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1364018f | 1 | /* Chains of recurrences. |
d353bf18 | 2 | Copyright (C) 2003-2015 Free Software Foundation, Inc. |
6b421feb | 3 | Contributed by Sebastian Pop <pop@cri.ensmp.fr> |
1364018f | 4 | |
5 | This file is part of GCC. | |
6 | ||
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 | |
8c4c00c1 | 9 | Software Foundation; either version 3, or (at your option) any later |
1364018f | 10 | version. |
11 | ||
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. | |
16 | ||
17 | You should have received a copy of the GNU General Public License | |
8c4c00c1 | 18 | along with GCC; see the file COPYING3. If not see |
19 | <http://www.gnu.org/licenses/>. */ | |
1364018f | 20 | |
21 | /* This file implements operations on chains of recurrences. Chains | |
22 | of recurrences are used for modeling evolution functions of scalar | |
23 | variables. | |
24 | */ | |
25 | ||
26 | #include "config.h" | |
27 | #include "system.h" | |
28 | #include "coretypes.h" | |
b20a8bb4 | 29 | #include "alias.h" |
30 | #include "symtab.h" | |
31 | #include "options.h" | |
0d9585ca | 32 | #include "tree.h" |
b20a8bb4 | 33 | #include "fold-const.h" |
ce084dfc | 34 | #include "tree-pretty-print.h" |
b3786ab3 | 35 | #include "cfgloop.h" |
94ea8568 | 36 | #include "predict.h" |
94ea8568 | 37 | #include "tm.h" |
38 | #include "hard-reg-set.h" | |
94ea8568 | 39 | #include "function.h" |
40 | #include "dominance.h" | |
41 | #include "cfg.h" | |
bc61cadb | 42 | #include "basic-block.h" |
43 | #include "gimple-expr.h" | |
05d9c18a | 44 | #include "tree-ssa-loop-ivopts.h" |
45 | #include "tree-ssa-loop-niter.h" | |
1364018f | 46 | #include "tree-chrec.h" |
b9ed1410 | 47 | #include "dumpfile.h" |
a89ef955 | 48 | #include "params.h" |
9887dd18 | 49 | #include "tree-scalar-evolution.h" |
1364018f | 50 | |
1364018f | 51 | /* Extended folder for chrecs. */ |
52 | ||
53 | /* Determines whether CST is not a constant evolution. */ | |
54 | ||
55 | static inline bool | |
7ecb5bb2 | 56 | is_not_constant_evolution (const_tree cst) |
1364018f | 57 | { |
58 | return (TREE_CODE (cst) == POLYNOMIAL_CHREC); | |
59 | } | |
60 | ||
61 | /* Fold CODE for a polynomial function and a constant. */ | |
62 | ||
48e1416a | 63 | static inline tree |
64 | chrec_fold_poly_cst (enum tree_code code, | |
65 | tree type, | |
66 | tree poly, | |
1364018f | 67 | tree cst) |
68 | { | |
8c0963c4 | 69 | gcc_assert (poly); |
70 | gcc_assert (cst); | |
71 | gcc_assert (TREE_CODE (poly) == POLYNOMIAL_CHREC); | |
24a12d10 | 72 | gcc_checking_assert (!is_not_constant_evolution (cst)); |
73 | gcc_checking_assert (useless_type_conversion_p (type, chrec_type (poly))); | |
f84a688a | 74 | |
1364018f | 75 | switch (code) |
76 | { | |
77 | case PLUS_EXPR: | |
48e1416a | 78 | return build_polynomial_chrec |
79 | (CHREC_VARIABLE (poly), | |
1364018f | 80 | chrec_fold_plus (type, CHREC_LEFT (poly), cst), |
81 | CHREC_RIGHT (poly)); | |
48e1416a | 82 | |
1364018f | 83 | case MINUS_EXPR: |
48e1416a | 84 | return build_polynomial_chrec |
85 | (CHREC_VARIABLE (poly), | |
1364018f | 86 | chrec_fold_minus (type, CHREC_LEFT (poly), cst), |
87 | CHREC_RIGHT (poly)); | |
48e1416a | 88 | |
1364018f | 89 | case MULT_EXPR: |
48e1416a | 90 | return build_polynomial_chrec |
91 | (CHREC_VARIABLE (poly), | |
1364018f | 92 | chrec_fold_multiply (type, CHREC_LEFT (poly), cst), |
93 | chrec_fold_multiply (type, CHREC_RIGHT (poly), cst)); | |
48e1416a | 94 | |
1364018f | 95 | default: |
96 | return chrec_dont_know; | |
97 | } | |
98 | } | |
99 | ||
100 | /* Fold the addition of two polynomial functions. */ | |
101 | ||
48e1416a | 102 | static inline tree |
103 | chrec_fold_plus_poly_poly (enum tree_code code, | |
104 | tree type, | |
105 | tree poly0, | |
1364018f | 106 | tree poly1) |
107 | { | |
108 | tree left, right; | |
3bbbcdff | 109 | struct loop *loop0 = get_chrec_loop (poly0); |
110 | struct loop *loop1 = get_chrec_loop (poly1); | |
a845d317 | 111 | tree rtype = code == POINTER_PLUS_EXPR ? chrec_type (poly1) : type; |
8c0963c4 | 112 | |
113 | gcc_assert (poly0); | |
114 | gcc_assert (poly1); | |
115 | gcc_assert (TREE_CODE (poly0) == POLYNOMIAL_CHREC); | |
116 | gcc_assert (TREE_CODE (poly1) == POLYNOMIAL_CHREC); | |
0de36bdb | 117 | if (POINTER_TYPE_P (chrec_type (poly0))) |
24a12d10 | 118 | gcc_checking_assert (ptrofftype_p (chrec_type (poly1)) |
119 | && useless_type_conversion_p (type, chrec_type (poly0))); | |
0de36bdb | 120 | else |
24a12d10 | 121 | gcc_checking_assert (useless_type_conversion_p (type, chrec_type (poly0)) |
122 | && useless_type_conversion_p (type, chrec_type (poly1))); | |
48e1416a | 123 | |
1364018f | 124 | /* |
125 | {a, +, b}_1 + {c, +, d}_2 -> {{a, +, b}_1 + c, +, d}_2, | |
126 | {a, +, b}_2 + {c, +, d}_1 -> {{c, +, d}_1 + a, +, b}_2, | |
127 | {a, +, b}_x + {c, +, d}_x -> {a+c, +, b+d}_x. */ | |
3bbbcdff | 128 | if (flow_loop_nested_p (loop0, loop1)) |
1364018f | 129 | { |
0de36bdb | 130 | if (code == PLUS_EXPR || code == POINTER_PLUS_EXPR) |
48e1416a | 131 | return build_polynomial_chrec |
132 | (CHREC_VARIABLE (poly1), | |
1364018f | 133 | chrec_fold_plus (type, poly0, CHREC_LEFT (poly1)), |
134 | CHREC_RIGHT (poly1)); | |
135 | else | |
48e1416a | 136 | return build_polynomial_chrec |
137 | (CHREC_VARIABLE (poly1), | |
1364018f | 138 | chrec_fold_minus (type, poly0, CHREC_LEFT (poly1)), |
48e1416a | 139 | chrec_fold_multiply (type, CHREC_RIGHT (poly1), |
eb105b17 | 140 | SCALAR_FLOAT_TYPE_P (type) |
141 | ? build_real (type, dconstm1) | |
142 | : build_int_cst_type (type, -1))); | |
1364018f | 143 | } |
48e1416a | 144 | |
3bbbcdff | 145 | if (flow_loop_nested_p (loop1, loop0)) |
1364018f | 146 | { |
0de36bdb | 147 | if (code == PLUS_EXPR || code == POINTER_PLUS_EXPR) |
48e1416a | 148 | return build_polynomial_chrec |
149 | (CHREC_VARIABLE (poly0), | |
1364018f | 150 | chrec_fold_plus (type, CHREC_LEFT (poly0), poly1), |
151 | CHREC_RIGHT (poly0)); | |
152 | else | |
48e1416a | 153 | return build_polynomial_chrec |
154 | (CHREC_VARIABLE (poly0), | |
1364018f | 155 | chrec_fold_minus (type, CHREC_LEFT (poly0), poly1), |
156 | CHREC_RIGHT (poly0)); | |
157 | } | |
48e1416a | 158 | |
3bbbcdff | 159 | /* This function should never be called for chrecs of loops that |
160 | do not belong to the same loop nest. */ | |
161 | gcc_assert (loop0 == loop1); | |
162 | ||
0de36bdb | 163 | if (code == PLUS_EXPR || code == POINTER_PLUS_EXPR) |
1364018f | 164 | { |
48e1416a | 165 | left = chrec_fold_plus |
1364018f | 166 | (type, CHREC_LEFT (poly0), CHREC_LEFT (poly1)); |
48e1416a | 167 | right = chrec_fold_plus |
0de36bdb | 168 | (rtype, CHREC_RIGHT (poly0), CHREC_RIGHT (poly1)); |
1364018f | 169 | } |
170 | else | |
171 | { | |
48e1416a | 172 | left = chrec_fold_minus |
1364018f | 173 | (type, CHREC_LEFT (poly0), CHREC_LEFT (poly1)); |
48e1416a | 174 | right = chrec_fold_minus |
1364018f | 175 | (type, CHREC_RIGHT (poly0), CHREC_RIGHT (poly1)); |
176 | } | |
177 | ||
178 | if (chrec_zerop (right)) | |
179 | return left; | |
180 | else | |
48e1416a | 181 | return build_polynomial_chrec |
182 | (CHREC_VARIABLE (poly0), left, right); | |
1364018f | 183 | } |
184 | ||
185 | \f | |
186 | ||
187 | /* Fold the multiplication of two polynomial functions. */ | |
188 | ||
48e1416a | 189 | static inline tree |
190 | chrec_fold_multiply_poly_poly (tree type, | |
191 | tree poly0, | |
1364018f | 192 | tree poly1) |
193 | { | |
20a25e6c | 194 | tree t0, t1, t2; |
195 | int var; | |
3bbbcdff | 196 | struct loop *loop0 = get_chrec_loop (poly0); |
197 | struct loop *loop1 = get_chrec_loop (poly1); | |
20a25e6c | 198 | |
8c0963c4 | 199 | gcc_assert (poly0); |
200 | gcc_assert (poly1); | |
201 | gcc_assert (TREE_CODE (poly0) == POLYNOMIAL_CHREC); | |
202 | gcc_assert (TREE_CODE (poly1) == POLYNOMIAL_CHREC); | |
24a12d10 | 203 | gcc_checking_assert (useless_type_conversion_p (type, chrec_type (poly0)) |
204 | && useless_type_conversion_p (type, chrec_type (poly1))); | |
48e1416a | 205 | |
1364018f | 206 | /* {a, +, b}_1 * {c, +, d}_2 -> {c*{a, +, b}_1, +, d}_2, |
207 | {a, +, b}_2 * {c, +, d}_1 -> {a*{c, +, d}_1, +, b}_2, | |
208 | {a, +, b}_x * {c, +, d}_x -> {a*c, +, a*d + b*c + b*d, +, 2*b*d}_x. */ | |
3bbbcdff | 209 | if (flow_loop_nested_p (loop0, loop1)) |
1364018f | 210 | /* poly0 is a constant wrt. poly1. */ |
48e1416a | 211 | return build_polynomial_chrec |
212 | (CHREC_VARIABLE (poly1), | |
1364018f | 213 | chrec_fold_multiply (type, CHREC_LEFT (poly1), poly0), |
214 | CHREC_RIGHT (poly1)); | |
48e1416a | 215 | |
3bbbcdff | 216 | if (flow_loop_nested_p (loop1, loop0)) |
1364018f | 217 | /* poly1 is a constant wrt. poly0. */ |
48e1416a | 218 | return build_polynomial_chrec |
219 | (CHREC_VARIABLE (poly0), | |
1364018f | 220 | chrec_fold_multiply (type, CHREC_LEFT (poly0), poly1), |
221 | CHREC_RIGHT (poly0)); | |
48e1416a | 222 | |
3bbbcdff | 223 | gcc_assert (loop0 == loop1); |
224 | ||
1364018f | 225 | /* poly0 and poly1 are two polynomials in the same variable, |
226 | {a, +, b}_x * {c, +, d}_x -> {a*c, +, a*d + b*c + b*d, +, 2*b*d}_x. */ | |
48e1416a | 227 | |
20a25e6c | 228 | /* "a*c". */ |
229 | t0 = chrec_fold_multiply (type, CHREC_LEFT (poly0), CHREC_LEFT (poly1)); | |
230 | ||
0f0057aa | 231 | /* "a*d + b*c". */ |
20a25e6c | 232 | t1 = chrec_fold_multiply (type, CHREC_LEFT (poly0), CHREC_RIGHT (poly1)); |
233 | t1 = chrec_fold_plus (type, t1, chrec_fold_multiply (type, | |
234 | CHREC_RIGHT (poly0), | |
235 | CHREC_LEFT (poly1))); | |
0f0057aa | 236 | /* "b*d". */ |
20a25e6c | 237 | t2 = chrec_fold_multiply (type, CHREC_RIGHT (poly0), CHREC_RIGHT (poly1)); |
0f0057aa | 238 | /* "a*d + b*c + b*d". */ |
239 | t1 = chrec_fold_plus (type, t1, t2); | |
240 | /* "2*b*d". */ | |
eb105b17 | 241 | t2 = chrec_fold_multiply (type, SCALAR_FLOAT_TYPE_P (type) |
242 | ? build_real (type, dconst2) | |
05db596e | 243 | : build_int_cst (type, 2), t2); |
20a25e6c | 244 | |
245 | var = CHREC_VARIABLE (poly0); | |
246 | return build_polynomial_chrec (var, t0, | |
247 | build_polynomial_chrec (var, t1, t2)); | |
1364018f | 248 | } |
249 | ||
250 | /* When the operands are automatically_generated_chrec_p, the fold has | |
251 | to respect the semantics of the operands. */ | |
252 | ||
48e1416a | 253 | static inline tree |
254 | chrec_fold_automatically_generated_operands (tree op0, | |
1364018f | 255 | tree op1) |
256 | { | |
257 | if (op0 == chrec_dont_know | |
258 | || op1 == chrec_dont_know) | |
259 | return chrec_dont_know; | |
48e1416a | 260 | |
1364018f | 261 | if (op0 == chrec_known |
262 | || op1 == chrec_known) | |
263 | return chrec_known; | |
48e1416a | 264 | |
1364018f | 265 | if (op0 == chrec_not_analyzed_yet |
266 | || op1 == chrec_not_analyzed_yet) | |
267 | return chrec_not_analyzed_yet; | |
48e1416a | 268 | |
fbf0afd1 | 269 | /* The default case produces a safe result. */ |
1364018f | 270 | return chrec_dont_know; |
271 | } | |
272 | ||
273 | /* Fold the addition of two chrecs. */ | |
274 | ||
275 | static tree | |
48e1416a | 276 | chrec_fold_plus_1 (enum tree_code code, tree type, |
f84a688a | 277 | tree op0, tree op1) |
1364018f | 278 | { |
279 | if (automatically_generated_chrec_p (op0) | |
280 | || automatically_generated_chrec_p (op1)) | |
281 | return chrec_fold_automatically_generated_operands (op0, op1); | |
48e1416a | 282 | |
1364018f | 283 | switch (TREE_CODE (op0)) |
284 | { | |
285 | case POLYNOMIAL_CHREC: | |
32e31826 | 286 | gcc_checking_assert |
287 | (!chrec_contains_symbols_defined_in_loop (op0, CHREC_VARIABLE (op0))); | |
1364018f | 288 | switch (TREE_CODE (op1)) |
289 | { | |
290 | case POLYNOMIAL_CHREC: | |
32e31826 | 291 | gcc_checking_assert |
292 | (!chrec_contains_symbols_defined_in_loop (op1, | |
293 | CHREC_VARIABLE (op1))); | |
1364018f | 294 | return chrec_fold_plus_poly_poly (code, type, op0, op1); |
295 | ||
f2a8ffd0 | 296 | CASE_CONVERT: |
297 | if (tree_contains_chrecs (op1, NULL)) | |
298 | return chrec_dont_know; | |
299 | ||
1364018f | 300 | default: |
0de36bdb | 301 | if (code == PLUS_EXPR || code == POINTER_PLUS_EXPR) |
48e1416a | 302 | return build_polynomial_chrec |
303 | (CHREC_VARIABLE (op0), | |
1364018f | 304 | chrec_fold_plus (type, CHREC_LEFT (op0), op1), |
305 | CHREC_RIGHT (op0)); | |
306 | else | |
48e1416a | 307 | return build_polynomial_chrec |
308 | (CHREC_VARIABLE (op0), | |
1364018f | 309 | chrec_fold_minus (type, CHREC_LEFT (op0), op1), |
310 | CHREC_RIGHT (op0)); | |
311 | } | |
312 | ||
f2a8ffd0 | 313 | CASE_CONVERT: |
314 | if (tree_contains_chrecs (op0, NULL)) | |
315 | return chrec_dont_know; | |
316 | ||
1364018f | 317 | default: |
318 | switch (TREE_CODE (op1)) | |
319 | { | |
320 | case POLYNOMIAL_CHREC: | |
32e31826 | 321 | gcc_checking_assert |
322 | (!chrec_contains_symbols_defined_in_loop (op1, | |
323 | CHREC_VARIABLE (op1))); | |
0de36bdb | 324 | if (code == PLUS_EXPR || code == POINTER_PLUS_EXPR) |
48e1416a | 325 | return build_polynomial_chrec |
326 | (CHREC_VARIABLE (op1), | |
1364018f | 327 | chrec_fold_plus (type, op0, CHREC_LEFT (op1)), |
328 | CHREC_RIGHT (op1)); | |
329 | else | |
48e1416a | 330 | return build_polynomial_chrec |
331 | (CHREC_VARIABLE (op1), | |
1364018f | 332 | chrec_fold_minus (type, op0, CHREC_LEFT (op1)), |
48e1416a | 333 | chrec_fold_multiply (type, CHREC_RIGHT (op1), |
eb105b17 | 334 | SCALAR_FLOAT_TYPE_P (type) |
335 | ? build_real (type, dconstm1) | |
336 | : build_int_cst_type (type, -1))); | |
1364018f | 337 | |
f2a8ffd0 | 338 | CASE_CONVERT: |
339 | if (tree_contains_chrecs (op1, NULL)) | |
340 | return chrec_dont_know; | |
341 | ||
1364018f | 342 | default: |
a89ef955 | 343 | { |
344 | int size = 0; | |
345 | if ((tree_contains_chrecs (op0, &size) | |
346 | || tree_contains_chrecs (op1, &size)) | |
347 | && size < PARAM_VALUE (PARAM_SCEV_MAX_EXPR_SIZE)) | |
348 | return build2 (code, type, op0, op1); | |
349 | else if (size < PARAM_VALUE (PARAM_SCEV_MAX_EXPR_SIZE)) | |
a0553bff | 350 | { |
351 | if (code == POINTER_PLUS_EXPR) | |
352 | return fold_build_pointer_plus (fold_convert (type, op0), | |
353 | op1); | |
354 | else | |
355 | return fold_build2 (code, type, | |
356 | fold_convert (type, op0), | |
357 | fold_convert (type, op1)); | |
358 | } | |
a89ef955 | 359 | else |
360 | return chrec_dont_know; | |
361 | } | |
1364018f | 362 | } |
363 | } | |
364 | } | |
365 | ||
366 | /* Fold the addition of two chrecs. */ | |
367 | ||
368 | tree | |
48e1416a | 369 | chrec_fold_plus (tree type, |
1364018f | 370 | tree op0, |
371 | tree op1) | |
372 | { | |
0de36bdb | 373 | enum tree_code code; |
f84a688a | 374 | if (automatically_generated_chrec_p (op0) |
375 | || automatically_generated_chrec_p (op1)) | |
376 | return chrec_fold_automatically_generated_operands (op0, op1); | |
377 | ||
1364018f | 378 | if (integer_zerop (op0)) |
75a70cf9 | 379 | return chrec_convert (type, op1, NULL); |
1364018f | 380 | if (integer_zerop (op1)) |
75a70cf9 | 381 | return chrec_convert (type, op0, NULL); |
0de36bdb | 382 | |
383 | if (POINTER_TYPE_P (type)) | |
384 | code = POINTER_PLUS_EXPR; | |
385 | else | |
386 | code = PLUS_EXPR; | |
48e1416a | 387 | |
0de36bdb | 388 | return chrec_fold_plus_1 (code, type, op0, op1); |
1364018f | 389 | } |
390 | ||
391 | /* Fold the subtraction of two chrecs. */ | |
392 | ||
48e1416a | 393 | tree |
394 | chrec_fold_minus (tree type, | |
395 | tree op0, | |
1364018f | 396 | tree op1) |
397 | { | |
f84a688a | 398 | if (automatically_generated_chrec_p (op0) |
399 | || automatically_generated_chrec_p (op1)) | |
400 | return chrec_fold_automatically_generated_operands (op0, op1); | |
401 | ||
1364018f | 402 | if (integer_zerop (op1)) |
403 | return op0; | |
48e1416a | 404 | |
1364018f | 405 | return chrec_fold_plus_1 (MINUS_EXPR, type, op0, op1); |
406 | } | |
407 | ||
408 | /* Fold the multiplication of two chrecs. */ | |
409 | ||
410 | tree | |
48e1416a | 411 | chrec_fold_multiply (tree type, |
1364018f | 412 | tree op0, |
413 | tree op1) | |
414 | { | |
415 | if (automatically_generated_chrec_p (op0) | |
416 | || automatically_generated_chrec_p (op1)) | |
417 | return chrec_fold_automatically_generated_operands (op0, op1); | |
48e1416a | 418 | |
1364018f | 419 | switch (TREE_CODE (op0)) |
420 | { | |
421 | case POLYNOMIAL_CHREC: | |
32e31826 | 422 | gcc_checking_assert |
423 | (!chrec_contains_symbols_defined_in_loop (op0, CHREC_VARIABLE (op0))); | |
1364018f | 424 | switch (TREE_CODE (op1)) |
425 | { | |
426 | case POLYNOMIAL_CHREC: | |
32e31826 | 427 | gcc_checking_assert |
428 | (!chrec_contains_symbols_defined_in_loop (op1, | |
429 | CHREC_VARIABLE (op1))); | |
1364018f | 430 | return chrec_fold_multiply_poly_poly (type, op0, op1); |
48e1416a | 431 | |
f2a8ffd0 | 432 | CASE_CONVERT: |
433 | if (tree_contains_chrecs (op1, NULL)) | |
434 | return chrec_dont_know; | |
435 | ||
1364018f | 436 | default: |
437 | if (integer_onep (op1)) | |
438 | return op0; | |
439 | if (integer_zerop (op1)) | |
05db596e | 440 | return build_int_cst (type, 0); |
48e1416a | 441 | |
442 | return build_polynomial_chrec | |
443 | (CHREC_VARIABLE (op0), | |
1364018f | 444 | chrec_fold_multiply (type, CHREC_LEFT (op0), op1), |
445 | chrec_fold_multiply (type, CHREC_RIGHT (op0), op1)); | |
446 | } | |
48e1416a | 447 | |
f2a8ffd0 | 448 | CASE_CONVERT: |
449 | if (tree_contains_chrecs (op0, NULL)) | |
450 | return chrec_dont_know; | |
451 | ||
1364018f | 452 | default: |
453 | if (integer_onep (op0)) | |
454 | return op1; | |
48e1416a | 455 | |
1364018f | 456 | if (integer_zerop (op0)) |
05db596e | 457 | return build_int_cst (type, 0); |
48e1416a | 458 | |
1364018f | 459 | switch (TREE_CODE (op1)) |
460 | { | |
461 | case POLYNOMIAL_CHREC: | |
32e31826 | 462 | gcc_checking_assert |
463 | (!chrec_contains_symbols_defined_in_loop (op1, | |
464 | CHREC_VARIABLE (op1))); | |
48e1416a | 465 | return build_polynomial_chrec |
466 | (CHREC_VARIABLE (op1), | |
1364018f | 467 | chrec_fold_multiply (type, CHREC_LEFT (op1), op0), |
468 | chrec_fold_multiply (type, CHREC_RIGHT (op1), op0)); | |
48e1416a | 469 | |
f2a8ffd0 | 470 | CASE_CONVERT: |
471 | if (tree_contains_chrecs (op1, NULL)) | |
472 | return chrec_dont_know; | |
473 | ||
1364018f | 474 | default: |
475 | if (integer_onep (op1)) | |
476 | return op0; | |
477 | if (integer_zerop (op1)) | |
05db596e | 478 | return build_int_cst (type, 0); |
a89ef955 | 479 | return fold_build2 (MULT_EXPR, type, op0, op1); |
1364018f | 480 | } |
481 | } | |
482 | } | |
483 | ||
484 | \f | |
485 | ||
486 | /* Operations. */ | |
487 | ||
9353326d | 488 | /* Evaluate the binomial coefficient. Return NULL_TREE if the intermediate |
489 | calculation overflows, otherwise return C(n,k) with type TYPE. */ | |
490 | ||
48e1416a | 491 | static tree |
9353326d | 492 | tree_fold_binomial (tree type, tree n, unsigned int k) |
1364018f | 493 | { |
d67b7119 | 494 | bool overflow; |
9353326d | 495 | unsigned int i; |
496 | tree res; | |
497 | ||
498 | /* Handle the most frequent cases. */ | |
499 | if (k == 0) | |
500 | return build_int_cst (type, 1); | |
501 | if (k == 1) | |
502 | return fold_convert (type, n); | |
503 | ||
504 | /* Check that k <= n. */ | |
c311b856 | 505 | if (wi::ltu_p (n, k)) |
9353326d | 506 | return NULL_TREE; |
507 | ||
9353326d | 508 | /* Denominator = 2. */ |
ab2c1de8 | 509 | wide_int denom = wi::two (TYPE_PRECISION (TREE_TYPE (n))); |
9353326d | 510 | |
511 | /* Index = Numerator-1. */ | |
c311b856 | 512 | wide_int idx = wi::sub (n, 1); |
1364018f | 513 | |
9353326d | 514 | /* Numerator = Numerator*Index = n*(n-1). */ |
c311b856 | 515 | wide_int num = wi::smul (n, idx, &overflow); |
d67b7119 | 516 | if (overflow) |
9353326d | 517 | return NULL_TREE; |
1364018f | 518 | |
9353326d | 519 | for (i = 3; i <= k; i++) |
520 | { | |
521 | /* Index--. */ | |
d67b7119 | 522 | --idx; |
9353326d | 523 | |
524 | /* Numerator *= Index. */ | |
796b6678 | 525 | num = wi::smul (num, idx, &overflow); |
d67b7119 | 526 | if (overflow) |
9353326d | 527 | return NULL_TREE; |
528 | ||
529 | /* Denominator *= i. */ | |
e913b5cd | 530 | denom *= i; |
9353326d | 531 | } |
532 | ||
533 | /* Result = Numerator / Denominator. */ | |
ab2c1de8 | 534 | wide_int di_res = wi::udiv_trunc (num, denom); |
e913b5cd | 535 | res = wide_int_to_tree (type, di_res); |
9353326d | 536 | return int_fits_type_p (res, type) ? res : NULL_TREE; |
1364018f | 537 | } |
538 | ||
539 | /* Helper function. Use the Newton's interpolating formula for | |
540 | evaluating the value of the evolution function. */ | |
541 | ||
48e1416a | 542 | static tree |
9353326d | 543 | chrec_evaluate (unsigned var, tree chrec, tree n, unsigned int k) |
1364018f | 544 | { |
9353326d | 545 | tree arg0, arg1, binomial_n_k; |
546 | tree type = TREE_TYPE (chrec); | |
41f75a99 | 547 | struct loop *var_loop = get_loop (cfun, var); |
9353326d | 548 | |
549 | while (TREE_CODE (chrec) == POLYNOMIAL_CHREC | |
3bbbcdff | 550 | && flow_loop_nested_p (var_loop, get_chrec_loop (chrec))) |
9353326d | 551 | chrec = CHREC_LEFT (chrec); |
552 | ||
553 | if (TREE_CODE (chrec) == POLYNOMIAL_CHREC | |
554 | && CHREC_VARIABLE (chrec) == var) | |
1364018f | 555 | { |
72aad60a | 556 | arg1 = chrec_evaluate (var, CHREC_RIGHT (chrec), n, k + 1); |
557 | if (arg1 == chrec_dont_know) | |
9353326d | 558 | return chrec_dont_know; |
559 | binomial_n_k = tree_fold_binomial (type, n, k); | |
560 | if (!binomial_n_k) | |
561 | return chrec_dont_know; | |
72aad60a | 562 | arg0 = fold_build2 (MULT_EXPR, type, |
a89ef955 | 563 | CHREC_LEFT (chrec), binomial_n_k); |
9353326d | 564 | return chrec_fold_plus (type, arg0, arg1); |
1364018f | 565 | } |
9353326d | 566 | |
567 | binomial_n_k = tree_fold_binomial (type, n, k); | |
568 | if (!binomial_n_k) | |
569 | return chrec_dont_know; | |
48e1416a | 570 | |
a89ef955 | 571 | return fold_build2 (MULT_EXPR, type, chrec, binomial_n_k); |
1364018f | 572 | } |
573 | ||
48e1416a | 574 | /* Evaluates "CHREC (X)" when the varying variable is VAR. |
575 | Example: Given the following parameters, | |
576 | ||
1364018f | 577 | var = 1 |
578 | chrec = {3, +, 4}_1 | |
579 | x = 10 | |
48e1416a | 580 | |
581 | The result is given by the Newton's interpolating formula: | |
1364018f | 582 | 3 * \binom{10}{0} + 4 * \binom{10}{1}. |
583 | */ | |
584 | ||
48e1416a | 585 | tree |
1364018f | 586 | chrec_apply (unsigned var, |
48e1416a | 587 | tree chrec, |
1364018f | 588 | tree x) |
589 | { | |
590 | tree type = chrec_type (chrec); | |
591 | tree res = chrec_dont_know; | |
592 | ||
593 | if (automatically_generated_chrec_p (chrec) | |
594 | || automatically_generated_chrec_p (x) | |
595 | ||
596 | /* When the symbols are defined in an outer loop, it is possible | |
597 | to symbolically compute the apply, since the symbols are | |
598 | constants with respect to the varying loop. */ | |
553b9523 | 599 | || chrec_contains_symbols_defined_in_loop (chrec, var)) |
1364018f | 600 | return chrec_dont_know; |
48e1416a | 601 | |
487a9bc1 | 602 | if (dump_file && (dump_flags & TDF_SCEV)) |
1364018f | 603 | fprintf (dump_file, "(chrec_apply \n"); |
604 | ||
dd2a65b3 | 605 | if (TREE_CODE (x) == INTEGER_CST && SCALAR_FLOAT_TYPE_P (type)) |
606 | x = build_real_from_int_cst (type, x); | |
607 | ||
9e4cd968 | 608 | switch (TREE_CODE (chrec)) |
1364018f | 609 | { |
9e4cd968 | 610 | case POLYNOMIAL_CHREC: |
611 | if (evolution_function_is_affine_p (chrec)) | |
612 | { | |
613 | if (CHREC_VARIABLE (chrec) != var) | |
614 | return build_polynomial_chrec | |
615 | (CHREC_VARIABLE (chrec), | |
616 | chrec_apply (var, CHREC_LEFT (chrec), x), | |
617 | chrec_apply (var, CHREC_RIGHT (chrec), x)); | |
618 | ||
619 | /* "{a, +, b} (x)" -> "a + b*x". */ | |
620 | x = chrec_convert_rhs (type, x, NULL); | |
621 | res = chrec_fold_multiply (TREE_TYPE (x), CHREC_RIGHT (chrec), x); | |
622 | res = chrec_fold_plus (type, CHREC_LEFT (chrec), res); | |
623 | } | |
624 | else if (TREE_CODE (x) == INTEGER_CST | |
625 | && tree_int_cst_sgn (x) == 1) | |
626 | /* testsuite/.../ssa-chrec-38.c. */ | |
627 | res = chrec_evaluate (var, chrec, x, 0); | |
628 | else | |
629 | res = chrec_dont_know; | |
630 | break; | |
48e1416a | 631 | |
9e4cd968 | 632 | CASE_CONVERT: |
633 | res = chrec_convert (TREE_TYPE (chrec), | |
634 | chrec_apply (var, TREE_OPERAND (chrec, 0), x), | |
635 | NULL); | |
636 | break; | |
48e1416a | 637 | |
9e4cd968 | 638 | default: |
639 | res = chrec; | |
640 | break; | |
641 | } | |
48e1416a | 642 | |
487a9bc1 | 643 | if (dump_file && (dump_flags & TDF_SCEV)) |
1364018f | 644 | { |
645 | fprintf (dump_file, " (varying_loop = %d\n", var); | |
646 | fprintf (dump_file, ")\n (chrec = "); | |
647 | print_generic_expr (dump_file, chrec, 0); | |
648 | fprintf (dump_file, ")\n (x = "); | |
649 | print_generic_expr (dump_file, x, 0); | |
650 | fprintf (dump_file, ")\n (res = "); | |
651 | print_generic_expr (dump_file, res, 0); | |
652 | fprintf (dump_file, "))\n"); | |
653 | } | |
48e1416a | 654 | |
1364018f | 655 | return res; |
656 | } | |
657 | ||
4ed27c8e | 658 | /* For a given CHREC and an induction variable map IV_MAP that maps |
659 | (loop->num, expr) for every loop number of the current_loops an | |
660 | expression, calls chrec_apply when the expression is not NULL. */ | |
661 | ||
662 | tree | |
f1f41a6c | 663 | chrec_apply_map (tree chrec, vec<tree> iv_map) |
4ed27c8e | 664 | { |
665 | int i; | |
666 | tree expr; | |
667 | ||
f1f41a6c | 668 | FOR_EACH_VEC_ELT (iv_map, i, expr) |
4ed27c8e | 669 | if (expr) |
670 | chrec = chrec_apply (i, chrec, expr); | |
671 | ||
672 | return chrec; | |
673 | } | |
674 | ||
1364018f | 675 | /* Replaces the initial condition in CHREC with INIT_COND. */ |
676 | ||
48e1416a | 677 | tree |
678 | chrec_replace_initial_condition (tree chrec, | |
1364018f | 679 | tree init_cond) |
680 | { | |
681 | if (automatically_generated_chrec_p (chrec)) | |
682 | return chrec; | |
f84a688a | 683 | |
684 | gcc_assert (chrec_type (chrec) == chrec_type (init_cond)); | |
685 | ||
1364018f | 686 | switch (TREE_CODE (chrec)) |
687 | { | |
688 | case POLYNOMIAL_CHREC: | |
48e1416a | 689 | return build_polynomial_chrec |
1364018f | 690 | (CHREC_VARIABLE (chrec), |
691 | chrec_replace_initial_condition (CHREC_LEFT (chrec), init_cond), | |
692 | CHREC_RIGHT (chrec)); | |
48e1416a | 693 | |
1364018f | 694 | default: |
695 | return init_cond; | |
696 | } | |
697 | } | |
698 | ||
699 | /* Returns the initial condition of a given CHREC. */ | |
700 | ||
48e1416a | 701 | tree |
1364018f | 702 | initial_condition (tree chrec) |
703 | { | |
704 | if (automatically_generated_chrec_p (chrec)) | |
705 | return chrec; | |
48e1416a | 706 | |
1364018f | 707 | if (TREE_CODE (chrec) == POLYNOMIAL_CHREC) |
708 | return initial_condition (CHREC_LEFT (chrec)); | |
709 | else | |
710 | return chrec; | |
711 | } | |
712 | ||
713 | /* Returns a univariate function that represents the evolution in | |
714 | LOOP_NUM. Mask the evolution of any other loop. */ | |
715 | ||
48e1416a | 716 | tree |
717 | hide_evolution_in_other_loops_than_loop (tree chrec, | |
1364018f | 718 | unsigned loop_num) |
719 | { | |
41f75a99 | 720 | struct loop *loop = get_loop (cfun, loop_num), *chloop; |
1364018f | 721 | if (automatically_generated_chrec_p (chrec)) |
722 | return chrec; | |
48e1416a | 723 | |
1364018f | 724 | switch (TREE_CODE (chrec)) |
725 | { | |
726 | case POLYNOMIAL_CHREC: | |
3bbbcdff | 727 | chloop = get_chrec_loop (chrec); |
728 | ||
729 | if (chloop == loop) | |
48e1416a | 730 | return build_polynomial_chrec |
731 | (loop_num, | |
732 | hide_evolution_in_other_loops_than_loop (CHREC_LEFT (chrec), | |
733 | loop_num), | |
1364018f | 734 | CHREC_RIGHT (chrec)); |
48e1416a | 735 | |
3bbbcdff | 736 | else if (flow_loop_nested_p (chloop, loop)) |
1364018f | 737 | /* There is no evolution in this loop. */ |
738 | return initial_condition (chrec); | |
48e1416a | 739 | |
1364018f | 740 | else |
3bbbcdff | 741 | { |
742 | gcc_assert (flow_loop_nested_p (loop, chloop)); | |
48e1416a | 743 | return hide_evolution_in_other_loops_than_loop (CHREC_LEFT (chrec), |
3bbbcdff | 744 | loop_num); |
745 | } | |
48e1416a | 746 | |
1364018f | 747 | default: |
748 | return chrec; | |
749 | } | |
750 | } | |
751 | ||
9ce81338 | 752 | /* Returns the evolution part of CHREC in LOOP_NUM when RIGHT is |
753 | true, otherwise returns the initial condition in LOOP_NUM. */ | |
1364018f | 754 | |
48e1416a | 755 | static tree |
756 | chrec_component_in_loop_num (tree chrec, | |
9ce81338 | 757 | unsigned loop_num, |
758 | bool right) | |
1364018f | 759 | { |
9ce81338 | 760 | tree component; |
41f75a99 | 761 | struct loop *loop = get_loop (cfun, loop_num), *chloop; |
9ce81338 | 762 | |
1364018f | 763 | if (automatically_generated_chrec_p (chrec)) |
764 | return chrec; | |
48e1416a | 765 | |
1364018f | 766 | switch (TREE_CODE (chrec)) |
767 | { | |
768 | case POLYNOMIAL_CHREC: | |
3bbbcdff | 769 | chloop = get_chrec_loop (chrec); |
770 | ||
771 | if (chloop == loop) | |
1364018f | 772 | { |
9ce81338 | 773 | if (right) |
774 | component = CHREC_RIGHT (chrec); | |
775 | else | |
776 | component = CHREC_LEFT (chrec); | |
777 | ||
1364018f | 778 | if (TREE_CODE (CHREC_LEFT (chrec)) != POLYNOMIAL_CHREC |
779 | || CHREC_VARIABLE (CHREC_LEFT (chrec)) != CHREC_VARIABLE (chrec)) | |
9ce81338 | 780 | return component; |
48e1416a | 781 | |
1364018f | 782 | else |
783 | return build_polynomial_chrec | |
48e1416a | 784 | (loop_num, |
785 | chrec_component_in_loop_num (CHREC_LEFT (chrec), | |
786 | loop_num, | |
787 | right), | |
9ce81338 | 788 | component); |
1364018f | 789 | } |
48e1416a | 790 | |
3bbbcdff | 791 | else if (flow_loop_nested_p (chloop, loop)) |
1364018f | 792 | /* There is no evolution part in this loop. */ |
793 | return NULL_TREE; | |
48e1416a | 794 | |
1364018f | 795 | else |
3bbbcdff | 796 | { |
797 | gcc_assert (flow_loop_nested_p (loop, chloop)); | |
48e1416a | 798 | return chrec_component_in_loop_num (CHREC_LEFT (chrec), |
799 | loop_num, | |
3bbbcdff | 800 | right); |
801 | } | |
48e1416a | 802 | |
9ce81338 | 803 | default: |
804 | if (right) | |
805 | return NULL_TREE; | |
806 | else | |
807 | return chrec; | |
1364018f | 808 | } |
809 | } | |
810 | ||
9ce81338 | 811 | /* Returns the evolution part in LOOP_NUM. Example: the call |
48e1416a | 812 | evolution_part_in_loop_num ({{0, +, 1}_1, +, 2}_1, 1) returns |
9ce81338 | 813 | {1, +, 2}_1 */ |
814 | ||
48e1416a | 815 | tree |
816 | evolution_part_in_loop_num (tree chrec, | |
9ce81338 | 817 | unsigned loop_num) |
818 | { | |
819 | return chrec_component_in_loop_num (chrec, loop_num, true); | |
820 | } | |
821 | ||
822 | /* Returns the initial condition in LOOP_NUM. Example: the call | |
48e1416a | 823 | initial_condition_in_loop_num ({{0, +, 1}_1, +, 2}_2, 2) returns |
9ce81338 | 824 | {0, +, 1}_1 */ |
825 | ||
48e1416a | 826 | tree |
827 | initial_condition_in_loop_num (tree chrec, | |
9ce81338 | 828 | unsigned loop_num) |
829 | { | |
830 | return chrec_component_in_loop_num (chrec, loop_num, false); | |
831 | } | |
832 | ||
1364018f | 833 | /* Set or reset the evolution of CHREC to NEW_EVOL in loop LOOP_NUM. |
834 | This function is essentially used for setting the evolution to | |
835 | chrec_dont_know, for example after having determined that it is | |
836 | impossible to say how many times a loop will execute. */ | |
837 | ||
48e1416a | 838 | tree |
1364018f | 839 | reset_evolution_in_loop (unsigned loop_num, |
48e1416a | 840 | tree chrec, |
1364018f | 841 | tree new_evol) |
842 | { | |
41f75a99 | 843 | struct loop *loop = get_loop (cfun, loop_num); |
3bbbcdff | 844 | |
0de36bdb | 845 | if (POINTER_TYPE_P (chrec_type (chrec))) |
a845d317 | 846 | gcc_assert (ptrofftype_p (chrec_type (new_evol))); |
0de36bdb | 847 | else |
848 | gcc_assert (chrec_type (chrec) == chrec_type (new_evol)); | |
f84a688a | 849 | |
1364018f | 850 | if (TREE_CODE (chrec) == POLYNOMIAL_CHREC |
3bbbcdff | 851 | && flow_loop_nested_p (loop, get_chrec_loop (chrec))) |
b74b8216 | 852 | { |
853 | tree left = reset_evolution_in_loop (loop_num, CHREC_LEFT (chrec), | |
854 | new_evol); | |
855 | tree right = reset_evolution_in_loop (loop_num, CHREC_RIGHT (chrec), | |
856 | new_evol); | |
857 | return build3 (POLYNOMIAL_CHREC, TREE_TYPE (left), | |
bad12c62 | 858 | CHREC_VAR (chrec), left, right); |
b74b8216 | 859 | } |
860 | ||
1364018f | 861 | while (TREE_CODE (chrec) == POLYNOMIAL_CHREC |
862 | && CHREC_VARIABLE (chrec) == loop_num) | |
863 | chrec = CHREC_LEFT (chrec); | |
48e1416a | 864 | |
1364018f | 865 | return build_polynomial_chrec (loop_num, chrec, new_evol); |
866 | } | |
867 | ||
868 | /* Merges two evolution functions that were found by following two | |
869 | alternate paths of a conditional expression. */ | |
870 | ||
871 | tree | |
48e1416a | 872 | chrec_merge (tree chrec1, |
1364018f | 873 | tree chrec2) |
874 | { | |
875 | if (chrec1 == chrec_dont_know | |
876 | || chrec2 == chrec_dont_know) | |
877 | return chrec_dont_know; | |
878 | ||
48e1416a | 879 | if (chrec1 == chrec_known |
1364018f | 880 | || chrec2 == chrec_known) |
881 | return chrec_known; | |
882 | ||
883 | if (chrec1 == chrec_not_analyzed_yet) | |
884 | return chrec2; | |
885 | if (chrec2 == chrec_not_analyzed_yet) | |
886 | return chrec1; | |
887 | ||
55feb6fa | 888 | if (eq_evolutions_p (chrec1, chrec2)) |
1364018f | 889 | return chrec1; |
890 | ||
891 | return chrec_dont_know; | |
892 | } | |
893 | ||
894 | \f | |
895 | ||
896 | /* Observers. */ | |
897 | ||
898 | /* Helper function for is_multivariate_chrec. */ | |
899 | ||
48e1416a | 900 | static bool |
7ecb5bb2 | 901 | is_multivariate_chrec_rec (const_tree chrec, unsigned int rec_var) |
1364018f | 902 | { |
903 | if (chrec == NULL_TREE) | |
904 | return false; | |
48e1416a | 905 | |
1364018f | 906 | if (TREE_CODE (chrec) == POLYNOMIAL_CHREC) |
907 | { | |
908 | if (CHREC_VARIABLE (chrec) != rec_var) | |
909 | return true; | |
910 | else | |
48e1416a | 911 | return (is_multivariate_chrec_rec (CHREC_LEFT (chrec), rec_var) |
1364018f | 912 | || is_multivariate_chrec_rec (CHREC_RIGHT (chrec), rec_var)); |
913 | } | |
914 | else | |
915 | return false; | |
916 | } | |
917 | ||
918 | /* Determine whether the given chrec is multivariate or not. */ | |
919 | ||
48e1416a | 920 | bool |
7ecb5bb2 | 921 | is_multivariate_chrec (const_tree chrec) |
1364018f | 922 | { |
923 | if (chrec == NULL_TREE) | |
924 | return false; | |
48e1416a | 925 | |
1364018f | 926 | if (TREE_CODE (chrec) == POLYNOMIAL_CHREC) |
48e1416a | 927 | return (is_multivariate_chrec_rec (CHREC_LEFT (chrec), |
1364018f | 928 | CHREC_VARIABLE (chrec)) |
48e1416a | 929 | || is_multivariate_chrec_rec (CHREC_RIGHT (chrec), |
1364018f | 930 | CHREC_VARIABLE (chrec))); |
931 | else | |
932 | return false; | |
933 | } | |
934 | ||
935 | /* Determines whether the chrec contains symbolic names or not. */ | |
936 | ||
48e1416a | 937 | bool |
7ecb5bb2 | 938 | chrec_contains_symbols (const_tree chrec) |
1364018f | 939 | { |
c2f47e15 | 940 | int i, n; |
941 | ||
1364018f | 942 | if (chrec == NULL_TREE) |
943 | return false; | |
48e1416a | 944 | |
1364018f | 945 | if (TREE_CODE (chrec) == SSA_NAME |
946 | || TREE_CODE (chrec) == VAR_DECL | |
947 | || TREE_CODE (chrec) == PARM_DECL | |
948 | || TREE_CODE (chrec) == FUNCTION_DECL | |
949 | || TREE_CODE (chrec) == LABEL_DECL | |
950 | || TREE_CODE (chrec) == RESULT_DECL | |
951 | || TREE_CODE (chrec) == FIELD_DECL) | |
952 | return true; | |
c2f47e15 | 953 | |
954 | n = TREE_OPERAND_LENGTH (chrec); | |
955 | for (i = 0; i < n; i++) | |
956 | if (chrec_contains_symbols (TREE_OPERAND (chrec, i))) | |
957 | return true; | |
958 | return false; | |
1364018f | 959 | } |
960 | ||
961 | /* Determines whether the chrec contains undetermined coefficients. */ | |
962 | ||
48e1416a | 963 | bool |
7ecb5bb2 | 964 | chrec_contains_undetermined (const_tree chrec) |
1364018f | 965 | { |
c2f47e15 | 966 | int i, n; |
967 | ||
c4e91ab3 | 968 | if (chrec == chrec_dont_know) |
1364018f | 969 | return true; |
c2f47e15 | 970 | |
c4e91ab3 | 971 | if (chrec == NULL_TREE) |
972 | return false; | |
973 | ||
c2f47e15 | 974 | n = TREE_OPERAND_LENGTH (chrec); |
975 | for (i = 0; i < n; i++) | |
976 | if (chrec_contains_undetermined (TREE_OPERAND (chrec, i))) | |
977 | return true; | |
978 | return false; | |
1364018f | 979 | } |
980 | ||
a89ef955 | 981 | /* Determines whether the tree EXPR contains chrecs, and increment |
982 | SIZE if it is not a NULL pointer by an estimation of the depth of | |
983 | the tree. */ | |
1364018f | 984 | |
985 | bool | |
7ecb5bb2 | 986 | tree_contains_chrecs (const_tree expr, int *size) |
1364018f | 987 | { |
c2f47e15 | 988 | int i, n; |
989 | ||
1364018f | 990 | if (expr == NULL_TREE) |
991 | return false; | |
a89ef955 | 992 | |
993 | if (size) | |
994 | (*size)++; | |
48e1416a | 995 | |
1364018f | 996 | if (tree_is_chrec (expr)) |
997 | return true; | |
a89ef955 | 998 | |
c2f47e15 | 999 | n = TREE_OPERAND_LENGTH (expr); |
1000 | for (i = 0; i < n; i++) | |
1001 | if (tree_contains_chrecs (TREE_OPERAND (expr, i), size)) | |
1002 | return true; | |
1003 | return false; | |
1364018f | 1004 | } |
1005 | ||
b3786ab3 | 1006 | /* Recursive helper function. */ |
1007 | ||
1008 | static bool | |
1009 | evolution_function_is_invariant_rec_p (tree chrec, int loopnum) | |
1010 | { | |
1011 | if (evolution_function_is_constant_p (chrec)) | |
1012 | return true; | |
1013 | ||
663608f5 | 1014 | if (TREE_CODE (chrec) == SSA_NAME |
1015 | && (loopnum == 0 | |
41f75a99 | 1016 | || expr_invariant_in_loop_p (get_loop (cfun, loopnum), chrec))) |
b3786ab3 | 1017 | return true; |
1018 | ||
87975961 | 1019 | if (TREE_CODE (chrec) == POLYNOMIAL_CHREC) |
1020 | { | |
1021 | if (CHREC_VARIABLE (chrec) == (unsigned) loopnum | |
41f75a99 | 1022 | || flow_loop_nested_p (get_loop (cfun, loopnum), |
1023 | get_chrec_loop (chrec)) | |
87975961 | 1024 | || !evolution_function_is_invariant_rec_p (CHREC_RIGHT (chrec), |
1025 | loopnum) | |
1026 | || !evolution_function_is_invariant_rec_p (CHREC_LEFT (chrec), | |
1027 | loopnum)) | |
1028 | return false; | |
1029 | return true; | |
1030 | } | |
b3786ab3 | 1031 | |
c2f47e15 | 1032 | switch (TREE_OPERAND_LENGTH (chrec)) |
b3786ab3 | 1033 | { |
1034 | case 2: | |
1035 | if (!evolution_function_is_invariant_rec_p (TREE_OPERAND (chrec, 1), | |
1036 | loopnum)) | |
1037 | return false; | |
48e1416a | 1038 | |
b3786ab3 | 1039 | case 1: |
1040 | if (!evolution_function_is_invariant_rec_p (TREE_OPERAND (chrec, 0), | |
1041 | loopnum)) | |
1042 | return false; | |
1043 | return true; | |
1044 | ||
1045 | default: | |
1046 | return false; | |
1047 | } | |
1048 | ||
1049 | return false; | |
1050 | } | |
1051 | ||
1052 | /* Return true if CHREC is invariant in loop LOOPNUM, false otherwise. */ | |
1053 | ||
1054 | bool | |
1055 | evolution_function_is_invariant_p (tree chrec, int loopnum) | |
1056 | { | |
7a3bf727 | 1057 | return evolution_function_is_invariant_rec_p (chrec, loopnum); |
b3786ab3 | 1058 | } |
1059 | ||
1364018f | 1060 | /* Determine whether the given tree is an affine multivariate |
1061 | evolution. */ | |
1062 | ||
48e1416a | 1063 | bool |
7ecb5bb2 | 1064 | evolution_function_is_affine_multivariate_p (const_tree chrec, int loopnum) |
1364018f | 1065 | { |
1066 | if (chrec == NULL_TREE) | |
1067 | return false; | |
48e1416a | 1068 | |
1364018f | 1069 | switch (TREE_CODE (chrec)) |
1070 | { | |
1071 | case POLYNOMIAL_CHREC: | |
9c77efff | 1072 | if (evolution_function_is_invariant_rec_p (CHREC_LEFT (chrec), loopnum)) |
1364018f | 1073 | { |
9c77efff | 1074 | if (evolution_function_is_invariant_rec_p (CHREC_RIGHT (chrec), loopnum)) |
1364018f | 1075 | return true; |
1076 | else | |
1077 | { | |
1078 | if (TREE_CODE (CHREC_RIGHT (chrec)) == POLYNOMIAL_CHREC | |
48e1416a | 1079 | && CHREC_VARIABLE (CHREC_RIGHT (chrec)) |
1364018f | 1080 | != CHREC_VARIABLE (chrec) |
48e1416a | 1081 | && evolution_function_is_affine_multivariate_p |
9c77efff | 1082 | (CHREC_RIGHT (chrec), loopnum)) |
1364018f | 1083 | return true; |
1084 | else | |
1085 | return false; | |
1086 | } | |
1087 | } | |
1088 | else | |
1089 | { | |
9c77efff | 1090 | if (evolution_function_is_invariant_rec_p (CHREC_RIGHT (chrec), loopnum) |
1364018f | 1091 | && TREE_CODE (CHREC_LEFT (chrec)) == POLYNOMIAL_CHREC |
1092 | && CHREC_VARIABLE (CHREC_LEFT (chrec)) != CHREC_VARIABLE (chrec) | |
48e1416a | 1093 | && evolution_function_is_affine_multivariate_p |
9c77efff | 1094 | (CHREC_LEFT (chrec), loopnum)) |
1364018f | 1095 | return true; |
1096 | else | |
1097 | return false; | |
1098 | } | |
48e1416a | 1099 | |
1364018f | 1100 | default: |
1101 | return false; | |
1102 | } | |
1103 | } | |
1104 | ||
48e1416a | 1105 | /* Determine whether the given tree is a function in zero or one |
1364018f | 1106 | variables. */ |
1107 | ||
1108 | bool | |
7ecb5bb2 | 1109 | evolution_function_is_univariate_p (const_tree chrec) |
1364018f | 1110 | { |
1111 | if (chrec == NULL_TREE) | |
1112 | return true; | |
48e1416a | 1113 | |
1364018f | 1114 | switch (TREE_CODE (chrec)) |
1115 | { | |
1116 | case POLYNOMIAL_CHREC: | |
1117 | switch (TREE_CODE (CHREC_LEFT (chrec))) | |
1118 | { | |
1119 | case POLYNOMIAL_CHREC: | |
1120 | if (CHREC_VARIABLE (chrec) != CHREC_VARIABLE (CHREC_LEFT (chrec))) | |
1121 | return false; | |
1122 | if (!evolution_function_is_univariate_p (CHREC_LEFT (chrec))) | |
1123 | return false; | |
1124 | break; | |
48e1416a | 1125 | |
1364018f | 1126 | default: |
08754147 | 1127 | if (tree_contains_chrecs (CHREC_LEFT (chrec), NULL)) |
1128 | return false; | |
1364018f | 1129 | break; |
1130 | } | |
48e1416a | 1131 | |
1364018f | 1132 | switch (TREE_CODE (CHREC_RIGHT (chrec))) |
1133 | { | |
1134 | case POLYNOMIAL_CHREC: | |
1135 | if (CHREC_VARIABLE (chrec) != CHREC_VARIABLE (CHREC_RIGHT (chrec))) | |
1136 | return false; | |
1137 | if (!evolution_function_is_univariate_p (CHREC_RIGHT (chrec))) | |
1138 | return false; | |
1139 | break; | |
48e1416a | 1140 | |
1364018f | 1141 | default: |
08754147 | 1142 | if (tree_contains_chrecs (CHREC_RIGHT (chrec), NULL)) |
1143 | return false; | |
48e1416a | 1144 | break; |
1364018f | 1145 | } |
48e1416a | 1146 | |
1364018f | 1147 | default: |
1148 | return true; | |
1149 | } | |
1150 | } | |
1151 | ||
bc3c8ad4 | 1152 | /* Returns the number of variables of CHREC. Example: the call |
1153 | nb_vars_in_chrec ({{0, +, 1}_5, +, 2}_6) returns 2. */ | |
1154 | ||
48e1416a | 1155 | unsigned |
bc3c8ad4 | 1156 | nb_vars_in_chrec (tree chrec) |
1157 | { | |
1158 | if (chrec == NULL_TREE) | |
1159 | return 0; | |
1160 | ||
1161 | switch (TREE_CODE (chrec)) | |
1162 | { | |
1163 | case POLYNOMIAL_CHREC: | |
48e1416a | 1164 | return 1 + nb_vars_in_chrec |
bc3c8ad4 | 1165 | (initial_condition_in_loop_num (chrec, CHREC_VARIABLE (chrec))); |
1166 | ||
1167 | default: | |
1168 | return 0; | |
1169 | } | |
1170 | } | |
1171 | ||
57e3f39a | 1172 | /* Converts BASE and STEP of affine scev to TYPE. LOOP is the loop whose iv |
1173 | the scev corresponds to. AT_STMT is the statement at that the scev is | |
1174 | evaluated. USE_OVERFLOW_SEMANTICS is true if this function should assume that | |
1175 | the rules for overflow of the given language apply (e.g., that signed | |
1176 | arithmetics in C does not overflow) -- i.e., to use them to avoid unnecessary | |
1177 | tests, but also to enforce that the result follows them. Returns true if the | |
1178 | conversion succeeded, false otherwise. */ | |
1179 | ||
1180 | bool | |
1181 | convert_affine_scev (struct loop *loop, tree type, | |
75a70cf9 | 1182 | tree *base, tree *step, gimple at_stmt, |
57e3f39a | 1183 | bool use_overflow_semantics) |
1184 | { | |
1185 | tree ct = TREE_TYPE (*step); | |
1186 | bool enforce_overflow_semantics; | |
1187 | bool must_check_src_overflow, must_check_rslt_overflow; | |
1188 | tree new_base, new_step; | |
0de36bdb | 1189 | tree step_type = POINTER_TYPE_P (type) ? sizetype : type; |
57e3f39a | 1190 | |
1191 | /* In general, | |
1192 | (TYPE) (BASE + STEP * i) = (TYPE) BASE + (TYPE -- sign extend) STEP * i, | |
1193 | but we must check some assumptions. | |
48e1416a | 1194 | |
57e3f39a | 1195 | 1) If [BASE, +, STEP] wraps, the equation is not valid when precision |
1196 | of CT is smaller than the precision of TYPE. For example, when we | |
1197 | cast unsigned char [254, +, 1] to unsigned, the values on left side | |
1198 | are 254, 255, 0, 1, ..., but those on the right side are | |
1199 | 254, 255, 256, 257, ... | |
1200 | 2) In case that we must also preserve the fact that signed ivs do not | |
1201 | overflow, we must additionally check that the new iv does not wrap. | |
1202 | For example, unsigned char [125, +, 1] casted to signed char could | |
1203 | become a wrapping variable with values 125, 126, 127, -128, -127, ..., | |
1204 | which would confuse optimizers that assume that this does not | |
1205 | happen. */ | |
1206 | must_check_src_overflow = TYPE_PRECISION (ct) < TYPE_PRECISION (type); | |
1207 | ||
1208 | enforce_overflow_semantics = (use_overflow_semantics | |
1209 | && nowrap_type_p (type)); | |
1210 | if (enforce_overflow_semantics) | |
1211 | { | |
1212 | /* We can avoid checking whether the result overflows in the following | |
1213 | cases: | |
1214 | ||
1215 | -- must_check_src_overflow is true, and the range of TYPE is superset | |
1216 | of the range of CT -- i.e., in all cases except if CT signed and | |
1217 | TYPE unsigned. | |
318a3281 | 1218 | -- both CT and TYPE have the same precision and signedness, and we |
1219 | verify instead that the source does not overflow (this may be | |
1220 | easier than verifying it for the result, as we may use the | |
1221 | information about the semantics of overflow in CT). */ | |
57e3f39a | 1222 | if (must_check_src_overflow) |
1223 | { | |
1224 | if (TYPE_UNSIGNED (type) && !TYPE_UNSIGNED (ct)) | |
1225 | must_check_rslt_overflow = true; | |
1226 | else | |
1227 | must_check_rslt_overflow = false; | |
1228 | } | |
1229 | else if (TYPE_UNSIGNED (ct) == TYPE_UNSIGNED (type) | |
1230 | && TYPE_PRECISION (ct) == TYPE_PRECISION (type)) | |
318a3281 | 1231 | { |
1232 | must_check_rslt_overflow = false; | |
1233 | must_check_src_overflow = true; | |
1234 | } | |
57e3f39a | 1235 | else |
1236 | must_check_rslt_overflow = true; | |
1237 | } | |
1238 | else | |
1239 | must_check_rslt_overflow = false; | |
1240 | ||
1241 | if (must_check_src_overflow | |
1242 | && scev_probably_wraps_p (*base, *step, at_stmt, loop, | |
1243 | use_overflow_semantics)) | |
1244 | return false; | |
1245 | ||
5fe66b3c | 1246 | new_base = chrec_convert (type, *base, at_stmt, use_overflow_semantics); |
57e3f39a | 1247 | /* The step must be sign extended, regardless of the signedness |
1248 | of CT and TYPE. This only needs to be handled specially when | |
1249 | CT is unsigned -- to avoid e.g. unsigned char [100, +, 255] | |
1250 | (with values 100, 99, 98, ...) from becoming signed or unsigned | |
48e1416a | 1251 | [100, +, 255] with values 100, 355, ...; the sign-extension is |
57e3f39a | 1252 | performed by default when CT is signed. */ |
1253 | new_step = *step; | |
0de36bdb | 1254 | if (TYPE_PRECISION (step_type) > TYPE_PRECISION (ct) && TYPE_UNSIGNED (ct)) |
0c2b2fc8 | 1255 | { |
1256 | tree signed_ct = build_nonstandard_integer_type (TYPE_PRECISION (ct), 0); | |
5fe66b3c | 1257 | new_step = chrec_convert (signed_ct, new_step, at_stmt, |
1258 | use_overflow_semantics); | |
0c2b2fc8 | 1259 | } |
5fe66b3c | 1260 | new_step = chrec_convert (step_type, new_step, at_stmt, |
1261 | use_overflow_semantics); | |
57e3f39a | 1262 | |
1263 | if (automatically_generated_chrec_p (new_base) | |
1264 | || automatically_generated_chrec_p (new_step)) | |
1265 | return false; | |
1266 | ||
1267 | if (must_check_rslt_overflow | |
1268 | /* Note that in this case we cannot use the fact that signed variables | |
1269 | do not overflow, as this is what we are verifying for the new iv. */ | |
1270 | && scev_probably_wraps_p (new_base, new_step, at_stmt, loop, false)) | |
1271 | return false; | |
1272 | ||
1273 | *base = new_base; | |
1274 | *step = new_step; | |
1275 | return true; | |
1276 | } | |
1364018f | 1277 | \f |
1278 | ||
d3746d81 | 1279 | /* Convert CHREC for the right hand side of a CHREC. |
0de36bdb | 1280 | The increment for a pointer type is always sizetype. */ |
d3746d81 | 1281 | |
48e1416a | 1282 | tree |
75a70cf9 | 1283 | chrec_convert_rhs (tree type, tree chrec, gimple at_stmt) |
0de36bdb | 1284 | { |
1285 | if (POINTER_TYPE_P (type)) | |
d3746d81 | 1286 | type = sizetype; |
1287 | ||
0de36bdb | 1288 | return chrec_convert (type, chrec, at_stmt); |
1289 | } | |
1290 | ||
57e3f39a | 1291 | /* Convert CHREC to TYPE. When the analyzer knows the context in |
1292 | which the CHREC is built, it sets AT_STMT to the statement that | |
1293 | contains the definition of the analyzed variable, otherwise the | |
1294 | conversion is less accurate: the information is used for | |
1295 | determining a more accurate estimation of the number of iterations. | |
1296 | By default AT_STMT could be safely set to NULL_TREE. | |
48e1416a | 1297 | |
57e3f39a | 1298 | USE_OVERFLOW_SEMANTICS is true if this function should assume that |
1299 | the rules for overflow of the given language apply (e.g., that signed | |
1300 | arithmetics in C does not overflow) -- i.e., to use them to avoid unnecessary | |
1301 | tests, but also to enforce that the result follows them. */ | |
1302 | ||
48e1416a | 1303 | static tree |
75a70cf9 | 1304 | chrec_convert_1 (tree type, tree chrec, gimple at_stmt, |
57e3f39a | 1305 | bool use_overflow_semantics) |
1364018f | 1306 | { |
b3786ab3 | 1307 | tree ct, res; |
57e3f39a | 1308 | tree base, step; |
1309 | struct loop *loop; | |
b3786ab3 | 1310 | |
1364018f | 1311 | if (automatically_generated_chrec_p (chrec)) |
1312 | return chrec; | |
48e1416a | 1313 | |
1364018f | 1314 | ct = chrec_type (chrec); |
24a12d10 | 1315 | if (useless_type_conversion_p (type, ct)) |
1364018f | 1316 | return chrec; |
1317 | ||
57e3f39a | 1318 | if (!evolution_function_is_affine_p (chrec)) |
1319 | goto keep_cast; | |
9887dd18 | 1320 | |
17519ba0 | 1321 | loop = get_chrec_loop (chrec); |
57e3f39a | 1322 | base = CHREC_LEFT (chrec); |
1323 | step = CHREC_RIGHT (chrec); | |
b3786ab3 | 1324 | |
57e3f39a | 1325 | if (convert_affine_scev (loop, type, &base, &step, at_stmt, |
1326 | use_overflow_semantics)) | |
1327 | return build_polynomial_chrec (loop->num, base, step); | |
1364018f | 1328 | |
57e3f39a | 1329 | /* If we cannot propagate the cast inside the chrec, just keep the cast. */ |
1330 | keep_cast: | |
b5a4c072 | 1331 | /* Fold will not canonicalize (long)(i - 1) to (long)i - 1 because that |
1332 | may be more expensive. We do want to perform this optimization here | |
1333 | though for canonicalization reasons. */ | |
1334 | if (use_overflow_semantics | |
1335 | && (TREE_CODE (chrec) == PLUS_EXPR | |
1336 | || TREE_CODE (chrec) == MINUS_EXPR) | |
04bdcc76 | 1337 | && TREE_CODE (type) == INTEGER_TYPE |
1338 | && TREE_CODE (ct) == INTEGER_TYPE | |
b5a4c072 | 1339 | && TYPE_PRECISION (type) > TYPE_PRECISION (ct) |
1340 | && TYPE_OVERFLOW_UNDEFINED (ct)) | |
1341 | res = fold_build2 (TREE_CODE (chrec), type, | |
1342 | fold_convert (type, TREE_OPERAND (chrec, 0)), | |
1343 | fold_convert (type, TREE_OPERAND (chrec, 1))); | |
3ef23449 | 1344 | /* Similar perform the trick that (signed char)((int)x + 2) can be |
1345 | narrowed to (signed char)((unsigned char)x + 2). */ | |
1346 | else if (use_overflow_semantics | |
1347 | && TREE_CODE (chrec) == POLYNOMIAL_CHREC | |
1348 | && TREE_CODE (ct) == INTEGER_TYPE | |
1349 | && TREE_CODE (type) == INTEGER_TYPE | |
1350 | && TYPE_OVERFLOW_UNDEFINED (type) | |
1351 | && TYPE_PRECISION (type) < TYPE_PRECISION (ct)) | |
1352 | { | |
1353 | tree utype = unsigned_type_for (type); | |
1354 | res = build_polynomial_chrec (CHREC_VARIABLE (chrec), | |
1355 | fold_convert (utype, | |
1356 | CHREC_LEFT (chrec)), | |
1357 | fold_convert (utype, | |
1358 | CHREC_RIGHT (chrec))); | |
1359 | res = chrec_convert_1 (type, res, at_stmt, use_overflow_semantics); | |
1360 | } | |
b5a4c072 | 1361 | else |
1362 | res = fold_convert (type, chrec); | |
562c4a0b | 1363 | |
b3786ab3 | 1364 | /* Don't propagate overflows. */ |
1365 | if (CONSTANT_CLASS_P (res)) | |
f96bd2bf | 1366 | TREE_OVERFLOW (res) = 0; |
b3786ab3 | 1367 | |
1368 | /* But reject constants that don't fit in their type after conversion. | |
1369 | This can happen if TYPE_MIN_VALUE or TYPE_MAX_VALUE are not the | |
1370 | natural values associated with TYPE_PRECISION and TYPE_UNSIGNED, | |
1371 | and can cause problems later when computing niters of loops. Note | |
1372 | that we don't do the check before converting because we don't want | |
1373 | to reject conversions of negative chrecs to unsigned types. */ | |
1374 | if (TREE_CODE (res) == INTEGER_CST | |
1375 | && TREE_CODE (type) == INTEGER_TYPE | |
1376 | && !int_fits_type_p (res, type)) | |
1377 | res = chrec_dont_know; | |
1378 | ||
1379 | return res; | |
1364018f | 1380 | } |
1381 | ||
5fe66b3c | 1382 | /* Convert CHREC to TYPE. When the analyzer knows the context in |
1383 | which the CHREC is built, it sets AT_STMT to the statement that | |
1384 | contains the definition of the analyzed variable, otherwise the | |
1385 | conversion is less accurate: the information is used for | |
1386 | determining a more accurate estimation of the number of iterations. | |
1387 | By default AT_STMT could be safely set to NULL_TREE. | |
1388 | ||
1389 | The following rule is always true: TREE_TYPE (chrec) == | |
1390 | TREE_TYPE (CHREC_LEFT (chrec)) == TREE_TYPE (CHREC_RIGHT (chrec)). | |
1391 | An example of what could happen when adding two chrecs and the type | |
1392 | of the CHREC_RIGHT is different than CHREC_LEFT is: | |
1393 | ||
1394 | {(uint) 0, +, (uchar) 10} + | |
1395 | {(uint) 0, +, (uchar) 250} | |
1396 | ||
1397 | that would produce a wrong result if CHREC_RIGHT is not (uint): | |
1398 | ||
1399 | {(uint) 0, +, (uchar) 4} | |
1400 | ||
1401 | instead of | |
1402 | ||
1403 | {(uint) 0, +, (uint) 260} | |
1404 | ||
1405 | USE_OVERFLOW_SEMANTICS is true if this function should assume that | |
1406 | the rules for overflow of the given language apply (e.g., that signed | |
1407 | arithmetics in C does not overflow) -- i.e., to use them to avoid unnecessary | |
1408 | tests, but also to enforce that the result follows them. */ | |
1409 | ||
1410 | tree | |
1411 | chrec_convert (tree type, tree chrec, gimple at_stmt, | |
1412 | bool use_overflow_semantics) | |
1413 | { | |
1414 | return chrec_convert_1 (type, chrec, at_stmt, use_overflow_semantics); | |
1415 | } | |
1416 | ||
88d02c9e | 1417 | /* Convert CHREC to TYPE, without regard to signed overflows. Returns the new |
1418 | chrec if something else than what chrec_convert would do happens, NULL_TREE | |
5fe66b3c | 1419 | otherwise. This function set TRUE to variable pointed by FOLD_CONVERSIONS |
1420 | if the result chrec may overflow. */ | |
88d02c9e | 1421 | |
1422 | tree | |
5fe66b3c | 1423 | chrec_convert_aggressive (tree type, tree chrec, bool *fold_conversions) |
88d02c9e | 1424 | { |
0de36bdb | 1425 | tree inner_type, left, right, lc, rc, rtype; |
88d02c9e | 1426 | |
5fe66b3c | 1427 | gcc_assert (fold_conversions != NULL); |
1428 | ||
88d02c9e | 1429 | if (automatically_generated_chrec_p (chrec) |
1430 | || TREE_CODE (chrec) != POLYNOMIAL_CHREC) | |
1431 | return NULL_TREE; | |
1432 | ||
1433 | inner_type = TREE_TYPE (chrec); | |
1434 | if (TYPE_PRECISION (type) > TYPE_PRECISION (inner_type)) | |
1435 | return NULL_TREE; | |
1436 | ||
5fe66b3c | 1437 | if (useless_type_conversion_p (type, inner_type)) |
1438 | return NULL_TREE; | |
1439 | ||
1440 | if (!*fold_conversions && evolution_function_is_affine_p (chrec)) | |
1441 | { | |
1442 | tree base, step; | |
1443 | struct loop *loop; | |
1444 | ||
1445 | loop = get_chrec_loop (chrec); | |
1446 | base = CHREC_LEFT (chrec); | |
1447 | step = CHREC_RIGHT (chrec); | |
1448 | if (convert_affine_scev (loop, type, &base, &step, NULL, true)) | |
1449 | return build_polynomial_chrec (loop->num, base, step); | |
1450 | } | |
0de36bdb | 1451 | rtype = POINTER_TYPE_P (type) ? sizetype : type; |
1452 | ||
88d02c9e | 1453 | left = CHREC_LEFT (chrec); |
1454 | right = CHREC_RIGHT (chrec); | |
5fe66b3c | 1455 | lc = chrec_convert_aggressive (type, left, fold_conversions); |
88d02c9e | 1456 | if (!lc) |
75a70cf9 | 1457 | lc = chrec_convert (type, left, NULL); |
5fe66b3c | 1458 | rc = chrec_convert_aggressive (rtype, right, fold_conversions); |
88d02c9e | 1459 | if (!rc) |
75a70cf9 | 1460 | rc = chrec_convert (rtype, right, NULL); |
48e1416a | 1461 | |
5fe66b3c | 1462 | *fold_conversions = true; |
1463 | ||
88d02c9e | 1464 | return build_polynomial_chrec (CHREC_VARIABLE (chrec), lc, rc); |
1465 | } | |
1466 | ||
6b421feb | 1467 | /* Returns true when CHREC0 == CHREC1. */ |
1468 | ||
48e1416a | 1469 | bool |
7ecb5bb2 | 1470 | eq_evolutions_p (const_tree chrec0, const_tree chrec1) |
6b421feb | 1471 | { |
1472 | if (chrec0 == NULL_TREE | |
1473 | || chrec1 == NULL_TREE | |
1474 | || TREE_CODE (chrec0) != TREE_CODE (chrec1)) | |
1475 | return false; | |
1476 | ||
1477 | if (chrec0 == chrec1) | |
1478 | return true; | |
1479 | ||
1480 | switch (TREE_CODE (chrec0)) | |
1481 | { | |
1482 | case INTEGER_CST: | |
f84a688a | 1483 | return operand_equal_p (chrec0, chrec1, 0); |
1484 | ||
6b421feb | 1485 | case POLYNOMIAL_CHREC: |
1486 | return (CHREC_VARIABLE (chrec0) == CHREC_VARIABLE (chrec1) | |
1487 | && eq_evolutions_p (CHREC_LEFT (chrec0), CHREC_LEFT (chrec1)) | |
1488 | && eq_evolutions_p (CHREC_RIGHT (chrec0), CHREC_RIGHT (chrec1))); | |
99c68579 | 1489 | |
1490 | case PLUS_EXPR: | |
1491 | case MULT_EXPR: | |
1492 | case MINUS_EXPR: | |
1493 | case POINTER_PLUS_EXPR: | |
1494 | return eq_evolutions_p (TREE_OPERAND (chrec0, 0), | |
1495 | TREE_OPERAND (chrec1, 0)) | |
1496 | && eq_evolutions_p (TREE_OPERAND (chrec0, 1), | |
1497 | TREE_OPERAND (chrec1, 1)); | |
1498 | ||
6b421feb | 1499 | default: |
1500 | return false; | |
48e1416a | 1501 | } |
6b421feb | 1502 | } |
1503 | ||
57e3f39a | 1504 | /* Returns EV_GROWS if CHREC grows (assuming that it does not overflow), |
1505 | EV_DECREASES if it decreases, and EV_UNKNOWN if we cannot determine | |
1506 | which of these cases happens. */ | |
1507 | ||
1508 | enum ev_direction | |
7ecb5bb2 | 1509 | scev_direction (const_tree chrec) |
57e3f39a | 1510 | { |
7ecb5bb2 | 1511 | const_tree step; |
57e3f39a | 1512 | |
1513 | if (!evolution_function_is_affine_p (chrec)) | |
1514 | return EV_DIR_UNKNOWN; | |
1515 | ||
1516 | step = CHREC_RIGHT (chrec); | |
1517 | if (TREE_CODE (step) != INTEGER_CST) | |
1518 | return EV_DIR_UNKNOWN; | |
1519 | ||
1520 | if (tree_int_cst_sign_bit (step)) | |
1521 | return EV_DIR_DECREASES; | |
1522 | else | |
1523 | return EV_DIR_GROWS; | |
1524 | } | |
255b6be7 | 1525 | |
1526 | /* Iterates over all the components of SCEV, and calls CBCK. */ | |
1527 | ||
1528 | void | |
1529 | for_each_scev_op (tree *scev, bool (*cbck) (tree *, void *), void *data) | |
1530 | { | |
1531 | switch (TREE_CODE_LENGTH (TREE_CODE (*scev))) | |
1532 | { | |
1533 | case 3: | |
1534 | for_each_scev_op (&TREE_OPERAND (*scev, 2), cbck, data); | |
1535 | ||
1536 | case 2: | |
1537 | for_each_scev_op (&TREE_OPERAND (*scev, 1), cbck, data); | |
7ed7512f | 1538 | |
255b6be7 | 1539 | case 1: |
1540 | for_each_scev_op (&TREE_OPERAND (*scev, 0), cbck, data); | |
1541 | ||
1542 | default: | |
1543 | cbck (scev, data); | |
1544 | break; | |
1545 | } | |
1546 | } | |
1547 | ||
145bdf6a | 1548 | /* Returns true when the operation can be part of a linear |
1549 | expression. */ | |
1550 | ||
1551 | static inline bool | |
1552 | operator_is_linear (tree scev) | |
1553 | { | |
1554 | switch (TREE_CODE (scev)) | |
1555 | { | |
1556 | case INTEGER_CST: | |
1557 | case POLYNOMIAL_CHREC: | |
1558 | case PLUS_EXPR: | |
1559 | case POINTER_PLUS_EXPR: | |
1560 | case MULT_EXPR: | |
1561 | case MINUS_EXPR: | |
1562 | case NEGATE_EXPR: | |
1563 | case SSA_NAME: | |
1564 | case NON_LVALUE_EXPR: | |
7ed7512f | 1565 | case BIT_NOT_EXPR: |
145bdf6a | 1566 | CASE_CONVERT: |
1567 | return true; | |
1568 | ||
1569 | default: | |
1570 | return false; | |
1571 | } | |
1572 | } | |
1573 | ||
1574 | /* Return true when SCEV is a linear expression. Linear expressions | |
1575 | can contain additions, substractions and multiplications. | |
1576 | Multiplications are restricted to constant scaling: "cst * x". */ | |
1577 | ||
1578 | bool | |
1579 | scev_is_linear_expression (tree scev) | |
1580 | { | |
1581 | if (scev == NULL | |
1582 | || !operator_is_linear (scev)) | |
1583 | return false; | |
1584 | ||
1585 | if (TREE_CODE (scev) == MULT_EXPR) | |
1586 | return !(tree_contains_chrecs (TREE_OPERAND (scev, 0), NULL) | |
1587 | && tree_contains_chrecs (TREE_OPERAND (scev, 1), NULL)); | |
1588 | ||
7ed7512f | 1589 | if (TREE_CODE (scev) == POLYNOMIAL_CHREC |
1590 | && !evolution_function_is_affine_multivariate_p (scev, CHREC_VARIABLE (scev))) | |
1591 | return false; | |
1592 | ||
145bdf6a | 1593 | switch (TREE_CODE_LENGTH (TREE_CODE (scev))) |
1594 | { | |
1595 | case 3: | |
1596 | return scev_is_linear_expression (TREE_OPERAND (scev, 0)) | |
1597 | && scev_is_linear_expression (TREE_OPERAND (scev, 1)) | |
1598 | && scev_is_linear_expression (TREE_OPERAND (scev, 2)); | |
1599 | ||
1600 | case 2: | |
1601 | return scev_is_linear_expression (TREE_OPERAND (scev, 0)) | |
1602 | && scev_is_linear_expression (TREE_OPERAND (scev, 1)); | |
7ed7512f | 1603 | |
145bdf6a | 1604 | case 1: |
1605 | return scev_is_linear_expression (TREE_OPERAND (scev, 0)); | |
1606 | ||
1607 | case 0: | |
1608 | return true; | |
1609 | ||
1610 | default: | |
1611 | return false; | |
1612 | } | |
1613 | } | |
e44bcf83 | 1614 | |
1615 | /* Determines whether the expression CHREC contains only interger consts | |
1616 | in the right parts. */ | |
1617 | ||
1618 | bool | |
1619 | evolution_function_right_is_integer_cst (const_tree chrec) | |
1620 | { | |
1621 | if (chrec == NULL_TREE) | |
1622 | return false; | |
1623 | ||
1624 | switch (TREE_CODE (chrec)) | |
1625 | { | |
1626 | case INTEGER_CST: | |
1627 | return true; | |
1628 | ||
1629 | case POLYNOMIAL_CHREC: | |
c4ccbe87 | 1630 | return TREE_CODE (CHREC_RIGHT (chrec)) == INTEGER_CST |
1631 | && (TREE_CODE (CHREC_LEFT (chrec)) != POLYNOMIAL_CHREC | |
1632 | || evolution_function_right_is_integer_cst (CHREC_LEFT (chrec))); | |
e44bcf83 | 1633 | |
c4ccbe87 | 1634 | CASE_CONVERT: |
1635 | return evolution_function_right_is_integer_cst (TREE_OPERAND (chrec, 0)); | |
e44bcf83 | 1636 | |
1637 | default: | |
1638 | return false; | |
1639 | } | |
1640 | } |