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4ee9c684 | 1 | /* Dependency analysis |
f1717362 | 2 | Copyright (C) 2000-2016 Free Software Foundation, Inc. |
4ee9c684 | 3 | Contributed by Paul Brook <paul@nowt.org> |
4 | ||
c84b470d | 5 | This file is part of GCC. |
4ee9c684 | 6 | |
c84b470d | 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 | |
bdabe786 | 9 | Software Foundation; either version 3, or (at your option) any later |
c84b470d | 10 | version. |
4ee9c684 | 11 | |
c84b470d | 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. | |
4ee9c684 | 16 | |
17 | You should have received a copy of the GNU General Public License | |
bdabe786 | 18 | along with GCC; see the file COPYING3. If not see |
19 | <http://www.gnu.org/licenses/>. */ | |
4ee9c684 | 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. */ | |
9caa6670 | 25 | |
4ee9c684 | 26 | #include "config.h" |
dca58d21 | 27 | #include "system.h" |
e4d6c7fc | 28 | #include "coretypes.h" |
4ee9c684 | 29 | #include "gfortran.h" |
30 | #include "dependency.h" | |
126387b5 | 31 | #include "constructor.h" |
80f5c112 | 32 | #include "arith.h" |
4ee9c684 | 33 | |
34 | /* static declarations */ | |
35 | /* Enums */ | |
36 | enum range {LHS, RHS, MID}; | |
37 | ||
38 | /* Dependency types. These must be in reverse order of priority. */ | |
6dc50383 | 39 | enum gfc_dependency |
4ee9c684 | 40 | { |
41 | GFC_DEP_ERROR, | |
42 | GFC_DEP_EQUAL, /* Identical Ranges. */ | |
25f9f93d | 43 | GFC_DEP_FORWARD, /* e.g., a(1:3) = a(2:4). */ |
44 | GFC_DEP_BACKWARD, /* e.g. a(2:4) = a(1:3). */ | |
4ee9c684 | 45 | GFC_DEP_OVERLAP, /* May overlap in some other way. */ |
46 | GFC_DEP_NODEP /* Distinct ranges. */ | |
6dc50383 | 47 | }; |
4ee9c684 | 48 | |
49 | /* Macros */ | |
50 | #define IS_ARRAY_EXPLICIT(as) ((as->type == AS_EXPLICIT ? 1 : 0)) | |
51 | ||
cca7236e | 52 | /* Forward declarations */ |
53 | ||
54 | static gfc_dependency check_section_vs_section (gfc_array_ref *, | |
55 | gfc_array_ref *, int); | |
4ee9c684 | 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 | |
1a9745d2 | 61 | gfc_expr_is_one (gfc_expr *expr, int def) |
4ee9c684 | 62 | { |
22d678e8 | 63 | gcc_assert (expr != NULL); |
4ee9c684 | 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 | ||
cca7236e | 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 | { | |
104 | gcc_assert (a1->dimen == a2->dimen); | |
105 | for (i = 0; i < a1->dimen; i++) | |
106 | { | |
107 | if (gfc_dep_compare_expr (a1->start[i], a2->start[i]) != 0) | |
108 | return false; | |
109 | } | |
110 | return true; | |
111 | } | |
112 | return false; | |
113 | } | |
114 | ||
115 | ||
116 | ||
117 | /* Return true for identical variables, checking for references if | |
118 | necessary. Calls identical_array_ref for checking array sections. */ | |
119 | ||
9fcec394 | 120 | static bool |
121 | are_identical_variables (gfc_expr *e1, gfc_expr *e2) | |
cca7236e | 122 | { |
123 | gfc_ref *r1, *r2; | |
124 | ||
39c7c892 | 125 | if (e1->symtree->n.sym->attr.dummy && e2->symtree->n.sym->attr.dummy) |
126 | { | |
127 | /* Dummy arguments: Only check for equal names. */ | |
128 | if (e1->symtree->n.sym->name != e2->symtree->n.sym->name) | |
129 | return false; | |
130 | } | |
131 | else | |
132 | { | |
133 | /* Check for equal symbols. */ | |
134 | if (e1->symtree->n.sym != e2->symtree->n.sym) | |
135 | return false; | |
136 | } | |
cca7236e | 137 | |
80f5c112 | 138 | /* Volatile variables should never compare equal to themselves. */ |
139 | ||
140 | if (e1->symtree->n.sym->attr.volatile_) | |
141 | return false; | |
142 | ||
cca7236e | 143 | r1 = e1->ref; |
144 | r2 = e2->ref; | |
145 | ||
146 | while (r1 != NULL || r2 != NULL) | |
147 | { | |
148 | ||
149 | /* Assume the variables are not equal if one has a reference and the | |
150 | other doesn't. | |
151 | TODO: Handle full references like comparing a(:) to a. | |
152 | */ | |
153 | ||
154 | if (r1 == NULL || r2 == NULL) | |
155 | return false; | |
156 | ||
157 | if (r1->type != r2->type) | |
158 | return false; | |
159 | ||
160 | switch (r1->type) | |
161 | { | |
162 | ||
163 | case REF_ARRAY: | |
164 | if (!identical_array_ref (&r1->u.ar, &r2->u.ar)) | |
165 | return false; | |
166 | ||
167 | break; | |
168 | ||
169 | case REF_COMPONENT: | |
170 | if (r1->u.c.component != r2->u.c.component) | |
171 | return false; | |
172 | break; | |
173 | ||
174 | case REF_SUBSTRING: | |
9bcaa3f0 | 175 | if (gfc_dep_compare_expr (r1->u.ss.start, r2->u.ss.start) != 0) |
cca7236e | 176 | return false; |
9bcaa3f0 | 177 | |
178 | /* If both are NULL, the end length compares equal, because we | |
179 | are looking at the same variable. This can only happen for | |
9caa6670 | 180 | assumed- or deferred-length character arguments. */ |
9bcaa3f0 | 181 | |
182 | if (r1->u.ss.end == NULL && r2->u.ss.end == NULL) | |
183 | break; | |
184 | ||
185 | if (gfc_dep_compare_expr (r1->u.ss.end, r2->u.ss.end) != 0) | |
186 | return false; | |
9caa6670 | 187 | |
cca7236e | 188 | break; |
189 | ||
190 | default: | |
9fcec394 | 191 | gfc_internal_error ("are_identical_variables: Bad type"); |
cca7236e | 192 | } |
193 | r1 = r1->next; | |
194 | r2 = r2->next; | |
195 | } | |
196 | return true; | |
197 | } | |
4ee9c684 | 198 | |
bf48f16e | 199 | /* Compare two functions for equality. Returns 0 if e1==e2, -2 otherwise. If |
200 | impure_ok is false, only return 0 for pure functions. */ | |
201 | ||
202 | int | |
203 | gfc_dep_compare_functions (gfc_expr *e1, gfc_expr *e2, bool impure_ok) | |
204 | { | |
205 | ||
206 | gfc_actual_arglist *args1; | |
207 | gfc_actual_arglist *args2; | |
9caa6670 | 208 | |
bf48f16e | 209 | if (e1->expr_type != EXPR_FUNCTION || e2->expr_type != EXPR_FUNCTION) |
210 | return -2; | |
211 | ||
212 | if ((e1->value.function.esym && e2->value.function.esym | |
213 | && e1->value.function.esym == e2->value.function.esym | |
214 | && (e1->value.function.esym->result->attr.pure || impure_ok)) | |
215 | || (e1->value.function.isym && e2->value.function.isym | |
216 | && e1->value.function.isym == e2->value.function.isym | |
217 | && (e1->value.function.isym->pure || impure_ok))) | |
218 | { | |
219 | args1 = e1->value.function.actual; | |
220 | args2 = e2->value.function.actual; | |
221 | ||
222 | /* Compare the argument lists for equality. */ | |
223 | while (args1 && args2) | |
224 | { | |
225 | /* Bitwise xor, since C has no non-bitwise xor operator. */ | |
226 | if ((args1->expr == NULL) ^ (args2->expr == NULL)) | |
227 | return -2; | |
9caa6670 | 228 | |
bf48f16e | 229 | if (args1->expr != NULL && args2->expr != NULL |
230 | && gfc_dep_compare_expr (args1->expr, args2->expr) != 0) | |
231 | return -2; | |
9caa6670 | 232 | |
bf48f16e | 233 | args1 = args1->next; |
234 | args2 = args2->next; | |
235 | } | |
236 | return (args1 || args2) ? -2 : 0; | |
237 | } | |
238 | else | |
9caa6670 | 239 | return -2; |
bf48f16e | 240 | } |
241 | ||
02e6443e | 242 | /* Helper function to look through parens, unary plus and widening |
243 | integer conversions. */ | |
244 | ||
a03c61f8 | 245 | gfc_expr * |
246 | gfc_discard_nops (gfc_expr *e) | |
02e6443e | 247 | { |
248 | gfc_actual_arglist *arglist; | |
249 | ||
250 | if (e == NULL) | |
251 | return NULL; | |
252 | ||
253 | while (true) | |
254 | { | |
255 | if (e->expr_type == EXPR_OP | |
256 | && (e->value.op.op == INTRINSIC_UPLUS | |
257 | || e->value.op.op == INTRINSIC_PARENTHESES)) | |
258 | { | |
259 | e = e->value.op.op1; | |
260 | continue; | |
261 | } | |
262 | ||
263 | if (e->expr_type == EXPR_FUNCTION && e->value.function.isym | |
264 | && e->value.function.isym->id == GFC_ISYM_CONVERSION | |
265 | && e->ts.type == BT_INTEGER) | |
266 | { | |
267 | arglist = e->value.function.actual; | |
268 | if (arglist->expr->ts.type == BT_INTEGER | |
269 | && e->ts.kind > arglist->expr->ts.kind) | |
270 | { | |
271 | e = arglist->expr; | |
272 | continue; | |
273 | } | |
274 | } | |
275 | break; | |
276 | } | |
277 | ||
278 | return e; | |
279 | } | |
280 | ||
281 | ||
61bc1860 | 282 | /* Compare two expressions. Return values: |
283 | * +1 if e1 > e2 | |
284 | * 0 if e1 == e2 | |
285 | * -1 if e1 < e2 | |
286 | * -2 if the relationship could not be determined | |
013ac408 | 287 | * -3 if e1 /= e2, but we cannot tell which one is larger. |
288 | REAL and COMPLEX constants are only compared for equality | |
289 | or inequality; if they are unequal, -2 is returned in all cases. */ | |
4ee9c684 | 290 | |
291 | int | |
1a9745d2 | 292 | gfc_dep_compare_expr (gfc_expr *e1, gfc_expr *e2) |
4ee9c684 | 293 | { |
294 | int i; | |
1c0efcba | 295 | |
a9f097cb | 296 | if (e1 == NULL && e2 == NULL) |
297 | return 0; | |
298 | ||
a03c61f8 | 299 | e1 = gfc_discard_nops (e1); |
300 | e2 = gfc_discard_nops (e2); | |
4d4677fd | 301 | |
dcb1b019 | 302 | if (e1->expr_type == EXPR_OP && e1->value.op.op == INTRINSIC_PLUS) |
4d4677fd | 303 | { |
013ac408 | 304 | /* Compare X+C vs. X, for INTEGER only. */ |
4d4677fd | 305 | if (e1->value.op.op2->expr_type == EXPR_CONSTANT |
306 | && e1->value.op.op2->ts.type == BT_INTEGER | |
307 | && gfc_dep_compare_expr (e1->value.op.op1, e2) == 0) | |
308 | return mpz_sgn (e1->value.op.op2->value.integer); | |
309 | ||
310 | /* Compare P+Q vs. R+S. */ | |
dcb1b019 | 311 | if (e2->expr_type == EXPR_OP && e2->value.op.op == INTRINSIC_PLUS) |
4d4677fd | 312 | { |
313 | int l, r; | |
314 | ||
315 | l = gfc_dep_compare_expr (e1->value.op.op1, e2->value.op.op1); | |
316 | r = gfc_dep_compare_expr (e1->value.op.op2, e2->value.op.op2); | |
317 | if (l == 0 && r == 0) | |
318 | return 0; | |
61bc1860 | 319 | if (l == 0 && r > -2) |
4d4677fd | 320 | return r; |
61bc1860 | 321 | if (l > -2 && r == 0) |
4d4677fd | 322 | return l; |
323 | if (l == 1 && r == 1) | |
324 | return 1; | |
325 | if (l == -1 && r == -1) | |
326 | return -1; | |
327 | ||
328 | l = gfc_dep_compare_expr (e1->value.op.op1, e2->value.op.op2); | |
329 | r = gfc_dep_compare_expr (e1->value.op.op2, e2->value.op.op1); | |
330 | if (l == 0 && r == 0) | |
331 | return 0; | |
61bc1860 | 332 | if (l == 0 && r > -2) |
4d4677fd | 333 | return r; |
61bc1860 | 334 | if (l > -2 && r == 0) |
4d4677fd | 335 | return l; |
336 | if (l == 1 && r == 1) | |
337 | return 1; | |
338 | if (l == -1 && r == -1) | |
339 | return -1; | |
340 | } | |
341 | } | |
342 | ||
013ac408 | 343 | /* Compare X vs. X+C, for INTEGER only. */ |
dcb1b019 | 344 | if (e2->expr_type == EXPR_OP && e2->value.op.op == INTRINSIC_PLUS) |
4d4677fd | 345 | { |
346 | if (e2->value.op.op2->expr_type == EXPR_CONSTANT | |
347 | && e2->value.op.op2->ts.type == BT_INTEGER | |
348 | && gfc_dep_compare_expr (e1, e2->value.op.op1) == 0) | |
349 | return -mpz_sgn (e2->value.op.op2->value.integer); | |
350 | } | |
351 | ||
013ac408 | 352 | /* Compare X-C vs. X, for INTEGER only. */ |
dcb1b019 | 353 | if (e1->expr_type == EXPR_OP && e1->value.op.op == INTRINSIC_MINUS) |
4d4677fd | 354 | { |
355 | if (e1->value.op.op2->expr_type == EXPR_CONSTANT | |
356 | && e1->value.op.op2->ts.type == BT_INTEGER | |
357 | && gfc_dep_compare_expr (e1->value.op.op1, e2) == 0) | |
358 | return -mpz_sgn (e1->value.op.op2->value.integer); | |
359 | ||
360 | /* Compare P-Q vs. R-S. */ | |
dcb1b019 | 361 | if (e2->expr_type == EXPR_OP && e2->value.op.op == INTRINSIC_MINUS) |
4d4677fd | 362 | { |
363 | int l, r; | |
364 | ||
365 | l = gfc_dep_compare_expr (e1->value.op.op1, e2->value.op.op1); | |
366 | r = gfc_dep_compare_expr (e1->value.op.op2, e2->value.op.op2); | |
367 | if (l == 0 && r == 0) | |
368 | return 0; | |
61bc1860 | 369 | if (l > -2 && r == 0) |
4d4677fd | 370 | return l; |
61bc1860 | 371 | if (l == 0 && r > -2) |
4d4677fd | 372 | return -r; |
373 | if (l == 1 && r == -1) | |
374 | return 1; | |
375 | if (l == -1 && r == 1) | |
376 | return -1; | |
377 | } | |
378 | } | |
379 | ||
80f5c112 | 380 | /* Compare A // B vs. C // D. */ |
381 | ||
382 | if (e1->expr_type == EXPR_OP && e1->value.op.op == INTRINSIC_CONCAT | |
383 | && e2->expr_type == EXPR_OP && e2->value.op.op == INTRINSIC_CONCAT) | |
384 | { | |
385 | int l, r; | |
386 | ||
387 | l = gfc_dep_compare_expr (e1->value.op.op1, e2->value.op.op1); | |
388 | r = gfc_dep_compare_expr (e1->value.op.op2, e2->value.op.op2); | |
389 | ||
b34ed2ef | 390 | if (l != 0) |
61bc1860 | 391 | return l; |
80f5c112 | 392 | |
b34ed2ef | 393 | /* Left expressions of // compare equal, but |
394 | watch out for 'A ' // x vs. 'A' // x. */ | |
395 | gfc_expr *e1_left = e1->value.op.op1; | |
396 | gfc_expr *e2_left = e2->value.op.op1; | |
397 | ||
398 | if (e1_left->expr_type == EXPR_CONSTANT | |
399 | && e2_left->expr_type == EXPR_CONSTANT | |
400 | && e1_left->value.character.length | |
401 | != e2_left->value.character.length) | |
402 | return -2; | |
80f5c112 | 403 | else |
b34ed2ef | 404 | return r; |
80f5c112 | 405 | } |
406 | ||
013ac408 | 407 | /* Compare X vs. X-C, for INTEGER only. */ |
dcb1b019 | 408 | if (e2->expr_type == EXPR_OP && e2->value.op.op == INTRINSIC_MINUS) |
4d4677fd | 409 | { |
410 | if (e2->value.op.op2->expr_type == EXPR_CONSTANT | |
411 | && e2->value.op.op2->ts.type == BT_INTEGER | |
412 | && gfc_dep_compare_expr (e1, e2->value.op.op1) == 0) | |
413 | return mpz_sgn (e2->value.op.op2->value.integer); | |
414 | } | |
415 | ||
4ee9c684 | 416 | if (e1->expr_type != e2->expr_type) |
61bc1860 | 417 | return -3; |
4ee9c684 | 418 | |
419 | switch (e1->expr_type) | |
420 | { | |
421 | case EXPR_CONSTANT: | |
80f5c112 | 422 | /* Compare strings for equality. */ |
423 | if (e1->ts.type == BT_CHARACTER && e2->ts.type == BT_CHARACTER) | |
424 | return gfc_compare_string (e1, e2); | |
425 | ||
013ac408 | 426 | /* Compare REAL and COMPLEX constants. Because of the |
427 | traps and pitfalls associated with comparing | |
428 | a + 1.0 with a + 0.5, check for equality only. */ | |
429 | if (e2->expr_type == EXPR_CONSTANT) | |
430 | { | |
431 | if (e1->ts.type == BT_REAL && e2->ts.type == BT_REAL) | |
432 | { | |
433 | if (mpfr_cmp (e1->value.real, e2->value.real) == 0) | |
434 | return 0; | |
435 | else | |
436 | return -2; | |
437 | } | |
438 | else if (e1->ts.type == BT_COMPLEX && e2->ts.type == BT_COMPLEX) | |
439 | { | |
440 | if (mpc_cmp (e1->value.complex, e2->value.complex) == 0) | |
441 | return 0; | |
442 | else | |
443 | return -2; | |
444 | } | |
445 | } | |
446 | ||
4ee9c684 | 447 | if (e1->ts.type != BT_INTEGER || e2->ts.type != BT_INTEGER) |
448 | return -2; | |
449 | ||
013ac408 | 450 | /* For INTEGER, all cases where e2 is not constant should have |
451 | been filtered out above. */ | |
452 | gcc_assert (e2->expr_type == EXPR_CONSTANT); | |
453 | ||
4ee9c684 | 454 | i = mpz_cmp (e1->value.integer, e2->value.integer); |
455 | if (i == 0) | |
456 | return 0; | |
457 | else if (i < 0) | |
458 | return -1; | |
459 | return 1; | |
460 | ||
461 | case EXPR_VARIABLE: | |
9fcec394 | 462 | if (are_identical_variables (e1, e2)) |
4ee9c684 | 463 | return 0; |
cca7236e | 464 | else |
61bc1860 | 465 | return -3; |
4ee9c684 | 466 | |
bee621f2 | 467 | case EXPR_OP: |
468 | /* Intrinsic operators are the same if their operands are the same. */ | |
dcb1b019 | 469 | if (e1->value.op.op != e2->value.op.op) |
bee621f2 | 470 | return -2; |
471 | if (e1->value.op.op2 == 0) | |
472 | { | |
473 | i = gfc_dep_compare_expr (e1->value.op.op1, e2->value.op.op1); | |
474 | return i == 0 ? 0 : -2; | |
475 | } | |
476 | if (gfc_dep_compare_expr (e1->value.op.op1, e2->value.op.op1) == 0 | |
477 | && gfc_dep_compare_expr (e1->value.op.op2, e2->value.op.op2) == 0) | |
478 | return 0; | |
9fcec394 | 479 | else if (e1->value.op.op == INTRINSIC_TIMES |
480 | && gfc_dep_compare_expr (e1->value.op.op1, e2->value.op.op2) == 0 | |
481 | && gfc_dep_compare_expr (e1->value.op.op2, e2->value.op.op1) == 0) | |
013ac408 | 482 | /* Commutativity of multiplication; addition is handled above. */ |
9fcec394 | 483 | return 0; |
484 | ||
bee621f2 | 485 | return -2; |
486 | ||
487 | case EXPR_FUNCTION: | |
bf48f16e | 488 | return gfc_dep_compare_functions (e1, e2, false); |
f33bc6d4 | 489 | break; |
bee621f2 | 490 | |
4ee9c684 | 491 | default: |
492 | return -2; | |
493 | } | |
494 | } | |
495 | ||
496 | ||
a642efd6 | 497 | /* Return the difference between two expressions. Integer expressions of |
9caa6670 | 498 | the form |
a642efd6 | 499 | |
500 | X + constant, X - constant and constant + X | |
501 | ||
502 | are handled. Return true on success, false on failure. result is assumed | |
503 | to be uninitialized on entry, and will be initialized on success. | |
504 | */ | |
505 | ||
506 | bool | |
507 | gfc_dep_difference (gfc_expr *e1, gfc_expr *e2, mpz_t *result) | |
508 | { | |
509 | gfc_expr *e1_op1, *e1_op2, *e2_op1, *e2_op2; | |
510 | ||
511 | if (e1 == NULL || e2 == NULL) | |
512 | return false; | |
513 | ||
514 | if (e1->ts.type != BT_INTEGER || e2->ts.type != BT_INTEGER) | |
515 | return false; | |
516 | ||
a03c61f8 | 517 | e1 = gfc_discard_nops (e1); |
518 | e2 = gfc_discard_nops (e2); | |
a642efd6 | 519 | |
520 | /* Inizialize tentatively, clear if we don't return anything. */ | |
521 | mpz_init (*result); | |
522 | ||
523 | /* Case 1: c1 - c2 = c1 - c2, trivially. */ | |
524 | ||
525 | if (e1->expr_type == EXPR_CONSTANT && e2->expr_type == EXPR_CONSTANT) | |
526 | { | |
527 | mpz_sub (*result, e1->value.integer, e2->value.integer); | |
528 | return true; | |
529 | } | |
530 | ||
531 | if (e1->expr_type == EXPR_OP && e1->value.op.op == INTRINSIC_PLUS) | |
532 | { | |
a03c61f8 | 533 | e1_op1 = gfc_discard_nops (e1->value.op.op1); |
534 | e1_op2 = gfc_discard_nops (e1->value.op.op2); | |
a642efd6 | 535 | |
536 | /* Case 2: (X + c1) - X = c1. */ | |
537 | if (e1_op2->expr_type == EXPR_CONSTANT | |
538 | && gfc_dep_compare_expr (e1_op1, e2) == 0) | |
539 | { | |
540 | mpz_set (*result, e1_op2->value.integer); | |
541 | return true; | |
542 | } | |
543 | ||
293d72e0 | 544 | /* Case 3: (c1 + X) - X = c1. */ |
a642efd6 | 545 | if (e1_op1->expr_type == EXPR_CONSTANT |
546 | && gfc_dep_compare_expr (e1_op2, e2) == 0) | |
547 | { | |
548 | mpz_set (*result, e1_op1->value.integer); | |
549 | return true; | |
550 | } | |
551 | ||
552 | if (e2->expr_type == EXPR_OP && e2->value.op.op == INTRINSIC_PLUS) | |
553 | { | |
a03c61f8 | 554 | e2_op1 = gfc_discard_nops (e2->value.op.op1); |
555 | e2_op2 = gfc_discard_nops (e2->value.op.op2); | |
a642efd6 | 556 | |
557 | if (e1_op2->expr_type == EXPR_CONSTANT) | |
558 | { | |
559 | /* Case 4: X + c1 - (X + c2) = c1 - c2. */ | |
560 | if (e2_op2->expr_type == EXPR_CONSTANT | |
561 | && gfc_dep_compare_expr (e1_op1, e2_op1) == 0) | |
562 | { | |
563 | mpz_sub (*result, e1_op2->value.integer, | |
564 | e2_op2->value.integer); | |
565 | return true; | |
566 | } | |
567 | /* Case 5: X + c1 - (c2 + X) = c1 - c2. */ | |
568 | if (e2_op1->expr_type == EXPR_CONSTANT | |
569 | && gfc_dep_compare_expr (e1_op1, e2_op2) == 0) | |
570 | { | |
571 | mpz_sub (*result, e1_op2->value.integer, | |
572 | e2_op1->value.integer); | |
573 | return true; | |
574 | } | |
575 | } | |
576 | else if (e1_op1->expr_type == EXPR_CONSTANT) | |
577 | { | |
578 | /* Case 6: c1 + X - (X + c2) = c1 - c2. */ | |
579 | if (e2_op2->expr_type == EXPR_CONSTANT | |
580 | && gfc_dep_compare_expr (e1_op2, e2_op1) == 0) | |
581 | { | |
582 | mpz_sub (*result, e1_op1->value.integer, | |
583 | e2_op2->value.integer); | |
584 | return true; | |
585 | } | |
586 | /* Case 7: c1 + X - (c2 + X) = c1 - c2. */ | |
587 | if (e2_op1->expr_type == EXPR_CONSTANT | |
588 | && gfc_dep_compare_expr (e1_op2, e2_op2) == 0) | |
589 | { | |
590 | mpz_sub (*result, e1_op1->value.integer, | |
591 | e2_op1->value.integer); | |
592 | return true; | |
593 | } | |
594 | } | |
595 | } | |
596 | ||
597 | if (e2->expr_type == EXPR_OP && e2->value.op.op == INTRINSIC_MINUS) | |
598 | { | |
a03c61f8 | 599 | e2_op1 = gfc_discard_nops (e2->value.op.op1); |
600 | e2_op2 = gfc_discard_nops (e2->value.op.op2); | |
a642efd6 | 601 | |
602 | if (e1_op2->expr_type == EXPR_CONSTANT) | |
603 | { | |
604 | /* Case 8: X + c1 - (X - c2) = c1 + c2. */ | |
605 | if (e2_op2->expr_type == EXPR_CONSTANT | |
606 | && gfc_dep_compare_expr (e1_op1, e2_op1) == 0) | |
607 | { | |
608 | mpz_add (*result, e1_op2->value.integer, | |
609 | e2_op2->value.integer); | |
610 | return true; | |
611 | } | |
612 | } | |
613 | if (e1_op1->expr_type == EXPR_CONSTANT) | |
614 | { | |
615 | /* Case 9: c1 + X - (X - c2) = c1 + c2. */ | |
616 | if (e2_op2->expr_type == EXPR_CONSTANT | |
617 | && gfc_dep_compare_expr (e1_op2, e2_op1) == 0) | |
618 | { | |
619 | mpz_add (*result, e1_op1->value.integer, | |
620 | e2_op2->value.integer); | |
621 | return true; | |
622 | } | |
623 | } | |
624 | } | |
625 | } | |
626 | ||
627 | if (e1->expr_type == EXPR_OP && e1->value.op.op == INTRINSIC_MINUS) | |
628 | { | |
a03c61f8 | 629 | e1_op1 = gfc_discard_nops (e1->value.op.op1); |
630 | e1_op2 = gfc_discard_nops (e1->value.op.op2); | |
a642efd6 | 631 | |
632 | if (e1_op2->expr_type == EXPR_CONSTANT) | |
633 | { | |
634 | /* Case 10: (X - c1) - X = -c1 */ | |
635 | ||
636 | if (gfc_dep_compare_expr (e1_op1, e2) == 0) | |
637 | { | |
638 | mpz_neg (*result, e1_op2->value.integer); | |
639 | return true; | |
640 | } | |
641 | ||
642 | if (e2->expr_type == EXPR_OP && e2->value.op.op == INTRINSIC_PLUS) | |
643 | { | |
a03c61f8 | 644 | e2_op1 = gfc_discard_nops (e2->value.op.op1); |
645 | e2_op2 = gfc_discard_nops (e2->value.op.op2); | |
a642efd6 | 646 | |
647 | /* Case 11: (X - c1) - (X + c2) = -( c1 + c2). */ | |
648 | if (e2_op2->expr_type == EXPR_CONSTANT | |
649 | && gfc_dep_compare_expr (e1_op1, e2_op1) == 0) | |
650 | { | |
651 | mpz_add (*result, e1_op2->value.integer, | |
652 | e2_op2->value.integer); | |
653 | mpz_neg (*result, *result); | |
654 | return true; | |
655 | } | |
656 | ||
657 | /* Case 12: X - c1 - (c2 + X) = - (c1 + c2). */ | |
658 | if (e2_op1->expr_type == EXPR_CONSTANT | |
659 | && gfc_dep_compare_expr (e1_op1, e2_op2) == 0) | |
660 | { | |
661 | mpz_add (*result, e1_op2->value.integer, | |
662 | e2_op1->value.integer); | |
663 | mpz_neg (*result, *result); | |
664 | return true; | |
665 | } | |
666 | } | |
667 | ||
668 | if (e2->expr_type == EXPR_OP && e2->value.op.op == INTRINSIC_MINUS) | |
669 | { | |
a03c61f8 | 670 | e2_op1 = gfc_discard_nops (e2->value.op.op1); |
671 | e2_op2 = gfc_discard_nops (e2->value.op.op2); | |
a642efd6 | 672 | |
673 | /* Case 13: (X - c1) - (X - c2) = c2 - c1. */ | |
674 | if (e2_op2->expr_type == EXPR_CONSTANT | |
675 | && gfc_dep_compare_expr (e1_op1, e2_op1) == 0) | |
676 | { | |
677 | mpz_sub (*result, e2_op2->value.integer, | |
678 | e1_op2->value.integer); | |
679 | return true; | |
680 | } | |
681 | } | |
682 | } | |
683 | if (e1_op1->expr_type == EXPR_CONSTANT) | |
684 | { | |
685 | if (e2->expr_type == EXPR_OP && e2->value.op.op == INTRINSIC_MINUS) | |
686 | { | |
a03c61f8 | 687 | e2_op1 = gfc_discard_nops (e2->value.op.op1); |
688 | e2_op2 = gfc_discard_nops (e2->value.op.op2); | |
9caa6670 | 689 | |
a642efd6 | 690 | /* Case 14: (c1 - X) - (c2 - X) == c1 - c2. */ |
691 | if (gfc_dep_compare_expr (e1_op2, e2_op2) == 0) | |
692 | { | |
693 | mpz_sub (*result, e1_op1->value.integer, | |
694 | e2_op1->value.integer); | |
695 | return true; | |
696 | } | |
697 | } | |
698 | ||
699 | } | |
700 | } | |
701 | ||
702 | if (e2->expr_type == EXPR_OP && e2->value.op.op == INTRINSIC_PLUS) | |
703 | { | |
a03c61f8 | 704 | e2_op1 = gfc_discard_nops (e2->value.op.op1); |
705 | e2_op2 = gfc_discard_nops (e2->value.op.op2); | |
a642efd6 | 706 | |
707 | /* Case 15: X - (X + c2) = -c2. */ | |
708 | if (e2_op2->expr_type == EXPR_CONSTANT | |
709 | && gfc_dep_compare_expr (e1, e2_op1) == 0) | |
710 | { | |
711 | mpz_neg (*result, e2_op2->value.integer); | |
712 | return true; | |
713 | } | |
714 | /* Case 16: X - (c2 + X) = -c2. */ | |
715 | if (e2_op1->expr_type == EXPR_CONSTANT | |
716 | && gfc_dep_compare_expr (e1, e2_op2) == 0) | |
717 | { | |
718 | mpz_neg (*result, e2_op1->value.integer); | |
719 | return true; | |
720 | } | |
721 | } | |
722 | ||
723 | if (e2->expr_type == EXPR_OP && e2->value.op.op == INTRINSIC_MINUS) | |
724 | { | |
a03c61f8 | 725 | e2_op1 = gfc_discard_nops (e2->value.op.op1); |
726 | e2_op2 = gfc_discard_nops (e2->value.op.op2); | |
a642efd6 | 727 | |
728 | /* Case 17: X - (X - c2) = c2. */ | |
729 | if (e2_op2->expr_type == EXPR_CONSTANT | |
730 | && gfc_dep_compare_expr (e1, e2_op1) == 0) | |
731 | { | |
732 | mpz_set (*result, e2_op2->value.integer); | |
733 | return true; | |
734 | } | |
735 | } | |
736 | ||
60e19868 | 737 | if (gfc_dep_compare_expr (e1, e2) == 0) |
a642efd6 | 738 | { |
739 | /* Case 18: X - X = 0. */ | |
740 | mpz_set_si (*result, 0); | |
741 | return true; | |
742 | } | |
743 | ||
744 | mpz_clear (*result); | |
745 | return false; | |
746 | } | |
747 | ||
9fcec394 | 748 | /* Returns 1 if the two ranges are the same and 0 if they are not (or if the |
749 | results are indeterminate). 'n' is the dimension to compare. */ | |
4ee9c684 | 750 | |
9fcec394 | 751 | static int |
752 | is_same_range (gfc_array_ref *ar1, gfc_array_ref *ar2, int n) | |
4ee9c684 | 753 | { |
754 | gfc_expr *e1; | |
755 | gfc_expr *e2; | |
756 | int i; | |
757 | ||
758 | /* TODO: More sophisticated range comparison. */ | |
22d678e8 | 759 | gcc_assert (ar1 && ar2); |
4ee9c684 | 760 | |
22d678e8 | 761 | gcc_assert (ar1->dimen_type[n] == ar2->dimen_type[n]); |
4ee9c684 | 762 | |
763 | e1 = ar1->stride[n]; | |
764 | e2 = ar2->stride[n]; | |
765 | /* Check for mismatching strides. A NULL stride means a stride of 1. */ | |
766 | if (e1 && !e2) | |
767 | { | |
768 | i = gfc_expr_is_one (e1, -1); | |
9fcec394 | 769 | if (i == -1 || i == 0) |
4ee9c684 | 770 | return 0; |
771 | } | |
772 | else if (e2 && !e1) | |
773 | { | |
774 | i = gfc_expr_is_one (e2, -1); | |
9fcec394 | 775 | if (i == -1 || i == 0) |
4ee9c684 | 776 | return 0; |
777 | } | |
778 | else if (e1 && e2) | |
779 | { | |
780 | i = gfc_dep_compare_expr (e1, e2); | |
9fcec394 | 781 | if (i != 0) |
4ee9c684 | 782 | return 0; |
783 | } | |
784 | /* The strides match. */ | |
785 | ||
786 | /* Check the range start. */ | |
787 | e1 = ar1->start[n]; | |
788 | e2 = ar2->start[n]; | |
a7455f80 | 789 | if (e1 || e2) |
790 | { | |
791 | /* Use the bound of the array if no bound is specified. */ | |
792 | if (ar1->as && !e1) | |
793 | e1 = ar1->as->lower[n]; | |
4ee9c684 | 794 | |
a7455f80 | 795 | if (ar2->as && !e2) |
796 | e2 = ar2->as->lower[n]; | |
4ee9c684 | 797 | |
a7455f80 | 798 | /* Check we have values for both. */ |
799 | if (!(e1 && e2)) | |
9fcec394 | 800 | return 0; |
4ee9c684 | 801 | |
a7455f80 | 802 | i = gfc_dep_compare_expr (e1, e2); |
9fcec394 | 803 | if (i != 0) |
a7455f80 | 804 | return 0; |
805 | } | |
4ee9c684 | 806 | |
a7455f80 | 807 | /* Check the range end. */ |
808 | e1 = ar1->end[n]; | |
809 | e2 = ar2->end[n]; | |
810 | if (e1 || e2) | |
811 | { | |
812 | /* Use the bound of the array if no bound is specified. */ | |
813 | if (ar1->as && !e1) | |
814 | e1 = ar1->as->upper[n]; | |
4ee9c684 | 815 | |
a7455f80 | 816 | if (ar2->as && !e2) |
817 | e2 = ar2->as->upper[n]; | |
4ee9c684 | 818 | |
a7455f80 | 819 | /* Check we have values for both. */ |
820 | if (!(e1 && e2)) | |
9fcec394 | 821 | return 0; |
a7455f80 | 822 | |
823 | i = gfc_dep_compare_expr (e1, e2); | |
9fcec394 | 824 | if (i != 0) |
a7455f80 | 825 | return 0; |
826 | } | |
827 | ||
828 | return 1; | |
4ee9c684 | 829 | } |
830 | ||
831 | ||
018ef8b8 | 832 | /* Some array-returning intrinsics can be implemented by reusing the |
22046c26 | 833 | data from one of the array arguments. For example, TRANSPOSE does |
018ef8b8 | 834 | not necessarily need to allocate new data: it can be implemented |
835 | by copying the original array's descriptor and simply swapping the | |
836 | two dimension specifications. | |
837 | ||
838 | If EXPR is a call to such an intrinsic, return the argument | |
839 | whose data can be reused, otherwise return NULL. */ | |
840 | ||
841 | gfc_expr * | |
1a9745d2 | 842 | gfc_get_noncopying_intrinsic_argument (gfc_expr *expr) |
018ef8b8 | 843 | { |
844 | if (expr->expr_type != EXPR_FUNCTION || !expr->value.function.isym) | |
845 | return NULL; | |
846 | ||
55cb4417 | 847 | switch (expr->value.function.isym->id) |
018ef8b8 | 848 | { |
849 | case GFC_ISYM_TRANSPOSE: | |
850 | return expr->value.function.actual->expr; | |
851 | ||
852 | default: | |
853 | return NULL; | |
854 | } | |
855 | } | |
856 | ||
857 | ||
c99d633f | 858 | /* Return true if the result of reference REF can only be constructed |
859 | using a temporary array. */ | |
860 | ||
861 | bool | |
862 | gfc_ref_needs_temporary_p (gfc_ref *ref) | |
863 | { | |
864 | int n; | |
865 | bool subarray_p; | |
866 | ||
867 | subarray_p = false; | |
868 | for (; ref; ref = ref->next) | |
869 | switch (ref->type) | |
870 | { | |
871 | case REF_ARRAY: | |
872 | /* Vector dimensions are generally not monotonic and must be | |
873 | handled using a temporary. */ | |
874 | if (ref->u.ar.type == AR_SECTION) | |
875 | for (n = 0; n < ref->u.ar.dimen; n++) | |
876 | if (ref->u.ar.dimen_type[n] == DIMEN_VECTOR) | |
877 | return true; | |
878 | ||
879 | subarray_p = true; | |
880 | break; | |
881 | ||
882 | case REF_SUBSTRING: | |
883 | /* Within an array reference, character substrings generally | |
884 | need a temporary. Character array strides are expressed as | |
885 | multiples of the element size (consistent with other array | |
886 | types), not in characters. */ | |
887 | return subarray_p; | |
888 | ||
889 | case REF_COMPONENT: | |
890 | break; | |
891 | } | |
892 | ||
893 | return false; | |
894 | } | |
895 | ||
896 | ||
f10a970e | 897 | static int |
0ed083d9 | 898 | gfc_is_data_pointer (gfc_expr *e) |
899 | { | |
900 | gfc_ref *ref; | |
901 | ||
1b922cfc | 902 | if (e->expr_type != EXPR_VARIABLE && e->expr_type != EXPR_FUNCTION) |
0ed083d9 | 903 | return 0; |
904 | ||
1b922cfc | 905 | /* No subreference if it is a function */ |
906 | gcc_assert (e->expr_type == EXPR_VARIABLE || !e->ref); | |
907 | ||
0ed083d9 | 908 | if (e->symtree->n.sym->attr.pointer) |
909 | return 1; | |
1b922cfc | 910 | |
0ed083d9 | 911 | for (ref = e->ref; ref; ref = ref->next) |
912 | if (ref->type == REF_COMPONENT && ref->u.c.component->attr.pointer) | |
913 | return 1; | |
914 | ||
915 | return 0; | |
916 | } | |
917 | ||
918 | ||
018ef8b8 | 919 | /* Return true if array variable VAR could be passed to the same function |
920 | as argument EXPR without interfering with EXPR. INTENT is the intent | |
921 | of VAR. | |
922 | ||
923 | This is considerably less conservative than other dependencies | |
924 | because many function arguments will already be copied into a | |
925 | temporary. */ | |
926 | ||
927 | static int | |
1a9745d2 | 928 | gfc_check_argument_var_dependency (gfc_expr *var, sym_intent intent, |
74e83bb9 | 929 | gfc_expr *expr, gfc_dep_check elemental) |
018ef8b8 | 930 | { |
74e83bb9 | 931 | gfc_expr *arg; |
932 | ||
018ef8b8 | 933 | gcc_assert (var->expr_type == EXPR_VARIABLE); |
934 | gcc_assert (var->rank > 0); | |
935 | ||
936 | switch (expr->expr_type) | |
937 | { | |
938 | case EXPR_VARIABLE: | |
9caa6670 | 939 | /* In case of elemental subroutines, there is no dependency |
74e83bb9 | 940 | between two same-range array references. */ |
941 | if (gfc_ref_needs_temporary_p (expr->ref) | |
08803898 | 942 | || gfc_check_dependency (var, expr, elemental == NOT_ELEMENTAL)) |
74e83bb9 | 943 | { |
9ed3ad48 | 944 | if (elemental == ELEM_DONT_CHECK_VARIABLE) |
74e83bb9 | 945 | { |
9ed3ad48 | 946 | /* Too many false positive with pointers. */ |
947 | if (!gfc_is_data_pointer (var) && !gfc_is_data_pointer (expr)) | |
948 | { | |
9caa6670 | 949 | /* Elemental procedures forbid unspecified intents, |
9ed3ad48 | 950 | and we don't check dependencies for INTENT_IN args. */ |
951 | gcc_assert (intent == INTENT_OUT || intent == INTENT_INOUT); | |
952 | ||
9caa6670 | 953 | /* We are told not to check dependencies. |
9ed3ad48 | 954 | We do it, however, and issue a warning in case we find one. |
9caa6670 | 955 | If a dependency is found in the case |
9ed3ad48 | 956 | elemental == ELEM_CHECK_VARIABLE, we will generate |
957 | a temporary, so we don't need to bother the user. */ | |
389a9009 | 958 | gfc_warning (0, "INTENT(%s) actual argument at %L might " |
9caa6670 | 959 | "interfere with actual argument at %L.", |
960 | intent == INTENT_OUT ? "OUT" : "INOUT", | |
9ed3ad48 | 961 | &var->where, &expr->where); |
962 | } | |
74e83bb9 | 963 | return 0; |
964 | } | |
965 | else | |
9caa6670 | 966 | return 1; |
74e83bb9 | 967 | } |
968 | return 0; | |
018ef8b8 | 969 | |
970 | case EXPR_ARRAY: | |
14460286 | 971 | /* the scalarizer always generates a temporary for array constructors, |
972 | so there is no dependency. */ | |
973 | return 0; | |
018ef8b8 | 974 | |
975 | case EXPR_FUNCTION: | |
1274527b | 976 | if (intent != INTENT_IN) |
977 | { | |
978 | arg = gfc_get_noncopying_intrinsic_argument (expr); | |
979 | if (arg != NULL) | |
980 | return gfc_check_argument_var_dependency (var, intent, arg, | |
981 | NOT_ELEMENTAL); | |
982 | } | |
983 | ||
984 | if (elemental != NOT_ELEMENTAL) | |
74e83bb9 | 985 | { |
986 | if ((expr->value.function.esym | |
987 | && expr->value.function.esym->attr.elemental) | |
988 | || (expr->value.function.isym | |
989 | && expr->value.function.isym->elemental)) | |
990 | return gfc_check_fncall_dependency (var, intent, NULL, | |
991 | expr->value.function.actual, | |
992 | ELEM_CHECK_VARIABLE); | |
efeb2b16 | 993 | |
994 | if (gfc_inline_intrinsic_function_p (expr)) | |
995 | { | |
996 | /* The TRANSPOSE case should have been caught in the | |
997 | noncopying intrinsic case above. */ | |
998 | gcc_assert (expr->value.function.isym->id != GFC_ISYM_TRANSPOSE); | |
999 | ||
1000 | return gfc_check_fncall_dependency (var, intent, NULL, | |
1001 | expr->value.function.actual, | |
1002 | ELEM_CHECK_VARIABLE); | |
1003 | } | |
74e83bb9 | 1004 | } |
1005 | return 0; | |
1006 | ||
1007 | case EXPR_OP: | |
1008 | /* In case of non-elemental procedures, there is no need to catch | |
1009 | dependencies, as we will make a temporary anyway. */ | |
1010 | if (elemental) | |
018ef8b8 | 1011 | { |
9caa6670 | 1012 | /* If the actual arg EXPR is an expression, we need to catch |
1013 | a dependency between variables in EXPR and VAR, | |
74e83bb9 | 1014 | an intent((IN)OUT) variable. */ |
1015 | if (expr->value.op.op1 | |
9caa6670 | 1016 | && gfc_check_argument_var_dependency (var, intent, |
1017 | expr->value.op.op1, | |
74e83bb9 | 1018 | ELEM_CHECK_VARIABLE)) |
1019 | return 1; | |
1020 | else if (expr->value.op.op2 | |
9caa6670 | 1021 | && gfc_check_argument_var_dependency (var, intent, |
1022 | expr->value.op.op2, | |
74e83bb9 | 1023 | ELEM_CHECK_VARIABLE)) |
1024 | return 1; | |
018ef8b8 | 1025 | } |
1026 | return 0; | |
1027 | ||
1028 | default: | |
1029 | return 0; | |
1030 | } | |
1031 | } | |
9caa6670 | 1032 | |
1033 | ||
018ef8b8 | 1034 | /* Like gfc_check_argument_var_dependency, but extended to any |
1035 | array expression OTHER, not just variables. */ | |
1036 | ||
1037 | static int | |
1a9745d2 | 1038 | gfc_check_argument_dependency (gfc_expr *other, sym_intent intent, |
74e83bb9 | 1039 | gfc_expr *expr, gfc_dep_check elemental) |
018ef8b8 | 1040 | { |
1041 | switch (other->expr_type) | |
1042 | { | |
1043 | case EXPR_VARIABLE: | |
74e83bb9 | 1044 | return gfc_check_argument_var_dependency (other, intent, expr, elemental); |
018ef8b8 | 1045 | |
1046 | case EXPR_FUNCTION: | |
1274527b | 1047 | other = gfc_get_noncopying_intrinsic_argument (other); |
1048 | if (other != NULL) | |
1049 | return gfc_check_argument_dependency (other, INTENT_IN, expr, | |
1050 | NOT_ELEMENTAL); | |
1051 | ||
018ef8b8 | 1052 | return 0; |
1053 | ||
1054 | default: | |
1055 | return 0; | |
1056 | } | |
1057 | } | |
1058 | ||
1059 | ||
1060 | /* Like gfc_check_argument_dependency, but check all the arguments in ACTUAL. | |
1061 | FNSYM is the function being called, or NULL if not known. */ | |
4ee9c684 | 1062 | |
1063 | int | |
1a9745d2 | 1064 | gfc_check_fncall_dependency (gfc_expr *other, sym_intent intent, |
74e83bb9 | 1065 | gfc_symbol *fnsym, gfc_actual_arglist *actual, |
1066 | gfc_dep_check elemental) | |
4ee9c684 | 1067 | { |
018ef8b8 | 1068 | gfc_formal_arglist *formal; |
4ee9c684 | 1069 | gfc_expr *expr; |
4ee9c684 | 1070 | |
6777213b | 1071 | formal = fnsym ? gfc_sym_get_dummy_args (fnsym) : NULL; |
018ef8b8 | 1072 | for (; actual; actual = actual->next, formal = formal ? formal->next : NULL) |
4ee9c684 | 1073 | { |
1074 | expr = actual->expr; | |
1075 | ||
1076 | /* Skip args which are not present. */ | |
1077 | if (!expr) | |
1078 | continue; | |
9960dc89 | 1079 | |
1080 | /* Skip other itself. */ | |
1081 | if (expr == other) | |
1082 | continue; | |
4ee9c684 | 1083 | |
018ef8b8 | 1084 | /* Skip intent(in) arguments if OTHER itself is intent(in). */ |
1a9745d2 | 1085 | if (formal && intent == INTENT_IN |
018ef8b8 | 1086 | && formal->sym->attr.intent == INTENT_IN) |
1087 | continue; | |
1088 | ||
74e83bb9 | 1089 | if (gfc_check_argument_dependency (other, intent, expr, elemental)) |
018ef8b8 | 1090 | return 1; |
4ee9c684 | 1091 | } |
1092 | ||
1093 | return 0; | |
1094 | } | |
1095 | ||
1096 | ||
0b5dc8b5 | 1097 | /* Return 1 if e1 and e2 are equivalenced arrays, either |
69b1505f | 1098 | directly or indirectly; i.e., equivalence (a,b) for a and b |
0b5dc8b5 | 1099 | or equivalence (a,c),(b,c). This function uses the equiv_ |
1100 | lists, generated in trans-common(add_equivalences), that are | |
78787e4b | 1101 | guaranteed to pick up indirect equivalences. We explicitly |
1102 | check for overlap using the offset and length of the equivalence. | |
1103 | This function is symmetric. | |
1104 | TODO: This function only checks whether the full top-level | |
1105 | symbols overlap. An improved implementation could inspect | |
1106 | e1->ref and e2->ref to determine whether the actually accessed | |
1107 | portions of these variables/arrays potentially overlap. */ | |
0b5dc8b5 | 1108 | |
1109 | int | |
1110 | gfc_are_equivalenced_arrays (gfc_expr *e1, gfc_expr *e2) | |
1111 | { | |
1112 | gfc_equiv_list *l; | |
1113 | gfc_equiv_info *s, *fl1, *fl2; | |
1114 | ||
1115 | gcc_assert (e1->expr_type == EXPR_VARIABLE | |
1a9745d2 | 1116 | && e2->expr_type == EXPR_VARIABLE); |
0b5dc8b5 | 1117 | |
1118 | if (!e1->symtree->n.sym->attr.in_equivalence | |
1a9745d2 | 1119 | || !e2->symtree->n.sym->attr.in_equivalence|| !e1->rank || !e2->rank) |
0b5dc8b5 | 1120 | return 0; |
1121 | ||
d60fed4c | 1122 | if (e1->symtree->n.sym->ns |
1123 | && e1->symtree->n.sym->ns != gfc_current_ns) | |
1124 | l = e1->symtree->n.sym->ns->equiv_lists; | |
1125 | else | |
1126 | l = gfc_current_ns->equiv_lists; | |
1127 | ||
0b5dc8b5 | 1128 | /* Go through the equiv_lists and return 1 if the variables |
1129 | e1 and e2 are members of the same group and satisfy the | |
1130 | requirement on their relative offsets. */ | |
d60fed4c | 1131 | for (; l; l = l->next) |
0b5dc8b5 | 1132 | { |
1133 | fl1 = NULL; | |
1134 | fl2 = NULL; | |
1135 | for (s = l->equiv; s; s = s->next) | |
1136 | { | |
1137 | if (s->sym == e1->symtree->n.sym) | |
78787e4b | 1138 | { |
1139 | fl1 = s; | |
1140 | if (fl2) | |
1141 | break; | |
1142 | } | |
0b5dc8b5 | 1143 | if (s->sym == e2->symtree->n.sym) |
78787e4b | 1144 | { |
1145 | fl2 = s; | |
1146 | if (fl1) | |
1147 | break; | |
1148 | } | |
1149 | } | |
1150 | ||
1151 | if (s) | |
1152 | { | |
1153 | /* Can these lengths be zero? */ | |
1154 | if (fl1->length <= 0 || fl2->length <= 0) | |
1155 | return 1; | |
9caa6670 | 1156 | /* These can't overlap if [f11,fl1+length] is before |
78787e4b | 1157 | [fl2,fl2+length], or [fl2,fl2+length] is before |
1158 | [fl1,fl1+length], otherwise they do overlap. */ | |
1159 | if (fl1->offset + fl1->length > fl2->offset | |
1160 | && fl2->offset + fl2->length > fl1->offset) | |
0b5dc8b5 | 1161 | return 1; |
1162 | } | |
1163 | } | |
78787e4b | 1164 | return 0; |
0b5dc8b5 | 1165 | } |
1166 | ||
1167 | ||
08803898 | 1168 | /* Return true if there is no possibility of aliasing because of a type |
1169 | mismatch between all the possible pointer references and the | |
1170 | potential target. Note that this function is asymmetric in the | |
1171 | arguments and so must be called twice with the arguments exchanged. */ | |
1172 | ||
1173 | static bool | |
1174 | check_data_pointer_types (gfc_expr *expr1, gfc_expr *expr2) | |
1175 | { | |
1176 | gfc_component *cm1; | |
1177 | gfc_symbol *sym1; | |
1178 | gfc_symbol *sym2; | |
1179 | gfc_ref *ref1; | |
1180 | bool seen_component_ref; | |
1181 | ||
1182 | if (expr1->expr_type != EXPR_VARIABLE | |
68cc384e | 1183 | || expr2->expr_type != EXPR_VARIABLE) |
08803898 | 1184 | return false; |
1185 | ||
1186 | sym1 = expr1->symtree->n.sym; | |
1187 | sym2 = expr2->symtree->n.sym; | |
1188 | ||
1189 | /* Keep it simple for now. */ | |
1190 | if (sym1->ts.type == BT_DERIVED && sym2->ts.type == BT_DERIVED) | |
1191 | return false; | |
1192 | ||
1193 | if (sym1->attr.pointer) | |
1194 | { | |
1195 | if (gfc_compare_types (&sym1->ts, &sym2->ts)) | |
1196 | return false; | |
1197 | } | |
1198 | ||
1199 | /* This is a conservative check on the components of the derived type | |
1200 | if no component references have been seen. Since we will not dig | |
1201 | into the components of derived type components, we play it safe by | |
1202 | returning false. First we check the reference chain and then, if | |
1203 | no component references have been seen, the components. */ | |
1204 | seen_component_ref = false; | |
1205 | if (sym1->ts.type == BT_DERIVED) | |
1206 | { | |
1207 | for (ref1 = expr1->ref; ref1; ref1 = ref1->next) | |
1208 | { | |
1209 | if (ref1->type != REF_COMPONENT) | |
1210 | continue; | |
1211 | ||
1212 | if (ref1->u.c.component->ts.type == BT_DERIVED) | |
1213 | return false; | |
1214 | ||
1215 | if ((sym2->attr.pointer || ref1->u.c.component->attr.pointer) | |
1216 | && gfc_compare_types (&ref1->u.c.component->ts, &sym2->ts)) | |
1217 | return false; | |
1218 | ||
1219 | seen_component_ref = true; | |
1220 | } | |
1221 | } | |
1222 | ||
1223 | if (sym1->ts.type == BT_DERIVED && !seen_component_ref) | |
1224 | { | |
1225 | for (cm1 = sym1->ts.u.derived->components; cm1; cm1 = cm1->next) | |
1226 | { | |
1227 | if (cm1->ts.type == BT_DERIVED) | |
1228 | return false; | |
1229 | ||
1230 | if ((sym2->attr.pointer || cm1->attr.pointer) | |
1231 | && gfc_compare_types (&cm1->ts, &sym2->ts)) | |
1232 | return false; | |
1233 | } | |
1234 | } | |
1235 | ||
1236 | return true; | |
1237 | } | |
1238 | ||
1239 | ||
4ee9c684 | 1240 | /* Return true if the statement body redefines the condition. Returns |
1241 | true if expr2 depends on expr1. expr1 should be a single term | |
dded0b23 | 1242 | suitable for the lhs of an assignment. The IDENTICAL flag indicates |
1243 | whether array references to the same symbol with identical range | |
1244 | references count as a dependency or not. Used for forall and where | |
4ee9c684 | 1245 | statements. Also used with functions returning arrays without a |
1246 | temporary. */ | |
1247 | ||
1248 | int | |
1a9745d2 | 1249 | gfc_check_dependency (gfc_expr *expr1, gfc_expr *expr2, bool identical) |
4ee9c684 | 1250 | { |
c5918475 | 1251 | gfc_actual_arglist *actual; |
1252 | gfc_constructor *c; | |
4ee9c684 | 1253 | int n; |
4ee9c684 | 1254 | |
22d678e8 | 1255 | gcc_assert (expr1->expr_type == EXPR_VARIABLE); |
4ee9c684 | 1256 | |
4ee9c684 | 1257 | switch (expr2->expr_type) |
1258 | { | |
1259 | case EXPR_OP: | |
dded0b23 | 1260 | n = gfc_check_dependency (expr1, expr2->value.op.op1, identical); |
4ee9c684 | 1261 | if (n) |
1262 | return n; | |
9b773341 | 1263 | if (expr2->value.op.op2) |
dded0b23 | 1264 | return gfc_check_dependency (expr1, expr2->value.op.op2, identical); |
4ee9c684 | 1265 | return 0; |
1266 | ||
1267 | case EXPR_VARIABLE: | |
e33c5890 | 1268 | /* The interesting cases are when the symbols don't match. */ |
1269 | if (expr1->symtree->n.sym != expr2->symtree->n.sym) | |
4ee9c684 | 1270 | { |
1869527c | 1271 | symbol_attribute attr1, attr2; |
e33c5890 | 1272 | gfc_typespec *ts1 = &expr1->symtree->n.sym->ts; |
1273 | gfc_typespec *ts2 = &expr2->symtree->n.sym->ts; | |
1274 | ||
1275 | /* Return 1 if expr1 and expr2 are equivalenced arrays. */ | |
1276 | if (gfc_are_equivalenced_arrays (expr1, expr2)) | |
4ee9c684 | 1277 | return 1; |
4ee9c684 | 1278 | |
e33c5890 | 1279 | /* Symbols can only alias if they have the same type. */ |
1a9745d2 | 1280 | if (ts1->type != BT_UNKNOWN && ts2->type != BT_UNKNOWN |
1281 | && ts1->type != BT_DERIVED && ts2->type != BT_DERIVED) | |
e33c5890 | 1282 | { |
1a9745d2 | 1283 | if (ts1->type != ts2->type || ts1->kind != ts2->kind) |
e33c5890 | 1284 | return 0; |
1285 | } | |
0b5dc8b5 | 1286 | |
1869527c | 1287 | /* We have to also include target-target as ptr%comp is not a |
1288 | pointer but it still alias with "dt%comp" for "ptr => dt". As | |
1289 | subcomponents and array access to pointers retains the target | |
1290 | attribute, that's sufficient. */ | |
1291 | attr1 = gfc_expr_attr (expr1); | |
1292 | attr2 = gfc_expr_attr (expr2); | |
1293 | if ((attr1.pointer || attr1.target) && (attr2.pointer || attr2.target)) | |
08803898 | 1294 | { |
1295 | if (check_data_pointer_types (expr1, expr2) | |
1296 | && check_data_pointer_types (expr2, expr1)) | |
1297 | return 0; | |
1298 | ||
1299 | return 1; | |
1300 | } | |
ec1eb337 | 1301 | else |
1302 | { | |
1303 | gfc_symbol *sym1 = expr1->symtree->n.sym; | |
1304 | gfc_symbol *sym2 = expr2->symtree->n.sym; | |
1305 | if (sym1->attr.target && sym2->attr.target | |
1306 | && ((sym1->attr.dummy && !sym1->attr.contiguous | |
1307 | && (!sym1->attr.dimension | |
1308 | || sym2->as->type == AS_ASSUMED_SHAPE)) | |
1309 | || (sym2->attr.dummy && !sym2->attr.contiguous | |
1310 | && (!sym2->attr.dimension | |
1311 | || sym2->as->type == AS_ASSUMED_SHAPE)))) | |
1312 | return 1; | |
1313 | } | |
e33c5890 | 1314 | |
1315 | /* Otherwise distinct symbols have no dependencies. */ | |
1316 | return 0; | |
1317 | } | |
4ee9c684 | 1318 | |
8311fe26 | 1319 | if (identical) |
1320 | return 1; | |
1321 | ||
80425127 | 1322 | /* Identical and disjoint ranges return 0, |
1323 | overlapping ranges return 1. */ | |
791d4123 | 1324 | if (expr1->ref && expr2->ref) |
8311fe26 | 1325 | return gfc_dep_resolver (expr1->ref, expr2->ref, NULL); |
dded0b23 | 1326 | |
4ee9c684 | 1327 | return 1; |
1328 | ||
1329 | case EXPR_FUNCTION: | |
1274527b | 1330 | if (gfc_get_noncopying_intrinsic_argument (expr2) != NULL) |
dded0b23 | 1331 | identical = 1; |
1274527b | 1332 | |
231e961a | 1333 | /* Remember possible differences between elemental and |
a7455f80 | 1334 | transformational functions. All functions inside a FORALL |
1335 | will be pure. */ | |
4ee9c684 | 1336 | for (actual = expr2->value.function.actual; |
1337 | actual; actual = actual->next) | |
1338 | { | |
1339 | if (!actual->expr) | |
1340 | continue; | |
dded0b23 | 1341 | n = gfc_check_dependency (expr1, actual->expr, identical); |
4ee9c684 | 1342 | if (n) |
1343 | return n; | |
1344 | } | |
1345 | return 0; | |
1346 | ||
1347 | case EXPR_CONSTANT: | |
11c3ed2a | 1348 | case EXPR_NULL: |
4ee9c684 | 1349 | return 0; |
1350 | ||
1351 | case EXPR_ARRAY: | |
c5918475 | 1352 | /* Loop through the array constructor's elements. */ |
126387b5 | 1353 | for (c = gfc_constructor_first (expr2->value.constructor); |
1354 | c; c = gfc_constructor_next (c)) | |
c5918475 | 1355 | { |
1356 | /* If this is an iterator, assume the worst. */ | |
1357 | if (c->iterator) | |
1358 | return 1; | |
1359 | /* Avoid recursion in the common case. */ | |
1360 | if (c->expr->expr_type == EXPR_CONSTANT) | |
1361 | continue; | |
1362 | if (gfc_check_dependency (expr1, c->expr, 1)) | |
1363 | return 1; | |
1364 | } | |
1365 | return 0; | |
4ee9c684 | 1366 | |
1367 | default: | |
1368 | return 1; | |
1369 | } | |
1370 | } | |
1371 | ||
1372 | ||
4ee9c684 | 1373 | /* Determines overlapping for two array sections. */ |
1374 | ||
1375 | static gfc_dependency | |
cca7236e | 1376 | check_section_vs_section (gfc_array_ref *l_ar, gfc_array_ref *r_ar, int n) |
4ee9c684 | 1377 | { |
1378 | gfc_expr *l_start; | |
1379 | gfc_expr *l_end; | |
1380 | gfc_expr *l_stride; | |
3f4feb44 | 1381 | gfc_expr *l_lower; |
1382 | gfc_expr *l_upper; | |
1383 | int l_dir; | |
4ee9c684 | 1384 | |
1385 | gfc_expr *r_start; | |
3f4feb44 | 1386 | gfc_expr *r_end; |
4ee9c684 | 1387 | gfc_expr *r_stride; |
3f4feb44 | 1388 | gfc_expr *r_lower; |
1389 | gfc_expr *r_upper; | |
65a182bc | 1390 | gfc_expr *one_expr; |
3f4feb44 | 1391 | int r_dir; |
65a182bc | 1392 | int stride_comparison; |
1393 | int start_comparison; | |
a642efd6 | 1394 | mpz_t tmp; |
4ee9c684 | 1395 | |
477c2f87 | 1396 | /* If they are the same range, return without more ado. */ |
9fcec394 | 1397 | if (is_same_range (l_ar, r_ar, n)) |
477c2f87 | 1398 | return GFC_DEP_EQUAL; |
4ee9c684 | 1399 | |
cca7236e | 1400 | l_start = l_ar->start[n]; |
1401 | l_end = l_ar->end[n]; | |
1402 | l_stride = l_ar->stride[n]; | |
3f4feb44 | 1403 | |
cca7236e | 1404 | r_start = r_ar->start[n]; |
1405 | r_end = r_ar->end[n]; | |
1406 | r_stride = r_ar->stride[n]; | |
4ee9c684 | 1407 | |
3f4feb44 | 1408 | /* If l_start is NULL take it from array specifier. */ |
cca7236e | 1409 | if (NULL == l_start && IS_ARRAY_EXPLICIT (l_ar->as)) |
1410 | l_start = l_ar->as->lower[n]; | |
3f4feb44 | 1411 | /* If l_end is NULL take it from array specifier. */ |
cca7236e | 1412 | if (NULL == l_end && IS_ARRAY_EXPLICIT (l_ar->as)) |
1413 | l_end = l_ar->as->upper[n]; | |
4ee9c684 | 1414 | |
3f4feb44 | 1415 | /* If r_start is NULL take it from array specifier. */ |
cca7236e | 1416 | if (NULL == r_start && IS_ARRAY_EXPLICIT (r_ar->as)) |
1417 | r_start = r_ar->as->lower[n]; | |
3f4feb44 | 1418 | /* If r_end is NULL take it from array specifier. */ |
cca7236e | 1419 | if (NULL == r_end && IS_ARRAY_EXPLICIT (r_ar->as)) |
1420 | r_end = r_ar->as->upper[n]; | |
3f4feb44 | 1421 | |
1422 | /* Determine whether the l_stride is positive or negative. */ | |
1423 | if (!l_stride) | |
1424 | l_dir = 1; | |
1425 | else if (l_stride->expr_type == EXPR_CONSTANT | |
1a9745d2 | 1426 | && l_stride->ts.type == BT_INTEGER) |
3f4feb44 | 1427 | l_dir = mpz_sgn (l_stride->value.integer); |
1428 | else if (l_start && l_end) | |
1429 | l_dir = gfc_dep_compare_expr (l_end, l_start); | |
1430 | else | |
1431 | l_dir = -2; | |
1432 | ||
1433 | /* Determine whether the r_stride is positive or negative. */ | |
1434 | if (!r_stride) | |
1435 | r_dir = 1; | |
1436 | else if (r_stride->expr_type == EXPR_CONSTANT | |
1a9745d2 | 1437 | && r_stride->ts.type == BT_INTEGER) |
3f4feb44 | 1438 | r_dir = mpz_sgn (r_stride->value.integer); |
1439 | else if (r_start && r_end) | |
1440 | r_dir = gfc_dep_compare_expr (r_end, r_start); | |
1441 | else | |
1442 | r_dir = -2; | |
4ee9c684 | 1443 | |
3f4feb44 | 1444 | /* The strides should never be zero. */ |
1445 | if (l_dir == 0 || r_dir == 0) | |
1446 | return GFC_DEP_OVERLAP; | |
4ee9c684 | 1447 | |
65a182bc | 1448 | /* Determine the relationship between the strides. Set stride_comparison to |
1449 | -2 if the dependency cannot be determined | |
1450 | -1 if l_stride < r_stride | |
1451 | 0 if l_stride == r_stride | |
1452 | 1 if l_stride > r_stride | |
1453 | as determined by gfc_dep_compare_expr. */ | |
60dd952b | 1454 | |
65a182bc | 1455 | one_expr = gfc_get_int_expr (gfc_index_integer_kind, NULL, 1); |
1456 | ||
1457 | stride_comparison = gfc_dep_compare_expr (l_stride ? l_stride : one_expr, | |
1458 | r_stride ? r_stride : one_expr); | |
1459 | ||
1460 | if (l_start && r_start) | |
1461 | start_comparison = gfc_dep_compare_expr (l_start, r_start); | |
60dd952b | 1462 | else |
65a182bc | 1463 | start_comparison = -2; |
9caa6670 | 1464 | |
a89260f1 | 1465 | gfc_free_expr (one_expr); |
60dd952b | 1466 | |
3f4feb44 | 1467 | /* Determine LHS upper and lower bounds. */ |
1468 | if (l_dir == 1) | |
1469 | { | |
1470 | l_lower = l_start; | |
1471 | l_upper = l_end; | |
1472 | } | |
1473 | else if (l_dir == -1) | |
1474 | { | |
1475 | l_lower = l_end; | |
1476 | l_upper = l_start; | |
1477 | } | |
4ee9c684 | 1478 | else |
3f4feb44 | 1479 | { |
1480 | l_lower = NULL; | |
1481 | l_upper = NULL; | |
1482 | } | |
4ee9c684 | 1483 | |
3f4feb44 | 1484 | /* Determine RHS upper and lower bounds. */ |
1485 | if (r_dir == 1) | |
1486 | { | |
1487 | r_lower = r_start; | |
1488 | r_upper = r_end; | |
1489 | } | |
1490 | else if (r_dir == -1) | |
1491 | { | |
1492 | r_lower = r_end; | |
1493 | r_upper = r_start; | |
1494 | } | |
1495 | else | |
1496 | { | |
1497 | r_lower = NULL; | |
1498 | r_upper = NULL; | |
1499 | } | |
1500 | ||
1501 | /* Check whether the ranges are disjoint. */ | |
1502 | if (l_upper && r_lower && gfc_dep_compare_expr (l_upper, r_lower) == -1) | |
1503 | return GFC_DEP_NODEP; | |
1504 | if (r_upper && l_lower && gfc_dep_compare_expr (r_upper, l_lower) == -1) | |
1505 | return GFC_DEP_NODEP; | |
1506 | ||
1507 | /* Handle cases like x:y:1 vs. x:z:-1 as GFC_DEP_EQUAL. */ | |
1508 | if (l_start && r_start && gfc_dep_compare_expr (l_start, r_start) == 0) | |
1509 | { | |
1510 | if (l_dir == 1 && r_dir == -1) | |
1a9745d2 | 1511 | return GFC_DEP_EQUAL; |
3f4feb44 | 1512 | if (l_dir == -1 && r_dir == 1) |
1a9745d2 | 1513 | return GFC_DEP_EQUAL; |
3f4feb44 | 1514 | } |
1515 | ||
1516 | /* Handle cases like x:y:1 vs. z:y:-1 as GFC_DEP_EQUAL. */ | |
1517 | if (l_end && r_end && gfc_dep_compare_expr (l_end, r_end) == 0) | |
1518 | { | |
1519 | if (l_dir == 1 && r_dir == -1) | |
1a9745d2 | 1520 | return GFC_DEP_EQUAL; |
3f4feb44 | 1521 | if (l_dir == -1 && r_dir == 1) |
1a9745d2 | 1522 | return GFC_DEP_EQUAL; |
3f4feb44 | 1523 | } |
1524 | ||
55f066ca | 1525 | /* Handle cases like x:y:2 vs. x+1:z:4 as GFC_DEP_NODEP. |
1526 | There is no dependency if the remainder of | |
1527 | (l_start - r_start) / gcd(l_stride, r_stride) is | |
1528 | nonzero. | |
1529 | TODO: | |
55f066ca | 1530 | - Cases like a(1:4:2) = a(2:3) are still not handled. |
1531 | */ | |
1532 | ||
1533 | #define IS_CONSTANT_INTEGER(a) ((a) && ((a)->expr_type == EXPR_CONSTANT) \ | |
1534 | && (a)->ts.type == BT_INTEGER) | |
1535 | ||
60e19868 | 1536 | if (IS_CONSTANT_INTEGER (l_stride) && IS_CONSTANT_INTEGER (r_stride) |
a642efd6 | 1537 | && gfc_dep_difference (l_start, r_start, &tmp)) |
55f066ca | 1538 | { |
a642efd6 | 1539 | mpz_t gcd; |
55f066ca | 1540 | int result; |
1541 | ||
1542 | mpz_init (gcd); | |
55f066ca | 1543 | mpz_gcd (gcd, l_stride->value.integer, r_stride->value.integer); |
55f066ca | 1544 | |
1545 | mpz_fdiv_r (tmp, tmp, gcd); | |
1546 | result = mpz_cmp_si (tmp, 0L); | |
1547 | ||
1548 | mpz_clear (gcd); | |
1549 | mpz_clear (tmp); | |
1550 | ||
1551 | if (result != 0) | |
1552 | return GFC_DEP_NODEP; | |
1553 | } | |
1554 | ||
1555 | #undef IS_CONSTANT_INTEGER | |
1556 | ||
293d72e0 | 1557 | /* Check for forward dependencies x:y vs. x+1:z and x:y:z vs. x:y:z+1. */ |
3f4feb44 | 1558 | |
65a182bc | 1559 | if (l_dir == 1 && r_dir == 1 && |
1560 | (start_comparison == 0 || start_comparison == -1) | |
1561 | && (stride_comparison == 0 || stride_comparison == -1)) | |
1562 | return GFC_DEP_FORWARD; | |
3f4feb44 | 1563 | |
65a182bc | 1564 | /* Check for forward dependencies x:y:-1 vs. x-1:z:-1 and |
1565 | x:y:-1 vs. x:y:-2. */ | |
9caa6670 | 1566 | if (l_dir == -1 && r_dir == -1 && |
65a182bc | 1567 | (start_comparison == 0 || start_comparison == 1) |
1568 | && (stride_comparison == 0 || stride_comparison == 1)) | |
1569 | return GFC_DEP_FORWARD; | |
1c9b57d0 | 1570 | |
65a182bc | 1571 | if (stride_comparison == 0 || stride_comparison == -1) |
25f9f93d | 1572 | { |
1c9b57d0 | 1573 | if (l_start && IS_ARRAY_EXPLICIT (l_ar->as)) |
1574 | { | |
1575 | ||
65a182bc | 1576 | /* Check for a(low:y:s) vs. a(z:x:s) or |
1577 | a(low:y:s) vs. a(z:x:s+1) where a has a lower bound | |
1c9b57d0 | 1578 | of low, which is always at least a forward dependence. */ |
1579 | ||
1580 | if (r_dir == 1 | |
1581 | && gfc_dep_compare_expr (l_start, l_ar->as->lower[n]) == 0) | |
1582 | return GFC_DEP_FORWARD; | |
65a182bc | 1583 | } |
1584 | } | |
1c9b57d0 | 1585 | |
65a182bc | 1586 | if (stride_comparison == 0 || stride_comparison == 1) |
1587 | { | |
1588 | if (l_start && IS_ARRAY_EXPLICIT (l_ar->as)) | |
1589 | { | |
9caa6670 | 1590 | |
65a182bc | 1591 | /* Check for a(high:y:-s) vs. a(z:x:-s) or |
1592 | a(high:y:-s vs. a(z:x:-s-1) where a has a higher bound | |
1c9b57d0 | 1593 | of high, which is always at least a forward dependence. */ |
1594 | ||
1595 | if (r_dir == -1 | |
1596 | && gfc_dep_compare_expr (l_start, l_ar->as->upper[n]) == 0) | |
1597 | return GFC_DEP_FORWARD; | |
1598 | } | |
65a182bc | 1599 | } |
1c9b57d0 | 1600 | |
65a182bc | 1601 | |
1602 | if (stride_comparison == 0) | |
1603 | { | |
1c9b57d0 | 1604 | /* From here, check for backwards dependencies. */ |
65a182bc | 1605 | /* x+1:y vs. x:z. */ |
1606 | if (l_dir == 1 && r_dir == 1 && start_comparison == 1) | |
25f9f93d | 1607 | return GFC_DEP_BACKWARD; |
1608 | ||
65a182bc | 1609 | /* x-1:y:-1 vs. x:z:-1. */ |
1610 | if (l_dir == -1 && r_dir == -1 && start_comparison == -1) | |
25f9f93d | 1611 | return GFC_DEP_BACKWARD; |
1612 | } | |
1613 | ||
3f4feb44 | 1614 | return GFC_DEP_OVERLAP; |
4ee9c684 | 1615 | } |
1616 | ||
1617 | ||
a6c8790e | 1618 | /* Determines overlapping for a single element and a section. */ |
4ee9c684 | 1619 | |
1620 | static gfc_dependency | |
1a9745d2 | 1621 | gfc_check_element_vs_section( gfc_ref *lref, gfc_ref *rref, int n) |
4ee9c684 | 1622 | { |
a6c8790e | 1623 | gfc_array_ref *ref; |
1624 | gfc_expr *elem; | |
1625 | gfc_expr *start; | |
1626 | gfc_expr *end; | |
1627 | gfc_expr *stride; | |
4ee9c684 | 1628 | int s; |
1629 | ||
a6c8790e | 1630 | elem = lref->u.ar.start[n]; |
1631 | if (!elem) | |
4ee9c684 | 1632 | return GFC_DEP_OVERLAP; |
1633 | ||
a6c8790e | 1634 | ref = &rref->u.ar; |
1635 | start = ref->start[n] ; | |
1636 | end = ref->end[n] ; | |
1637 | stride = ref->stride[n]; | |
1638 | ||
1639 | if (!start && IS_ARRAY_EXPLICIT (ref->as)) | |
1640 | start = ref->as->lower[n]; | |
1641 | if (!end && IS_ARRAY_EXPLICIT (ref->as)) | |
1642 | end = ref->as->upper[n]; | |
1643 | ||
1644 | /* Determine whether the stride is positive or negative. */ | |
1645 | if (!stride) | |
1646 | s = 1; | |
1647 | else if (stride->expr_type == EXPR_CONSTANT | |
1648 | && stride->ts.type == BT_INTEGER) | |
1649 | s = mpz_sgn (stride->value.integer); | |
1650 | else | |
1651 | s = -2; | |
4ee9c684 | 1652 | |
a6c8790e | 1653 | /* Stride should never be zero. */ |
1654 | if (s == 0) | |
4ee9c684 | 1655 | return GFC_DEP_OVERLAP; |
1656 | ||
a6c8790e | 1657 | /* Positive strides. */ |
4ee9c684 | 1658 | if (s == 1) |
1659 | { | |
a6c8790e | 1660 | /* Check for elem < lower. */ |
1661 | if (start && gfc_dep_compare_expr (elem, start) == -1) | |
1662 | return GFC_DEP_NODEP; | |
1663 | /* Check for elem > upper. */ | |
1664 | if (end && gfc_dep_compare_expr (elem, end) == 1) | |
1665 | return GFC_DEP_NODEP; | |
1666 | ||
1667 | if (start && end) | |
1668 | { | |
1669 | s = gfc_dep_compare_expr (start, end); | |
1670 | /* Check for an empty range. */ | |
1671 | if (s == 1) | |
1672 | return GFC_DEP_NODEP; | |
1673 | if (s == 0 && gfc_dep_compare_expr (elem, start) == 0) | |
1674 | return GFC_DEP_EQUAL; | |
1675 | } | |
1676 | } | |
1677 | /* Negative strides. */ | |
1678 | else if (s == -1) | |
1679 | { | |
1680 | /* Check for elem > upper. */ | |
1681 | if (end && gfc_dep_compare_expr (elem, start) == 1) | |
1682 | return GFC_DEP_NODEP; | |
1683 | /* Check for elem < lower. */ | |
1684 | if (start && gfc_dep_compare_expr (elem, end) == -1) | |
1685 | return GFC_DEP_NODEP; | |
1686 | ||
1687 | if (start && end) | |
1688 | { | |
1689 | s = gfc_dep_compare_expr (start, end); | |
1690 | /* Check for an empty range. */ | |
1691 | if (s == -1) | |
1692 | return GFC_DEP_NODEP; | |
1693 | if (s == 0 && gfc_dep_compare_expr (elem, start) == 0) | |
1694 | return GFC_DEP_EQUAL; | |
1695 | } | |
4ee9c684 | 1696 | } |
a6c8790e | 1697 | /* Unknown strides. */ |
4ee9c684 | 1698 | else |
1699 | { | |
a6c8790e | 1700 | if (!start || !end) |
1701 | return GFC_DEP_OVERLAP; | |
1702 | s = gfc_dep_compare_expr (start, end); | |
61bc1860 | 1703 | if (s <= -2) |
4ee9c684 | 1704 | return GFC_DEP_OVERLAP; |
a6c8790e | 1705 | /* Assume positive stride. */ |
1706 | if (s == -1) | |
1707 | { | |
1708 | /* Check for elem < lower. */ | |
1709 | if (gfc_dep_compare_expr (elem, start) == -1) | |
1710 | return GFC_DEP_NODEP; | |
1711 | /* Check for elem > upper. */ | |
1712 | if (gfc_dep_compare_expr (elem, end) == 1) | |
1713 | return GFC_DEP_NODEP; | |
1714 | } | |
1715 | /* Assume negative stride. */ | |
1716 | else if (s == 1) | |
1717 | { | |
1718 | /* Check for elem > upper. */ | |
1719 | if (gfc_dep_compare_expr (elem, start) == 1) | |
1720 | return GFC_DEP_NODEP; | |
1721 | /* Check for elem < lower. */ | |
1722 | if (gfc_dep_compare_expr (elem, end) == -1) | |
1723 | return GFC_DEP_NODEP; | |
1724 | } | |
1725 | /* Equal bounds. */ | |
1726 | else if (s == 0) | |
1727 | { | |
1728 | s = gfc_dep_compare_expr (elem, start); | |
1729 | if (s == 0) | |
1730 | return GFC_DEP_EQUAL; | |
1731 | if (s == 1 || s == -1) | |
1732 | return GFC_DEP_NODEP; | |
1733 | } | |
4ee9c684 | 1734 | } |
4ee9c684 | 1735 | |
a6c8790e | 1736 | return GFC_DEP_OVERLAP; |
4ee9c684 | 1737 | } |
1738 | ||
1739 | ||
bf0a0eb6 | 1740 | /* Traverse expr, checking all EXPR_VARIABLE symbols for their |
1741 | forall_index attribute. Return true if any variable may be | |
1742 | being used as a FORALL index. Its safe to pessimistically | |
1743 | return true, and assume a dependency. */ | |
1744 | ||
1745 | static bool | |
1a9745d2 | 1746 | contains_forall_index_p (gfc_expr *expr) |
bf0a0eb6 | 1747 | { |
1748 | gfc_actual_arglist *arg; | |
1749 | gfc_constructor *c; | |
1750 | gfc_ref *ref; | |
1751 | int i; | |
1752 | ||
1753 | if (!expr) | |
1754 | return false; | |
1755 | ||
1756 | switch (expr->expr_type) | |
1757 | { | |
1758 | case EXPR_VARIABLE: | |
1759 | if (expr->symtree->n.sym->forall_index) | |
1760 | return true; | |
1761 | break; | |
1762 | ||
1763 | case EXPR_OP: | |
1764 | if (contains_forall_index_p (expr->value.op.op1) | |
1765 | || contains_forall_index_p (expr->value.op.op2)) | |
1766 | return true; | |
1767 | break; | |
1768 | ||
1769 | case EXPR_FUNCTION: | |
1770 | for (arg = expr->value.function.actual; arg; arg = arg->next) | |
1771 | if (contains_forall_index_p (arg->expr)) | |
1772 | return true; | |
1773 | break; | |
1774 | ||
1775 | case EXPR_CONSTANT: | |
1776 | case EXPR_NULL: | |
1777 | case EXPR_SUBSTRING: | |
1778 | break; | |
1779 | ||
1780 | case EXPR_STRUCTURE: | |
1781 | case EXPR_ARRAY: | |
126387b5 | 1782 | for (c = gfc_constructor_first (expr->value.constructor); |
1783 | c; gfc_constructor_next (c)) | |
bf0a0eb6 | 1784 | if (contains_forall_index_p (c->expr)) |
1785 | return true; | |
1786 | break; | |
1787 | ||
1788 | default: | |
1789 | gcc_unreachable (); | |
1790 | } | |
1791 | ||
1792 | for (ref = expr->ref; ref; ref = ref->next) | |
1793 | switch (ref->type) | |
1794 | { | |
1795 | case REF_ARRAY: | |
1796 | for (i = 0; i < ref->u.ar.dimen; i++) | |
1797 | if (contains_forall_index_p (ref->u.ar.start[i]) | |
1798 | || contains_forall_index_p (ref->u.ar.end[i]) | |
1799 | || contains_forall_index_p (ref->u.ar.stride[i])) | |
1800 | return true; | |
1801 | break; | |
1802 | ||
1803 | case REF_COMPONENT: | |
1804 | break; | |
1805 | ||
1806 | case REF_SUBSTRING: | |
1807 | if (contains_forall_index_p (ref->u.ss.start) | |
1808 | || contains_forall_index_p (ref->u.ss.end)) | |
1809 | return true; | |
1810 | break; | |
1811 | ||
1812 | default: | |
1813 | gcc_unreachable (); | |
1814 | } | |
1815 | ||
1816 | return false; | |
1817 | } | |
1818 | ||
4ee9c684 | 1819 | /* Determines overlapping for two single element array references. */ |
1820 | ||
1821 | static gfc_dependency | |
1a9745d2 | 1822 | gfc_check_element_vs_element (gfc_ref *lref, gfc_ref *rref, int n) |
4ee9c684 | 1823 | { |
1824 | gfc_array_ref l_ar; | |
1825 | gfc_array_ref r_ar; | |
1826 | gfc_expr *l_start; | |
1827 | gfc_expr *r_start; | |
80425127 | 1828 | int i; |
4ee9c684 | 1829 | |
80425127 | 1830 | l_ar = lref->u.ar; |
1831 | r_ar = rref->u.ar; | |
1832 | l_start = l_ar.start[n] ; | |
1833 | r_start = r_ar.start[n] ; | |
1834 | i = gfc_dep_compare_expr (r_start, l_start); | |
1835 | if (i == 0) | |
1836 | return GFC_DEP_EQUAL; | |
bf0a0eb6 | 1837 | |
1838 | /* Treat two scalar variables as potentially equal. This allows | |
1839 | us to prove that a(i,:) and a(j,:) have no dependency. See | |
1840 | Gerald Roth, "Evaluation of Array Syntax Dependence Analysis", | |
1841 | Proceedings of the International Conference on Parallel and | |
1842 | Distributed Processing Techniques and Applications (PDPTA2001), | |
1843 | Las Vegas, Nevada, June 2001. */ | |
1844 | /* However, we need to be careful when either scalar expression | |
1845 | contains a FORALL index, as these can potentially change value | |
1846 | during the scalarization/traversal of this array reference. */ | |
1a9745d2 | 1847 | if (contains_forall_index_p (r_start) || contains_forall_index_p (l_start)) |
17c67d08 | 1848 | return GFC_DEP_OVERLAP; |
bf0a0eb6 | 1849 | |
61bc1860 | 1850 | if (i > -2) |
4d4677fd | 1851 | return GFC_DEP_NODEP; |
bf0a0eb6 | 1852 | return GFC_DEP_EQUAL; |
4ee9c684 | 1853 | } |
1854 | ||
2c9c0c1f | 1855 | /* Callback function for checking if an expression depends on a |
1856 | dummy variable which is any other than INTENT(IN). */ | |
1857 | ||
1858 | static int | |
1859 | callback_dummy_intent_not_in (gfc_expr **ep, | |
1860 | int *walk_subtrees ATTRIBUTE_UNUSED, | |
1861 | void *data ATTRIBUTE_UNUSED) | |
1862 | { | |
1863 | gfc_expr *e = *ep; | |
1864 | ||
1865 | if (e->expr_type == EXPR_VARIABLE && e->symtree | |
1866 | && e->symtree->n.sym->attr.dummy) | |
1867 | return e->symtree->n.sym->attr.intent != INTENT_IN; | |
1868 | else | |
1869 | return 0; | |
1870 | } | |
1871 | ||
1872 | /* Auxiliary function to check if subexpressions have dummy variables which | |
1873 | are not intent(in). | |
1874 | */ | |
1875 | ||
1876 | static bool | |
1877 | dummy_intent_not_in (gfc_expr **ep) | |
1878 | { | |
1879 | return gfc_expr_walker (ep, callback_dummy_intent_not_in, NULL); | |
1880 | } | |
4ee9c684 | 1881 | |
eb89ca84 | 1882 | /* Determine if an array ref, usually an array section specifies the |
8d60cc46 | 1883 | entire array. In addition, if the second, pointer argument is |
1884 | provided, the function will return true if the reference is | |
2c9c0c1f | 1885 | contiguous; eg. (:, 1) gives true but (1,:) gives false. |
1886 | If one of the bounds depends on a dummy variable which is | |
1887 | not INTENT(IN), also return false, because the user may | |
1888 | have changed the variable. */ | |
eb89ca84 | 1889 | |
1890 | bool | |
8d60cc46 | 1891 | gfc_full_array_ref_p (gfc_ref *ref, bool *contiguous) |
eb89ca84 | 1892 | { |
1893 | int i; | |
9bf78879 | 1894 | int n; |
8d60cc46 | 1895 | bool lbound_OK = true; |
1896 | bool ubound_OK = true; | |
eb89ca84 | 1897 | |
88a37d69 | 1898 | if (contiguous) |
1899 | *contiguous = false; | |
1900 | ||
eb89ca84 | 1901 | if (ref->type != REF_ARRAY) |
1902 | return false; | |
9bf78879 | 1903 | |
eb89ca84 | 1904 | if (ref->u.ar.type == AR_FULL) |
88a37d69 | 1905 | { |
1906 | if (contiguous) | |
1907 | *contiguous = true; | |
1908 | return true; | |
1909 | } | |
9bf78879 | 1910 | |
eb89ca84 | 1911 | if (ref->u.ar.type != AR_SECTION) |
1912 | return false; | |
538374c5 | 1913 | if (ref->next) |
1914 | return false; | |
eb89ca84 | 1915 | |
1916 | for (i = 0; i < ref->u.ar.dimen; i++) | |
1917 | { | |
9bf78879 | 1918 | /* If we have a single element in the reference, for the reference |
1919 | to be full, we need to ascertain that the array has a single | |
1920 | element in this dimension and that we actually reference the | |
1921 | correct element. */ | |
3d3e0f7d | 1922 | if (ref->u.ar.dimen_type[i] == DIMEN_ELEMENT) |
1923 | { | |
9bf78879 | 1924 | /* This is unconditionally a contiguous reference if all the |
1925 | remaining dimensions are elements. */ | |
8d60cc46 | 1926 | if (contiguous) |
9bf78879 | 1927 | { |
1928 | *contiguous = true; | |
1929 | for (n = i + 1; n < ref->u.ar.dimen; n++) | |
1930 | if (ref->u.ar.dimen_type[n] != DIMEN_ELEMENT) | |
1931 | *contiguous = false; | |
1932 | } | |
8d60cc46 | 1933 | |
3d3e0f7d | 1934 | if (!ref->u.ar.as |
1935 | || !ref->u.ar.as->lower[i] | |
1936 | || !ref->u.ar.as->upper[i] | |
1937 | || gfc_dep_compare_expr (ref->u.ar.as->lower[i], | |
1938 | ref->u.ar.as->upper[i]) | |
1939 | || !ref->u.ar.start[i] | |
1940 | || gfc_dep_compare_expr (ref->u.ar.start[i], | |
1941 | ref->u.ar.as->lower[i])) | |
1942 | return false; | |
1943 | else | |
1944 | continue; | |
1945 | } | |
1946 | ||
eb89ca84 | 1947 | /* Check the lower bound. */ |
1948 | if (ref->u.ar.start[i] | |
1949 | && (!ref->u.ar.as | |
1950 | || !ref->u.ar.as->lower[i] | |
1951 | || gfc_dep_compare_expr (ref->u.ar.start[i], | |
2c9c0c1f | 1952 | ref->u.ar.as->lower[i]) |
1953 | || dummy_intent_not_in (&ref->u.ar.start[i]))) | |
8d60cc46 | 1954 | lbound_OK = false; |
eb89ca84 | 1955 | /* Check the upper bound. */ |
1956 | if (ref->u.ar.end[i] | |
1957 | && (!ref->u.ar.as | |
1958 | || !ref->u.ar.as->upper[i] | |
1959 | || gfc_dep_compare_expr (ref->u.ar.end[i], | |
2c9c0c1f | 1960 | ref->u.ar.as->upper[i]) |
1961 | || dummy_intent_not_in (&ref->u.ar.end[i]))) | |
8d60cc46 | 1962 | ubound_OK = false; |
eb89ca84 | 1963 | /* Check the stride. */ |
9bf78879 | 1964 | if (ref->u.ar.stride[i] |
1965 | && !gfc_expr_is_one (ref->u.ar.stride[i], 0)) | |
eb89ca84 | 1966 | return false; |
8d60cc46 | 1967 | |
9bf78879 | 1968 | /* This is unconditionally a contiguous reference as long as all |
1969 | the subsequent dimensions are elements. */ | |
8d60cc46 | 1970 | if (contiguous) |
9bf78879 | 1971 | { |
1972 | *contiguous = true; | |
1973 | for (n = i + 1; n < ref->u.ar.dimen; n++) | |
1974 | if (ref->u.ar.dimen_type[n] != DIMEN_ELEMENT) | |
1975 | *contiguous = false; | |
1976 | } | |
8d60cc46 | 1977 | |
1978 | if (!lbound_OK || !ubound_OK) | |
1979 | return false; | |
eb89ca84 | 1980 | } |
1981 | return true; | |
1982 | } | |
1983 | ||
1984 | ||
4992c81a | 1985 | /* Determine if a full array is the same as an array section with one |
1986 | variable limit. For this to be so, the strides must both be unity | |
1987 | and one of either start == lower or end == upper must be true. */ | |
1988 | ||
1989 | static bool | |
1990 | ref_same_as_full_array (gfc_ref *full_ref, gfc_ref *ref) | |
1991 | { | |
1992 | int i; | |
1993 | bool upper_or_lower; | |
1994 | ||
1995 | if (full_ref->type != REF_ARRAY) | |
1996 | return false; | |
1997 | if (full_ref->u.ar.type != AR_FULL) | |
1998 | return false; | |
1999 | if (ref->type != REF_ARRAY) | |
2000 | return false; | |
2001 | if (ref->u.ar.type != AR_SECTION) | |
2002 | return false; | |
2003 | ||
2004 | for (i = 0; i < ref->u.ar.dimen; i++) | |
2005 | { | |
2006 | /* If we have a single element in the reference, we need to check | |
2007 | that the array has a single element and that we actually reference | |
2008 | the correct element. */ | |
2009 | if (ref->u.ar.dimen_type[i] == DIMEN_ELEMENT) | |
2010 | { | |
2011 | if (!full_ref->u.ar.as | |
2012 | || !full_ref->u.ar.as->lower[i] | |
2013 | || !full_ref->u.ar.as->upper[i] | |
2014 | || gfc_dep_compare_expr (full_ref->u.ar.as->lower[i], | |
2015 | full_ref->u.ar.as->upper[i]) | |
2016 | || !ref->u.ar.start[i] | |
2017 | || gfc_dep_compare_expr (ref->u.ar.start[i], | |
2018 | full_ref->u.ar.as->lower[i])) | |
2019 | return false; | |
2020 | } | |
2021 | ||
2022 | /* Check the strides. */ | |
2023 | if (full_ref->u.ar.stride[i] && !gfc_expr_is_one (full_ref->u.ar.stride[i], 0)) | |
2024 | return false; | |
2025 | if (ref->u.ar.stride[i] && !gfc_expr_is_one (ref->u.ar.stride[i], 0)) | |
2026 | return false; | |
2027 | ||
2028 | upper_or_lower = false; | |
2029 | /* Check the lower bound. */ | |
2030 | if (ref->u.ar.start[i] | |
2031 | && (ref->u.ar.as | |
2032 | && full_ref->u.ar.as->lower[i] | |
2033 | && gfc_dep_compare_expr (ref->u.ar.start[i], | |
2034 | full_ref->u.ar.as->lower[i]) == 0)) | |
2035 | upper_or_lower = true; | |
2036 | /* Check the upper bound. */ | |
2037 | if (ref->u.ar.end[i] | |
2038 | && (ref->u.ar.as | |
2039 | && full_ref->u.ar.as->upper[i] | |
2040 | && gfc_dep_compare_expr (ref->u.ar.end[i], | |
2041 | full_ref->u.ar.as->upper[i]) == 0)) | |
2042 | upper_or_lower = true; | |
2043 | if (!upper_or_lower) | |
2044 | return false; | |
2045 | } | |
2046 | return true; | |
2047 | } | |
2048 | ||
2049 | ||
4ee9c684 | 2050 | /* Finds if two array references are overlapping or not. |
2051 | Return value | |
25f9f93d | 2052 | 2 : array references are overlapping but reversal of one or |
2053 | more dimensions will clear the dependency. | |
4ee9c684 | 2054 | 1 : array references are overlapping. |
8311fe26 | 2055 | 0 : array references are identical or not overlapping. */ |
4ee9c684 | 2056 | |
2057 | int | |
25f9f93d | 2058 | gfc_dep_resolver (gfc_ref *lref, gfc_ref *rref, gfc_reverse *reverse) |
4ee9c684 | 2059 | { |
2060 | int n; | |
9caa6670 | 2061 | int m; |
4ee9c684 | 2062 | gfc_dependency fin_dep; |
2063 | gfc_dependency this_dep; | |
2064 | ||
25f9f93d | 2065 | this_dep = GFC_DEP_ERROR; |
4ee9c684 | 2066 | fin_dep = GFC_DEP_ERROR; |
2067 | /* Dependencies due to pointers should already have been identified. | |
2068 | We only need to check for overlapping array references. */ | |
2069 | ||
2070 | while (lref && rref) | |
2071 | { | |
2072 | /* We're resolving from the same base symbol, so both refs should be | |
69b1505f | 2073 | the same type. We traverse the reference chain until we find ranges |
4ee9c684 | 2074 | that are not equal. */ |
22d678e8 | 2075 | gcc_assert (lref->type == rref->type); |
4ee9c684 | 2076 | switch (lref->type) |
2077 | { | |
2078 | case REF_COMPONENT: | |
2079 | /* The two ranges can't overlap if they are from different | |
2080 | components. */ | |
2081 | if (lref->u.c.component != rref->u.c.component) | |
8311fe26 | 2082 | return 0; |
4ee9c684 | 2083 | break; |
9caa6670 | 2084 | |
4ee9c684 | 2085 | case REF_SUBSTRING: |
791d4123 | 2086 | /* Substring overlaps are handled by the string assignment code |
2087 | if there is not an underlying dependency. */ | |
8311fe26 | 2088 | return (fin_dep == GFC_DEP_OVERLAP) ? 1 : 0; |
9caa6670 | 2089 | |
4ee9c684 | 2090 | case REF_ARRAY: |
4992c81a | 2091 | |
2092 | if (ref_same_as_full_array (lref, rref)) | |
8311fe26 | 2093 | return 0; |
4992c81a | 2094 | |
2095 | if (ref_same_as_full_array (rref, lref)) | |
8311fe26 | 2096 | return 0; |
4992c81a | 2097 | |
1a9745d2 | 2098 | if (lref->u.ar.dimen != rref->u.ar.dimen) |
eb89ca84 | 2099 | { |
2100 | if (lref->u.ar.type == AR_FULL) | |
8d60cc46 | 2101 | fin_dep = gfc_full_array_ref_p (rref, NULL) ? GFC_DEP_EQUAL |
2102 | : GFC_DEP_OVERLAP; | |
eb89ca84 | 2103 | else if (rref->u.ar.type == AR_FULL) |
8d60cc46 | 2104 | fin_dep = gfc_full_array_ref_p (lref, NULL) ? GFC_DEP_EQUAL |
2105 | : GFC_DEP_OVERLAP; | |
eb89ca84 | 2106 | else |
8311fe26 | 2107 | return 1; |
eb89ca84 | 2108 | break; |
2109 | } | |
2110 | ||
9caa6670 | 2111 | /* Index for the reverse array. */ |
2112 | m = -1; | |
4ee9c684 | 2113 | for (n=0; n < lref->u.ar.dimen; n++) |
2114 | { | |
7243e979 | 2115 | /* Handle dependency when either of array reference is vector |
2116 | subscript. There is no dependency if the vector indices | |
2117 | are equal or if indices are known to be different in a | |
2118 | different dimension. */ | |
4ee9c684 | 2119 | if (lref->u.ar.dimen_type[n] == DIMEN_VECTOR |
2120 | || rref->u.ar.dimen_type[n] == DIMEN_VECTOR) | |
7243e979 | 2121 | { |
9caa6670 | 2122 | if (lref->u.ar.dimen_type[n] == DIMEN_VECTOR |
7243e979 | 2123 | && rref->u.ar.dimen_type[n] == DIMEN_VECTOR |
2124 | && gfc_dep_compare_expr (lref->u.ar.start[n], | |
2125 | rref->u.ar.start[n]) == 0) | |
2126 | this_dep = GFC_DEP_EQUAL; | |
2127 | else | |
2128 | this_dep = GFC_DEP_OVERLAP; | |
2129 | ||
2130 | goto update_fin_dep; | |
2131 | } | |
25f9f93d | 2132 | |
4ee9c684 | 2133 | if (lref->u.ar.dimen_type[n] == DIMEN_RANGE |
2134 | && rref->u.ar.dimen_type[n] == DIMEN_RANGE) | |
cca7236e | 2135 | this_dep = check_section_vs_section (&lref->u.ar, &rref->u.ar, n); |
4ee9c684 | 2136 | else if (lref->u.ar.dimen_type[n] == DIMEN_ELEMENT |
2137 | && rref->u.ar.dimen_type[n] == DIMEN_RANGE) | |
2138 | this_dep = gfc_check_element_vs_section (lref, rref, n); | |
2139 | else if (rref->u.ar.dimen_type[n] == DIMEN_ELEMENT | |
2140 | && lref->u.ar.dimen_type[n] == DIMEN_RANGE) | |
2141 | this_dep = gfc_check_element_vs_section (rref, lref, n); | |
9caa6670 | 2142 | else |
4ee9c684 | 2143 | { |
22d678e8 | 2144 | gcc_assert (rref->u.ar.dimen_type[n] == DIMEN_ELEMENT |
a7455f80 | 2145 | && lref->u.ar.dimen_type[n] == DIMEN_ELEMENT); |
4ee9c684 | 2146 | this_dep = gfc_check_element_vs_element (rref, lref, n); |
2147 | } | |
2148 | ||
2149 | /* If any dimension doesn't overlap, we have no dependency. */ | |
2150 | if (this_dep == GFC_DEP_NODEP) | |
8311fe26 | 2151 | return 0; |
4ee9c684 | 2152 | |
25f9f93d | 2153 | /* Now deal with the loop reversal logic: This only works on |
2154 | ranges and is activated by setting | |
66c674b6 | 2155 | reverse[n] == GFC_ENABLE_REVERSE |
25f9f93d | 2156 | The ability to reverse or not is set by previous conditions |
2157 | in this dimension. If reversal is not activated, the | |
2158 | value GFC_DEP_BACKWARD is reset to GFC_DEP_OVERLAP. */ | |
9caa6670 | 2159 | |
2160 | /* Get the indexing right for the scalarizing loop. If this | |
2161 | is an element, there is no corresponding loop. */ | |
2162 | if (lref->u.ar.dimen_type[n] != DIMEN_ELEMENT) | |
2163 | m++; | |
2164 | ||
25f9f93d | 2165 | if (rref->u.ar.dimen_type[n] == DIMEN_RANGE |
2166 | && lref->u.ar.dimen_type[n] == DIMEN_RANGE) | |
2167 | { | |
2168 | /* Set reverse if backward dependence and not inhibited. */ | |
9caa6670 | 2169 | if (reverse && reverse[m] == GFC_ENABLE_REVERSE) |
2170 | reverse[m] = (this_dep == GFC_DEP_BACKWARD) ? | |
2171 | GFC_REVERSE_SET : reverse[m]; | |
25f9f93d | 2172 | |
66c674b6 | 2173 | /* Set forward if forward dependence and not inhibited. */ |
9caa6670 | 2174 | if (reverse && reverse[m] == GFC_ENABLE_REVERSE) |
2175 | reverse[m] = (this_dep == GFC_DEP_FORWARD) ? | |
2176 | GFC_FORWARD_SET : reverse[m]; | |
66c674b6 | 2177 | |
2178 | /* Flag up overlap if dependence not compatible with | |
2179 | the overall state of the expression. */ | |
9caa6670 | 2180 | if (reverse && reverse[m] == GFC_REVERSE_SET |
66c674b6 | 2181 | && this_dep == GFC_DEP_FORWARD) |
2182 | { | |
9caa6670 | 2183 | reverse[m] = GFC_INHIBIT_REVERSE; |
66c674b6 | 2184 | this_dep = GFC_DEP_OVERLAP; |
2185 | } | |
9caa6670 | 2186 | else if (reverse && reverse[m] == GFC_FORWARD_SET |
66c674b6 | 2187 | && this_dep == GFC_DEP_BACKWARD) |
25f9f93d | 2188 | { |
9caa6670 | 2189 | reverse[m] = GFC_INHIBIT_REVERSE; |
66c674b6 | 2190 | this_dep = GFC_DEP_OVERLAP; |
25f9f93d | 2191 | } |
2192 | ||
2193 | /* If no intention of reversing or reversing is explicitly | |
2194 | inhibited, convert backward dependence to overlap. */ | |
66c674b6 | 2195 | if ((reverse == NULL && this_dep == GFC_DEP_BACKWARD) |
9caa6670 | 2196 | || (reverse != NULL && reverse[m] == GFC_INHIBIT_REVERSE)) |
25f9f93d | 2197 | this_dep = GFC_DEP_OVERLAP; |
2198 | } | |
2199 | ||
4ee9c684 | 2200 | /* Overlap codes are in order of priority. We only need to |
a7455f80 | 2201 | know the worst one.*/ |
7243e979 | 2202 | |
2203 | update_fin_dep: | |
4ee9c684 | 2204 | if (this_dep > fin_dep) |
2205 | fin_dep = this_dep; | |
2206 | } | |
caea6886 | 2207 | |
2208 | /* If this is an equal element, we have to keep going until we find | |
2209 | the "real" array reference. */ | |
2210 | if (lref->u.ar.type == AR_ELEMENT | |
2211 | && rref->u.ar.type == AR_ELEMENT | |
2212 | && fin_dep == GFC_DEP_EQUAL) | |
2213 | break; | |
2214 | ||
4ee9c684 | 2215 | /* Exactly matching and forward overlapping ranges don't cause a |
2216 | dependency. */ | |
25f9f93d | 2217 | if (fin_dep < GFC_DEP_BACKWARD) |
8311fe26 | 2218 | return 0; |
4ee9c684 | 2219 | |
2220 | /* Keep checking. We only have a dependency if | |
2221 | subsequent references also overlap. */ | |
2222 | break; | |
2223 | ||
2224 | default: | |
22d678e8 | 2225 | gcc_unreachable (); |
4ee9c684 | 2226 | } |
2227 | lref = lref->next; | |
2228 | rref = rref->next; | |
2229 | } | |
2230 | ||
2231 | /* If we haven't seen any array refs then something went wrong. */ | |
22d678e8 | 2232 | gcc_assert (fin_dep != GFC_DEP_ERROR); |
4ee9c684 | 2233 | |
80425127 | 2234 | /* Assume the worst if we nest to different depths. */ |
2235 | if (lref || rref) | |
8311fe26 | 2236 | return 1; |
80425127 | 2237 | |
8311fe26 | 2238 | return fin_dep == GFC_DEP_OVERLAP; |
4ee9c684 | 2239 | } |