2 TK |
140 | /* Volatile variables should never compare equal to themselves. */ |
141 | ||
142 | if (e1->symtree->n.sym->attr.volatile_) | |
143 | return false; | |
144 | ||
071bdb5f TK |
145 | r1 = e1->ref; |
146 | r2 = e2->ref; | |
147 | ||
148 | while (r1 != NULL || r2 != NULL) | |
149 | { | |
150 | ||
151 | /* Assume the variables are not equal if one has a reference and the | |
152 | other doesn't. | |
153 | TODO: Handle full references like comparing a(:) to a. | |
154 | */ | |
155 | ||
156 | if (r1 == NULL || r2 == NULL) | |
157 | return false; | |
158 | ||
159 | if (r1->type != r2->type) | |
160 | return false; | |
161 | ||
162 | switch (r1->type) | |
163 | { | |
164 | ||
165 | case REF_ARRAY: | |
166 | if (!identical_array_ref (&r1->u.ar, &r2->u.ar)) | |
167 | return false; | |
168 | ||
169 | break; | |
170 | ||
171 | case REF_COMPONENT: | |
172 | if (r1->u.c.component != r2->u.c.component) | |
173 | return false; | |
174 | break; | |
175 | ||
176 | case REF_SUBSTRING: | |
671b487d | 177 | if (gfc_dep_compare_expr (r1->u.ss.start, r2->u.ss.start) != 0) |
071bdb5f | 178 | return false; |
671b487d TK |
179 | |
180 | /* If both are NULL, the end length compares equal, because we | |
181 | are looking at the same variable. This can only happen for | |
f8ec0561 | 182 | assumed- or deferred-length character arguments. */ |
671b487d TK |
183 | |
184 | if (r1->u.ss.end == NULL && r2->u.ss.end == NULL) | |
185 | break; | |
186 | ||
187 | if (gfc_dep_compare_expr (r1->u.ss.end, r2->u.ss.end) != 0) | |
188 | return false; | |
f8ec0561 | 189 | |
071bdb5f TK |
190 | break; |
191 | ||
192 | default: | |
99fc1b90 | 193 | gfc_internal_error ("are_identical_variables: Bad type"); |
071bdb5f TK |
194 | } |
195 | r1 = r1->next; | |
196 | r2 = r2->next; | |
197 | } | |
198 | return true; | |
199 | } | |
6de9cd9a | 200 | |
2757d5ec TK |
201 | /* Compare two functions for equality. Returns 0 if e1==e2, -2 otherwise. If |
202 | impure_ok is false, only return 0 for pure functions. */ | |
203 | ||
204 | int | |
205 | gfc_dep_compare_functions (gfc_expr *e1, gfc_expr *e2, bool impure_ok) | |
206 | { | |
207 | ||
208 | gfc_actual_arglist *args1; | |
209 | gfc_actual_arglist *args2; | |
f8ec0561 | 210 | |
2757d5ec TK |
211 | if (e1->expr_type != EXPR_FUNCTION || e2->expr_type != EXPR_FUNCTION) |
212 | return -2; | |
213 | ||
214 | if ((e1->value.function.esym && e2->value.function.esym | |
215 | && e1->value.function.esym == e2->value.function.esym | |
216 | && (e1->value.function.esym->result->attr.pure || impure_ok)) | |
217 | || (e1->value.function.isym && e2->value.function.isym | |
218 | && e1->value.function.isym == e2->value.function.isym | |
219 | && (e1->value.function.isym->pure || impure_ok))) | |
220 | { | |
221 | args1 = e1->value.function.actual; | |
222 | args2 = e2->value.function.actual; | |
223 | ||
224 | /* Compare the argument lists for equality. */ | |
225 | while (args1 && args2) | |
226 | { | |
227 | /* Bitwise xor, since C has no non-bitwise xor operator. */ | |
228 | if ((args1->expr == NULL) ^ (args2->expr == NULL)) | |
229 | return -2; | |
f8ec0561 | 230 | |
15876cee TK |
231 | if (args1->expr != NULL && args2->expr != NULL) |
232 | { | |
233 | gfc_expr *e1, *e2; | |
234 | e1 = args1->expr; | |
235 | e2 = args2->expr; | |
236 | ||
237 | if (gfc_dep_compare_expr (e1, e2) != 0) | |
238 | return -2; | |
239 | ||
240 | /* Special case: String arguments which compare equal can have | |
241 | different lengths, which makes them different in calls to | |
242 | procedures. */ | |
243 | ||
244 | if (e1->expr_type == EXPR_CONSTANT | |
245 | && e1->ts.type == BT_CHARACTER | |
246 | && e2->expr_type == EXPR_CONSTANT | |
247 | && e2->ts.type == BT_CHARACTER | |
248 | && e1->value.character.length != e2->value.character.length) | |
249 | return -2; | |
250 | } | |
f8ec0561 | 251 | |
2757d5ec TK |
252 | args1 = args1->next; |
253 | args2 = args2->next; | |
254 | } | |
255 | return (args1 || args2) ? -2 : 0; | |
256 | } | |
257 | else | |
f8ec0561 | 258 | return -2; |
2757d5ec TK |
259 | } |
260 | ||
8cd61b3c TK |
261 | /* Helper function to look through parens, unary plus and widening |
262 | integer conversions. */ | |
263 | ||
8b7cec58 TK |
264 | gfc_expr * |
265 | gfc_discard_nops (gfc_expr *e) | |
8cd61b3c TK |
266 | { |
267 | gfc_actual_arglist *arglist; | |
268 | ||
269 | if (e == NULL) | |
270 | return NULL; | |
271 | ||
272 | while (true) | |
273 | { | |
274 | if (e->expr_type == EXPR_OP | |
275 | && (e->value.op.op == INTRINSIC_UPLUS | |
276 | || e->value.op.op == INTRINSIC_PARENTHESES)) | |
277 | { | |
278 | e = e->value.op.op1; | |
279 | continue; | |
280 | } | |
281 | ||
282 | if (e->expr_type == EXPR_FUNCTION && e->value.function.isym | |
283 | && e->value.function.isym->id == GFC_ISYM_CONVERSION | |
284 | && e->ts.type == BT_INTEGER) | |
285 | { | |
286 | arglist = e->value.function.actual; | |
287 | if (arglist->expr->ts.type == BT_INTEGER | |
288 | && e->ts.kind > arglist->expr->ts.kind) | |
289 | { | |
290 | e = arglist->expr; | |
291 | continue; | |
292 | } | |
293 | } | |
294 | break; | |
295 | } | |
296 | ||
297 | return e; | |
298 | } | |
299 | ||
300 | ||
13001f33 JW |
301 | /* Compare two expressions. Return values: |
302 | * +1 if e1 > e2 | |
303 | * 0 if e1 == e2 | |
304 | * -1 if e1 < e2 | |
305 | * -2 if the relationship could not be determined | |
d8e5eb57 TK |
306 | * -3 if e1 /= e2, but we cannot tell which one is larger. |
307 | REAL and COMPLEX constants are only compared for equality | |
308 | or inequality; if they are unequal, -2 is returned in all cases. */ | |
6de9cd9a DN |
309 | |
310 | int | |
636dff67 | 311 | gfc_dep_compare_expr (gfc_expr *e1, gfc_expr *e2) |
6de9cd9a DN |
312 | { |
313 | int i; | |
15b71db3 | 314 | |
8539d639 JW |
315 | if (e1 == NULL && e2 == NULL) |
316 | return 0; | |
317 | ||
8b7cec58 TK |
318 | e1 = gfc_discard_nops (e1); |
319 | e2 = gfc_discard_nops (e2); | |
d765523a | 320 | |
a1ee985f | 321 | if (e1->expr_type == EXPR_OP && e1->value.op.op == INTRINSIC_PLUS) |
d765523a | 322 | { |
d8e5eb57 | 323 | /* Compare X+C vs. X, for INTEGER only. */ |
d765523a RS |
324 | if (e1->value.op.op2->expr_type == EXPR_CONSTANT |
325 | && e1->value.op.op2->ts.type == BT_INTEGER | |
326 | && gfc_dep_compare_expr (e1->value.op.op1, e2) == 0) | |
327 | return mpz_sgn (e1->value.op.op2->value.integer); | |
328 | ||
329 | /* Compare P+Q vs. R+S. */ | |
a1ee985f | 330 | if (e2->expr_type == EXPR_OP && e2->value.op.op == INTRINSIC_PLUS) |
d765523a RS |
331 | { |
332 | int l, r; | |
333 | ||
334 | l = gfc_dep_compare_expr (e1->value.op.op1, e2->value.op.op1); | |
335 | r = gfc_dep_compare_expr (e1->value.op.op2, e2->value.op.op2); | |
336 | if (l == 0 && r == 0) | |
337 | return 0; | |
13001f33 | 338 | if (l == 0 && r > -2) |
d765523a | 339 | return r; |
13001f33 | 340 | if (l > -2 && r == 0) |
d765523a RS |
341 | return l; |
342 | if (l == 1 && r == 1) | |
343 | return 1; | |
344 | if (l == -1 && r == -1) | |
345 | return -1; | |
346 | ||
347 | l = gfc_dep_compare_expr (e1->value.op.op1, e2->value.op.op2); | |
348 | r = gfc_dep_compare_expr (e1->value.op.op2, e2->value.op.op1); | |
349 | if (l == 0 && r == 0) | |
350 | return 0; | |
13001f33 | 351 | if (l == 0 && r > -2) |
d765523a | 352 | return r; |
13001f33 | 353 | if (l > -2 && r == 0) |
d765523a RS |
354 | return l; |
355 | if (l == 1 && r == 1) | |
356 | return 1; | |
357 | if (l == -1 && r == -1) | |
358 | return -1; | |
359 | } | |
360 | } | |
361 | ||
d8e5eb57 | 362 | /* Compare X vs. X+C, for INTEGER only. */ |
a1ee985f | 363 | if (e2->expr_type == EXPR_OP && e2->value.op.op == INTRINSIC_PLUS) |
d765523a RS |
364 | { |
365 | if (e2->value.op.op2->expr_type == EXPR_CONSTANT | |
366 | && e2->value.op.op2->ts.type == BT_INTEGER | |
367 | && gfc_dep_compare_expr (e1, e2->value.op.op1) == 0) | |
368 | return -mpz_sgn (e2->value.op.op2->value.integer); | |
369 | } | |
370 | ||
d8e5eb57 | 371 | /* Compare X-C vs. X, for INTEGER only. */ |
a1ee985f | 372 | if (e1->expr_type == EXPR_OP && e1->value.op.op == INTRINSIC_MINUS) |
d765523a RS |
373 | { |
374 | if (e1->value.op.op2->expr_type == EXPR_CONSTANT | |
375 | && e1->value.op.op2->ts.type == BT_INTEGER | |
376 | && gfc_dep_compare_expr (e1->value.op.op1, e2) == 0) | |
377 | return -mpz_sgn (e1->value.op.op2->value.integer); | |
378 | ||
379 | /* Compare P-Q vs. R-S. */ | |
a1ee985f | 380 | if (e2->expr_type == EXPR_OP && e2->value.op.op == INTRINSIC_MINUS) |
d765523a RS |
381 | { |
382 | int l, r; | |
383 | ||
384 | l = gfc_dep_compare_expr (e1->value.op.op1, e2->value.op.op1); | |
385 | r = gfc_dep_compare_expr (e1->value.op.op2, e2->value.op.op2); | |
386 | if (l == 0 && r == 0) | |
387 | return 0; | |
13001f33 | 388 | if (l > -2 && r == 0) |
d765523a | 389 | return l; |
13001f33 | 390 | if (l == 0 && r > -2) |
d765523a RS |
391 | return -r; |
392 | if (l == 1 && r == -1) | |
393 | return 1; | |
394 | if (l == -1 && r == 1) | |
395 | return -1; | |
396 | } | |
397 | } | |
398 | ||
32af57e2 TK |
399 | /* Compare A // B vs. C // D. */ |
400 | ||
401 | if (e1->expr_type == EXPR_OP && e1->value.op.op == INTRINSIC_CONCAT | |
402 | && e2->expr_type == EXPR_OP && e2->value.op.op == INTRINSIC_CONCAT) | |
403 | { | |
404 | int l, r; | |
405 | ||
406 | l = gfc_dep_compare_expr (e1->value.op.op1, e2->value.op.op1); | |
407 | r = gfc_dep_compare_expr (e1->value.op.op2, e2->value.op.op2); | |
408 | ||
840171d2 | 409 | if (l != 0) |
13001f33 | 410 | return l; |
32af57e2 | 411 | |
840171d2 TK |
412 | /* Left expressions of // compare equal, but |
413 | watch out for 'A ' // x vs. 'A' // x. */ | |
414 | gfc_expr *e1_left = e1->value.op.op1; | |
415 | gfc_expr *e2_left = e2->value.op.op1; | |
416 | ||
417 | if (e1_left->expr_type == EXPR_CONSTANT | |
418 | && e2_left->expr_type == EXPR_CONSTANT | |
419 | && e1_left->value.character.length | |
420 | != e2_left->value.character.length) | |
421 | return -2; | |
32af57e2 | 422 | else |
840171d2 | 423 | return r; |
32af57e2 TK |
424 | } |
425 | ||
d8e5eb57 | 426 | /* Compare X vs. X-C, for INTEGER only. */ |
a1ee985f | 427 | if (e2->expr_type == EXPR_OP && e2->value.op.op == INTRINSIC_MINUS) |
d765523a RS |
428 | { |
429 | if (e2->value.op.op2->expr_type == EXPR_CONSTANT | |
430 | && e2->value.op.op2->ts.type == BT_INTEGER | |
431 | && gfc_dep_compare_expr (e1, e2->value.op.op1) == 0) | |
432 | return mpz_sgn (e2->value.op.op2->value.integer); | |
433 | } | |
434 | ||
6de9cd9a | 435 | if (e1->expr_type != e2->expr_type) |
13001f33 | 436 | return -3; |
6de9cd9a DN |
437 | |
438 | switch (e1->expr_type) | |
439 | { | |
440 | case EXPR_CONSTANT: | |
32af57e2 TK |
441 | /* Compare strings for equality. */ |
442 | if (e1->ts.type == BT_CHARACTER && e2->ts.type == BT_CHARACTER) | |
443 | return gfc_compare_string (e1, e2); | |
444 | ||
d8e5eb57 TK |
445 | /* Compare REAL and COMPLEX constants. Because of the |
446 | traps and pitfalls associated with comparing | |
447 | a + 1.0 with a + 0.5, check for equality only. */ | |
448 | if (e2->expr_type == EXPR_CONSTANT) | |
449 | { | |
450 | if (e1->ts.type == BT_REAL && e2->ts.type == BT_REAL) | |
451 | { | |
452 | if (mpfr_cmp (e1->value.real, e2->value.real) == 0) | |
453 | return 0; | |
454 | else | |
455 | return -2; | |
456 | } | |
457 | else if (e1->ts.type == BT_COMPLEX && e2->ts.type == BT_COMPLEX) | |
458 | { | |
459 | if (mpc_cmp (e1->value.complex, e2->value.complex) == 0) | |
460 | return 0; | |
461 | else | |
462 | return -2; | |
463 | } | |
464 | } | |
465 | ||
6de9cd9a DN |
466 | if (e1->ts.type != BT_INTEGER || e2->ts.type != BT_INTEGER) |
467 | return -2; | |
468 | ||
d8e5eb57 TK |
469 | /* For INTEGER, all cases where e2 is not constant should have |
470 | been filtered out above. */ | |
471 | gcc_assert (e2->expr_type == EXPR_CONSTANT); | |
472 | ||
6de9cd9a DN |
473 | i = mpz_cmp (e1->value.integer, e2->value.integer); |
474 | if (i == 0) | |
475 | return 0; | |
476 | else if (i < 0) | |
477 | return -1; | |
478 | return 1; | |
479 | ||
480 | case EXPR_VARIABLE: | |
99fc1b90 | 481 | if (are_identical_variables (e1, e2)) |
6de9cd9a | 482 | return 0; |
071bdb5f | 483 | else |
13001f33 | 484 | return -3; |
6de9cd9a | 485 | |
37ad72f2 RS |
486 | case EXPR_OP: |
487 | /* Intrinsic operators are the same if their operands are the same. */ | |
a1ee985f | 488 | if (e1->value.op.op != e2->value.op.op) |
37ad72f2 RS |
489 | return -2; |
490 | if (e1->value.op.op2 == 0) | |
491 | { | |
492 | i = gfc_dep_compare_expr (e1->value.op.op1, e2->value.op.op1); | |
493 | return i == 0 ? 0 : -2; | |
494 | } | |
495 | if (gfc_dep_compare_expr (e1->value.op.op1, e2->value.op.op1) == 0 | |
496 | && gfc_dep_compare_expr (e1->value.op.op2, e2->value.op.op2) == 0) | |
497 | return 0; | |
99fc1b90 JW |
498 | else if (e1->value.op.op == INTRINSIC_TIMES |
499 | && gfc_dep_compare_expr (e1->value.op.op1, e2->value.op.op2) == 0 | |
500 | && gfc_dep_compare_expr (e1->value.op.op2, e2->value.op.op1) == 0) | |
d8e5eb57 | 501 | /* Commutativity of multiplication; addition is handled above. */ |
99fc1b90 JW |
502 | return 0; |
503 | ||
37ad72f2 RS |
504 | return -2; |
505 | ||
506 | case EXPR_FUNCTION: | |
2757d5ec | 507 | return gfc_dep_compare_functions (e1, e2, false); |
37ad72f2 | 508 | |
6de9cd9a DN |
509 | default: |
510 | return -2; | |
511 | } | |
512 | } | |
513 | ||
514 | ||
eab19a1a | 515 | /* Return the difference between two expressions. Integer expressions of |
f8ec0561 | 516 | the form |
eab19a1a TK |
517 | |
518 | X + constant, X - constant and constant + X | |
519 | ||
520 | are handled. Return true on success, false on failure. result is assumed | |
521 | to be uninitialized on entry, and will be initialized on success. | |
522 | */ | |
523 | ||
524 | bool | |
525 | gfc_dep_difference (gfc_expr *e1, gfc_expr *e2, mpz_t *result) | |
526 | { | |
527 | gfc_expr *e1_op1, *e1_op2, *e2_op1, *e2_op2; | |
528 | ||
529 | if (e1 == NULL || e2 == NULL) | |
530 | return false; | |
531 | ||
532 | if (e1->ts.type != BT_INTEGER || e2->ts.type != BT_INTEGER) | |
533 | return false; | |
534 | ||
8b7cec58 TK |
535 | e1 = gfc_discard_nops (e1); |
536 | e2 = gfc_discard_nops (e2); | |
eab19a1a TK |
537 | |
538 | /* Inizialize tentatively, clear if we don't return anything. */ | |
539 | mpz_init (*result); | |
540 | ||
541 | /* Case 1: c1 - c2 = c1 - c2, trivially. */ | |
542 | ||
543 | if (e1->expr_type == EXPR_CONSTANT && e2->expr_type == EXPR_CONSTANT) | |
544 | { | |
545 | mpz_sub (*result, e1->value.integer, e2->value.integer); | |
546 | return true; | |
547 | } | |
548 | ||
549 | if (e1->expr_type == EXPR_OP && e1->value.op.op == INTRINSIC_PLUS) | |
550 | { | |
8b7cec58 TK |
551 | e1_op1 = gfc_discard_nops (e1->value.op.op1); |
552 | e1_op2 = gfc_discard_nops (e1->value.op.op2); | |
eab19a1a TK |
553 | |
554 | /* Case 2: (X + c1) - X = c1. */ | |
555 | if (e1_op2->expr_type == EXPR_CONSTANT | |
556 | && gfc_dep_compare_expr (e1_op1, e2) == 0) | |
557 | { | |
558 | mpz_set (*result, e1_op2->value.integer); | |
559 | return true; | |
560 | } | |
561 | ||
1cc0e193 | 562 | /* Case 3: (c1 + X) - X = c1. */ |
eab19a1a TK |
563 | if (e1_op1->expr_type == EXPR_CONSTANT |
564 | && gfc_dep_compare_expr (e1_op2, e2) == 0) | |
565 | { | |
566 | mpz_set (*result, e1_op1->value.integer); | |
567 | return true; | |
568 | } | |
569 | ||
570 | if (e2->expr_type == EXPR_OP && e2->value.op.op == INTRINSIC_PLUS) | |
571 | { | |
8b7cec58 TK |
572 | e2_op1 = gfc_discard_nops (e2->value.op.op1); |
573 | e2_op2 = gfc_discard_nops (e2->value.op.op2); | |
eab19a1a TK |
574 | |
575 | if (e1_op2->expr_type == EXPR_CONSTANT) | |
576 | { | |
577 | /* Case 4: X + c1 - (X + c2) = c1 - c2. */ | |
578 | if (e2_op2->expr_type == EXPR_CONSTANT | |
579 | && gfc_dep_compare_expr (e1_op1, e2_op1) == 0) | |
580 | { | |
581 | mpz_sub (*result, e1_op2->value.integer, | |
582 | e2_op2->value.integer); | |
583 | return true; | |
584 | } | |
585 | /* Case 5: X + c1 - (c2 + X) = c1 - c2. */ | |
586 | if (e2_op1->expr_type == EXPR_CONSTANT | |
587 | && gfc_dep_compare_expr (e1_op1, e2_op2) == 0) | |
588 | { | |
589 | mpz_sub (*result, e1_op2->value.integer, | |
590 | e2_op1->value.integer); | |
591 | return true; | |
592 | } | |
593 | } | |
594 | else if (e1_op1->expr_type == EXPR_CONSTANT) | |
595 | { | |
596 | /* Case 6: c1 + X - (X + c2) = c1 - c2. */ | |
597 | if (e2_op2->expr_type == EXPR_CONSTANT | |
598 | && gfc_dep_compare_expr (e1_op2, e2_op1) == 0) | |
599 | { | |
600 | mpz_sub (*result, e1_op1->value.integer, | |
601 | e2_op2->value.integer); | |
602 | return true; | |
603 | } | |
604 | /* Case 7: c1 + X - (c2 + X) = c1 - c2. */ | |
605 | if (e2_op1->expr_type == EXPR_CONSTANT | |
606 | && gfc_dep_compare_expr (e1_op2, e2_op2) == 0) | |
607 | { | |
608 | mpz_sub (*result, e1_op1->value.integer, | |
609 | e2_op1->value.integer); | |
610 | return true; | |
611 | } | |
612 | } | |
613 | } | |
614 | ||
615 | if (e2->expr_type == EXPR_OP && e2->value.op.op == INTRINSIC_MINUS) | |
616 | { | |
8b7cec58 TK |
617 | e2_op1 = gfc_discard_nops (e2->value.op.op1); |
618 | e2_op2 = gfc_discard_nops (e2->value.op.op2); | |
eab19a1a TK |
619 | |
620 | if (e1_op2->expr_type == EXPR_CONSTANT) | |
621 | { | |
622 | /* Case 8: X + c1 - (X - c2) = c1 + c2. */ | |
623 | if (e2_op2->expr_type == EXPR_CONSTANT | |
624 | && gfc_dep_compare_expr (e1_op1, e2_op1) == 0) | |
625 | { | |
626 | mpz_add (*result, e1_op2->value.integer, | |
627 | e2_op2->value.integer); | |
628 | return true; | |
629 | } | |
630 | } | |
631 | if (e1_op1->expr_type == EXPR_CONSTANT) | |
632 | { | |
633 | /* Case 9: c1 + X - (X - c2) = c1 + c2. */ | |
634 | if (e2_op2->expr_type == EXPR_CONSTANT | |
635 | && gfc_dep_compare_expr (e1_op2, e2_op1) == 0) | |
636 | { | |
637 | mpz_add (*result, e1_op1->value.integer, | |
638 | e2_op2->value.integer); | |
639 | return true; | |
640 | } | |
641 | } | |
642 | } | |
643 | } | |
644 | ||
645 | if (e1->expr_type == EXPR_OP && e1->value.op.op == INTRINSIC_MINUS) | |
646 | { | |
8b7cec58 TK |
647 | e1_op1 = gfc_discard_nops (e1->value.op.op1); |
648 | e1_op2 = gfc_discard_nops (e1->value.op.op2); | |
eab19a1a TK |
649 | |
650 | if (e1_op2->expr_type == EXPR_CONSTANT) | |
651 | { | |
652 | /* Case 10: (X - c1) - X = -c1 */ | |
653 | ||
654 | if (gfc_dep_compare_expr (e1_op1, e2) == 0) | |
655 | { | |
656 | mpz_neg (*result, e1_op2->value.integer); | |
657 | return true; | |
658 | } | |
659 | ||
660 | if (e2->expr_type == EXPR_OP && e2->value.op.op == INTRINSIC_PLUS) | |
661 | { | |
8b7cec58 TK |
662 | e2_op1 = gfc_discard_nops (e2->value.op.op1); |
663 | e2_op2 = gfc_discard_nops (e2->value.op.op2); | |
eab19a1a TK |
664 | |
665 | /* Case 11: (X - c1) - (X + c2) = -( c1 + c2). */ | |
666 | if (e2_op2->expr_type == EXPR_CONSTANT | |
667 | && gfc_dep_compare_expr (e1_op1, e2_op1) == 0) | |
668 | { | |
669 | mpz_add (*result, e1_op2->value.integer, | |
670 | e2_op2->value.integer); | |
671 | mpz_neg (*result, *result); | |
672 | return true; | |
673 | } | |
674 | ||
675 | /* Case 12: X - c1 - (c2 + X) = - (c1 + c2). */ | |
676 | if (e2_op1->expr_type == EXPR_CONSTANT | |
677 | && gfc_dep_compare_expr (e1_op1, e2_op2) == 0) | |
678 | { | |
679 | mpz_add (*result, e1_op2->value.integer, | |
680 | e2_op1->value.integer); | |
681 | mpz_neg (*result, *result); | |
682 | return true; | |
683 | } | |
684 | } | |
685 | ||
686 | if (e2->expr_type == EXPR_OP && e2->value.op.op == INTRINSIC_MINUS) | |
687 | { | |
8b7cec58 TK |
688 | e2_op1 = gfc_discard_nops (e2->value.op.op1); |
689 | e2_op2 = gfc_discard_nops (e2->value.op.op2); | |
eab19a1a TK |
690 | |
691 | /* Case 13: (X - c1) - (X - c2) = c2 - c1. */ | |
692 | if (e2_op2->expr_type == EXPR_CONSTANT | |
693 | && gfc_dep_compare_expr (e1_op1, e2_op1) == 0) | |
694 | { | |
695 | mpz_sub (*result, e2_op2->value.integer, | |
696 | e1_op2->value.integer); | |
697 | return true; | |
698 | } | |
699 | } | |
700 | } | |
701 | if (e1_op1->expr_type == EXPR_CONSTANT) | |
702 | { | |
703 | if (e2->expr_type == EXPR_OP && e2->value.op.op == INTRINSIC_MINUS) | |
704 | { | |
8b7cec58 TK |
705 | e2_op1 = gfc_discard_nops (e2->value.op.op1); |
706 | e2_op2 = gfc_discard_nops (e2->value.op.op2); | |
f8ec0561 | 707 | |
eab19a1a TK |
708 | /* Case 14: (c1 - X) - (c2 - X) == c1 - c2. */ |
709 | if (gfc_dep_compare_expr (e1_op2, e2_op2) == 0) | |
710 | { | |
711 | mpz_sub (*result, e1_op1->value.integer, | |
712 | e2_op1->value.integer); | |
713 | return true; | |
714 | } | |
715 | } | |
716 | ||
717 | } | |
718 | } | |
719 | ||
720 | if (e2->expr_type == EXPR_OP && e2->value.op.op == INTRINSIC_PLUS) | |
721 | { | |
8b7cec58 TK |
722 | e2_op1 = gfc_discard_nops (e2->value.op.op1); |
723 | e2_op2 = gfc_discard_nops (e2->value.op.op2); | |
eab19a1a TK |
724 | |
725 | /* Case 15: X - (X + c2) = -c2. */ | |
726 | if (e2_op2->expr_type == EXPR_CONSTANT | |
727 | && gfc_dep_compare_expr (e1, e2_op1) == 0) | |
728 | { | |
729 | mpz_neg (*result, e2_op2->value.integer); | |
730 | return true; | |
731 | } | |
732 | /* Case 16: X - (c2 + X) = -c2. */ | |
733 | if (e2_op1->expr_type == EXPR_CONSTANT | |
734 | && gfc_dep_compare_expr (e1, e2_op2) == 0) | |
735 | { | |
736 | mpz_neg (*result, e2_op1->value.integer); | |
737 | return true; | |
738 | } | |
739 | } | |
740 | ||
741 | if (e2->expr_type == EXPR_OP && e2->value.op.op == INTRINSIC_MINUS) | |
742 | { | |
8b7cec58 TK |
743 | e2_op1 = gfc_discard_nops (e2->value.op.op1); |
744 | e2_op2 = gfc_discard_nops (e2->value.op.op2); | |
eab19a1a TK |
745 | |
746 | /* Case 17: X - (X - c2) = c2. */ | |
747 | if (e2_op2->expr_type == EXPR_CONSTANT | |
748 | && gfc_dep_compare_expr (e1, e2_op1) == 0) | |
749 | { | |
750 | mpz_set (*result, e2_op2->value.integer); | |
751 | return true; | |
752 | } | |
753 | } | |
754 | ||
524af0d6 | 755 | if (gfc_dep_compare_expr (e1, e2) == 0) |
eab19a1a TK |
756 | { |
757 | /* Case 18: X - X = 0. */ | |
758 | mpz_set_si (*result, 0); | |
759 | return true; | |
760 | } | |
761 | ||
762 | mpz_clear (*result); | |
763 | return false; | |
764 | } | |
765 | ||
99fc1b90 JW |
766 | /* Returns 1 if the two ranges are the same and 0 if they are not (or if the |
767 | results are indeterminate). 'n' is the dimension to compare. */ | |
6de9cd9a | 768 | |
99fc1b90 JW |
769 | static int |
770 | is_same_range (gfc_array_ref *ar1, gfc_array_ref *ar2, int n) | |
6de9cd9a DN |
771 | { |
772 | gfc_expr *e1; | |
773 | gfc_expr *e2; | |
774 | int i; | |
775 | ||
776 | /* TODO: More sophisticated range comparison. */ | |
6e45f57b | 777 | gcc_assert (ar1 && ar2); |
6de9cd9a | 778 | |
6e45f57b | 779 | gcc_assert (ar1->dimen_type[n] == ar2->dimen_type[n]); |
6de9cd9a DN |
780 | |
781 | e1 = ar1->stride[n]; | |
782 | e2 = ar2->stride[n]; | |
783 | /* Check for mismatching strides. A NULL stride means a stride of 1. */ | |
784 | if (e1 && !e2) | |
785 | { | |
786 | i = gfc_expr_is_one (e1, -1); | |
99fc1b90 | 787 | if (i == -1 || i == 0) |
6de9cd9a DN |
788 | return 0; |
789 | } | |
790 | else if (e2 && !e1) | |
791 | { | |
792 | i = gfc_expr_is_one (e2, -1); | |
99fc1b90 | 793 | if (i == -1 || i == 0) |
6de9cd9a DN |
794 | return 0; |
795 | } | |
796 | else if (e1 && e2) | |
797 | { | |
798 | i = gfc_dep_compare_expr (e1, e2); | |
99fc1b90 | 799 | if (i != 0) |
6de9cd9a DN |
800 | return 0; |
801 | } | |
802 | /* The strides match. */ | |
803 | ||
804 | /* Check the range start. */ | |
805 | e1 = ar1->start[n]; | |
806 | e2 = ar2->start[n]; | |
c10bc6e9 RS |
807 | if (e1 || e2) |
808 | { | |
809 | /* Use the bound of the array if no bound is specified. */ | |
810 | if (ar1->as && !e1) | |
811 | e1 = ar1->as->lower[n]; | |
6de9cd9a | 812 | |
c10bc6e9 RS |
813 | if (ar2->as && !e2) |
814 | e2 = ar2->as->lower[n]; | |
6de9cd9a | 815 | |
c10bc6e9 RS |
816 | /* Check we have values for both. */ |
817 | if (!(e1 && e2)) | |
99fc1b90 | 818 | return 0; |
6de9cd9a | 819 | |
c10bc6e9 | 820 | i = gfc_dep_compare_expr (e1, e2); |
99fc1b90 | 821 | if (i != 0) |
c10bc6e9 RS |
822 | return 0; |
823 | } | |
6de9cd9a | 824 | |
c10bc6e9 RS |
825 | /* Check the range end. */ |
826 | e1 = ar1->end[n]; | |
827 | e2 = ar2->end[n]; | |
828 | if (e1 || e2) | |
829 | { | |
830 | /* Use the bound of the array if no bound is specified. */ | |
831 | if (ar1->as && !e1) | |
832 | e1 = ar1->as->upper[n]; | |
6de9cd9a | 833 | |
c10bc6e9 RS |
834 | if (ar2->as && !e2) |
835 | e2 = ar2->as->upper[n]; | |
6de9cd9a | 836 | |
c10bc6e9 RS |
837 | /* Check we have values for both. */ |
838 | if (!(e1 && e2)) | |
99fc1b90 | 839 | return 0; |
c10bc6e9 RS |
840 | |
841 | i = gfc_dep_compare_expr (e1, e2); | |
99fc1b90 | 842 | if (i != 0) |
c10bc6e9 RS |
843 | return 0; |
844 | } | |
845 | ||
846 | return 1; | |
6de9cd9a DN |
847 | } |
848 | ||
849 | ||
1524f80b | 850 | /* Some array-returning intrinsics can be implemented by reusing the |
8a6c4339 | 851 | data from one of the array arguments. For example, TRANSPOSE does |
1524f80b RS |
852 | not necessarily need to allocate new data: it can be implemented |
853 | by copying the original array's descriptor and simply swapping the | |
854 | two dimension specifications. | |
855 | ||
856 | If EXPR is a call to such an intrinsic, return the argument | |
857 | whose data can be reused, otherwise return NULL. */ | |
858 | ||
859 | gfc_expr * | |
636dff67 | 860 | gfc_get_noncopying_intrinsic_argument (gfc_expr *expr) |
1524f80b RS |
861 | { |
862 | if (expr->expr_type != EXPR_FUNCTION || !expr->value.function.isym) | |
863 | return NULL; | |
864 | ||
cd5ecab6 | 865 | switch (expr->value.function.isym->id) |
1524f80b RS |
866 | { |
867 | case GFC_ISYM_TRANSPOSE: | |
868 | return expr->value.function.actual->expr; | |
869 | ||
870 | default: | |
871 | return NULL; | |
872 | } | |
873 | } | |
874 | ||
875 | ||
7a70c12d RS |
876 | /* Return true if the result of reference REF can only be constructed |
877 | using a temporary array. */ | |
878 | ||
879 | bool | |
880 | gfc_ref_needs_temporary_p (gfc_ref *ref) | |
881 | { | |
882 | int n; | |
883 | bool subarray_p; | |
884 | ||
885 | subarray_p = false; | |
886 | for (; ref; ref = ref->next) | |
887 | switch (ref->type) | |
888 | { | |
889 | case REF_ARRAY: | |
890 | /* Vector dimensions are generally not monotonic and must be | |
891 | handled using a temporary. */ | |
892 | if (ref->u.ar.type == AR_SECTION) | |
893 | for (n = 0; n < ref->u.ar.dimen; n++) | |
894 | if (ref->u.ar.dimen_type[n] == DIMEN_VECTOR) | |
895 | return true; | |
896 | ||
897 | subarray_p = true; | |
898 | break; | |
899 | ||
900 | case REF_SUBSTRING: | |
901 | /* Within an array reference, character substrings generally | |
902 | need a temporary. Character array strides are expressed as | |
903 | multiples of the element size (consistent with other array | |
904 | types), not in characters. */ | |
905 | return subarray_p; | |
906 | ||
907 | case REF_COMPONENT: | |
908 | break; | |
909 | } | |
910 | ||
911 | return false; | |
912 | } | |
913 | ||
914 | ||
f6199e63 | 915 | static int |
ea4547bb MM |
916 | gfc_is_data_pointer (gfc_expr *e) |
917 | { | |
918 | gfc_ref *ref; | |
919 | ||
23f2d017 | 920 | if (e->expr_type != EXPR_VARIABLE && e->expr_type != EXPR_FUNCTION) |
ea4547bb MM |
921 | return 0; |
922 | ||
23f2d017 MM |
923 | /* No subreference if it is a function */ |
924 | gcc_assert (e->expr_type == EXPR_VARIABLE || !e->ref); | |
925 | ||
ea4547bb MM |
926 | if (e->symtree->n.sym->attr.pointer) |
927 | return 1; | |
23f2d017 | 928 | |
ea4547bb MM |
929 | for (ref = e->ref; ref; ref = ref->next) |
930 | if (ref->type == REF_COMPONENT && ref->u.c.component->attr.pointer) | |
931 | return 1; | |
932 | ||
933 | return 0; | |
934 | } | |
935 | ||
936 | ||
1524f80b RS |
937 | /* Return true if array variable VAR could be passed to the same function |
938 | as argument EXPR without interfering with EXPR. INTENT is the intent | |
939 | of VAR. | |
940 | ||
941 | This is considerably less conservative than other dependencies | |
942 | because many function arguments will already be copied into a | |
943 | temporary. */ | |
944 | ||
945 | static int | |
636dff67 | 946 | gfc_check_argument_var_dependency (gfc_expr *var, sym_intent intent, |
2b0bd714 | 947 | gfc_expr *expr, gfc_dep_check elemental) |
1524f80b | 948 | { |
2b0bd714 MM |
949 | gfc_expr *arg; |
950 | ||
1524f80b RS |
951 | gcc_assert (var->expr_type == EXPR_VARIABLE); |
952 | gcc_assert (var->rank > 0); | |
953 | ||
954 | switch (expr->expr_type) | |
955 | { | |
956 | case EXPR_VARIABLE: | |
f8ec0561 | 957 | /* In case of elemental subroutines, there is no dependency |
2b0bd714 MM |
958 | between two same-range array references. */ |
959 | if (gfc_ref_needs_temporary_p (expr->ref) | |
f7172b55 | 960 | || gfc_check_dependency (var, expr, elemental == NOT_ELEMENTAL)) |
2b0bd714 | 961 | { |
70e72065 | 962 | if (elemental == ELEM_DONT_CHECK_VARIABLE) |
2b0bd714 | 963 | { |
70e72065 MM |
964 | /* Too many false positive with pointers. */ |
965 | if (!gfc_is_data_pointer (var) && !gfc_is_data_pointer (expr)) | |
966 | { | |
f8ec0561 | 967 | /* Elemental procedures forbid unspecified intents, |
70e72065 MM |
968 | and we don't check dependencies for INTENT_IN args. */ |
969 | gcc_assert (intent == INTENT_OUT || intent == INTENT_INOUT); | |
970 | ||
f8ec0561 | 971 | /* We are told not to check dependencies. |
70e72065 | 972 | We do it, however, and issue a warning in case we find one. |
f8ec0561 | 973 | If a dependency is found in the case |
70e72065 MM |
974 | elemental == ELEM_CHECK_VARIABLE, we will generate |
975 | a temporary, so we don't need to bother the user. */ | |
2a2703a2 | 976 | gfc_warning (0, "INTENT(%s) actual argument at %L might " |
f8ec0561 PT |
977 | "interfere with actual argument at %L.", |
978 | intent == INTENT_OUT ? "OUT" : "INOUT", | |
70e72065 MM |
979 | &var->where, &expr->where); |
980 | } | |
2b0bd714 MM |
981 | return 0; |
982 | } | |
983 | else | |
f8ec0561 | 984 | return 1; |
2b0bd714 MM |
985 | } |
986 | return 0; | |
1524f80b RS |
987 | |
988 | case EXPR_ARRAY: | |
e3f62a5a MM |
989 | /* the scalarizer always generates a temporary for array constructors, |
990 | so there is no dependency. */ | |
991 | return 0; | |
1524f80b RS |
992 | |
993 | case EXPR_FUNCTION: | |
712efae1 MM |
994 | if (intent != INTENT_IN) |
995 | { | |
996 | arg = gfc_get_noncopying_intrinsic_argument (expr); | |
997 | if (arg != NULL) | |
998 | return gfc_check_argument_var_dependency (var, intent, arg, | |
999 | NOT_ELEMENTAL); | |
1000 | } | |
1001 | ||
1002 | if (elemental != NOT_ELEMENTAL) | |
2b0bd714 MM |
1003 | { |
1004 | if ((expr->value.function.esym | |
1005 | && expr->value.function.esym->attr.elemental) | |
1006 | || (expr->value.function.isym | |
1007 | && expr->value.function.isym->elemental)) | |
1008 | return gfc_check_fncall_dependency (var, intent, NULL, | |
1009 | expr->value.function.actual, | |
1010 | ELEM_CHECK_VARIABLE); | |
9645e798 MM |
1011 | |
1012 | if (gfc_inline_intrinsic_function_p (expr)) | |
1013 | { | |
1014 | /* The TRANSPOSE case should have been caught in the | |
1015 | noncopying intrinsic case above. */ | |
1016 | gcc_assert (expr->value.function.isym->id != GFC_ISYM_TRANSPOSE); | |
1017 | ||
1018 | return gfc_check_fncall_dependency (var, intent, NULL, | |
1019 | expr->value.function.actual, | |
1020 | ELEM_CHECK_VARIABLE); | |
1021 | } | |
2b0bd714 MM |
1022 | } |
1023 | return 0; | |
1024 | ||
1025 | case EXPR_OP: | |
1026 | /* In case of non-elemental procedures, there is no need to catch | |
1027 | dependencies, as we will make a temporary anyway. */ | |
1028 | if (elemental) | |
1524f80b | 1029 | { |
f8ec0561 PT |
1030 | /* If the actual arg EXPR is an expression, we need to catch |
1031 | a dependency between variables in EXPR and VAR, | |
2b0bd714 MM |
1032 | an intent((IN)OUT) variable. */ |
1033 | if (expr->value.op.op1 | |
f8ec0561 PT |
1034 | && gfc_check_argument_var_dependency (var, intent, |
1035 | expr->value.op.op1, | |
2b0bd714 MM |
1036 | ELEM_CHECK_VARIABLE)) |
1037 | return 1; | |
1038 | else if (expr->value.op.op2 | |
f8ec0561 PT |
1039 | && gfc_check_argument_var_dependency (var, intent, |
1040 | expr->value.op.op2, | |
2b0bd714 MM |
1041 | ELEM_CHECK_VARIABLE)) |
1042 | return 1; | |
1524f80b RS |
1043 | } |
1044 | return 0; | |
1045 | ||
1046 | default: | |
1047 | return 0; | |
1048 | } | |
1049 | } | |
f8ec0561 PT |
1050 | |
1051 | ||
1524f80b RS |
1052 | /* Like gfc_check_argument_var_dependency, but extended to any |
1053 | array expression OTHER, not just variables. */ | |
1054 | ||
1055 | static int | |
636dff67 | 1056 | gfc_check_argument_dependency (gfc_expr *other, sym_intent intent, |
2b0bd714 | 1057 | gfc_expr *expr, gfc_dep_check elemental) |
1524f80b RS |
1058 | { |
1059 | switch (other->expr_type) | |
1060 | { | |
1061 | case EXPR_VARIABLE: | |
2b0bd714 | 1062 | return gfc_check_argument_var_dependency (other, intent, expr, elemental); |
1524f80b RS |
1063 | |
1064 | case EXPR_FUNCTION: | |
712efae1 MM |
1065 | other = gfc_get_noncopying_intrinsic_argument (other); |
1066 | if (other != NULL) | |
1067 | return gfc_check_argument_dependency (other, INTENT_IN, expr, | |
1068 | NOT_ELEMENTAL); | |
1069 | ||
1524f80b RS |
1070 | return 0; |
1071 | ||
1072 | default: | |
1073 | return 0; | |
1074 | } | |
1075 | } | |
1076 | ||
1077 | ||
1078 | /* Like gfc_check_argument_dependency, but check all the arguments in ACTUAL. | |
1079 | FNSYM is the function being called, or NULL if not known. */ | |
6de9cd9a DN |
1080 | |
1081 | int | |
636dff67 | 1082 | gfc_check_fncall_dependency (gfc_expr *other, sym_intent intent, |
2b0bd714 MM |
1083 | gfc_symbol *fnsym, gfc_actual_arglist *actual, |
1084 | gfc_dep_check elemental) | |
6de9cd9a | 1085 | { |
1524f80b | 1086 | gfc_formal_arglist *formal; |
6de9cd9a | 1087 | gfc_expr *expr; |
6de9cd9a | 1088 | |
4cbc9039 | 1089 | formal = fnsym ? gfc_sym_get_dummy_args (fnsym) : NULL; |
1524f80b | 1090 | for (; actual; actual = actual->next, formal = formal ? formal->next : NULL) |
6de9cd9a DN |
1091 | { |
1092 | expr = actual->expr; | |
1093 | ||
1094 | /* Skip args which are not present. */ | |
1095 | if (!expr) | |
1096 | continue; | |
476220e7 PT |
1097 | |
1098 | /* Skip other itself. */ | |
1099 | if (expr == other) | |
1100 | continue; | |
6de9cd9a | 1101 | |
1524f80b | 1102 | /* Skip intent(in) arguments if OTHER itself is intent(in). */ |
636dff67 | 1103 | if (formal && intent == INTENT_IN |
1524f80b RS |
1104 | && formal->sym->attr.intent == INTENT_IN) |
1105 | continue; | |
1106 | ||
2b0bd714 | 1107 | if (gfc_check_argument_dependency (other, intent, expr, elemental)) |
1524f80b | 1108 | return 1; |
6de9cd9a DN |
1109 | } |
1110 | ||
1111 | return 0; | |
1112 | } | |
1113 | ||
1114 | ||
61321991 | 1115 | /* Return 1 if e1 and e2 are equivalenced arrays, either |
df2fba9e | 1116 | directly or indirectly; i.e., equivalence (a,b) for a and b |
61321991 PT |
1117 | or equivalence (a,c),(b,c). This function uses the equiv_ |
1118 | lists, generated in trans-common(add_equivalences), that are | |
37311e71 RS |
1119 | guaranteed to pick up indirect equivalences. We explicitly |
1120 | check for overlap using the offset and length of the equivalence. | |
1121 | This function is symmetric. | |
1122 | TODO: This function only checks whether the full top-level | |
1123 | symbols overlap. An improved implementation could inspect | |
1124 | e1->ref and e2->ref to determine whether the actually accessed | |
1125 | portions of these variables/arrays potentially overlap. */ | |
61321991 PT |
1126 | |
1127 | int | |
1128 | gfc_are_equivalenced_arrays (gfc_expr *e1, gfc_expr *e2) | |
1129 | { | |
1130 | gfc_equiv_list *l; | |
1131 | gfc_equiv_info *s, *fl1, *fl2; | |
1132 | ||
1133 | gcc_assert (e1->expr_type == EXPR_VARIABLE | |
636dff67 | 1134 | && e2->expr_type == EXPR_VARIABLE); |
61321991 PT |
1135 | |
1136 | if (!e1->symtree->n.sym->attr.in_equivalence | |
636dff67 | 1137 | || !e2->symtree->n.sym->attr.in_equivalence|| !e1->rank || !e2->rank) |
61321991 PT |
1138 | return 0; |
1139 | ||
b803690a PT |
1140 | if (e1->symtree->n.sym->ns |
1141 | && e1->symtree->n.sym->ns != gfc_current_ns) | |
1142 | l = e1->symtree->n.sym->ns->equiv_lists; | |
1143 | else | |
1144 | l = gfc_current_ns->equiv_lists; | |
1145 | ||
61321991 PT |
1146 | /* Go through the equiv_lists and return 1 if the variables |
1147 | e1 and e2 are members of the same group and satisfy the | |
1148 | requirement on their relative offsets. */ | |
b803690a | 1149 | for (; l; l = l->next) |
61321991 PT |
1150 | { |
1151 | fl1 = NULL; | |
1152 | fl2 = NULL; | |
1153 | for (s = l->equiv; s; s = s->next) | |
1154 | { | |
1155 | if (s->sym == e1->symtree->n.sym) | |
37311e71 RS |
1156 | { |
1157 | fl1 = s; | |
1158 | if (fl2) | |
1159 | break; | |
1160 | } | |
61321991 | 1161 | if (s->sym == e2->symtree->n.sym) |
37311e71 RS |
1162 | { |
1163 | fl2 = s; | |
1164 | if (fl1) | |
1165 | break; | |
1166 | } | |
1167 | } | |
1168 | ||
1169 | if (s) | |
1170 | { | |
1171 | /* Can these lengths be zero? */ | |
1172 | if (fl1->length <= 0 || fl2->length <= 0) | |
1173 | return 1; | |
f8ec0561 | 1174 | /* These can't overlap if [f11,fl1+length] is before |
37311e71 RS |
1175 | [fl2,fl2+length], or [fl2,fl2+length] is before |
1176 | [fl1,fl1+length], otherwise they do overlap. */ | |
1177 | if (fl1->offset + fl1->length > fl2->offset | |
1178 | && fl2->offset + fl2->length > fl1->offset) | |
61321991 PT |
1179 | return 1; |
1180 | } | |
1181 | } | |
37311e71 | 1182 | return 0; |
61321991 PT |
1183 | } |
1184 | ||
1185 | ||
f7172b55 PT |
1186 | /* Return true if there is no possibility of aliasing because of a type |
1187 | mismatch between all the possible pointer references and the | |
1188 | potential target. Note that this function is asymmetric in the | |
1189 | arguments and so must be called twice with the arguments exchanged. */ | |
1190 | ||
1191 | static bool | |
1192 | check_data_pointer_types (gfc_expr *expr1, gfc_expr *expr2) | |
1193 | { | |
1194 | gfc_component *cm1; | |
1195 | gfc_symbol *sym1; | |
1196 | gfc_symbol *sym2; | |
1197 | gfc_ref *ref1; | |
1198 | bool seen_component_ref; | |
1199 | ||
1200 | if (expr1->expr_type != EXPR_VARIABLE | |
adede54c | 1201 | || expr2->expr_type != EXPR_VARIABLE) |
f7172b55 PT |
1202 | return false; |
1203 | ||
1204 | sym1 = expr1->symtree->n.sym; | |
1205 | sym2 = expr2->symtree->n.sym; | |
1206 | ||
1207 | /* Keep it simple for now. */ | |
1208 | if (sym1->ts.type == BT_DERIVED && sym2->ts.type == BT_DERIVED) | |
1209 | return false; | |
1210 | ||
1211 | if (sym1->attr.pointer) | |
1212 | { | |
1213 | if (gfc_compare_types (&sym1->ts, &sym2->ts)) | |
1214 | return false; | |
1215 | } | |
1216 | ||
1217 | /* This is a conservative check on the components of the derived type | |
1218 | if no component references have been seen. Since we will not dig | |
1219 | into the components of derived type components, we play it safe by | |
1220 | returning false. First we check the reference chain and then, if | |
1221 | no component references have been seen, the components. */ | |
1222 | seen_component_ref = false; | |
1223 | if (sym1->ts.type == BT_DERIVED) | |
1224 | { | |
1225 | for (ref1 = expr1->ref; ref1; ref1 = ref1->next) | |
1226 | { | |
1227 | if (ref1->type != REF_COMPONENT) | |
1228 | continue; | |
1229 | ||
1230 | if (ref1->u.c.component->ts.type == BT_DERIVED) | |
1231 | return false; | |
1232 | ||
1233 | if ((sym2->attr.pointer || ref1->u.c.component->attr.pointer) | |
1234 | && gfc_compare_types (&ref1->u.c.component->ts, &sym2->ts)) | |
1235 | return false; | |
1236 | ||
1237 | seen_component_ref = true; | |
1238 | } | |
1239 | } | |
1240 | ||
1241 | if (sym1->ts.type == BT_DERIVED && !seen_component_ref) | |
1242 | { | |
1243 | for (cm1 = sym1->ts.u.derived->components; cm1; cm1 = cm1->next) | |
1244 | { | |
1245 | if (cm1->ts.type == BT_DERIVED) | |
1246 | return false; | |
1247 | ||
1248 | if ((sym2->attr.pointer || cm1->attr.pointer) | |
1249 | && gfc_compare_types (&cm1->ts, &sym2->ts)) | |
1250 | return false; | |
1251 | } | |
1252 | } | |
1253 | ||
1254 | return true; | |
1255 | } | |
1256 | ||
1257 | ||
6de9cd9a DN |
1258 | /* Return true if the statement body redefines the condition. Returns |
1259 | true if expr2 depends on expr1. expr1 should be a single term | |
3ded6210 RS |
1260 | suitable for the lhs of an assignment. The IDENTICAL flag indicates |
1261 | whether array references to the same symbol with identical range | |
1262 | references count as a dependency or not. Used for forall and where | |
6de9cd9a DN |
1263 | statements. Also used with functions returning arrays without a |
1264 | temporary. */ | |
1265 | ||
1266 | int | |
636dff67 | 1267 | gfc_check_dependency (gfc_expr *expr1, gfc_expr *expr2, bool identical) |
6de9cd9a | 1268 | { |
d4f8b567 RS |
1269 | gfc_actual_arglist *actual; |
1270 | gfc_constructor *c; | |
6de9cd9a | 1271 | int n; |
6de9cd9a | 1272 | |
602f77a6 SK |
1273 | /* -fcoarray=lib can end up here with expr1->expr_type set to EXPR_FUNCTION |
1274 | and a reference to _F.caf_get, so skip the assert. */ | |
1275 | if (expr1->expr_type == EXPR_FUNCTION | |
1276 | && strcmp (expr1->value.function.name, "_F.caf_get") == 0) | |
1277 | return 0; | |
1278 | ||
9b597c1f SK |
1279 | if (expr1->expr_type != EXPR_VARIABLE) |
1280 | gfc_internal_error ("gfc_check_dependency: expecting an EXPR_VARIABLE"); | |
6de9cd9a | 1281 | |
6de9cd9a DN |
1282 | switch (expr2->expr_type) |
1283 | { | |
1284 | case EXPR_OP: | |
3ded6210 | 1285 | n = gfc_check_dependency (expr1, expr2->value.op.op1, identical); |
6de9cd9a DN |
1286 | if (n) |
1287 | return n; | |
58b03ab2 | 1288 | if (expr2->value.op.op2) |
3ded6210 | 1289 | return gfc_check_dependency (expr1, expr2->value.op.op2, identical); |
6de9cd9a DN |
1290 | return 0; |
1291 | ||
1292 | case EXPR_VARIABLE: | |
bfd022c1 RS |
1293 | /* The interesting cases are when the symbols don't match. */ |
1294 | if (expr1->symtree->n.sym != expr2->symtree->n.sym) | |
6de9cd9a | 1295 | { |
e284dec5 | 1296 | symbol_attribute attr1, attr2; |
bfd022c1 RS |
1297 | gfc_typespec *ts1 = &expr1->symtree->n.sym->ts; |
1298 | gfc_typespec *ts2 = &expr2->symtree->n.sym->ts; | |
1299 | ||
1300 | /* Return 1 if expr1 and expr2 are equivalenced arrays. */ | |
1301 | if (gfc_are_equivalenced_arrays (expr1, expr2)) | |
6de9cd9a | 1302 | return 1; |
6de9cd9a | 1303 | |
bfd022c1 | 1304 | /* Symbols can only alias if they have the same type. */ |
636dff67 SK |
1305 | if (ts1->type != BT_UNKNOWN && ts2->type != BT_UNKNOWN |
1306 | && ts1->type != BT_DERIVED && ts2->type != BT_DERIVED) | |
bfd022c1 | 1307 | { |
636dff67 | 1308 | if (ts1->type != ts2->type || ts1->kind != ts2->kind) |
bfd022c1 RS |
1309 | return 0; |
1310 | } | |
61321991 | 1311 | |
e284dec5 TB |
1312 | /* We have to also include target-target as ptr%comp is not a |
1313 | pointer but it still alias with "dt%comp" for "ptr => dt". As | |
1314 | subcomponents and array access to pointers retains the target | |
1315 | attribute, that's sufficient. */ | |
1316 | attr1 = gfc_expr_attr (expr1); | |
1317 | attr2 = gfc_expr_attr (expr2); | |
1318 | if ((attr1.pointer || attr1.target) && (attr2.pointer || attr2.target)) | |
f7172b55 PT |
1319 | { |
1320 | if (check_data_pointer_types (expr1, expr2) | |
1321 | && check_data_pointer_types (expr2, expr1)) | |
1322 | return 0; | |
1323 | ||
1324 | return 1; | |
1325 | } | |
e1d818f7 TB |
1326 | else |
1327 | { | |
1328 | gfc_symbol *sym1 = expr1->symtree->n.sym; | |
1329 | gfc_symbol *sym2 = expr2->symtree->n.sym; | |
1330 | if (sym1->attr.target && sym2->attr.target | |
1331 | && ((sym1->attr.dummy && !sym1->attr.contiguous | |
1332 | && (!sym1->attr.dimension | |
1333 | || sym2->as->type == AS_ASSUMED_SHAPE)) | |
1334 | || (sym2->attr.dummy && !sym2->attr.contiguous | |
1335 | && (!sym2->attr.dimension | |
1336 | || sym2->as->type == AS_ASSUMED_SHAPE)))) | |
1337 | return 1; | |
1338 | } | |
bfd022c1 RS |
1339 | |
1340 | /* Otherwise distinct symbols have no dependencies. */ | |
1341 | return 0; | |
1342 | } | |
6de9cd9a | 1343 | |
7c428aa2 RL |
1344 | if (identical) |
1345 | return 1; | |
1346 | ||
0b8f2ce4 RS |
1347 | /* Identical and disjoint ranges return 0, |
1348 | overlapping ranges return 1. */ | |
640670c7 | 1349 | if (expr1->ref && expr2->ref) |
7c428aa2 | 1350 | return gfc_dep_resolver (expr1->ref, expr2->ref, NULL); |
3ded6210 | 1351 | |
6de9cd9a DN |
1352 | return 1; |
1353 | ||
1354 | case EXPR_FUNCTION: | |
712efae1 | 1355 | if (gfc_get_noncopying_intrinsic_argument (expr2) != NULL) |
3ded6210 | 1356 | identical = 1; |
712efae1 | 1357 | |
1f2959f0 | 1358 | /* Remember possible differences between elemental and |
c10bc6e9 RS |
1359 | transformational functions. All functions inside a FORALL |
1360 | will be pure. */ | |
6de9cd9a DN |
1361 | for (actual = expr2->value.function.actual; |
1362 | actual; actual = actual->next) | |
1363 | { | |
1364 | if (!actual->expr) | |
1365 | continue; | |
3ded6210 | 1366 | n = gfc_check_dependency (expr1, actual->expr, identical); |
6de9cd9a DN |
1367 | if (n) |
1368 | return n; | |
1369 | } | |
1370 | return 0; | |
1371 | ||
1372 | case EXPR_CONSTANT: | |
681150cd | 1373 | case EXPR_NULL: |
6de9cd9a DN |
1374 | return 0; |
1375 | ||
1376 | case EXPR_ARRAY: | |
d4f8b567 | 1377 | /* Loop through the array constructor's elements. */ |
b7e75771 JD |
1378 | for (c = gfc_constructor_first (expr2->value.constructor); |
1379 | c; c = gfc_constructor_next (c)) | |
d4f8b567 RS |
1380 | { |
1381 | /* If this is an iterator, assume the worst. */ | |
1382 | if (c->iterator) | |
1383 | return 1; | |
1384 | /* Avoid recursion in the common case. */ | |
1385 | if (c->expr->expr_type == EXPR_CONSTANT) | |
1386 | continue; | |
1387 | if (gfc_check_dependency (expr1, c->expr, 1)) | |
1388 | return 1; | |
1389 | } | |
1390 | return 0; | |
6de9cd9a DN |
1391 | |
1392 | default: | |
1393 | return 1; | |
1394 | } | |
1395 | } | |
1396 | ||
1397 | ||
6de9cd9a DN |
1398 | /* Determines overlapping for two array sections. */ |
1399 | ||
1400 | static gfc_dependency | |
071bdb5f | 1401 | check_section_vs_section (gfc_array_ref *l_ar, gfc_array_ref *r_ar, int n) |
6de9cd9a DN |
1402 | { |
1403 | gfc_expr *l_start; | |
1404 | gfc_expr *l_end; | |
1405 | gfc_expr *l_stride; | |
06a103af RS |
1406 | gfc_expr *l_lower; |
1407 | gfc_expr *l_upper; | |
1408 | int l_dir; | |
6de9cd9a DN |
1409 | |
1410 | gfc_expr *r_start; | |
06a103af | 1411 | gfc_expr *r_end; |
6de9cd9a | 1412 | gfc_expr *r_stride; |
06a103af RS |
1413 | gfc_expr *r_lower; |
1414 | gfc_expr *r_upper; | |
8976d513 | 1415 | gfc_expr *one_expr; |
06a103af | 1416 | int r_dir; |
8976d513 TK |
1417 | int stride_comparison; |
1418 | int start_comparison; | |
eab19a1a | 1419 | mpz_t tmp; |
6de9cd9a | 1420 | |
8a0b57b3 | 1421 | /* If they are the same range, return without more ado. */ |
99fc1b90 | 1422 | if (is_same_range (l_ar, r_ar, n)) |
8a0b57b3 | 1423 | return GFC_DEP_EQUAL; |
6de9cd9a | 1424 | |
071bdb5f TK |
1425 | l_start = l_ar->start[n]; |
1426 | l_end = l_ar->end[n]; | |
1427 | l_stride = l_ar->stride[n]; | |
06a103af | 1428 | |
071bdb5f TK |
1429 | r_start = r_ar->start[n]; |
1430 | r_end = r_ar->end[n]; | |
1431 | r_stride = r_ar->stride[n]; | |
6de9cd9a | 1432 | |
06a103af | 1433 | /* If l_start is NULL take it from array specifier. */ |
071bdb5f TK |
1434 | if (NULL == l_start && IS_ARRAY_EXPLICIT (l_ar->as)) |
1435 | l_start = l_ar->as->lower[n]; | |
06a103af | 1436 | /* If l_end is NULL take it from array specifier. */ |
071bdb5f TK |
1437 | if (NULL == l_end && IS_ARRAY_EXPLICIT (l_ar->as)) |
1438 | l_end = l_ar->as->upper[n]; | |
6de9cd9a | 1439 | |
06a103af | 1440 | /* If r_start is NULL take it from array specifier. */ |
071bdb5f TK |
1441 | if (NULL == r_start && IS_ARRAY_EXPLICIT (r_ar->as)) |
1442 | r_start = r_ar->as->lower[n]; | |
06a103af | 1443 | /* If r_end is NULL take it from array specifier. */ |
071bdb5f TK |
1444 | if (NULL == r_end && IS_ARRAY_EXPLICIT (r_ar->as)) |
1445 | r_end = r_ar->as->upper[n]; | |
06a103af RS |
1446 | |
1447 | /* Determine whether the l_stride is positive or negative. */ | |
1448 | if (!l_stride) | |
1449 | l_dir = 1; | |
1450 | else if (l_stride->expr_type == EXPR_CONSTANT | |
636dff67 | 1451 | && l_stride->ts.type == BT_INTEGER) |
06a103af RS |
1452 | l_dir = mpz_sgn (l_stride->value.integer); |
1453 | else if (l_start && l_end) | |
1454 | l_dir = gfc_dep_compare_expr (l_end, l_start); | |
1455 | else | |
1456 | l_dir = -2; | |
1457 | ||
1458 | /* Determine whether the r_stride is positive or negative. */ | |
1459 | if (!r_stride) | |
1460 | r_dir = 1; | |
1461 | else if (r_stride->expr_type == EXPR_CONSTANT | |
636dff67 | 1462 | && r_stride->ts.type == BT_INTEGER) |
06a103af RS |
1463 | r_dir = mpz_sgn (r_stride->value.integer); |
1464 | else if (r_start && r_end) | |
1465 | r_dir = gfc_dep_compare_expr (r_end, r_start); | |
1466 | else | |
1467 | r_dir = -2; | |
6de9cd9a | 1468 | |
06a103af RS |
1469 | /* The strides should never be zero. */ |
1470 | if (l_dir == 0 || r_dir == 0) | |
1471 | return GFC_DEP_OVERLAP; | |
6de9cd9a | 1472 | |
8976d513 TK |
1473 | /* Determine the relationship between the strides. Set stride_comparison to |
1474 | -2 if the dependency cannot be determined | |
1475 | -1 if l_stride < r_stride | |
1476 | 0 if l_stride == r_stride | |
1477 | 1 if l_stride > r_stride | |
1478 | as determined by gfc_dep_compare_expr. */ | |
e240f0f4 | 1479 | |
8976d513 TK |
1480 | one_expr = gfc_get_int_expr (gfc_index_integer_kind, NULL, 1); |
1481 | ||
1482 | stride_comparison = gfc_dep_compare_expr (l_stride ? l_stride : one_expr, | |
1483 | r_stride ? r_stride : one_expr); | |
1484 | ||
1485 | if (l_start && r_start) | |
1486 | start_comparison = gfc_dep_compare_expr (l_start, r_start); | |
e240f0f4 | 1487 | else |
8976d513 | 1488 | start_comparison = -2; |
f8ec0561 | 1489 | |
15a611c0 | 1490 | gfc_free_expr (one_expr); |
e240f0f4 | 1491 | |
06a103af RS |
1492 | /* Determine LHS upper and lower bounds. */ |
1493 | if (l_dir == 1) | |
1494 | { | |
1495 | l_lower = l_start; | |
1496 | l_upper = l_end; | |
1497 | } | |
1498 | else if (l_dir == -1) | |
1499 | { | |
1500 | l_lower = l_end; | |
1501 | l_upper = l_start; | |
1502 | } | |
6de9cd9a | 1503 | else |
06a103af RS |
1504 | { |
1505 | l_lower = NULL; | |
1506 | l_upper = NULL; | |
1507 | } | |
6de9cd9a | 1508 | |
06a103af RS |
1509 | /* Determine RHS upper and lower bounds. */ |
1510 | if (r_dir == 1) | |
1511 | { | |
1512 | r_lower = r_start; | |
1513 | r_upper = r_end; | |
1514 | } | |
1515 | else if (r_dir == -1) | |
1516 | { | |
1517 | r_lower = r_end; | |
1518 | r_upper = r_start; | |
1519 | } | |
1520 | else | |
1521 | { | |
1522 | r_lower = NULL; | |
1523 | r_upper = NULL; | |
1524 | } | |
1525 | ||
1526 | /* Check whether the ranges are disjoint. */ | |
1527 | if (l_upper && r_lower && gfc_dep_compare_expr (l_upper, r_lower) == -1) | |
1528 | return GFC_DEP_NODEP; | |
1529 | if (r_upper && l_lower && gfc_dep_compare_expr (r_upper, l_lower) == -1) | |
1530 | return GFC_DEP_NODEP; | |
1531 | ||
1532 | /* Handle cases like x:y:1 vs. x:z:-1 as GFC_DEP_EQUAL. */ | |
1533 | if (l_start && r_start && gfc_dep_compare_expr (l_start, r_start) == 0) | |
1534 | { | |
1535 | if (l_dir == 1 && r_dir == -1) | |
636dff67 | 1536 | return GFC_DEP_EQUAL; |
06a103af | 1537 | if (l_dir == -1 && r_dir == 1) |
636dff67 | 1538 | return GFC_DEP_EQUAL; |
06a103af RS |
1539 | } |
1540 | ||
1541 | /* Handle cases like x:y:1 vs. z:y:-1 as GFC_DEP_EQUAL. */ | |
1542 | if (l_end && r_end && gfc_dep_compare_expr (l_end, r_end) == 0) | |
1543 | { | |
1544 | if (l_dir == 1 && r_dir == -1) | |
636dff67 | 1545 | return GFC_DEP_EQUAL; |
06a103af | 1546 | if (l_dir == -1 && r_dir == 1) |
636dff67 | 1547 | return GFC_DEP_EQUAL; |
06a103af RS |
1548 | } |
1549 | ||
e2113565 TK |
1550 | /* Handle cases like x:y:2 vs. x+1:z:4 as GFC_DEP_NODEP. |
1551 | There is no dependency if the remainder of | |
1552 | (l_start - r_start) / gcd(l_stride, r_stride) is | |
1553 | nonzero. | |
1554 | TODO: | |
e2113565 TK |
1555 | - Cases like a(1:4:2) = a(2:3) are still not handled. |
1556 | */ | |
1557 | ||
1558 | #define IS_CONSTANT_INTEGER(a) ((a) && ((a)->expr_type == EXPR_CONSTANT) \ | |
1559 | && (a)->ts.type == BT_INTEGER) | |
1560 | ||
524af0d6 | 1561 | if (IS_CONSTANT_INTEGER (l_stride) && IS_CONSTANT_INTEGER (r_stride) |
eab19a1a | 1562 | && gfc_dep_difference (l_start, r_start, &tmp)) |
e2113565 | 1563 | { |
eab19a1a | 1564 | mpz_t gcd; |
e2113565 TK |
1565 | int result; |
1566 | ||
1567 | mpz_init (gcd); | |
e2113565 | 1568 | mpz_gcd (gcd, l_stride->value.integer, r_stride->value.integer); |
e2113565 TK |
1569 | |
1570 | mpz_fdiv_r (tmp, tmp, gcd); | |
1571 | result = mpz_cmp_si (tmp, 0L); | |
1572 | ||
1573 | mpz_clear (gcd); | |
1574 | mpz_clear (tmp); | |
1575 | ||
1576 | if (result != 0) | |
1577 | return GFC_DEP_NODEP; | |
1578 | } | |
1579 | ||
1580 | #undef IS_CONSTANT_INTEGER | |
1581 | ||
1cc0e193 | 1582 | /* Check for forward dependencies x:y vs. x+1:z and x:y:z vs. x:y:z+1. */ |
06a103af | 1583 | |
8976d513 TK |
1584 | if (l_dir == 1 && r_dir == 1 && |
1585 | (start_comparison == 0 || start_comparison == -1) | |
1586 | && (stride_comparison == 0 || stride_comparison == -1)) | |
1587 | return GFC_DEP_FORWARD; | |
06a103af | 1588 | |
8976d513 TK |
1589 | /* Check for forward dependencies x:y:-1 vs. x-1:z:-1 and |
1590 | x:y:-1 vs. x:y:-2. */ | |
f8ec0561 | 1591 | if (l_dir == -1 && r_dir == -1 && |
8976d513 TK |
1592 | (start_comparison == 0 || start_comparison == 1) |
1593 | && (stride_comparison == 0 || stride_comparison == 1)) | |
1594 | return GFC_DEP_FORWARD; | |
8a0f25c3 | 1595 | |
8976d513 | 1596 | if (stride_comparison == 0 || stride_comparison == -1) |
3d03ead0 | 1597 | { |
8a0f25c3 TK |
1598 | if (l_start && IS_ARRAY_EXPLICIT (l_ar->as)) |
1599 | { | |
1600 | ||
8976d513 TK |
1601 | /* Check for a(low:y:s) vs. a(z:x:s) or |
1602 | a(low:y:s) vs. a(z:x:s+1) where a has a lower bound | |
8a0f25c3 TK |
1603 | of low, which is always at least a forward dependence. */ |
1604 | ||
1605 | if (r_dir == 1 | |
1606 | && gfc_dep_compare_expr (l_start, l_ar->as->lower[n]) == 0) | |
1607 | return GFC_DEP_FORWARD; | |
8976d513 TK |
1608 | } |
1609 | } | |
8a0f25c3 | 1610 | |
8976d513 TK |
1611 | if (stride_comparison == 0 || stride_comparison == 1) |
1612 | { | |
1613 | if (l_start && IS_ARRAY_EXPLICIT (l_ar->as)) | |
1614 | { | |
f8ec0561 | 1615 | |
8976d513 TK |
1616 | /* Check for a(high:y:-s) vs. a(z:x:-s) or |
1617 | a(high:y:-s vs. a(z:x:-s-1) where a has a higher bound | |
8a0f25c3 TK |
1618 | of high, which is always at least a forward dependence. */ |
1619 | ||
1620 | if (r_dir == -1 | |
1621 | && gfc_dep_compare_expr (l_start, l_ar->as->upper[n]) == 0) | |
1622 | return GFC_DEP_FORWARD; | |
1623 | } | |
8976d513 | 1624 | } |
8a0f25c3 | 1625 | |
8976d513 TK |
1626 | |
1627 | if (stride_comparison == 0) | |
1628 | { | |
8a0f25c3 | 1629 | /* From here, check for backwards dependencies. */ |
8976d513 TK |
1630 | /* x+1:y vs. x:z. */ |
1631 | if (l_dir == 1 && r_dir == 1 && start_comparison == 1) | |
3d03ead0 PT |
1632 | return GFC_DEP_BACKWARD; |
1633 | ||
8976d513 TK |
1634 | /* x-1:y:-1 vs. x:z:-1. */ |
1635 | if (l_dir == -1 && r_dir == -1 && start_comparison == -1) | |
3d03ead0 PT |
1636 | return GFC_DEP_BACKWARD; |
1637 | } | |
1638 | ||
06a103af | 1639 | return GFC_DEP_OVERLAP; |
6de9cd9a DN |
1640 | } |
1641 | ||
1642 | ||
9ccab91c | 1643 | /* Determines overlapping for a single element and a section. */ |
6de9cd9a DN |
1644 | |
1645 | static gfc_dependency | |
636dff67 | 1646 | gfc_check_element_vs_section( gfc_ref *lref, gfc_ref *rref, int n) |
6de9cd9a | 1647 | { |
9ccab91c RS |
1648 | gfc_array_ref *ref; |
1649 | gfc_expr *elem; | |
1650 | gfc_expr *start; | |
1651 | gfc_expr *end; | |
1652 | gfc_expr *stride; | |
6de9cd9a DN |
1653 | int s; |
1654 | ||
9ccab91c RS |
1655 | elem = lref->u.ar.start[n]; |
1656 | if (!elem) | |
6de9cd9a DN |
1657 | return GFC_DEP_OVERLAP; |
1658 | ||
9ccab91c RS |
1659 | ref = &rref->u.ar; |
1660 | start = ref->start[n] ; | |
1661 | end = ref->end[n] ; | |
1662 | stride = ref->stride[n]; | |
1663 | ||
1664 | if (!start && IS_ARRAY_EXPLICIT (ref->as)) | |
1665 | start = ref->as->lower[n]; | |
1666 | if (!end && IS_ARRAY_EXPLICIT (ref->as)) | |
1667 | end = ref->as->upper[n]; | |
1668 | ||
1669 | /* Determine whether the stride is positive or negative. */ | |
1670 | if (!stride) | |
1671 | s = 1; | |
1672 | else if (stride->expr_type == EXPR_CONSTANT | |
1673 | && stride->ts.type == BT_INTEGER) | |
1674 | s = mpz_sgn (stride->value.integer); | |
1675 | else | |
1676 | s = -2; | |
6de9cd9a | 1677 | |
9ccab91c RS |
1678 | /* Stride should never be zero. */ |
1679 | if (s == 0) | |
6de9cd9a DN |
1680 | return GFC_DEP_OVERLAP; |
1681 | ||
9ccab91c | 1682 | /* Positive strides. */ |
6de9cd9a DN |
1683 | if (s == 1) |
1684 | { | |
9ccab91c RS |
1685 | /* Check for elem < lower. */ |
1686 | if (start && gfc_dep_compare_expr (elem, start) == -1) | |
1687 | return GFC_DEP_NODEP; | |
1688 | /* Check for elem > upper. */ | |
1689 | if (end && gfc_dep_compare_expr (elem, end) == 1) | |
1690 | return GFC_DEP_NODEP; | |
1691 | ||
1692 | if (start && end) | |
1693 | { | |
1694 | s = gfc_dep_compare_expr (start, end); | |
1695 | /* Check for an empty range. */ | |
1696 | if (s == 1) | |
1697 | return GFC_DEP_NODEP; | |
1698 | if (s == 0 && gfc_dep_compare_expr (elem, start) == 0) | |
1699 | return GFC_DEP_EQUAL; | |
1700 | } | |
1701 | } | |
1702 | /* Negative strides. */ | |
1703 | else if (s == -1) | |
1704 | { | |
1705 | /* Check for elem > upper. */ | |
1706 | if (end && gfc_dep_compare_expr (elem, start) == 1) | |
1707 | return GFC_DEP_NODEP; | |
1708 | /* Check for elem < lower. */ | |
1709 | if (start && gfc_dep_compare_expr (elem, end) == -1) | |
1710 | return GFC_DEP_NODEP; | |
1711 | ||
1712 | if (start && end) | |
1713 | { | |
1714 | s = gfc_dep_compare_expr (start, end); | |
1715 | /* Check for an empty range. */ | |
1716 | if (s == -1) | |
1717 | return GFC_DEP_NODEP; | |
1718 | if (s == 0 && gfc_dep_compare_expr (elem, start) == 0) | |
1719 | return GFC_DEP_EQUAL; | |
1720 | } | |
6de9cd9a | 1721 | } |
9ccab91c | 1722 | /* Unknown strides. */ |
6de9cd9a DN |
1723 | else |
1724 | { | |
9ccab91c RS |
1725 | if (!start || !end) |
1726 | return GFC_DEP_OVERLAP; | |
1727 | s = gfc_dep_compare_expr (start, end); | |
13001f33 | 1728 | if (s <= -2) |
6de9cd9a | 1729 | return GFC_DEP_OVERLAP; |
9ccab91c RS |
1730 | /* Assume positive stride. */ |
1731 | if (s == -1) | |
1732 | { | |
1733 | /* Check for elem < lower. */ | |
1734 | if (gfc_dep_compare_expr (elem, start) == -1) | |
1735 | return GFC_DEP_NODEP; | |
1736 | /* Check for elem > upper. */ | |
1737 | if (gfc_dep_compare_expr (elem, end) == 1) | |
1738 | return GFC_DEP_NODEP; | |
1739 | } | |
1740 | /* Assume negative stride. */ | |
1741 | else if (s == 1) | |
1742 | { | |
1743 | /* Check for elem > upper. */ | |
1744 | if (gfc_dep_compare_expr (elem, start) == 1) | |
1745 | return GFC_DEP_NODEP; | |
1746 | /* Check for elem < lower. */ | |
1747 | if (gfc_dep_compare_expr (elem, end) == -1) | |
1748 | return GFC_DEP_NODEP; | |
1749 | } | |
1750 | /* Equal bounds. */ | |
1751 | else if (s == 0) | |
1752 | { | |
1753 | s = gfc_dep_compare_expr (elem, start); | |
1754 | if (s == 0) | |
1755 | return GFC_DEP_EQUAL; | |
1756 | if (s == 1 || s == -1) | |
1757 | return GFC_DEP_NODEP; | |
1758 | } | |
6de9cd9a | 1759 | } |
6de9cd9a | 1760 | |
9ccab91c | 1761 | return GFC_DEP_OVERLAP; |
6de9cd9a DN |
1762 | } |
1763 | ||
1764 | ||
31708dc6 RS |
1765 | /* Traverse expr, checking all EXPR_VARIABLE symbols for their |
1766 | forall_index attribute. Return true if any variable may be | |
1767 | being used as a FORALL index. Its safe to pessimistically | |
1768 | return true, and assume a dependency. */ | |
1769 | ||
1770 | static bool | |
636dff67 | 1771 | contains_forall_index_p (gfc_expr *expr) |
31708dc6 RS |
1772 | { |
1773 | gfc_actual_arglist *arg; | |
1774 | gfc_constructor *c; | |
1775 | gfc_ref *ref; | |
1776 | int i; | |
1777 | ||
1778 | if (!expr) | |
1779 | return false; | |
1780 | ||
1781 | switch (expr->expr_type) | |
1782 | { | |
1783 | case EXPR_VARIABLE: | |
1784 | if (expr->symtree->n.sym->forall_index) | |
1785 | return true; | |
1786 | break; | |
1787 | ||
1788 | case EXPR_OP: | |
1789 | if (contains_forall_index_p (expr->value.op.op1) | |
1790 | || contains_forall_index_p (expr->value.op.op2)) | |
1791 | return true; | |
1792 | break; | |
1793 | ||
1794 | case EXPR_FUNCTION: | |
1795 | for (arg = expr->value.function.actual; arg; arg = arg->next) | |
1796 | if (contains_forall_index_p (arg->expr)) | |
1797 | return true; | |
1798 | break; | |
1799 | ||
1800 | case EXPR_CONSTANT: | |
1801 | case EXPR_NULL: | |
1802 | case EXPR_SUBSTRING: | |
1803 | break; | |
1804 | ||
1805 | case EXPR_STRUCTURE: | |
1806 | case EXPR_ARRAY: | |
b7e75771 JD |
1807 | for (c = gfc_constructor_first (expr->value.constructor); |
1808 | c; gfc_constructor_next (c)) | |
31708dc6 RS |
1809 | if (contains_forall_index_p (c->expr)) |
1810 | return true; | |
1811 | break; | |
1812 | ||
1813 | default: | |
1814 | gcc_unreachable (); | |
1815 | } | |
1816 | ||
1817 | for (ref = expr->ref; ref; ref = ref->next) | |
1818 | switch (ref->type) | |
1819 | { | |
1820 | case REF_ARRAY: | |
1821 | for (i = 0; i < ref->u.ar.dimen; i++) | |
1822 | if (contains_forall_index_p (ref->u.ar.start[i]) | |
1823 | || contains_forall_index_p (ref->u.ar.end[i]) | |
1824 | || contains_forall_index_p (ref->u.ar.stride[i])) | |
1825 | return true; | |
1826 | break; | |
1827 | ||
1828 | case REF_COMPONENT: | |
1829 | break; | |
1830 | ||
1831 | case REF_SUBSTRING: | |
1832 | if (contains_forall_index_p (ref->u.ss.start) | |
1833 | || contains_forall_index_p (ref->u.ss.end)) | |
1834 | return true; | |
1835 | break; | |
1836 | ||
1837 | default: | |
1838 | gcc_unreachable (); | |
1839 | } | |
1840 | ||
1841 | return false; | |
1842 | } | |
1843 | ||
6de9cd9a DN |
1844 | /* Determines overlapping for two single element array references. */ |
1845 | ||
1846 | static gfc_dependency | |
636dff67 | 1847 | gfc_check_element_vs_element (gfc_ref *lref, gfc_ref *rref, int n) |
6de9cd9a DN |
1848 | { |
1849 | gfc_array_ref l_ar; | |
1850 | gfc_array_ref r_ar; | |
1851 | gfc_expr *l_start; | |
1852 | gfc_expr *r_start; | |
0b8f2ce4 | 1853 | int i; |
6de9cd9a | 1854 | |
0b8f2ce4 RS |
1855 | l_ar = lref->u.ar; |
1856 | r_ar = rref->u.ar; | |
1857 | l_start = l_ar.start[n] ; | |
1858 | r_start = r_ar.start[n] ; | |
1859 | i = gfc_dep_compare_expr (r_start, l_start); | |
1860 | if (i == 0) | |
1861 | return GFC_DEP_EQUAL; | |
31708dc6 RS |
1862 | |
1863 | /* Treat two scalar variables as potentially equal. This allows | |
1864 | us to prove that a(i,:) and a(j,:) have no dependency. See | |
1865 | Gerald Roth, "Evaluation of Array Syntax Dependence Analysis", | |
1866 | Proceedings of the International Conference on Parallel and | |
1867 | Distributed Processing Techniques and Applications (PDPTA2001), | |
1868 | Las Vegas, Nevada, June 2001. */ | |
1869 | /* However, we need to be careful when either scalar expression | |
1870 | contains a FORALL index, as these can potentially change value | |
1871 | during the scalarization/traversal of this array reference. */ | |
636dff67 | 1872 | if (contains_forall_index_p (r_start) || contains_forall_index_p (l_start)) |
636ffc57 | 1873 | return GFC_DEP_OVERLAP; |
31708dc6 | 1874 | |
13001f33 | 1875 | if (i > -2) |
d765523a | 1876 | return GFC_DEP_NODEP; |
31708dc6 | 1877 | return GFC_DEP_EQUAL; |
6de9cd9a DN |
1878 | } |
1879 | ||
4195393b TK |
1880 | /* Callback function for checking if an expression depends on a |
1881 | dummy variable which is any other than INTENT(IN). */ | |
1882 | ||
1883 | static int | |
1884 | callback_dummy_intent_not_in (gfc_expr **ep, | |
1885 | int *walk_subtrees ATTRIBUTE_UNUSED, | |
1886 | void *data ATTRIBUTE_UNUSED) | |
1887 | { | |
1888 | gfc_expr *e = *ep; | |
1889 | ||
1890 | if (e->expr_type == EXPR_VARIABLE && e->symtree | |
1891 | && e->symtree->n.sym->attr.dummy) | |
1892 | return e->symtree->n.sym->attr.intent != INTENT_IN; | |
1893 | else | |
1894 | return 0; | |
1895 | } | |
1896 | ||
1897 | /* Auxiliary function to check if subexpressions have dummy variables which | |
1898 | are not intent(in). | |
1899 | */ | |
1900 | ||
1901 | static bool | |
1902 | dummy_intent_not_in (gfc_expr **ep) | |
1903 | { | |
1904 | return gfc_expr_walker (ep, callback_dummy_intent_not_in, NULL); | |
1905 | } | |
6de9cd9a | 1906 | |
fcd44320 | 1907 | /* Determine if an array ref, usually an array section specifies the |
a61a36ab PT |
1908 | entire array. In addition, if the second, pointer argument is |
1909 | provided, the function will return true if the reference is | |
4195393b TK |
1910 | contiguous; eg. (:, 1) gives true but (1,:) gives false. |
1911 | If one of the bounds depends on a dummy variable which is | |
1912 | not INTENT(IN), also return false, because the user may | |
1913 | have changed the variable. */ | |
fcd44320 RS |
1914 | |
1915 | bool | |
a61a36ab | 1916 | gfc_full_array_ref_p (gfc_ref *ref, bool *contiguous) |
fcd44320 RS |
1917 | { |
1918 | int i; | |
f80c558f | 1919 | int n; |
a61a36ab PT |
1920 | bool lbound_OK = true; |
1921 | bool ubound_OK = true; | |
fcd44320 | 1922 | |
37a40b53 PT |
1923 | if (contiguous) |
1924 | *contiguous = false; | |
1925 | ||
fcd44320 RS |
1926 | if (ref->type != REF_ARRAY) |
1927 | return false; | |
f80c558f | 1928 | |
fcd44320 | 1929 | if (ref->u.ar.type == AR_FULL) |
37a40b53 PT |
1930 | { |
1931 | if (contiguous) | |
1932 | *contiguous = true; | |
1933 | return true; | |
1934 | } | |
f80c558f | 1935 | |
fcd44320 RS |
1936 | if (ref->u.ar.type != AR_SECTION) |
1937 | return false; | |
b01e2f88 RS |
1938 | if (ref->next) |
1939 | return false; | |
fcd44320 RS |
1940 | |
1941 | for (i = 0; i < ref->u.ar.dimen; i++) | |
1942 | { | |
f80c558f PT |
1943 | /* If we have a single element in the reference, for the reference |
1944 | to be full, we need to ascertain that the array has a single | |
1945 | element in this dimension and that we actually reference the | |
1946 | correct element. */ | |
3e94065c TK |
1947 | if (ref->u.ar.dimen_type[i] == DIMEN_ELEMENT) |
1948 | { | |
f80c558f PT |
1949 | /* This is unconditionally a contiguous reference if all the |
1950 | remaining dimensions are elements. */ | |
a61a36ab | 1951 | if (contiguous) |
f80c558f PT |
1952 | { |
1953 | *contiguous = true; | |
1954 | for (n = i + 1; n < ref->u.ar.dimen; n++) | |
1955 | if (ref->u.ar.dimen_type[n] != DIMEN_ELEMENT) | |
1956 | *contiguous = false; | |
1957 | } | |
a61a36ab | 1958 | |
3e94065c TK |
1959 | if (!ref->u.ar.as |
1960 | || !ref->u.ar.as->lower[i] | |
1961 | || !ref->u.ar.as->upper[i] | |
1962 | || gfc_dep_compare_expr (ref->u.ar.as->lower[i], | |
1963 | ref->u.ar.as->upper[i]) | |
1964 | || !ref->u.ar.start[i] | |
1965 | || gfc_dep_compare_expr (ref->u.ar.start[i], | |
1966 | ref->u.ar.as->lower[i])) | |
1967 | return false; | |
1968 | else | |
1969 | continue; | |
1970 | } | |
1971 | ||
fcd44320 RS |
1972 | /* Check the lower bound. */ |
1973 | if (ref->u.ar.start[i] | |
1974 | && (!ref->u.ar.as | |
1975 | || !ref->u.ar.as->lower[i] | |
1976 | || gfc_dep_compare_expr (ref->u.ar.start[i], | |
4195393b TK |
1977 | ref->u.ar.as->lower[i]) |
1978 | || dummy_intent_not_in (&ref->u.ar.start[i]))) | |
a61a36ab | 1979 | lbound_OK = false; |
fcd44320 RS |
1980 | /* Check the upper bound. */ |
1981 | if (ref->u.ar.end[i] | |
1982 | && (!ref->u.ar.as | |
1983 | || !ref->u.ar.as->upper[i] | |
1984 | || gfc_dep_compare_expr (ref->u.ar.end[i], | |
4195393b TK |
1985 | ref->u.ar.as->upper[i]) |
1986 | || dummy_intent_not_in (&ref->u.ar.end[i]))) | |
a61a36ab | 1987 | ubound_OK = false; |
fcd44320 | 1988 | /* Check the stride. */ |
f80c558f PT |
1989 | if (ref->u.ar.stride[i] |
1990 | && !gfc_expr_is_one (ref->u.ar.stride[i], 0)) | |
fcd44320 | 1991 | return false; |
a61a36ab | 1992 | |
f80c558f PT |
1993 | /* This is unconditionally a contiguous reference as long as all |
1994 | the subsequent dimensions are elements. */ | |
a61a36ab | 1995 | if (contiguous) |
f80c558f PT |
1996 | { |
1997 | *contiguous = true; | |
1998 | for (n = i + 1; n < ref->u.ar.dimen; n++) | |
1999 | if (ref->u.ar.dimen_type[n] != DIMEN_ELEMENT) | |
2000 | *contiguous = false; | |
2001 | } | |
a61a36ab PT |
2002 | |
2003 | if (!lbound_OK || !ubound_OK) | |
2004 | return false; | |
fcd44320 RS |
2005 | } |
2006 | return true; | |
2007 | } | |
2008 | ||
2009 | ||
ea0a374b PT |
2010 | /* Determine if a full array is the same as an array section with one |
2011 | variable limit. For this to be so, the strides must both be unity | |
2012 | and one of either start == lower or end == upper must be true. */ | |
2013 | ||
2014 | static bool | |
2015 | ref_same_as_full_array (gfc_ref *full_ref, gfc_ref *ref) | |
2016 | { | |
2017 | int i; | |
2018 | bool upper_or_lower; | |
2019 | ||
2020 | if (full_ref->type != REF_ARRAY) | |
2021 | return false; | |
2022 | if (full_ref->u.ar.type != AR_FULL) | |
2023 | return false; | |
2024 | if (ref->type != REF_ARRAY) | |
2025 | return false; | |
2026 | if (ref->u.ar.type != AR_SECTION) | |
2027 | return false; | |
2028 | ||
2029 | for (i = 0; i < ref->u.ar.dimen; i++) | |
2030 | { | |
2031 | /* If we have a single element in the reference, we need to check | |
2032 | that the array has a single element and that we actually reference | |
2033 | the correct element. */ | |
2034 | if (ref->u.ar.dimen_type[i] == DIMEN_ELEMENT) | |
2035 | { | |
2036 | if (!full_ref->u.ar.as | |
2037 | || !full_ref->u.ar.as->lower[i] | |
2038 | || !full_ref->u.ar.as->upper[i] | |
2039 | || gfc_dep_compare_expr (full_ref->u.ar.as->lower[i], | |
2040 | full_ref->u.ar.as->upper[i]) | |
2041 | || !ref->u.ar.start[i] | |
2042 | || gfc_dep_compare_expr (ref->u.ar.start[i], | |
2043 | full_ref->u.ar.as->lower[i])) | |
2044 | return false; | |
2045 | } | |
2046 | ||
2047 | /* Check the strides. */ | |
2048 | if (full_ref->u.ar.stride[i] && !gfc_expr_is_one (full_ref->u.ar.stride[i], 0)) | |
2049 | return false; | |
2050 | if (ref->u.ar.stride[i] && !gfc_expr_is_one (ref->u.ar.stride[i], 0)) | |
2051 | return false; | |
2052 | ||
2053 | upper_or_lower = false; | |
2054 | /* Check the lower bound. */ | |
2055 | if (ref->u.ar.start[i] | |
2056 | && (ref->u.ar.as | |
2057 | && full_ref->u.ar.as->lower[i] | |
2058 | && gfc_dep_compare_expr (ref->u.ar.start[i], | |
2059 | full_ref->u.ar.as->lower[i]) == 0)) | |
2060 | upper_or_lower = true; | |
2061 | /* Check the upper bound. */ | |
2062 | if (ref->u.ar.end[i] | |
2063 | && (ref->u.ar.as | |
2064 | && full_ref->u.ar.as->upper[i] | |
2065 | && gfc_dep_compare_expr (ref->u.ar.end[i], | |
2066 | full_ref->u.ar.as->upper[i]) == 0)) | |
2067 | upper_or_lower = true; | |
2068 | if (!upper_or_lower) | |
2069 | return false; | |
2070 | } | |
2071 | return true; | |
2072 | } | |
2073 | ||
2074 | ||
6de9cd9a DN |
2075 | /* Finds if two array references are overlapping or not. |
2076 | Return value | |
3d03ead0 PT |
2077 | 2 : array references are overlapping but reversal of one or |
2078 | more dimensions will clear the dependency. | |
6de9cd9a | 2079 | 1 : array references are overlapping. |
7c428aa2 | 2080 | 0 : array references are identical or not overlapping. */ |
6de9cd9a DN |
2081 | |
2082 | int | |
3d03ead0 | 2083 | gfc_dep_resolver (gfc_ref *lref, gfc_ref *rref, gfc_reverse *reverse) |
6de9cd9a DN |
2084 | { |
2085 | int n; | |
f8ec0561 | 2086 | int m; |
6de9cd9a DN |
2087 | gfc_dependency fin_dep; |
2088 | gfc_dependency this_dep; | |
2089 | ||
3d03ead0 | 2090 | this_dep = GFC_DEP_ERROR; |
6de9cd9a DN |
2091 | fin_dep = GFC_DEP_ERROR; |
2092 | /* Dependencies due to pointers should already have been identified. | |
2093 | We only need to check for overlapping array references. */ | |
2094 | ||
2095 | while (lref && rref) | |
2096 | { | |
2097 | /* We're resolving from the same base symbol, so both refs should be | |
df2fba9e | 2098 | the same type. We traverse the reference chain until we find ranges |
6de9cd9a | 2099 | that are not equal. */ |
6e45f57b | 2100 | gcc_assert (lref->type == rref->type); |
6de9cd9a DN |
2101 | switch (lref->type) |
2102 | { | |
2103 | case REF_COMPONENT: | |
2104 | /* The two ranges can't overlap if they are from different | |
2105 | components. */ | |
2106 | if (lref->u.c.component != rref->u.c.component) | |
7c428aa2 | 2107 | return 0; |
6de9cd9a | 2108 | break; |
f8ec0561 | 2109 | |
6de9cd9a | 2110 | case REF_SUBSTRING: |
640670c7 PT |
2111 | /* Substring overlaps are handled by the string assignment code |
2112 | if there is not an underlying dependency. */ | |
7c428aa2 | 2113 | return (fin_dep == GFC_DEP_OVERLAP) ? 1 : 0; |
f8ec0561 | 2114 | |
6de9cd9a | 2115 | case REF_ARRAY: |
ea0a374b PT |
2116 | |
2117 | if (ref_same_as_full_array (lref, rref)) | |
7c428aa2 | 2118 | return 0; |
ea0a374b PT |
2119 | |
2120 | if (ref_same_as_full_array (rref, lref)) | |
7c428aa2 | 2121 | return 0; |
ea0a374b | 2122 | |
636dff67 | 2123 | if (lref->u.ar.dimen != rref->u.ar.dimen) |
fcd44320 RS |
2124 | { |
2125 | if (lref->u.ar.type == AR_FULL) | |
a61a36ab PT |
2126 | fin_dep = gfc_full_array_ref_p (rref, NULL) ? GFC_DEP_EQUAL |
2127 | : GFC_DEP_OVERLAP; | |
fcd44320 | 2128 | else if (rref->u.ar.type == AR_FULL) |
a61a36ab PT |
2129 | fin_dep = gfc_full_array_ref_p (lref, NULL) ? GFC_DEP_EQUAL |
2130 | : GFC_DEP_OVERLAP; | |
fcd44320 | 2131 | else |
7c428aa2 | 2132 | return 1; |
fcd44320 RS |
2133 | break; |
2134 | } | |
2135 | ||
f8ec0561 PT |
2136 | /* Index for the reverse array. */ |
2137 | m = -1; | |
6de9cd9a DN |
2138 | for (n=0; n < lref->u.ar.dimen; n++) |
2139 | { | |
94b15070 TK |
2140 | /* Handle dependency when either of array reference is vector |
2141 | subscript. There is no dependency if the vector indices | |
2142 | are equal or if indices are known to be different in a | |
2143 | different dimension. */ | |
6de9cd9a DN |
2144 | if (lref->u.ar.dimen_type[n] == DIMEN_VECTOR |
2145 | || rref->u.ar.dimen_type[n] == DIMEN_VECTOR) | |
94b15070 | 2146 | { |
f8ec0561 | 2147 | if (lref->u.ar.dimen_type[n] == DIMEN_VECTOR |
94b15070 TK |
2148 | && rref->u.ar.dimen_type[n] == DIMEN_VECTOR |
2149 | && gfc_dep_compare_expr (lref->u.ar.start[n], | |
2150 | rref->u.ar.start[n]) == 0) | |
2151 | this_dep = GFC_DEP_EQUAL; | |
2152 | else | |
2153 | this_dep = GFC_DEP_OVERLAP; | |
2154 | ||
2155 | goto update_fin_dep; | |
2156 | } | |
3d03ead0 | 2157 | |
6de9cd9a DN |
2158 | if (lref->u.ar.dimen_type[n] == DIMEN_RANGE |
2159 | && rref->u.ar.dimen_type[n] == DIMEN_RANGE) | |
071bdb5f | 2160 | this_dep = check_section_vs_section (&lref->u.ar, &rref->u.ar, n); |
6de9cd9a DN |
2161 | else if (lref->u.ar.dimen_type[n] == DIMEN_ELEMENT |
2162 | && rref->u.ar.dimen_type[n] == DIMEN_RANGE) | |
2163 | this_dep = gfc_check_element_vs_section (lref, rref, n); | |
2164 | else if (rref->u.ar.dimen_type[n] == DIMEN_ELEMENT | |
2165 | && lref->u.ar.dimen_type[n] == DIMEN_RANGE) | |
2166 | this_dep = gfc_check_element_vs_section (rref, lref, n); | |
f8ec0561 | 2167 | else |
6de9cd9a | 2168 | { |
6e45f57b | 2169 | gcc_assert (rref->u.ar.dimen_type[n] == DIMEN_ELEMENT |
c10bc6e9 | 2170 | && lref->u.ar.dimen_type[n] == DIMEN_ELEMENT); |
6de9cd9a DN |
2171 | this_dep = gfc_check_element_vs_element (rref, lref, n); |
2172 | } | |
2173 | ||
2174 | /* If any dimension doesn't overlap, we have no dependency. */ | |
2175 | if (this_dep == GFC_DEP_NODEP) | |
7c428aa2 | 2176 | return 0; |
6de9cd9a | 2177 | |
3d03ead0 PT |
2178 | /* Now deal with the loop reversal logic: This only works on |
2179 | ranges and is activated by setting | |
aed5574e | 2180 | reverse[n] == GFC_ENABLE_REVERSE |
3d03ead0 PT |
2181 | The ability to reverse or not is set by previous conditions |
2182 | in this dimension. If reversal is not activated, the | |
2183 | value GFC_DEP_BACKWARD is reset to GFC_DEP_OVERLAP. */ | |
f8ec0561 PT |
2184 | |
2185 | /* Get the indexing right for the scalarizing loop. If this | |
2186 | is an element, there is no corresponding loop. */ | |
2187 | if (lref->u.ar.dimen_type[n] != DIMEN_ELEMENT) | |
2188 | m++; | |
2189 | ||
3d03ead0 PT |
2190 | if (rref->u.ar.dimen_type[n] == DIMEN_RANGE |
2191 | && lref->u.ar.dimen_type[n] == DIMEN_RANGE) | |
2192 | { | |
2193 | /* Set reverse if backward dependence and not inhibited. */ | |
f8ec0561 PT |
2194 | if (reverse && reverse[m] == GFC_ENABLE_REVERSE) |
2195 | reverse[m] = (this_dep == GFC_DEP_BACKWARD) ? | |
2196 | GFC_REVERSE_SET : reverse[m]; | |
3d03ead0 | 2197 | |
aed5574e | 2198 | /* Set forward if forward dependence and not inhibited. */ |
f8ec0561 PT |
2199 | if (reverse && reverse[m] == GFC_ENABLE_REVERSE) |
2200 | reverse[m] = (this_dep == GFC_DEP_FORWARD) ? | |
2201 | GFC_FORWARD_SET : reverse[m]; | |
aed5574e PT |
2202 | |
2203 | /* Flag up overlap if dependence not compatible with | |
2204 | the overall state of the expression. */ | |
f8ec0561 | 2205 | if (reverse && reverse[m] == GFC_REVERSE_SET |
aed5574e PT |
2206 | && this_dep == GFC_DEP_FORWARD) |
2207 | { | |
f8ec0561 | 2208 | reverse[m] = GFC_INHIBIT_REVERSE; |
aed5574e PT |
2209 | this_dep = GFC_DEP_OVERLAP; |
2210 | } | |
f8ec0561 | 2211 | else if (reverse && reverse[m] == GFC_FORWARD_SET |
aed5574e | 2212 | && this_dep == GFC_DEP_BACKWARD) |
3d03ead0 | 2213 | { |
f8ec0561 | 2214 | reverse[m] = GFC_INHIBIT_REVERSE; |
aed5574e | 2215 | this_dep = GFC_DEP_OVERLAP; |
3d03ead0 PT |
2216 | } |
2217 | ||
2218 | /* If no intention of reversing or reversing is explicitly | |
2219 | inhibited, convert backward dependence to overlap. */ | |
aed5574e | 2220 | if ((reverse == NULL && this_dep == GFC_DEP_BACKWARD) |
f8ec0561 | 2221 | || (reverse != NULL && reverse[m] == GFC_INHIBIT_REVERSE)) |
3d03ead0 PT |
2222 | this_dep = GFC_DEP_OVERLAP; |
2223 | } | |
2224 | ||
6de9cd9a | 2225 | /* Overlap codes are in order of priority. We only need to |
c10bc6e9 | 2226 | know the worst one.*/ |
94b15070 TK |
2227 | |
2228 | update_fin_dep: | |
6de9cd9a DN |
2229 | if (this_dep > fin_dep) |
2230 | fin_dep = this_dep; | |
2231 | } | |
18c87fd5 PT |
2232 | |
2233 | /* If this is an equal element, we have to keep going until we find | |
2234 | the "real" array reference. */ | |
2235 | if (lref->u.ar.type == AR_ELEMENT | |
2236 | && rref->u.ar.type == AR_ELEMENT | |
2237 | && fin_dep == GFC_DEP_EQUAL) | |
2238 | break; | |
2239 | ||
6de9cd9a DN |
2240 | /* Exactly matching and forward overlapping ranges don't cause a |
2241 | dependency. */ | |
3d03ead0 | 2242 | if (fin_dep < GFC_DEP_BACKWARD) |
7c428aa2 | 2243 | return 0; |
6de9cd9a DN |
2244 | |
2245 | /* Keep checking. We only have a dependency if | |
2246 | subsequent references also overlap. */ | |
2247 | break; | |
2248 | ||
2249 | default: | |
6e45f57b | 2250 | gcc_unreachable (); |
6de9cd9a DN |
2251 | } |
2252 | lref = lref->next; | |
2253 | rref = rref->next; | |
2254 | } | |
2255 | ||
2256 | /* If we haven't seen any array refs then something went wrong. */ | |
6e45f57b | 2257 | gcc_assert (fin_dep != GFC_DEP_ERROR); |
6de9cd9a | 2258 | |
0b8f2ce4 RS |
2259 | /* Assume the worst if we nest to different depths. */ |
2260 | if (lref || rref) | |
7c428aa2 | 2261 | return 1; |
0b8f2ce4 | 2262 | |
7c428aa2 | 2263 | return fin_dep == GFC_DEP_OVERLAP; |
6de9cd9a | 2264 | } |