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1364018f | 1 | /* Chains of recurrences. |
f1717362 | 2 | Copyright (C) 2003-2016 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" | |
9ef16211 | 29 | #include "backend.h" |
7c29e30e | 30 | #include "tree.h" |
bc61cadb | 31 | #include "gimple-expr.h" |
7c29e30e | 32 | #include "tree-pretty-print.h" |
7c29e30e | 33 | #include "fold-const.h" |
34 | #include "cfgloop.h" | |
05d9c18a | 35 | #include "tree-ssa-loop-ivopts.h" |
36 | #include "tree-ssa-loop-niter.h" | |
1364018f | 37 | #include "tree-chrec.h" |
b9ed1410 | 38 | #include "dumpfile.h" |
a89ef955 | 39 | #include "params.h" |
9887dd18 | 40 | #include "tree-scalar-evolution.h" |
1364018f | 41 | |
1364018f | 42 | /* Extended folder for chrecs. */ |
43 | ||
44 | /* Determines whether CST is not a constant evolution. */ | |
45 | ||
46 | static inline bool | |
7ecb5bb2 | 47 | is_not_constant_evolution (const_tree cst) |
1364018f | 48 | { |
49 | return (TREE_CODE (cst) == POLYNOMIAL_CHREC); | |
50 | } | |
51 | ||
52 | /* Fold CODE for a polynomial function and a constant. */ | |
53 | ||
48e1416a | 54 | static inline tree |
55 | chrec_fold_poly_cst (enum tree_code code, | |
56 | tree type, | |
57 | tree poly, | |
1364018f | 58 | tree cst) |
59 | { | |
8c0963c4 | 60 | gcc_assert (poly); |
61 | gcc_assert (cst); | |
62 | gcc_assert (TREE_CODE (poly) == POLYNOMIAL_CHREC); | |
24a12d10 | 63 | gcc_checking_assert (!is_not_constant_evolution (cst)); |
64 | gcc_checking_assert (useless_type_conversion_p (type, chrec_type (poly))); | |
f84a688a | 65 | |
1364018f | 66 | switch (code) |
67 | { | |
68 | case PLUS_EXPR: | |
48e1416a | 69 | return build_polynomial_chrec |
70 | (CHREC_VARIABLE (poly), | |
1364018f | 71 | chrec_fold_plus (type, CHREC_LEFT (poly), cst), |
72 | CHREC_RIGHT (poly)); | |
48e1416a | 73 | |
1364018f | 74 | case MINUS_EXPR: |
48e1416a | 75 | return build_polynomial_chrec |
76 | (CHREC_VARIABLE (poly), | |
1364018f | 77 | chrec_fold_minus (type, CHREC_LEFT (poly), cst), |
78 | CHREC_RIGHT (poly)); | |
48e1416a | 79 | |
1364018f | 80 | case MULT_EXPR: |
48e1416a | 81 | return build_polynomial_chrec |
82 | (CHREC_VARIABLE (poly), | |
1364018f | 83 | chrec_fold_multiply (type, CHREC_LEFT (poly), cst), |
84 | chrec_fold_multiply (type, CHREC_RIGHT (poly), cst)); | |
48e1416a | 85 | |
1364018f | 86 | default: |
87 | return chrec_dont_know; | |
88 | } | |
89 | } | |
90 | ||
91 | /* Fold the addition of two polynomial functions. */ | |
92 | ||
48e1416a | 93 | static inline tree |
94 | chrec_fold_plus_poly_poly (enum tree_code code, | |
95 | tree type, | |
96 | tree poly0, | |
1364018f | 97 | tree poly1) |
98 | { | |
99 | tree left, right; | |
3bbbcdff | 100 | struct loop *loop0 = get_chrec_loop (poly0); |
101 | struct loop *loop1 = get_chrec_loop (poly1); | |
a845d317 | 102 | tree rtype = code == POINTER_PLUS_EXPR ? chrec_type (poly1) : type; |
8c0963c4 | 103 | |
104 | gcc_assert (poly0); | |
105 | gcc_assert (poly1); | |
106 | gcc_assert (TREE_CODE (poly0) == POLYNOMIAL_CHREC); | |
107 | gcc_assert (TREE_CODE (poly1) == POLYNOMIAL_CHREC); | |
0de36bdb | 108 | if (POINTER_TYPE_P (chrec_type (poly0))) |
24a12d10 | 109 | gcc_checking_assert (ptrofftype_p (chrec_type (poly1)) |
110 | && useless_type_conversion_p (type, chrec_type (poly0))); | |
0de36bdb | 111 | else |
24a12d10 | 112 | gcc_checking_assert (useless_type_conversion_p (type, chrec_type (poly0)) |
113 | && useless_type_conversion_p (type, chrec_type (poly1))); | |
48e1416a | 114 | |
1364018f | 115 | /* |
116 | {a, +, b}_1 + {c, +, d}_2 -> {{a, +, b}_1 + c, +, d}_2, | |
117 | {a, +, b}_2 + {c, +, d}_1 -> {{c, +, d}_1 + a, +, b}_2, | |
118 | {a, +, b}_x + {c, +, d}_x -> {a+c, +, b+d}_x. */ | |
3bbbcdff | 119 | if (flow_loop_nested_p (loop0, loop1)) |
1364018f | 120 | { |
0de36bdb | 121 | if (code == PLUS_EXPR || code == POINTER_PLUS_EXPR) |
48e1416a | 122 | return build_polynomial_chrec |
123 | (CHREC_VARIABLE (poly1), | |
1364018f | 124 | chrec_fold_plus (type, poly0, CHREC_LEFT (poly1)), |
125 | CHREC_RIGHT (poly1)); | |
126 | else | |
48e1416a | 127 | return build_polynomial_chrec |
128 | (CHREC_VARIABLE (poly1), | |
1364018f | 129 | chrec_fold_minus (type, poly0, CHREC_LEFT (poly1)), |
48e1416a | 130 | chrec_fold_multiply (type, CHREC_RIGHT (poly1), |
eb105b17 | 131 | SCALAR_FLOAT_TYPE_P (type) |
132 | ? build_real (type, dconstm1) | |
133 | : build_int_cst_type (type, -1))); | |
1364018f | 134 | } |
48e1416a | 135 | |
3bbbcdff | 136 | if (flow_loop_nested_p (loop1, loop0)) |
1364018f | 137 | { |
0de36bdb | 138 | if (code == PLUS_EXPR || code == POINTER_PLUS_EXPR) |
48e1416a | 139 | return build_polynomial_chrec |
140 | (CHREC_VARIABLE (poly0), | |
1364018f | 141 | chrec_fold_plus (type, CHREC_LEFT (poly0), poly1), |
142 | CHREC_RIGHT (poly0)); | |
143 | else | |
48e1416a | 144 | return build_polynomial_chrec |
145 | (CHREC_VARIABLE (poly0), | |
1364018f | 146 | chrec_fold_minus (type, CHREC_LEFT (poly0), poly1), |
147 | CHREC_RIGHT (poly0)); | |
148 | } | |
48e1416a | 149 | |
3bbbcdff | 150 | /* This function should never be called for chrecs of loops that |
151 | do not belong to the same loop nest. */ | |
152 | gcc_assert (loop0 == loop1); | |
153 | ||
0de36bdb | 154 | if (code == PLUS_EXPR || code == POINTER_PLUS_EXPR) |
1364018f | 155 | { |
48e1416a | 156 | left = chrec_fold_plus |
1364018f | 157 | (type, CHREC_LEFT (poly0), CHREC_LEFT (poly1)); |
48e1416a | 158 | right = chrec_fold_plus |
0de36bdb | 159 | (rtype, CHREC_RIGHT (poly0), CHREC_RIGHT (poly1)); |
1364018f | 160 | } |
161 | else | |
162 | { | |
48e1416a | 163 | left = chrec_fold_minus |
1364018f | 164 | (type, CHREC_LEFT (poly0), CHREC_LEFT (poly1)); |
48e1416a | 165 | right = chrec_fold_minus |
1364018f | 166 | (type, CHREC_RIGHT (poly0), CHREC_RIGHT (poly1)); |
167 | } | |
168 | ||
169 | if (chrec_zerop (right)) | |
170 | return left; | |
171 | else | |
48e1416a | 172 | return build_polynomial_chrec |
173 | (CHREC_VARIABLE (poly0), left, right); | |
1364018f | 174 | } |
175 | ||
176 | \f | |
177 | ||
178 | /* Fold the multiplication of two polynomial functions. */ | |
179 | ||
48e1416a | 180 | static inline tree |
181 | chrec_fold_multiply_poly_poly (tree type, | |
182 | tree poly0, | |
1364018f | 183 | tree poly1) |
184 | { | |
20a25e6c | 185 | tree t0, t1, t2; |
186 | int var; | |
3bbbcdff | 187 | struct loop *loop0 = get_chrec_loop (poly0); |
188 | struct loop *loop1 = get_chrec_loop (poly1); | |
20a25e6c | 189 | |
8c0963c4 | 190 | gcc_assert (poly0); |
191 | gcc_assert (poly1); | |
192 | gcc_assert (TREE_CODE (poly0) == POLYNOMIAL_CHREC); | |
193 | gcc_assert (TREE_CODE (poly1) == POLYNOMIAL_CHREC); | |
24a12d10 | 194 | gcc_checking_assert (useless_type_conversion_p (type, chrec_type (poly0)) |
195 | && useless_type_conversion_p (type, chrec_type (poly1))); | |
48e1416a | 196 | |
1364018f | 197 | /* {a, +, b}_1 * {c, +, d}_2 -> {c*{a, +, b}_1, +, d}_2, |
198 | {a, +, b}_2 * {c, +, d}_1 -> {a*{c, +, d}_1, +, b}_2, | |
199 | {a, +, b}_x * {c, +, d}_x -> {a*c, +, a*d + b*c + b*d, +, 2*b*d}_x. */ | |
3bbbcdff | 200 | if (flow_loop_nested_p (loop0, loop1)) |
1364018f | 201 | /* poly0 is a constant wrt. poly1. */ |
48e1416a | 202 | return build_polynomial_chrec |
203 | (CHREC_VARIABLE (poly1), | |
1364018f | 204 | chrec_fold_multiply (type, CHREC_LEFT (poly1), poly0), |
205 | CHREC_RIGHT (poly1)); | |
48e1416a | 206 | |
3bbbcdff | 207 | if (flow_loop_nested_p (loop1, loop0)) |
1364018f | 208 | /* poly1 is a constant wrt. poly0. */ |
48e1416a | 209 | return build_polynomial_chrec |
210 | (CHREC_VARIABLE (poly0), | |
1364018f | 211 | chrec_fold_multiply (type, CHREC_LEFT (poly0), poly1), |
212 | CHREC_RIGHT (poly0)); | |
48e1416a | 213 | |
3bbbcdff | 214 | gcc_assert (loop0 == loop1); |
215 | ||
1364018f | 216 | /* poly0 and poly1 are two polynomials in the same variable, |
217 | {a, +, b}_x * {c, +, d}_x -> {a*c, +, a*d + b*c + b*d, +, 2*b*d}_x. */ | |
48e1416a | 218 | |
20a25e6c | 219 | /* "a*c". */ |
220 | t0 = chrec_fold_multiply (type, CHREC_LEFT (poly0), CHREC_LEFT (poly1)); | |
221 | ||
0f0057aa | 222 | /* "a*d + b*c". */ |
20a25e6c | 223 | t1 = chrec_fold_multiply (type, CHREC_LEFT (poly0), CHREC_RIGHT (poly1)); |
224 | t1 = chrec_fold_plus (type, t1, chrec_fold_multiply (type, | |
225 | CHREC_RIGHT (poly0), | |
226 | CHREC_LEFT (poly1))); | |
0f0057aa | 227 | /* "b*d". */ |
20a25e6c | 228 | t2 = chrec_fold_multiply (type, CHREC_RIGHT (poly0), CHREC_RIGHT (poly1)); |
0f0057aa | 229 | /* "a*d + b*c + b*d". */ |
230 | t1 = chrec_fold_plus (type, t1, t2); | |
231 | /* "2*b*d". */ | |
eb105b17 | 232 | t2 = chrec_fold_multiply (type, SCALAR_FLOAT_TYPE_P (type) |
233 | ? build_real (type, dconst2) | |
05db596e | 234 | : build_int_cst (type, 2), t2); |
20a25e6c | 235 | |
236 | var = CHREC_VARIABLE (poly0); | |
237 | return build_polynomial_chrec (var, t0, | |
238 | build_polynomial_chrec (var, t1, t2)); | |
1364018f | 239 | } |
240 | ||
241 | /* When the operands are automatically_generated_chrec_p, the fold has | |
242 | to respect the semantics of the operands. */ | |
243 | ||
48e1416a | 244 | static inline tree |
245 | chrec_fold_automatically_generated_operands (tree op0, | |
1364018f | 246 | tree op1) |
247 | { | |
248 | if (op0 == chrec_dont_know | |
249 | || op1 == chrec_dont_know) | |
250 | return chrec_dont_know; | |
48e1416a | 251 | |
1364018f | 252 | if (op0 == chrec_known |
253 | || op1 == chrec_known) | |
254 | return chrec_known; | |
48e1416a | 255 | |
1364018f | 256 | if (op0 == chrec_not_analyzed_yet |
257 | || op1 == chrec_not_analyzed_yet) | |
258 | return chrec_not_analyzed_yet; | |
48e1416a | 259 | |
fbf0afd1 | 260 | /* The default case produces a safe result. */ |
1364018f | 261 | return chrec_dont_know; |
262 | } | |
263 | ||
264 | /* Fold the addition of two chrecs. */ | |
265 | ||
266 | static tree | |
48e1416a | 267 | chrec_fold_plus_1 (enum tree_code code, tree type, |
f84a688a | 268 | tree op0, tree op1) |
1364018f | 269 | { |
270 | if (automatically_generated_chrec_p (op0) | |
271 | || automatically_generated_chrec_p (op1)) | |
272 | return chrec_fold_automatically_generated_operands (op0, op1); | |
48e1416a | 273 | |
1364018f | 274 | switch (TREE_CODE (op0)) |
275 | { | |
276 | case POLYNOMIAL_CHREC: | |
32e31826 | 277 | gcc_checking_assert |
278 | (!chrec_contains_symbols_defined_in_loop (op0, CHREC_VARIABLE (op0))); | |
1364018f | 279 | switch (TREE_CODE (op1)) |
280 | { | |
281 | case POLYNOMIAL_CHREC: | |
32e31826 | 282 | gcc_checking_assert |
283 | (!chrec_contains_symbols_defined_in_loop (op1, | |
284 | CHREC_VARIABLE (op1))); | |
1364018f | 285 | return chrec_fold_plus_poly_poly (code, type, op0, op1); |
286 | ||
f2a8ffd0 | 287 | CASE_CONVERT: |
288 | if (tree_contains_chrecs (op1, NULL)) | |
289 | return chrec_dont_know; | |
290 | ||
1364018f | 291 | default: |
0de36bdb | 292 | if (code == PLUS_EXPR || code == POINTER_PLUS_EXPR) |
48e1416a | 293 | return build_polynomial_chrec |
294 | (CHREC_VARIABLE (op0), | |
1364018f | 295 | chrec_fold_plus (type, CHREC_LEFT (op0), op1), |
296 | CHREC_RIGHT (op0)); | |
297 | else | |
48e1416a | 298 | return build_polynomial_chrec |
299 | (CHREC_VARIABLE (op0), | |
1364018f | 300 | chrec_fold_minus (type, CHREC_LEFT (op0), op1), |
301 | CHREC_RIGHT (op0)); | |
302 | } | |
303 | ||
f2a8ffd0 | 304 | CASE_CONVERT: |
305 | if (tree_contains_chrecs (op0, NULL)) | |
306 | return chrec_dont_know; | |
307 | ||
1364018f | 308 | default: |
309 | switch (TREE_CODE (op1)) | |
310 | { | |
311 | case POLYNOMIAL_CHREC: | |
32e31826 | 312 | gcc_checking_assert |
313 | (!chrec_contains_symbols_defined_in_loop (op1, | |
314 | CHREC_VARIABLE (op1))); | |
0de36bdb | 315 | if (code == PLUS_EXPR || code == POINTER_PLUS_EXPR) |
48e1416a | 316 | return build_polynomial_chrec |
317 | (CHREC_VARIABLE (op1), | |
1364018f | 318 | chrec_fold_plus (type, op0, CHREC_LEFT (op1)), |
319 | CHREC_RIGHT (op1)); | |
320 | else | |
48e1416a | 321 | return build_polynomial_chrec |
322 | (CHREC_VARIABLE (op1), | |
1364018f | 323 | chrec_fold_minus (type, op0, CHREC_LEFT (op1)), |
48e1416a | 324 | chrec_fold_multiply (type, CHREC_RIGHT (op1), |
eb105b17 | 325 | SCALAR_FLOAT_TYPE_P (type) |
326 | ? build_real (type, dconstm1) | |
327 | : build_int_cst_type (type, -1))); | |
1364018f | 328 | |
f2a8ffd0 | 329 | CASE_CONVERT: |
330 | if (tree_contains_chrecs (op1, NULL)) | |
331 | return chrec_dont_know; | |
332 | ||
1364018f | 333 | default: |
a89ef955 | 334 | { |
335 | int size = 0; | |
336 | if ((tree_contains_chrecs (op0, &size) | |
337 | || tree_contains_chrecs (op1, &size)) | |
338 | && size < PARAM_VALUE (PARAM_SCEV_MAX_EXPR_SIZE)) | |
339 | return build2 (code, type, op0, op1); | |
340 | else if (size < PARAM_VALUE (PARAM_SCEV_MAX_EXPR_SIZE)) | |
a0553bff | 341 | { |
342 | if (code == POINTER_PLUS_EXPR) | |
343 | return fold_build_pointer_plus (fold_convert (type, op0), | |
344 | op1); | |
345 | else | |
346 | return fold_build2 (code, type, | |
347 | fold_convert (type, op0), | |
348 | fold_convert (type, op1)); | |
349 | } | |
a89ef955 | 350 | else |
351 | return chrec_dont_know; | |
352 | } | |
1364018f | 353 | } |
354 | } | |
355 | } | |
356 | ||
357 | /* Fold the addition of two chrecs. */ | |
358 | ||
359 | tree | |
48e1416a | 360 | chrec_fold_plus (tree type, |
1364018f | 361 | tree op0, |
362 | tree op1) | |
363 | { | |
0de36bdb | 364 | enum tree_code code; |
f84a688a | 365 | if (automatically_generated_chrec_p (op0) |
366 | || automatically_generated_chrec_p (op1)) | |
367 | return chrec_fold_automatically_generated_operands (op0, op1); | |
368 | ||
1364018f | 369 | if (integer_zerop (op0)) |
75a70cf9 | 370 | return chrec_convert (type, op1, NULL); |
1364018f | 371 | if (integer_zerop (op1)) |
75a70cf9 | 372 | return chrec_convert (type, op0, NULL); |
0de36bdb | 373 | |
374 | if (POINTER_TYPE_P (type)) | |
375 | code = POINTER_PLUS_EXPR; | |
376 | else | |
377 | code = PLUS_EXPR; | |
48e1416a | 378 | |
0de36bdb | 379 | return chrec_fold_plus_1 (code, type, op0, op1); |
1364018f | 380 | } |
381 | ||
382 | /* Fold the subtraction of two chrecs. */ | |
383 | ||
48e1416a | 384 | tree |
385 | chrec_fold_minus (tree type, | |
386 | tree op0, | |
1364018f | 387 | tree op1) |
388 | { | |
f84a688a | 389 | if (automatically_generated_chrec_p (op0) |
390 | || automatically_generated_chrec_p (op1)) | |
391 | return chrec_fold_automatically_generated_operands (op0, op1); | |
392 | ||
1364018f | 393 | if (integer_zerop (op1)) |
394 | return op0; | |
48e1416a | 395 | |
1364018f | 396 | return chrec_fold_plus_1 (MINUS_EXPR, type, op0, op1); |
397 | } | |
398 | ||
399 | /* Fold the multiplication of two chrecs. */ | |
400 | ||
401 | tree | |
48e1416a | 402 | chrec_fold_multiply (tree type, |
1364018f | 403 | tree op0, |
404 | tree op1) | |
405 | { | |
406 | if (automatically_generated_chrec_p (op0) | |
407 | || automatically_generated_chrec_p (op1)) | |
408 | return chrec_fold_automatically_generated_operands (op0, op1); | |
48e1416a | 409 | |
1364018f | 410 | switch (TREE_CODE (op0)) |
411 | { | |
412 | case POLYNOMIAL_CHREC: | |
32e31826 | 413 | gcc_checking_assert |
414 | (!chrec_contains_symbols_defined_in_loop (op0, CHREC_VARIABLE (op0))); | |
1364018f | 415 | switch (TREE_CODE (op1)) |
416 | { | |
417 | case POLYNOMIAL_CHREC: | |
32e31826 | 418 | gcc_checking_assert |
419 | (!chrec_contains_symbols_defined_in_loop (op1, | |
420 | CHREC_VARIABLE (op1))); | |
1364018f | 421 | return chrec_fold_multiply_poly_poly (type, op0, op1); |
48e1416a | 422 | |
f2a8ffd0 | 423 | CASE_CONVERT: |
424 | if (tree_contains_chrecs (op1, NULL)) | |
425 | return chrec_dont_know; | |
426 | ||
1364018f | 427 | default: |
428 | if (integer_onep (op1)) | |
429 | return op0; | |
430 | if (integer_zerop (op1)) | |
05db596e | 431 | return build_int_cst (type, 0); |
48e1416a | 432 | |
433 | return build_polynomial_chrec | |
434 | (CHREC_VARIABLE (op0), | |
1364018f | 435 | chrec_fold_multiply (type, CHREC_LEFT (op0), op1), |
436 | chrec_fold_multiply (type, CHREC_RIGHT (op0), op1)); | |
437 | } | |
48e1416a | 438 | |
f2a8ffd0 | 439 | CASE_CONVERT: |
440 | if (tree_contains_chrecs (op0, NULL)) | |
441 | return chrec_dont_know; | |
442 | ||
1364018f | 443 | default: |
444 | if (integer_onep (op0)) | |
445 | return op1; | |
48e1416a | 446 | |
1364018f | 447 | if (integer_zerop (op0)) |
05db596e | 448 | return build_int_cst (type, 0); |
48e1416a | 449 | |
1364018f | 450 | switch (TREE_CODE (op1)) |
451 | { | |
452 | case POLYNOMIAL_CHREC: | |
32e31826 | 453 | gcc_checking_assert |
454 | (!chrec_contains_symbols_defined_in_loop (op1, | |
455 | CHREC_VARIABLE (op1))); | |
48e1416a | 456 | return build_polynomial_chrec |
457 | (CHREC_VARIABLE (op1), | |
1364018f | 458 | chrec_fold_multiply (type, CHREC_LEFT (op1), op0), |
459 | chrec_fold_multiply (type, CHREC_RIGHT (op1), op0)); | |
48e1416a | 460 | |
f2a8ffd0 | 461 | CASE_CONVERT: |
462 | if (tree_contains_chrecs (op1, NULL)) | |
463 | return chrec_dont_know; | |
464 | ||
1364018f | 465 | default: |
466 | if (integer_onep (op1)) | |
467 | return op0; | |
468 | if (integer_zerop (op1)) | |
05db596e | 469 | return build_int_cst (type, 0); |
a89ef955 | 470 | return fold_build2 (MULT_EXPR, type, op0, op1); |
1364018f | 471 | } |
472 | } | |
473 | } | |
474 | ||
475 | \f | |
476 | ||
477 | /* Operations. */ | |
478 | ||
9353326d | 479 | /* Evaluate the binomial coefficient. Return NULL_TREE if the intermediate |
480 | calculation overflows, otherwise return C(n,k) with type TYPE. */ | |
481 | ||
48e1416a | 482 | static tree |
9353326d | 483 | tree_fold_binomial (tree type, tree n, unsigned int k) |
1364018f | 484 | { |
d67b7119 | 485 | bool overflow; |
9353326d | 486 | unsigned int i; |
487 | tree res; | |
488 | ||
489 | /* Handle the most frequent cases. */ | |
490 | if (k == 0) | |
491 | return build_int_cst (type, 1); | |
492 | if (k == 1) | |
493 | return fold_convert (type, n); | |
494 | ||
495 | /* Check that k <= n. */ | |
c311b856 | 496 | if (wi::ltu_p (n, k)) |
9353326d | 497 | return NULL_TREE; |
498 | ||
9353326d | 499 | /* Denominator = 2. */ |
ab2c1de8 | 500 | wide_int denom = wi::two (TYPE_PRECISION (TREE_TYPE (n))); |
9353326d | 501 | |
502 | /* Index = Numerator-1. */ | |
c311b856 | 503 | wide_int idx = wi::sub (n, 1); |
1364018f | 504 | |
9353326d | 505 | /* Numerator = Numerator*Index = n*(n-1). */ |
c311b856 | 506 | wide_int num = wi::smul (n, idx, &overflow); |
d67b7119 | 507 | if (overflow) |
9353326d | 508 | return NULL_TREE; |
1364018f | 509 | |
9353326d | 510 | for (i = 3; i <= k; i++) |
511 | { | |
512 | /* Index--. */ | |
d67b7119 | 513 | --idx; |
9353326d | 514 | |
515 | /* Numerator *= Index. */ | |
796b6678 | 516 | num = wi::smul (num, idx, &overflow); |
d67b7119 | 517 | if (overflow) |
9353326d | 518 | return NULL_TREE; |
519 | ||
520 | /* Denominator *= i. */ | |
e913b5cd | 521 | denom *= i; |
9353326d | 522 | } |
523 | ||
524 | /* Result = Numerator / Denominator. */ | |
ab2c1de8 | 525 | wide_int di_res = wi::udiv_trunc (num, denom); |
e913b5cd | 526 | res = wide_int_to_tree (type, di_res); |
9353326d | 527 | return int_fits_type_p (res, type) ? res : NULL_TREE; |
1364018f | 528 | } |
529 | ||
530 | /* Helper function. Use the Newton's interpolating formula for | |
531 | evaluating the value of the evolution function. */ | |
532 | ||
48e1416a | 533 | static tree |
9353326d | 534 | chrec_evaluate (unsigned var, tree chrec, tree n, unsigned int k) |
1364018f | 535 | { |
9353326d | 536 | tree arg0, arg1, binomial_n_k; |
537 | tree type = TREE_TYPE (chrec); | |
41f75a99 | 538 | struct loop *var_loop = get_loop (cfun, var); |
9353326d | 539 | |
540 | while (TREE_CODE (chrec) == POLYNOMIAL_CHREC | |
3bbbcdff | 541 | && flow_loop_nested_p (var_loop, get_chrec_loop (chrec))) |
9353326d | 542 | chrec = CHREC_LEFT (chrec); |
543 | ||
544 | if (TREE_CODE (chrec) == POLYNOMIAL_CHREC | |
545 | && CHREC_VARIABLE (chrec) == var) | |
1364018f | 546 | { |
72aad60a | 547 | arg1 = chrec_evaluate (var, CHREC_RIGHT (chrec), n, k + 1); |
548 | if (arg1 == chrec_dont_know) | |
9353326d | 549 | return chrec_dont_know; |
550 | binomial_n_k = tree_fold_binomial (type, n, k); | |
551 | if (!binomial_n_k) | |
552 | return chrec_dont_know; | |
72aad60a | 553 | arg0 = fold_build2 (MULT_EXPR, type, |
a89ef955 | 554 | CHREC_LEFT (chrec), binomial_n_k); |
9353326d | 555 | return chrec_fold_plus (type, arg0, arg1); |
1364018f | 556 | } |
9353326d | 557 | |
558 | binomial_n_k = tree_fold_binomial (type, n, k); | |
559 | if (!binomial_n_k) | |
560 | return chrec_dont_know; | |
48e1416a | 561 | |
a89ef955 | 562 | return fold_build2 (MULT_EXPR, type, chrec, binomial_n_k); |
1364018f | 563 | } |
564 | ||
48e1416a | 565 | /* Evaluates "CHREC (X)" when the varying variable is VAR. |
566 | Example: Given the following parameters, | |
567 | ||
1364018f | 568 | var = 1 |
569 | chrec = {3, +, 4}_1 | |
570 | x = 10 | |
48e1416a | 571 | |
572 | The result is given by the Newton's interpolating formula: | |
1364018f | 573 | 3 * \binom{10}{0} + 4 * \binom{10}{1}. |
574 | */ | |
575 | ||
48e1416a | 576 | tree |
1364018f | 577 | chrec_apply (unsigned var, |
48e1416a | 578 | tree chrec, |
1364018f | 579 | tree x) |
580 | { | |
581 | tree type = chrec_type (chrec); | |
582 | tree res = chrec_dont_know; | |
583 | ||
584 | if (automatically_generated_chrec_p (chrec) | |
585 | || automatically_generated_chrec_p (x) | |
586 | ||
587 | /* When the symbols are defined in an outer loop, it is possible | |
588 | to symbolically compute the apply, since the symbols are | |
589 | constants with respect to the varying loop. */ | |
553b9523 | 590 | || chrec_contains_symbols_defined_in_loop (chrec, var)) |
1364018f | 591 | return chrec_dont_know; |
48e1416a | 592 | |
487a9bc1 | 593 | if (dump_file && (dump_flags & TDF_SCEV)) |
1364018f | 594 | fprintf (dump_file, "(chrec_apply \n"); |
595 | ||
dd2a65b3 | 596 | if (TREE_CODE (x) == INTEGER_CST && SCALAR_FLOAT_TYPE_P (type)) |
597 | x = build_real_from_int_cst (type, x); | |
598 | ||
9e4cd968 | 599 | switch (TREE_CODE (chrec)) |
1364018f | 600 | { |
9e4cd968 | 601 | case POLYNOMIAL_CHREC: |
602 | if (evolution_function_is_affine_p (chrec)) | |
603 | { | |
604 | if (CHREC_VARIABLE (chrec) != var) | |
605 | return build_polynomial_chrec | |
606 | (CHREC_VARIABLE (chrec), | |
607 | chrec_apply (var, CHREC_LEFT (chrec), x), | |
608 | chrec_apply (var, CHREC_RIGHT (chrec), x)); | |
609 | ||
610 | /* "{a, +, b} (x)" -> "a + b*x". */ | |
611 | x = chrec_convert_rhs (type, x, NULL); | |
612 | res = chrec_fold_multiply (TREE_TYPE (x), CHREC_RIGHT (chrec), x); | |
613 | res = chrec_fold_plus (type, CHREC_LEFT (chrec), res); | |
614 | } | |
615 | else if (TREE_CODE (x) == INTEGER_CST | |
616 | && tree_int_cst_sgn (x) == 1) | |
617 | /* testsuite/.../ssa-chrec-38.c. */ | |
618 | res = chrec_evaluate (var, chrec, x, 0); | |
619 | else | |
620 | res = chrec_dont_know; | |
621 | break; | |
48e1416a | 622 | |
9e4cd968 | 623 | CASE_CONVERT: |
624 | res = chrec_convert (TREE_TYPE (chrec), | |
625 | chrec_apply (var, TREE_OPERAND (chrec, 0), x), | |
626 | NULL); | |
627 | break; | |
48e1416a | 628 | |
9e4cd968 | 629 | default: |
630 | res = chrec; | |
631 | break; | |
632 | } | |
48e1416a | 633 | |
487a9bc1 | 634 | if (dump_file && (dump_flags & TDF_SCEV)) |
1364018f | 635 | { |
636 | fprintf (dump_file, " (varying_loop = %d\n", var); | |
637 | fprintf (dump_file, ")\n (chrec = "); | |
638 | print_generic_expr (dump_file, chrec, 0); | |
639 | fprintf (dump_file, ")\n (x = "); | |
640 | print_generic_expr (dump_file, x, 0); | |
641 | fprintf (dump_file, ")\n (res = "); | |
642 | print_generic_expr (dump_file, res, 0); | |
643 | fprintf (dump_file, "))\n"); | |
644 | } | |
48e1416a | 645 | |
1364018f | 646 | return res; |
647 | } | |
648 | ||
4ed27c8e | 649 | /* For a given CHREC and an induction variable map IV_MAP that maps |
650 | (loop->num, expr) for every loop number of the current_loops an | |
651 | expression, calls chrec_apply when the expression is not NULL. */ | |
652 | ||
653 | tree | |
f1f41a6c | 654 | chrec_apply_map (tree chrec, vec<tree> iv_map) |
4ed27c8e | 655 | { |
656 | int i; | |
657 | tree expr; | |
658 | ||
f1f41a6c | 659 | FOR_EACH_VEC_ELT (iv_map, i, expr) |
4ed27c8e | 660 | if (expr) |
661 | chrec = chrec_apply (i, chrec, expr); | |
662 | ||
663 | return chrec; | |
664 | } | |
665 | ||
1364018f | 666 | /* Replaces the initial condition in CHREC with INIT_COND. */ |
667 | ||
48e1416a | 668 | tree |
669 | chrec_replace_initial_condition (tree chrec, | |
1364018f | 670 | tree init_cond) |
671 | { | |
672 | if (automatically_generated_chrec_p (chrec)) | |
673 | return chrec; | |
f84a688a | 674 | |
675 | gcc_assert (chrec_type (chrec) == chrec_type (init_cond)); | |
676 | ||
1364018f | 677 | switch (TREE_CODE (chrec)) |
678 | { | |
679 | case POLYNOMIAL_CHREC: | |
48e1416a | 680 | return build_polynomial_chrec |
1364018f | 681 | (CHREC_VARIABLE (chrec), |
682 | chrec_replace_initial_condition (CHREC_LEFT (chrec), init_cond), | |
683 | CHREC_RIGHT (chrec)); | |
48e1416a | 684 | |
1364018f | 685 | default: |
686 | return init_cond; | |
687 | } | |
688 | } | |
689 | ||
690 | /* Returns the initial condition of a given CHREC. */ | |
691 | ||
48e1416a | 692 | tree |
1364018f | 693 | initial_condition (tree chrec) |
694 | { | |
695 | if (automatically_generated_chrec_p (chrec)) | |
696 | return chrec; | |
48e1416a | 697 | |
1364018f | 698 | if (TREE_CODE (chrec) == POLYNOMIAL_CHREC) |
699 | return initial_condition (CHREC_LEFT (chrec)); | |
700 | else | |
701 | return chrec; | |
702 | } | |
703 | ||
704 | /* Returns a univariate function that represents the evolution in | |
705 | LOOP_NUM. Mask the evolution of any other loop. */ | |
706 | ||
48e1416a | 707 | tree |
708 | hide_evolution_in_other_loops_than_loop (tree chrec, | |
1364018f | 709 | unsigned loop_num) |
710 | { | |
41f75a99 | 711 | struct loop *loop = get_loop (cfun, loop_num), *chloop; |
1364018f | 712 | if (automatically_generated_chrec_p (chrec)) |
713 | return chrec; | |
48e1416a | 714 | |
1364018f | 715 | switch (TREE_CODE (chrec)) |
716 | { | |
717 | case POLYNOMIAL_CHREC: | |
3bbbcdff | 718 | chloop = get_chrec_loop (chrec); |
719 | ||
720 | if (chloop == loop) | |
48e1416a | 721 | return build_polynomial_chrec |
722 | (loop_num, | |
723 | hide_evolution_in_other_loops_than_loop (CHREC_LEFT (chrec), | |
724 | loop_num), | |
1364018f | 725 | CHREC_RIGHT (chrec)); |
48e1416a | 726 | |
3bbbcdff | 727 | else if (flow_loop_nested_p (chloop, loop)) |
1364018f | 728 | /* There is no evolution in this loop. */ |
729 | return initial_condition (chrec); | |
48e1416a | 730 | |
1364018f | 731 | else |
3bbbcdff | 732 | { |
733 | gcc_assert (flow_loop_nested_p (loop, chloop)); | |
48e1416a | 734 | return hide_evolution_in_other_loops_than_loop (CHREC_LEFT (chrec), |
3bbbcdff | 735 | loop_num); |
736 | } | |
48e1416a | 737 | |
1364018f | 738 | default: |
739 | return chrec; | |
740 | } | |
741 | } | |
742 | ||
9ce81338 | 743 | /* Returns the evolution part of CHREC in LOOP_NUM when RIGHT is |
744 | true, otherwise returns the initial condition in LOOP_NUM. */ | |
1364018f | 745 | |
48e1416a | 746 | static tree |
747 | chrec_component_in_loop_num (tree chrec, | |
9ce81338 | 748 | unsigned loop_num, |
749 | bool right) | |
1364018f | 750 | { |
9ce81338 | 751 | tree component; |
41f75a99 | 752 | struct loop *loop = get_loop (cfun, loop_num), *chloop; |
9ce81338 | 753 | |
1364018f | 754 | if (automatically_generated_chrec_p (chrec)) |
755 | return chrec; | |
48e1416a | 756 | |
1364018f | 757 | switch (TREE_CODE (chrec)) |
758 | { | |
759 | case POLYNOMIAL_CHREC: | |
3bbbcdff | 760 | chloop = get_chrec_loop (chrec); |
761 | ||
762 | if (chloop == loop) | |
1364018f | 763 | { |
9ce81338 | 764 | if (right) |
765 | component = CHREC_RIGHT (chrec); | |
766 | else | |
767 | component = CHREC_LEFT (chrec); | |
768 | ||
1364018f | 769 | if (TREE_CODE (CHREC_LEFT (chrec)) != POLYNOMIAL_CHREC |
770 | || CHREC_VARIABLE (CHREC_LEFT (chrec)) != CHREC_VARIABLE (chrec)) | |
9ce81338 | 771 | return component; |
48e1416a | 772 | |
1364018f | 773 | else |
774 | return build_polynomial_chrec | |
48e1416a | 775 | (loop_num, |
776 | chrec_component_in_loop_num (CHREC_LEFT (chrec), | |
777 | loop_num, | |
778 | right), | |
9ce81338 | 779 | component); |
1364018f | 780 | } |
48e1416a | 781 | |
3bbbcdff | 782 | else if (flow_loop_nested_p (chloop, loop)) |
1364018f | 783 | /* There is no evolution part in this loop. */ |
784 | return NULL_TREE; | |
48e1416a | 785 | |
1364018f | 786 | else |
3bbbcdff | 787 | { |
788 | gcc_assert (flow_loop_nested_p (loop, chloop)); | |
48e1416a | 789 | return chrec_component_in_loop_num (CHREC_LEFT (chrec), |
790 | loop_num, | |
3bbbcdff | 791 | right); |
792 | } | |
48e1416a | 793 | |
9ce81338 | 794 | default: |
795 | if (right) | |
796 | return NULL_TREE; | |
797 | else | |
798 | return chrec; | |
1364018f | 799 | } |
800 | } | |
801 | ||
9ce81338 | 802 | /* Returns the evolution part in LOOP_NUM. Example: the call |
48e1416a | 803 | evolution_part_in_loop_num ({{0, +, 1}_1, +, 2}_1, 1) returns |
9ce81338 | 804 | {1, +, 2}_1 */ |
805 | ||
48e1416a | 806 | tree |
807 | evolution_part_in_loop_num (tree chrec, | |
9ce81338 | 808 | unsigned loop_num) |
809 | { | |
810 | return chrec_component_in_loop_num (chrec, loop_num, true); | |
811 | } | |
812 | ||
813 | /* Returns the initial condition in LOOP_NUM. Example: the call | |
48e1416a | 814 | initial_condition_in_loop_num ({{0, +, 1}_1, +, 2}_2, 2) returns |
9ce81338 | 815 | {0, +, 1}_1 */ |
816 | ||
48e1416a | 817 | tree |
818 | initial_condition_in_loop_num (tree chrec, | |
9ce81338 | 819 | unsigned loop_num) |
820 | { | |
821 | return chrec_component_in_loop_num (chrec, loop_num, false); | |
822 | } | |
823 | ||
1364018f | 824 | /* Set or reset the evolution of CHREC to NEW_EVOL in loop LOOP_NUM. |
825 | This function is essentially used for setting the evolution to | |
826 | chrec_dont_know, for example after having determined that it is | |
827 | impossible to say how many times a loop will execute. */ | |
828 | ||
48e1416a | 829 | tree |
1364018f | 830 | reset_evolution_in_loop (unsigned loop_num, |
48e1416a | 831 | tree chrec, |
1364018f | 832 | tree new_evol) |
833 | { | |
41f75a99 | 834 | struct loop *loop = get_loop (cfun, loop_num); |
3bbbcdff | 835 | |
0de36bdb | 836 | if (POINTER_TYPE_P (chrec_type (chrec))) |
a845d317 | 837 | gcc_assert (ptrofftype_p (chrec_type (new_evol))); |
0de36bdb | 838 | else |
839 | gcc_assert (chrec_type (chrec) == chrec_type (new_evol)); | |
f84a688a | 840 | |
1364018f | 841 | if (TREE_CODE (chrec) == POLYNOMIAL_CHREC |
3bbbcdff | 842 | && flow_loop_nested_p (loop, get_chrec_loop (chrec))) |
b74b8216 | 843 | { |
844 | tree left = reset_evolution_in_loop (loop_num, CHREC_LEFT (chrec), | |
845 | new_evol); | |
846 | tree right = reset_evolution_in_loop (loop_num, CHREC_RIGHT (chrec), | |
847 | new_evol); | |
848 | return build3 (POLYNOMIAL_CHREC, TREE_TYPE (left), | |
bad12c62 | 849 | CHREC_VAR (chrec), left, right); |
b74b8216 | 850 | } |
851 | ||
1364018f | 852 | while (TREE_CODE (chrec) == POLYNOMIAL_CHREC |
853 | && CHREC_VARIABLE (chrec) == loop_num) | |
854 | chrec = CHREC_LEFT (chrec); | |
48e1416a | 855 | |
1364018f | 856 | return build_polynomial_chrec (loop_num, chrec, new_evol); |
857 | } | |
858 | ||
859 | /* Merges two evolution functions that were found by following two | |
860 | alternate paths of a conditional expression. */ | |
861 | ||
862 | tree | |
48e1416a | 863 | chrec_merge (tree chrec1, |
1364018f | 864 | tree chrec2) |
865 | { | |
866 | if (chrec1 == chrec_dont_know | |
867 | || chrec2 == chrec_dont_know) | |
868 | return chrec_dont_know; | |
869 | ||
48e1416a | 870 | if (chrec1 == chrec_known |
1364018f | 871 | || chrec2 == chrec_known) |
872 | return chrec_known; | |
873 | ||
874 | if (chrec1 == chrec_not_analyzed_yet) | |
875 | return chrec2; | |
876 | if (chrec2 == chrec_not_analyzed_yet) | |
877 | return chrec1; | |
878 | ||
55feb6fa | 879 | if (eq_evolutions_p (chrec1, chrec2)) |
1364018f | 880 | return chrec1; |
881 | ||
882 | return chrec_dont_know; | |
883 | } | |
884 | ||
885 | \f | |
886 | ||
887 | /* Observers. */ | |
888 | ||
889 | /* Helper function for is_multivariate_chrec. */ | |
890 | ||
48e1416a | 891 | static bool |
7ecb5bb2 | 892 | is_multivariate_chrec_rec (const_tree chrec, unsigned int rec_var) |
1364018f | 893 | { |
894 | if (chrec == NULL_TREE) | |
895 | return false; | |
48e1416a | 896 | |
1364018f | 897 | if (TREE_CODE (chrec) == POLYNOMIAL_CHREC) |
898 | { | |
899 | if (CHREC_VARIABLE (chrec) != rec_var) | |
900 | return true; | |
901 | else | |
48e1416a | 902 | return (is_multivariate_chrec_rec (CHREC_LEFT (chrec), rec_var) |
1364018f | 903 | || is_multivariate_chrec_rec (CHREC_RIGHT (chrec), rec_var)); |
904 | } | |
905 | else | |
906 | return false; | |
907 | } | |
908 | ||
909 | /* Determine whether the given chrec is multivariate or not. */ | |
910 | ||
48e1416a | 911 | bool |
7ecb5bb2 | 912 | is_multivariate_chrec (const_tree chrec) |
1364018f | 913 | { |
914 | if (chrec == NULL_TREE) | |
915 | return false; | |
48e1416a | 916 | |
1364018f | 917 | if (TREE_CODE (chrec) == POLYNOMIAL_CHREC) |
48e1416a | 918 | return (is_multivariate_chrec_rec (CHREC_LEFT (chrec), |
1364018f | 919 | CHREC_VARIABLE (chrec)) |
48e1416a | 920 | || is_multivariate_chrec_rec (CHREC_RIGHT (chrec), |
1364018f | 921 | CHREC_VARIABLE (chrec))); |
922 | else | |
923 | return false; | |
924 | } | |
925 | ||
926 | /* Determines whether the chrec contains symbolic names or not. */ | |
927 | ||
48e1416a | 928 | bool |
7ecb5bb2 | 929 | chrec_contains_symbols (const_tree chrec) |
1364018f | 930 | { |
c2f47e15 | 931 | int i, n; |
932 | ||
1364018f | 933 | if (chrec == NULL_TREE) |
934 | return false; | |
48e1416a | 935 | |
1364018f | 936 | if (TREE_CODE (chrec) == SSA_NAME |
937 | || TREE_CODE (chrec) == VAR_DECL | |
938 | || TREE_CODE (chrec) == PARM_DECL | |
939 | || TREE_CODE (chrec) == FUNCTION_DECL | |
940 | || TREE_CODE (chrec) == LABEL_DECL | |
941 | || TREE_CODE (chrec) == RESULT_DECL | |
942 | || TREE_CODE (chrec) == FIELD_DECL) | |
943 | return true; | |
c2f47e15 | 944 | |
945 | n = TREE_OPERAND_LENGTH (chrec); | |
946 | for (i = 0; i < n; i++) | |
947 | if (chrec_contains_symbols (TREE_OPERAND (chrec, i))) | |
948 | return true; | |
949 | return false; | |
1364018f | 950 | } |
951 | ||
952 | /* Determines whether the chrec contains undetermined coefficients. */ | |
953 | ||
48e1416a | 954 | bool |
7ecb5bb2 | 955 | chrec_contains_undetermined (const_tree chrec) |
1364018f | 956 | { |
c2f47e15 | 957 | int i, n; |
958 | ||
c4e91ab3 | 959 | if (chrec == chrec_dont_know) |
1364018f | 960 | return true; |
c2f47e15 | 961 | |
c4e91ab3 | 962 | if (chrec == NULL_TREE) |
963 | return false; | |
964 | ||
c2f47e15 | 965 | n = TREE_OPERAND_LENGTH (chrec); |
966 | for (i = 0; i < n; i++) | |
967 | if (chrec_contains_undetermined (TREE_OPERAND (chrec, i))) | |
968 | return true; | |
969 | return false; | |
1364018f | 970 | } |
971 | ||
a89ef955 | 972 | /* Determines whether the tree EXPR contains chrecs, and increment |
973 | SIZE if it is not a NULL pointer by an estimation of the depth of | |
974 | the tree. */ | |
1364018f | 975 | |
976 | bool | |
7ecb5bb2 | 977 | tree_contains_chrecs (const_tree expr, int *size) |
1364018f | 978 | { |
c2f47e15 | 979 | int i, n; |
980 | ||
1364018f | 981 | if (expr == NULL_TREE) |
982 | return false; | |
a89ef955 | 983 | |
984 | if (size) | |
985 | (*size)++; | |
48e1416a | 986 | |
1364018f | 987 | if (tree_is_chrec (expr)) |
988 | return true; | |
a89ef955 | 989 | |
c2f47e15 | 990 | n = TREE_OPERAND_LENGTH (expr); |
991 | for (i = 0; i < n; i++) | |
992 | if (tree_contains_chrecs (TREE_OPERAND (expr, i), size)) | |
993 | return true; | |
994 | return false; | |
1364018f | 995 | } |
996 | ||
b3786ab3 | 997 | /* Recursive helper function. */ |
998 | ||
999 | static bool | |
1000 | evolution_function_is_invariant_rec_p (tree chrec, int loopnum) | |
1001 | { | |
1002 | if (evolution_function_is_constant_p (chrec)) | |
1003 | return true; | |
1004 | ||
663608f5 | 1005 | if (TREE_CODE (chrec) == SSA_NAME |
1006 | && (loopnum == 0 | |
41f75a99 | 1007 | || expr_invariant_in_loop_p (get_loop (cfun, loopnum), chrec))) |
b3786ab3 | 1008 | return true; |
1009 | ||
87975961 | 1010 | if (TREE_CODE (chrec) == POLYNOMIAL_CHREC) |
1011 | { | |
1012 | if (CHREC_VARIABLE (chrec) == (unsigned) loopnum | |
41f75a99 | 1013 | || flow_loop_nested_p (get_loop (cfun, loopnum), |
1014 | get_chrec_loop (chrec)) | |
87975961 | 1015 | || !evolution_function_is_invariant_rec_p (CHREC_RIGHT (chrec), |
1016 | loopnum) | |
1017 | || !evolution_function_is_invariant_rec_p (CHREC_LEFT (chrec), | |
1018 | loopnum)) | |
1019 | return false; | |
1020 | return true; | |
1021 | } | |
b3786ab3 | 1022 | |
c2f47e15 | 1023 | switch (TREE_OPERAND_LENGTH (chrec)) |
b3786ab3 | 1024 | { |
1025 | case 2: | |
1026 | if (!evolution_function_is_invariant_rec_p (TREE_OPERAND (chrec, 1), | |
1027 | loopnum)) | |
1028 | return false; | |
48e1416a | 1029 | |
b3786ab3 | 1030 | case 1: |
1031 | if (!evolution_function_is_invariant_rec_p (TREE_OPERAND (chrec, 0), | |
1032 | loopnum)) | |
1033 | return false; | |
1034 | return true; | |
1035 | ||
1036 | default: | |
1037 | return false; | |
1038 | } | |
1039 | ||
1040 | return false; | |
1041 | } | |
1042 | ||
1043 | /* Return true if CHREC is invariant in loop LOOPNUM, false otherwise. */ | |
1044 | ||
1045 | bool | |
1046 | evolution_function_is_invariant_p (tree chrec, int loopnum) | |
1047 | { | |
7a3bf727 | 1048 | return evolution_function_is_invariant_rec_p (chrec, loopnum); |
b3786ab3 | 1049 | } |
1050 | ||
1364018f | 1051 | /* Determine whether the given tree is an affine multivariate |
1052 | evolution. */ | |
1053 | ||
48e1416a | 1054 | bool |
7ecb5bb2 | 1055 | evolution_function_is_affine_multivariate_p (const_tree chrec, int loopnum) |
1364018f | 1056 | { |
1057 | if (chrec == NULL_TREE) | |
1058 | return false; | |
48e1416a | 1059 | |
1364018f | 1060 | switch (TREE_CODE (chrec)) |
1061 | { | |
1062 | case POLYNOMIAL_CHREC: | |
9c77efff | 1063 | if (evolution_function_is_invariant_rec_p (CHREC_LEFT (chrec), loopnum)) |
1364018f | 1064 | { |
9c77efff | 1065 | if (evolution_function_is_invariant_rec_p (CHREC_RIGHT (chrec), loopnum)) |
1364018f | 1066 | return true; |
1067 | else | |
1068 | { | |
1069 | if (TREE_CODE (CHREC_RIGHT (chrec)) == POLYNOMIAL_CHREC | |
48e1416a | 1070 | && CHREC_VARIABLE (CHREC_RIGHT (chrec)) |
1364018f | 1071 | != CHREC_VARIABLE (chrec) |
48e1416a | 1072 | && evolution_function_is_affine_multivariate_p |
9c77efff | 1073 | (CHREC_RIGHT (chrec), loopnum)) |
1364018f | 1074 | return true; |
1075 | else | |
1076 | return false; | |
1077 | } | |
1078 | } | |
1079 | else | |
1080 | { | |
9c77efff | 1081 | if (evolution_function_is_invariant_rec_p (CHREC_RIGHT (chrec), loopnum) |
1364018f | 1082 | && TREE_CODE (CHREC_LEFT (chrec)) == POLYNOMIAL_CHREC |
1083 | && CHREC_VARIABLE (CHREC_LEFT (chrec)) != CHREC_VARIABLE (chrec) | |
48e1416a | 1084 | && evolution_function_is_affine_multivariate_p |
9c77efff | 1085 | (CHREC_LEFT (chrec), loopnum)) |
1364018f | 1086 | return true; |
1087 | else | |
1088 | return false; | |
1089 | } | |
48e1416a | 1090 | |
1364018f | 1091 | default: |
1092 | return false; | |
1093 | } | |
1094 | } | |
1095 | ||
48e1416a | 1096 | /* Determine whether the given tree is a function in zero or one |
1364018f | 1097 | variables. */ |
1098 | ||
1099 | bool | |
7ecb5bb2 | 1100 | evolution_function_is_univariate_p (const_tree chrec) |
1364018f | 1101 | { |
1102 | if (chrec == NULL_TREE) | |
1103 | return true; | |
48e1416a | 1104 | |
1364018f | 1105 | switch (TREE_CODE (chrec)) |
1106 | { | |
1107 | case POLYNOMIAL_CHREC: | |
1108 | switch (TREE_CODE (CHREC_LEFT (chrec))) | |
1109 | { | |
1110 | case POLYNOMIAL_CHREC: | |
1111 | if (CHREC_VARIABLE (chrec) != CHREC_VARIABLE (CHREC_LEFT (chrec))) | |
1112 | return false; | |
1113 | if (!evolution_function_is_univariate_p (CHREC_LEFT (chrec))) | |
1114 | return false; | |
1115 | break; | |
48e1416a | 1116 | |
1364018f | 1117 | default: |
08754147 | 1118 | if (tree_contains_chrecs (CHREC_LEFT (chrec), NULL)) |
1119 | return false; | |
1364018f | 1120 | break; |
1121 | } | |
48e1416a | 1122 | |
1364018f | 1123 | switch (TREE_CODE (CHREC_RIGHT (chrec))) |
1124 | { | |
1125 | case POLYNOMIAL_CHREC: | |
1126 | if (CHREC_VARIABLE (chrec) != CHREC_VARIABLE (CHREC_RIGHT (chrec))) | |
1127 | return false; | |
1128 | if (!evolution_function_is_univariate_p (CHREC_RIGHT (chrec))) | |
1129 | return false; | |
1130 | break; | |
48e1416a | 1131 | |
1364018f | 1132 | default: |
08754147 | 1133 | if (tree_contains_chrecs (CHREC_RIGHT (chrec), NULL)) |
1134 | return false; | |
48e1416a | 1135 | break; |
1364018f | 1136 | } |
48e1416a | 1137 | |
1364018f | 1138 | default: |
1139 | return true; | |
1140 | } | |
1141 | } | |
1142 | ||
bc3c8ad4 | 1143 | /* Returns the number of variables of CHREC. Example: the call |
1144 | nb_vars_in_chrec ({{0, +, 1}_5, +, 2}_6) returns 2. */ | |
1145 | ||
48e1416a | 1146 | unsigned |
bc3c8ad4 | 1147 | nb_vars_in_chrec (tree chrec) |
1148 | { | |
1149 | if (chrec == NULL_TREE) | |
1150 | return 0; | |
1151 | ||
1152 | switch (TREE_CODE (chrec)) | |
1153 | { | |
1154 | case POLYNOMIAL_CHREC: | |
48e1416a | 1155 | return 1 + nb_vars_in_chrec |
bc3c8ad4 | 1156 | (initial_condition_in_loop_num (chrec, CHREC_VARIABLE (chrec))); |
1157 | ||
1158 | default: | |
1159 | return 0; | |
1160 | } | |
1161 | } | |
1162 | ||
57e3f39a | 1163 | /* Converts BASE and STEP of affine scev to TYPE. LOOP is the loop whose iv |
1164 | the scev corresponds to. AT_STMT is the statement at that the scev is | |
1165 | evaluated. USE_OVERFLOW_SEMANTICS is true if this function should assume that | |
1166 | the rules for overflow of the given language apply (e.g., that signed | |
1167 | arithmetics in C does not overflow) -- i.e., to use them to avoid unnecessary | |
1168 | tests, but also to enforce that the result follows them. Returns true if the | |
1169 | conversion succeeded, false otherwise. */ | |
1170 | ||
1171 | bool | |
1172 | convert_affine_scev (struct loop *loop, tree type, | |
42acab1c | 1173 | tree *base, tree *step, gimple *at_stmt, |
57e3f39a | 1174 | bool use_overflow_semantics) |
1175 | { | |
1176 | tree ct = TREE_TYPE (*step); | |
1177 | bool enforce_overflow_semantics; | |
1178 | bool must_check_src_overflow, must_check_rslt_overflow; | |
1179 | tree new_base, new_step; | |
0de36bdb | 1180 | tree step_type = POINTER_TYPE_P (type) ? sizetype : type; |
57e3f39a | 1181 | |
1182 | /* In general, | |
1183 | (TYPE) (BASE + STEP * i) = (TYPE) BASE + (TYPE -- sign extend) STEP * i, | |
1184 | but we must check some assumptions. | |
48e1416a | 1185 | |
57e3f39a | 1186 | 1) If [BASE, +, STEP] wraps, the equation is not valid when precision |
1187 | of CT is smaller than the precision of TYPE. For example, when we | |
1188 | cast unsigned char [254, +, 1] to unsigned, the values on left side | |
1189 | are 254, 255, 0, 1, ..., but those on the right side are | |
1190 | 254, 255, 256, 257, ... | |
1191 | 2) In case that we must also preserve the fact that signed ivs do not | |
1192 | overflow, we must additionally check that the new iv does not wrap. | |
1193 | For example, unsigned char [125, +, 1] casted to signed char could | |
1194 | become a wrapping variable with values 125, 126, 127, -128, -127, ..., | |
1195 | which would confuse optimizers that assume that this does not | |
1196 | happen. */ | |
1197 | must_check_src_overflow = TYPE_PRECISION (ct) < TYPE_PRECISION (type); | |
1198 | ||
1199 | enforce_overflow_semantics = (use_overflow_semantics | |
1200 | && nowrap_type_p (type)); | |
1201 | if (enforce_overflow_semantics) | |
1202 | { | |
1203 | /* We can avoid checking whether the result overflows in the following | |
1204 | cases: | |
1205 | ||
1206 | -- must_check_src_overflow is true, and the range of TYPE is superset | |
1207 | of the range of CT -- i.e., in all cases except if CT signed and | |
1208 | TYPE unsigned. | |
318a3281 | 1209 | -- both CT and TYPE have the same precision and signedness, and we |
1210 | verify instead that the source does not overflow (this may be | |
1211 | easier than verifying it for the result, as we may use the | |
1212 | information about the semantics of overflow in CT). */ | |
57e3f39a | 1213 | if (must_check_src_overflow) |
1214 | { | |
1215 | if (TYPE_UNSIGNED (type) && !TYPE_UNSIGNED (ct)) | |
1216 | must_check_rslt_overflow = true; | |
1217 | else | |
1218 | must_check_rslt_overflow = false; | |
1219 | } | |
1220 | else if (TYPE_UNSIGNED (ct) == TYPE_UNSIGNED (type) | |
1221 | && TYPE_PRECISION (ct) == TYPE_PRECISION (type)) | |
318a3281 | 1222 | { |
1223 | must_check_rslt_overflow = false; | |
1224 | must_check_src_overflow = true; | |
1225 | } | |
57e3f39a | 1226 | else |
1227 | must_check_rslt_overflow = true; | |
1228 | } | |
1229 | else | |
1230 | must_check_rslt_overflow = false; | |
1231 | ||
1232 | if (must_check_src_overflow | |
1233 | && scev_probably_wraps_p (*base, *step, at_stmt, loop, | |
1234 | use_overflow_semantics)) | |
1235 | return false; | |
1236 | ||
5fe66b3c | 1237 | new_base = chrec_convert (type, *base, at_stmt, use_overflow_semantics); |
57e3f39a | 1238 | /* The step must be sign extended, regardless of the signedness |
1239 | of CT and TYPE. This only needs to be handled specially when | |
1240 | CT is unsigned -- to avoid e.g. unsigned char [100, +, 255] | |
1241 | (with values 100, 99, 98, ...) from becoming signed or unsigned | |
48e1416a | 1242 | [100, +, 255] with values 100, 355, ...; the sign-extension is |
57e3f39a | 1243 | performed by default when CT is signed. */ |
1244 | new_step = *step; | |
0de36bdb | 1245 | if (TYPE_PRECISION (step_type) > TYPE_PRECISION (ct) && TYPE_UNSIGNED (ct)) |
0c2b2fc8 | 1246 | { |
1247 | tree signed_ct = build_nonstandard_integer_type (TYPE_PRECISION (ct), 0); | |
5fe66b3c | 1248 | new_step = chrec_convert (signed_ct, new_step, at_stmt, |
1249 | use_overflow_semantics); | |
0c2b2fc8 | 1250 | } |
5fe66b3c | 1251 | new_step = chrec_convert (step_type, new_step, at_stmt, |
1252 | use_overflow_semantics); | |
57e3f39a | 1253 | |
1254 | if (automatically_generated_chrec_p (new_base) | |
1255 | || automatically_generated_chrec_p (new_step)) | |
1256 | return false; | |
1257 | ||
1258 | if (must_check_rslt_overflow | |
1259 | /* Note that in this case we cannot use the fact that signed variables | |
1260 | do not overflow, as this is what we are verifying for the new iv. */ | |
1261 | && scev_probably_wraps_p (new_base, new_step, at_stmt, loop, false)) | |
1262 | return false; | |
1263 | ||
1264 | *base = new_base; | |
1265 | *step = new_step; | |
1266 | return true; | |
1267 | } | |
1364018f | 1268 | \f |
1269 | ||
d3746d81 | 1270 | /* Convert CHREC for the right hand side of a CHREC. |
0de36bdb | 1271 | The increment for a pointer type is always sizetype. */ |
d3746d81 | 1272 | |
48e1416a | 1273 | tree |
42acab1c | 1274 | chrec_convert_rhs (tree type, tree chrec, gimple *at_stmt) |
0de36bdb | 1275 | { |
1276 | if (POINTER_TYPE_P (type)) | |
d3746d81 | 1277 | type = sizetype; |
1278 | ||
0de36bdb | 1279 | return chrec_convert (type, chrec, at_stmt); |
1280 | } | |
1281 | ||
57e3f39a | 1282 | /* Convert CHREC to TYPE. When the analyzer knows the context in |
1283 | which the CHREC is built, it sets AT_STMT to the statement that | |
1284 | contains the definition of the analyzed variable, otherwise the | |
1285 | conversion is less accurate: the information is used for | |
1286 | determining a more accurate estimation of the number of iterations. | |
1287 | By default AT_STMT could be safely set to NULL_TREE. | |
48e1416a | 1288 | |
57e3f39a | 1289 | USE_OVERFLOW_SEMANTICS is true if this function should assume that |
1290 | the rules for overflow of the given language apply (e.g., that signed | |
1291 | arithmetics in C does not overflow) -- i.e., to use them to avoid unnecessary | |
1292 | tests, but also to enforce that the result follows them. */ | |
1293 | ||
48e1416a | 1294 | static tree |
42acab1c | 1295 | chrec_convert_1 (tree type, tree chrec, gimple *at_stmt, |
57e3f39a | 1296 | bool use_overflow_semantics) |
1364018f | 1297 | { |
b3786ab3 | 1298 | tree ct, res; |
57e3f39a | 1299 | tree base, step; |
1300 | struct loop *loop; | |
b3786ab3 | 1301 | |
1364018f | 1302 | if (automatically_generated_chrec_p (chrec)) |
1303 | return chrec; | |
48e1416a | 1304 | |
1364018f | 1305 | ct = chrec_type (chrec); |
24a12d10 | 1306 | if (useless_type_conversion_p (type, ct)) |
1364018f | 1307 | return chrec; |
1308 | ||
57e3f39a | 1309 | if (!evolution_function_is_affine_p (chrec)) |
1310 | goto keep_cast; | |
9887dd18 | 1311 | |
17519ba0 | 1312 | loop = get_chrec_loop (chrec); |
57e3f39a | 1313 | base = CHREC_LEFT (chrec); |
1314 | step = CHREC_RIGHT (chrec); | |
b3786ab3 | 1315 | |
57e3f39a | 1316 | if (convert_affine_scev (loop, type, &base, &step, at_stmt, |
1317 | use_overflow_semantics)) | |
1318 | return build_polynomial_chrec (loop->num, base, step); | |
1364018f | 1319 | |
57e3f39a | 1320 | /* If we cannot propagate the cast inside the chrec, just keep the cast. */ |
1321 | keep_cast: | |
b5a4c072 | 1322 | /* Fold will not canonicalize (long)(i - 1) to (long)i - 1 because that |
1323 | may be more expensive. We do want to perform this optimization here | |
1324 | though for canonicalization reasons. */ | |
1325 | if (use_overflow_semantics | |
1326 | && (TREE_CODE (chrec) == PLUS_EXPR | |
1327 | || TREE_CODE (chrec) == MINUS_EXPR) | |
04bdcc76 | 1328 | && TREE_CODE (type) == INTEGER_TYPE |
1329 | && TREE_CODE (ct) == INTEGER_TYPE | |
b5a4c072 | 1330 | && TYPE_PRECISION (type) > TYPE_PRECISION (ct) |
1331 | && TYPE_OVERFLOW_UNDEFINED (ct)) | |
1332 | res = fold_build2 (TREE_CODE (chrec), type, | |
1333 | fold_convert (type, TREE_OPERAND (chrec, 0)), | |
1334 | fold_convert (type, TREE_OPERAND (chrec, 1))); | |
3ef23449 | 1335 | /* Similar perform the trick that (signed char)((int)x + 2) can be |
1336 | narrowed to (signed char)((unsigned char)x + 2). */ | |
1337 | else if (use_overflow_semantics | |
1338 | && TREE_CODE (chrec) == POLYNOMIAL_CHREC | |
1339 | && TREE_CODE (ct) == INTEGER_TYPE | |
1340 | && TREE_CODE (type) == INTEGER_TYPE | |
1341 | && TYPE_OVERFLOW_UNDEFINED (type) | |
1342 | && TYPE_PRECISION (type) < TYPE_PRECISION (ct)) | |
1343 | { | |
1344 | tree utype = unsigned_type_for (type); | |
1345 | res = build_polynomial_chrec (CHREC_VARIABLE (chrec), | |
1346 | fold_convert (utype, | |
1347 | CHREC_LEFT (chrec)), | |
1348 | fold_convert (utype, | |
1349 | CHREC_RIGHT (chrec))); | |
1350 | res = chrec_convert_1 (type, res, at_stmt, use_overflow_semantics); | |
1351 | } | |
b5a4c072 | 1352 | else |
1353 | res = fold_convert (type, chrec); | |
562c4a0b | 1354 | |
b3786ab3 | 1355 | /* Don't propagate overflows. */ |
1356 | if (CONSTANT_CLASS_P (res)) | |
f96bd2bf | 1357 | TREE_OVERFLOW (res) = 0; |
b3786ab3 | 1358 | |
1359 | /* But reject constants that don't fit in their type after conversion. | |
1360 | This can happen if TYPE_MIN_VALUE or TYPE_MAX_VALUE are not the | |
1361 | natural values associated with TYPE_PRECISION and TYPE_UNSIGNED, | |
1362 | and can cause problems later when computing niters of loops. Note | |
1363 | that we don't do the check before converting because we don't want | |
1364 | to reject conversions of negative chrecs to unsigned types. */ | |
1365 | if (TREE_CODE (res) == INTEGER_CST | |
1366 | && TREE_CODE (type) == INTEGER_TYPE | |
1367 | && !int_fits_type_p (res, type)) | |
1368 | res = chrec_dont_know; | |
1369 | ||
1370 | return res; | |
1364018f | 1371 | } |
1372 | ||
5fe66b3c | 1373 | /* Convert CHREC to TYPE. When the analyzer knows the context in |
1374 | which the CHREC is built, it sets AT_STMT to the statement that | |
1375 | contains the definition of the analyzed variable, otherwise the | |
1376 | conversion is less accurate: the information is used for | |
1377 | determining a more accurate estimation of the number of iterations. | |
1378 | By default AT_STMT could be safely set to NULL_TREE. | |
1379 | ||
1380 | The following rule is always true: TREE_TYPE (chrec) == | |
1381 | TREE_TYPE (CHREC_LEFT (chrec)) == TREE_TYPE (CHREC_RIGHT (chrec)). | |
1382 | An example of what could happen when adding two chrecs and the type | |
1383 | of the CHREC_RIGHT is different than CHREC_LEFT is: | |
1384 | ||
1385 | {(uint) 0, +, (uchar) 10} + | |
1386 | {(uint) 0, +, (uchar) 250} | |
1387 | ||
1388 | that would produce a wrong result if CHREC_RIGHT is not (uint): | |
1389 | ||
1390 | {(uint) 0, +, (uchar) 4} | |
1391 | ||
1392 | instead of | |
1393 | ||
1394 | {(uint) 0, +, (uint) 260} | |
1395 | ||
1396 | USE_OVERFLOW_SEMANTICS is true if this function should assume that | |
1397 | the rules for overflow of the given language apply (e.g., that signed | |
1398 | arithmetics in C does not overflow) -- i.e., to use them to avoid unnecessary | |
1399 | tests, but also to enforce that the result follows them. */ | |
1400 | ||
1401 | tree | |
42acab1c | 1402 | chrec_convert (tree type, tree chrec, gimple *at_stmt, |
5fe66b3c | 1403 | bool use_overflow_semantics) |
1404 | { | |
1405 | return chrec_convert_1 (type, chrec, at_stmt, use_overflow_semantics); | |
1406 | } | |
1407 | ||
88d02c9e | 1408 | /* Convert CHREC to TYPE, without regard to signed overflows. Returns the new |
1409 | chrec if something else than what chrec_convert would do happens, NULL_TREE | |
5fe66b3c | 1410 | otherwise. This function set TRUE to variable pointed by FOLD_CONVERSIONS |
1411 | if the result chrec may overflow. */ | |
88d02c9e | 1412 | |
1413 | tree | |
5fe66b3c | 1414 | chrec_convert_aggressive (tree type, tree chrec, bool *fold_conversions) |
88d02c9e | 1415 | { |
0de36bdb | 1416 | tree inner_type, left, right, lc, rc, rtype; |
88d02c9e | 1417 | |
5fe66b3c | 1418 | gcc_assert (fold_conversions != NULL); |
1419 | ||
88d02c9e | 1420 | if (automatically_generated_chrec_p (chrec) |
1421 | || TREE_CODE (chrec) != POLYNOMIAL_CHREC) | |
1422 | return NULL_TREE; | |
1423 | ||
1424 | inner_type = TREE_TYPE (chrec); | |
1425 | if (TYPE_PRECISION (type) > TYPE_PRECISION (inner_type)) | |
1426 | return NULL_TREE; | |
1427 | ||
5fe66b3c | 1428 | if (useless_type_conversion_p (type, inner_type)) |
1429 | return NULL_TREE; | |
1430 | ||
1431 | if (!*fold_conversions && evolution_function_is_affine_p (chrec)) | |
1432 | { | |
1433 | tree base, step; | |
1434 | struct loop *loop; | |
1435 | ||
1436 | loop = get_chrec_loop (chrec); | |
1437 | base = CHREC_LEFT (chrec); | |
1438 | step = CHREC_RIGHT (chrec); | |
1439 | if (convert_affine_scev (loop, type, &base, &step, NULL, true)) | |
1440 | return build_polynomial_chrec (loop->num, base, step); | |
1441 | } | |
0de36bdb | 1442 | rtype = POINTER_TYPE_P (type) ? sizetype : type; |
1443 | ||
88d02c9e | 1444 | left = CHREC_LEFT (chrec); |
1445 | right = CHREC_RIGHT (chrec); | |
5fe66b3c | 1446 | lc = chrec_convert_aggressive (type, left, fold_conversions); |
88d02c9e | 1447 | if (!lc) |
75a70cf9 | 1448 | lc = chrec_convert (type, left, NULL); |
5fe66b3c | 1449 | rc = chrec_convert_aggressive (rtype, right, fold_conversions); |
88d02c9e | 1450 | if (!rc) |
75a70cf9 | 1451 | rc = chrec_convert (rtype, right, NULL); |
48e1416a | 1452 | |
5fe66b3c | 1453 | *fold_conversions = true; |
1454 | ||
88d02c9e | 1455 | return build_polynomial_chrec (CHREC_VARIABLE (chrec), lc, rc); |
1456 | } | |
1457 | ||
6b421feb | 1458 | /* Returns true when CHREC0 == CHREC1. */ |
1459 | ||
48e1416a | 1460 | bool |
7ecb5bb2 | 1461 | eq_evolutions_p (const_tree chrec0, const_tree chrec1) |
6b421feb | 1462 | { |
1463 | if (chrec0 == NULL_TREE | |
1464 | || chrec1 == NULL_TREE | |
1465 | || TREE_CODE (chrec0) != TREE_CODE (chrec1)) | |
1466 | return false; | |
1467 | ||
1468 | if (chrec0 == chrec1) | |
1469 | return true; | |
1470 | ||
1471 | switch (TREE_CODE (chrec0)) | |
1472 | { | |
1473 | case INTEGER_CST: | |
f84a688a | 1474 | return operand_equal_p (chrec0, chrec1, 0); |
1475 | ||
6b421feb | 1476 | case POLYNOMIAL_CHREC: |
1477 | return (CHREC_VARIABLE (chrec0) == CHREC_VARIABLE (chrec1) | |
1478 | && eq_evolutions_p (CHREC_LEFT (chrec0), CHREC_LEFT (chrec1)) | |
1479 | && eq_evolutions_p (CHREC_RIGHT (chrec0), CHREC_RIGHT (chrec1))); | |
99c68579 | 1480 | |
1481 | case PLUS_EXPR: | |
1482 | case MULT_EXPR: | |
1483 | case MINUS_EXPR: | |
1484 | case POINTER_PLUS_EXPR: | |
1485 | return eq_evolutions_p (TREE_OPERAND (chrec0, 0), | |
1486 | TREE_OPERAND (chrec1, 0)) | |
1487 | && eq_evolutions_p (TREE_OPERAND (chrec0, 1), | |
1488 | TREE_OPERAND (chrec1, 1)); | |
1489 | ||
6b421feb | 1490 | default: |
1491 | return false; | |
48e1416a | 1492 | } |
6b421feb | 1493 | } |
1494 | ||
57e3f39a | 1495 | /* Returns EV_GROWS if CHREC grows (assuming that it does not overflow), |
1496 | EV_DECREASES if it decreases, and EV_UNKNOWN if we cannot determine | |
1497 | which of these cases happens. */ | |
1498 | ||
1499 | enum ev_direction | |
7ecb5bb2 | 1500 | scev_direction (const_tree chrec) |
57e3f39a | 1501 | { |
7ecb5bb2 | 1502 | const_tree step; |
57e3f39a | 1503 | |
1504 | if (!evolution_function_is_affine_p (chrec)) | |
1505 | return EV_DIR_UNKNOWN; | |
1506 | ||
1507 | step = CHREC_RIGHT (chrec); | |
1508 | if (TREE_CODE (step) != INTEGER_CST) | |
1509 | return EV_DIR_UNKNOWN; | |
1510 | ||
1511 | if (tree_int_cst_sign_bit (step)) | |
1512 | return EV_DIR_DECREASES; | |
1513 | else | |
1514 | return EV_DIR_GROWS; | |
1515 | } | |
255b6be7 | 1516 | |
1517 | /* Iterates over all the components of SCEV, and calls CBCK. */ | |
1518 | ||
1519 | void | |
1520 | for_each_scev_op (tree *scev, bool (*cbck) (tree *, void *), void *data) | |
1521 | { | |
1522 | switch (TREE_CODE_LENGTH (TREE_CODE (*scev))) | |
1523 | { | |
1524 | case 3: | |
1525 | for_each_scev_op (&TREE_OPERAND (*scev, 2), cbck, data); | |
1526 | ||
1527 | case 2: | |
1528 | for_each_scev_op (&TREE_OPERAND (*scev, 1), cbck, data); | |
7ed7512f | 1529 | |
255b6be7 | 1530 | case 1: |
1531 | for_each_scev_op (&TREE_OPERAND (*scev, 0), cbck, data); | |
1532 | ||
1533 | default: | |
1534 | cbck (scev, data); | |
1535 | break; | |
1536 | } | |
1537 | } | |
1538 | ||
145bdf6a | 1539 | /* Returns true when the operation can be part of a linear |
1540 | expression. */ | |
1541 | ||
1542 | static inline bool | |
1543 | operator_is_linear (tree scev) | |
1544 | { | |
1545 | switch (TREE_CODE (scev)) | |
1546 | { | |
1547 | case INTEGER_CST: | |
1548 | case POLYNOMIAL_CHREC: | |
1549 | case PLUS_EXPR: | |
1550 | case POINTER_PLUS_EXPR: | |
1551 | case MULT_EXPR: | |
1552 | case MINUS_EXPR: | |
1553 | case NEGATE_EXPR: | |
1554 | case SSA_NAME: | |
1555 | case NON_LVALUE_EXPR: | |
7ed7512f | 1556 | case BIT_NOT_EXPR: |
145bdf6a | 1557 | CASE_CONVERT: |
1558 | return true; | |
1559 | ||
1560 | default: | |
1561 | return false; | |
1562 | } | |
1563 | } | |
1564 | ||
1565 | /* Return true when SCEV is a linear expression. Linear expressions | |
1566 | can contain additions, substractions and multiplications. | |
1567 | Multiplications are restricted to constant scaling: "cst * x". */ | |
1568 | ||
1569 | bool | |
1570 | scev_is_linear_expression (tree scev) | |
1571 | { | |
1572 | if (scev == NULL | |
1573 | || !operator_is_linear (scev)) | |
1574 | return false; | |
1575 | ||
1576 | if (TREE_CODE (scev) == MULT_EXPR) | |
1577 | return !(tree_contains_chrecs (TREE_OPERAND (scev, 0), NULL) | |
1578 | && tree_contains_chrecs (TREE_OPERAND (scev, 1), NULL)); | |
1579 | ||
7ed7512f | 1580 | if (TREE_CODE (scev) == POLYNOMIAL_CHREC |
1581 | && !evolution_function_is_affine_multivariate_p (scev, CHREC_VARIABLE (scev))) | |
1582 | return false; | |
1583 | ||
145bdf6a | 1584 | switch (TREE_CODE_LENGTH (TREE_CODE (scev))) |
1585 | { | |
1586 | case 3: | |
1587 | return scev_is_linear_expression (TREE_OPERAND (scev, 0)) | |
1588 | && scev_is_linear_expression (TREE_OPERAND (scev, 1)) | |
1589 | && scev_is_linear_expression (TREE_OPERAND (scev, 2)); | |
1590 | ||
1591 | case 2: | |
1592 | return scev_is_linear_expression (TREE_OPERAND (scev, 0)) | |
1593 | && scev_is_linear_expression (TREE_OPERAND (scev, 1)); | |
7ed7512f | 1594 | |
145bdf6a | 1595 | case 1: |
1596 | return scev_is_linear_expression (TREE_OPERAND (scev, 0)); | |
1597 | ||
1598 | case 0: | |
1599 | return true; | |
1600 | ||
1601 | default: | |
1602 | return false; | |
1603 | } | |
1604 | } | |
e44bcf83 | 1605 | |
1606 | /* Determines whether the expression CHREC contains only interger consts | |
1607 | in the right parts. */ | |
1608 | ||
1609 | bool | |
1610 | evolution_function_right_is_integer_cst (const_tree chrec) | |
1611 | { | |
1612 | if (chrec == NULL_TREE) | |
1613 | return false; | |
1614 | ||
1615 | switch (TREE_CODE (chrec)) | |
1616 | { | |
1617 | case INTEGER_CST: | |
1618 | return true; | |
1619 | ||
1620 | case POLYNOMIAL_CHREC: | |
c4ccbe87 | 1621 | return TREE_CODE (CHREC_RIGHT (chrec)) == INTEGER_CST |
1622 | && (TREE_CODE (CHREC_LEFT (chrec)) != POLYNOMIAL_CHREC | |
1623 | || evolution_function_right_is_integer_cst (CHREC_LEFT (chrec))); | |
e44bcf83 | 1624 | |
c4ccbe87 | 1625 | CASE_CONVERT: |
1626 | return evolution_function_right_is_integer_cst (TREE_OPERAND (chrec, 0)); | |
e44bcf83 | 1627 | |
1628 | default: | |
1629 | return false; | |
1630 | } | |
1631 | } |