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e9eb809d | 1 | /* Scalar evolution detector. |
5624e564 | 2 | Copyright (C) 2003-2015 Free Software Foundation, Inc. |
e9eb809d ZD |
3 | Contributed by Sebastian Pop <s.pop@laposte.net> |
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 | |
9dcd6f09 | 9 | Software Foundation; either version 3, or (at your option) any later |
e9eb809d ZD |
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 | |
9dcd6f09 NC |
18 | along with GCC; see the file COPYING3. If not see |
19 | <http://www.gnu.org/licenses/>. */ | |
e9eb809d | 20 | |
b8698a0f L |
21 | /* |
22 | Description: | |
23 | ||
9baba81b SP |
24 | This pass analyzes the evolution of scalar variables in loop |
25 | structures. The algorithm is based on the SSA representation, | |
26 | and on the loop hierarchy tree. This algorithm is not based on | |
27 | the notion of versions of a variable, as it was the case for the | |
28 | previous implementations of the scalar evolution algorithm, but | |
29 | it assumes that each defined name is unique. | |
30 | ||
31 | The notation used in this file is called "chains of recurrences", | |
32 | and has been proposed by Eugene Zima, Robert Van Engelen, and | |
33 | others for describing induction variables in programs. For example | |
34 | "b -> {0, +, 2}_1" means that the scalar variable "b" is equal to 0 | |
35 | when entering in the loop_1 and has a step 2 in this loop, in other | |
36 | words "for (b = 0; b < N; b+=2);". Note that the coefficients of | |
37 | this chain of recurrence (or chrec [shrek]) can contain the name of | |
38 | other variables, in which case they are called parametric chrecs. | |
39 | For example, "b -> {a, +, 2}_1" means that the initial value of "b" | |
40 | is the value of "a". In most of the cases these parametric chrecs | |
41 | are fully instantiated before their use because symbolic names can | |
42 | hide some difficult cases such as self-references described later | |
43 | (see the Fibonacci example). | |
b8698a0f | 44 | |
9baba81b | 45 | A short sketch of the algorithm is: |
b8698a0f | 46 | |
9baba81b SP |
47 | Given a scalar variable to be analyzed, follow the SSA edge to |
48 | its definition: | |
b8698a0f | 49 | |
726a989a | 50 | - When the definition is a GIMPLE_ASSIGN: if the right hand side |
9baba81b | 51 | (RHS) of the definition cannot be statically analyzed, the answer |
b8698a0f | 52 | of the analyzer is: "don't know". |
9baba81b SP |
53 | Otherwise, for all the variables that are not yet analyzed in the |
54 | RHS, try to determine their evolution, and finally try to | |
55 | evaluate the operation of the RHS that gives the evolution | |
56 | function of the analyzed variable. | |
57 | ||
58 | - When the definition is a condition-phi-node: determine the | |
59 | evolution function for all the branches of the phi node, and | |
60 | finally merge these evolutions (see chrec_merge). | |
61 | ||
62 | - When the definition is a loop-phi-node: determine its initial | |
63 | condition, that is the SSA edge defined in an outer loop, and | |
64 | keep it symbolic. Then determine the SSA edges that are defined | |
65 | in the body of the loop. Follow the inner edges until ending on | |
66 | another loop-phi-node of the same analyzed loop. If the reached | |
67 | loop-phi-node is not the starting loop-phi-node, then we keep | |
68 | this definition under a symbolic form. If the reached | |
69 | loop-phi-node is the same as the starting one, then we compute a | |
70 | symbolic stride on the return path. The result is then the | |
71 | symbolic chrec {initial_condition, +, symbolic_stride}_loop. | |
72 | ||
73 | Examples: | |
b8698a0f | 74 | |
9baba81b | 75 | Example 1: Illustration of the basic algorithm. |
b8698a0f | 76 | |
9baba81b SP |
77 | | a = 3 |
78 | | loop_1 | |
79 | | b = phi (a, c) | |
80 | | c = b + 1 | |
81 | | if (c > 10) exit_loop | |
82 | | endloop | |
b8698a0f | 83 | |
9baba81b SP |
84 | Suppose that we want to know the number of iterations of the |
85 | loop_1. The exit_loop is controlled by a COND_EXPR (c > 10). We | |
86 | ask the scalar evolution analyzer two questions: what's the | |
87 | scalar evolution (scev) of "c", and what's the scev of "10". For | |
88 | "10" the answer is "10" since it is a scalar constant. For the | |
89 | scalar variable "c", it follows the SSA edge to its definition, | |
90 | "c = b + 1", and then asks again what's the scev of "b". | |
91 | Following the SSA edge, we end on a loop-phi-node "b = phi (a, | |
92 | c)", where the initial condition is "a", and the inner loop edge | |
93 | is "c". The initial condition is kept under a symbolic form (it | |
94 | may be the case that the copy constant propagation has done its | |
95 | work and we end with the constant "3" as one of the edges of the | |
96 | loop-phi-node). The update edge is followed to the end of the | |
97 | loop, and until reaching again the starting loop-phi-node: b -> c | |
98 | -> b. At this point we have drawn a path from "b" to "b" from | |
99 | which we compute the stride in the loop: in this example it is | |
100 | "+1". The resulting scev for "b" is "b -> {a, +, 1}_1". Now | |
101 | that the scev for "b" is known, it is possible to compute the | |
102 | scev for "c", that is "c -> {a + 1, +, 1}_1". In order to | |
103 | determine the number of iterations in the loop_1, we have to | |
3f227a8c | 104 | instantiate_parameters (loop_1, {a + 1, +, 1}_1), that gives after some |
9baba81b SP |
105 | more analysis the scev {4, +, 1}_1, or in other words, this is |
106 | the function "f (x) = x + 4", where x is the iteration count of | |
107 | the loop_1. Now we have to solve the inequality "x + 4 > 10", | |
108 | and take the smallest iteration number for which the loop is | |
109 | exited: x = 7. This loop runs from x = 0 to x = 7, and in total | |
110 | there are 8 iterations. In terms of loop normalization, we have | |
111 | created a variable that is implicitly defined, "x" or just "_1", | |
112 | and all the other analyzed scalars of the loop are defined in | |
113 | function of this variable: | |
b8698a0f | 114 | |
9baba81b SP |
115 | a -> 3 |
116 | b -> {3, +, 1}_1 | |
117 | c -> {4, +, 1}_1 | |
b8698a0f L |
118 | |
119 | or in terms of a C program: | |
120 | ||
9baba81b SP |
121 | | a = 3 |
122 | | for (x = 0; x <= 7; x++) | |
123 | | { | |
124 | | b = x + 3 | |
125 | | c = x + 4 | |
126 | | } | |
b8698a0f | 127 | |
3f227a8c | 128 | Example 2a: Illustration of the algorithm on nested loops. |
b8698a0f | 129 | |
9baba81b SP |
130 | | loop_1 |
131 | | a = phi (1, b) | |
132 | | c = a + 2 | |
133 | | loop_2 10 times | |
134 | | b = phi (c, d) | |
135 | | d = b + 3 | |
136 | | endloop | |
137 | | endloop | |
b8698a0f | 138 | |
9baba81b SP |
139 | For analyzing the scalar evolution of "a", the algorithm follows |
140 | the SSA edge into the loop's body: "a -> b". "b" is an inner | |
b8698a0f L |
141 | loop-phi-node, and its analysis as in Example 1, gives: |
142 | ||
9baba81b SP |
143 | b -> {c, +, 3}_2 |
144 | d -> {c + 3, +, 3}_2 | |
b8698a0f | 145 | |
9baba81b SP |
146 | Following the SSA edge for the initial condition, we end on "c = a |
147 | + 2", and then on the starting loop-phi-node "a". From this point, | |
148 | the loop stride is computed: back on "c = a + 2" we get a "+2" in | |
149 | the loop_1, then on the loop-phi-node "b" we compute the overall | |
150 | effect of the inner loop that is "b = c + 30", and we get a "+30" | |
151 | in the loop_1. That means that the overall stride in loop_1 is | |
b8698a0f L |
152 | equal to "+32", and the result is: |
153 | ||
9baba81b SP |
154 | a -> {1, +, 32}_1 |
155 | c -> {3, +, 32}_1 | |
3f227a8c JS |
156 | |
157 | Example 2b: Multivariate chains of recurrences. | |
158 | ||
159 | | loop_1 | |
160 | | k = phi (0, k + 1) | |
161 | | loop_2 4 times | |
162 | | j = phi (0, j + 1) | |
163 | | loop_3 4 times | |
164 | | i = phi (0, i + 1) | |
165 | | A[j + k] = ... | |
166 | | endloop | |
167 | | endloop | |
168 | | endloop | |
169 | ||
170 | Analyzing the access function of array A with | |
171 | instantiate_parameters (loop_1, "j + k"), we obtain the | |
172 | instantiation and the analysis of the scalar variables "j" and "k" | |
173 | in loop_1. This leads to the scalar evolution {4, +, 1}_1: the end | |
174 | value of loop_2 for "j" is 4, and the evolution of "k" in loop_1 is | |
175 | {0, +, 1}_1. To obtain the evolution function in loop_3 and | |
176 | instantiate the scalar variables up to loop_1, one has to use: | |
a213b219 SP |
177 | instantiate_scev (block_before_loop (loop_1), loop_3, "j + k"). |
178 | The result of this call is {{0, +, 1}_1, +, 1}_2. | |
3f227a8c | 179 | |
9baba81b | 180 | Example 3: Higher degree polynomials. |
b8698a0f | 181 | |
9baba81b SP |
182 | | loop_1 |
183 | | a = phi (2, b) | |
184 | | c = phi (5, d) | |
185 | | b = a + 1 | |
186 | | d = c + a | |
187 | | endloop | |
b8698a0f | 188 | |
9baba81b SP |
189 | a -> {2, +, 1}_1 |
190 | b -> {3, +, 1}_1 | |
191 | c -> {5, +, a}_1 | |
192 | d -> {5 + a, +, a}_1 | |
b8698a0f | 193 | |
3f227a8c JS |
194 | instantiate_parameters (loop_1, {5, +, a}_1) -> {5, +, 2, +, 1}_1 |
195 | instantiate_parameters (loop_1, {5 + a, +, a}_1) -> {7, +, 3, +, 1}_1 | |
b8698a0f | 196 | |
9baba81b | 197 | Example 4: Lucas, Fibonacci, or mixers in general. |
b8698a0f | 198 | |
9baba81b SP |
199 | | loop_1 |
200 | | a = phi (1, b) | |
201 | | c = phi (3, d) | |
202 | | b = c | |
203 | | d = c + a | |
204 | | endloop | |
b8698a0f | 205 | |
9baba81b SP |
206 | a -> (1, c)_1 |
207 | c -> {3, +, a}_1 | |
b8698a0f | 208 | |
9baba81b SP |
209 | The syntax "(1, c)_1" stands for a PEELED_CHREC that has the |
210 | following semantics: during the first iteration of the loop_1, the | |
211 | variable contains the value 1, and then it contains the value "c". | |
212 | Note that this syntax is close to the syntax of the loop-phi-node: | |
213 | "a -> (1, c)_1" vs. "a = phi (1, c)". | |
b8698a0f | 214 | |
9baba81b SP |
215 | The symbolic chrec representation contains all the semantics of the |
216 | original code. What is more difficult is to use this information. | |
b8698a0f | 217 | |
9baba81b | 218 | Example 5: Flip-flops, or exchangers. |
b8698a0f | 219 | |
9baba81b SP |
220 | | loop_1 |
221 | | a = phi (1, b) | |
222 | | c = phi (3, d) | |
223 | | b = c | |
224 | | d = a | |
225 | | endloop | |
b8698a0f | 226 | |
9baba81b SP |
227 | a -> (1, c)_1 |
228 | c -> (3, a)_1 | |
b8698a0f | 229 | |
9baba81b | 230 | Based on these symbolic chrecs, it is possible to refine this |
b8698a0f L |
231 | information into the more precise PERIODIC_CHRECs: |
232 | ||
9baba81b SP |
233 | a -> |1, 3|_1 |
234 | c -> |3, 1|_1 | |
b8698a0f | 235 | |
9baba81b | 236 | This transformation is not yet implemented. |
b8698a0f | 237 | |
9baba81b | 238 | Further readings: |
b8698a0f | 239 | |
9baba81b SP |
240 | You can find a more detailed description of the algorithm in: |
241 | http://icps.u-strasbg.fr/~pop/DEA_03_Pop.pdf | |
242 | http://icps.u-strasbg.fr/~pop/DEA_03_Pop.ps.gz. But note that | |
243 | this is a preliminary report and some of the details of the | |
244 | algorithm have changed. I'm working on a research report that | |
245 | updates the description of the algorithms to reflect the design | |
246 | choices used in this implementation. | |
b8698a0f | 247 | |
9baba81b SP |
248 | A set of slides show a high level overview of the algorithm and run |
249 | an example through the scalar evolution analyzer: | |
250 | http://cri.ensmp.fr/~pop/gcc/mar04/slides.pdf | |
251 | ||
252 | The slides that I have presented at the GCC Summit'04 are available | |
253 | at: http://cri.ensmp.fr/~pop/gcc/20040604/gccsummit-lno-spop.pdf | |
254 | */ | |
255 | ||
e9eb809d ZD |
256 | #include "config.h" |
257 | #include "system.h" | |
258 | #include "coretypes.h" | |
40e23961 MC |
259 | #include "hash-set.h" |
260 | #include "machmode.h" | |
261 | #include "vec.h" | |
262 | #include "double-int.h" | |
263 | #include "input.h" | |
264 | #include "alias.h" | |
265 | #include "symtab.h" | |
266 | #include "options.h" | |
267 | #include "wide-int.h" | |
268 | #include "inchash.h" | |
cf2d1b38 | 269 | #include "tree.h" |
40e23961 | 270 | #include "fold-const.h" |
d8a2d370 | 271 | #include "expr.h" |
cf835838 | 272 | #include "gimple-pretty-print.h" |
60393bbc | 273 | #include "predict.h" |
60393bbc AM |
274 | #include "tm.h" |
275 | #include "hard-reg-set.h" | |
276 | #include "input.h" | |
277 | #include "function.h" | |
278 | #include "dominance.h" | |
279 | #include "cfg.h" | |
2fb9a547 AM |
280 | #include "basic-block.h" |
281 | #include "tree-ssa-alias.h" | |
282 | #include "internal-fn.h" | |
283 | #include "gimple-expr.h" | |
284 | #include "is-a.h" | |
18f429e2 | 285 | #include "gimple.h" |
45b0be94 | 286 | #include "gimplify.h" |
5be5c238 | 287 | #include "gimple-iterator.h" |
18f429e2 | 288 | #include "gimplify-me.h" |
442b4905 AM |
289 | #include "gimple-ssa.h" |
290 | #include "tree-cfg.h" | |
291 | #include "tree-phinodes.h" | |
d8a2d370 | 292 | #include "stringpool.h" |
442b4905 | 293 | #include "tree-ssanames.h" |
e28030cf AM |
294 | #include "tree-ssa-loop-ivopts.h" |
295 | #include "tree-ssa-loop-manip.h" | |
296 | #include "tree-ssa-loop-niter.h" | |
442b4905 | 297 | #include "tree-ssa-loop.h" |
7a300452 | 298 | #include "tree-ssa.h" |
e9eb809d ZD |
299 | #include "cfgloop.h" |
300 | #include "tree-chrec.h" | |
b83b5507 | 301 | #include "tree-affine.h" |
e9eb809d | 302 | #include "tree-scalar-evolution.h" |
7ee2468b | 303 | #include "dumpfile.h" |
c59dabbe | 304 | #include "params.h" |
744730a4 | 305 | #include "tree-ssa-propagate.h" |
19e51b40 JJ |
306 | #include "gimple-fold.h" |
307 | #include "gimplify-me.h" | |
9baba81b SP |
308 | |
309 | static tree analyze_scalar_evolution_1 (struct loop *, tree, tree); | |
bef28ced JL |
310 | static tree analyze_scalar_evolution_for_address_of (struct loop *loop, |
311 | tree var); | |
9baba81b | 312 | |
a3cc13cc RB |
313 | /* The cached information about an SSA name with version NAME_VERSION, |
314 | claiming that below basic block with index INSTANTIATED_BELOW, the | |
315 | value of the SSA name can be expressed as CHREC. */ | |
9baba81b | 316 | |
907dadbd | 317 | struct GTY((for_user)) scev_info_str { |
a3cc13cc RB |
318 | unsigned int name_version; |
319 | int instantiated_below; | |
9baba81b SP |
320 | tree chrec; |
321 | }; | |
322 | ||
323 | /* Counters for the scev database. */ | |
324 | static unsigned nb_set_scev = 0; | |
325 | static unsigned nb_get_scev = 0; | |
326 | ||
327 | /* The following trees are unique elements. Thus the comparison of | |
328 | another element to these elements should be done on the pointer to | |
329 | these trees, and not on their value. */ | |
330 | ||
331 | /* The SSA_NAMEs that are not yet analyzed are qualified with NULL_TREE. */ | |
332 | tree chrec_not_analyzed_yet; | |
333 | ||
334 | /* Reserved to the cases where the analyzer has detected an | |
335 | undecidable property at compile time. */ | |
336 | tree chrec_dont_know; | |
337 | ||
338 | /* When the analyzer has detected that a property will never | |
339 | happen, then it qualifies it with chrec_known. */ | |
340 | tree chrec_known; | |
341 | ||
907dadbd TS |
342 | struct scev_info_hasher : ggc_hasher<scev_info_str *> |
343 | { | |
344 | static hashval_t hash (scev_info_str *i); | |
345 | static bool equal (const scev_info_str *a, const scev_info_str *b); | |
346 | }; | |
347 | ||
348 | static GTY (()) hash_table<scev_info_hasher> *scalar_evolution_info; | |
9baba81b SP |
349 | |
350 | \f | |
a213b219 | 351 | /* Constructs a new SCEV_INFO_STR structure for VAR and INSTANTIATED_BELOW. */ |
9baba81b SP |
352 | |
353 | static inline struct scev_info_str * | |
a213b219 | 354 | new_scev_info_str (basic_block instantiated_below, tree var) |
9baba81b SP |
355 | { |
356 | struct scev_info_str *res; | |
b8698a0f | 357 | |
766090c2 | 358 | res = ggc_alloc<scev_info_str> (); |
a3cc13cc | 359 | res->name_version = SSA_NAME_VERSION (var); |
9baba81b | 360 | res->chrec = chrec_not_analyzed_yet; |
a3cc13cc | 361 | res->instantiated_below = instantiated_below->index; |
a213b219 | 362 | |
9baba81b SP |
363 | return res; |
364 | } | |
365 | ||
366 | /* Computes a hash function for database element ELT. */ | |
367 | ||
907dadbd TS |
368 | hashval_t |
369 | scev_info_hasher::hash (scev_info_str *elt) | |
9baba81b | 370 | { |
a3cc13cc | 371 | return elt->name_version ^ elt->instantiated_below; |
9baba81b SP |
372 | } |
373 | ||
374 | /* Compares database elements E1 and E2. */ | |
375 | ||
907dadbd TS |
376 | bool |
377 | scev_info_hasher::equal (const scev_info_str *elt1, const scev_info_str *elt2) | |
9baba81b | 378 | { |
a3cc13cc | 379 | return (elt1->name_version == elt2->name_version |
a213b219 | 380 | && elt1->instantiated_below == elt2->instantiated_below); |
9baba81b SP |
381 | } |
382 | ||
a213b219 SP |
383 | /* Get the scalar evolution of VAR for INSTANTIATED_BELOW basic block. |
384 | A first query on VAR returns chrec_not_analyzed_yet. */ | |
9baba81b SP |
385 | |
386 | static tree * | |
a213b219 | 387 | find_var_scev_info (basic_block instantiated_below, tree var) |
9baba81b SP |
388 | { |
389 | struct scev_info_str *res; | |
390 | struct scev_info_str tmp; | |
9baba81b | 391 | |
a3cc13cc RB |
392 | tmp.name_version = SSA_NAME_VERSION (var); |
393 | tmp.instantiated_below = instantiated_below->index; | |
907dadbd | 394 | scev_info_str **slot = scalar_evolution_info->find_slot (&tmp, INSERT); |
9baba81b SP |
395 | |
396 | if (!*slot) | |
a213b219 | 397 | *slot = new_scev_info_str (instantiated_below, var); |
907dadbd | 398 | res = *slot; |
9baba81b SP |
399 | |
400 | return &res->chrec; | |
401 | } | |
402 | ||
9baba81b SP |
403 | /* Return true when CHREC contains symbolic names defined in |
404 | LOOP_NB. */ | |
405 | ||
b8698a0f | 406 | bool |
ed7a4b4b | 407 | chrec_contains_symbols_defined_in_loop (const_tree chrec, unsigned loop_nb) |
9baba81b | 408 | { |
5039610b SL |
409 | int i, n; |
410 | ||
9baba81b SP |
411 | if (chrec == NULL_TREE) |
412 | return false; | |
413 | ||
ad6003f2 | 414 | if (is_gimple_min_invariant (chrec)) |
9baba81b SP |
415 | return false; |
416 | ||
9baba81b SP |
417 | if (TREE_CODE (chrec) == SSA_NAME) |
418 | { | |
492e5456 SP |
419 | gimple def; |
420 | loop_p def_loop, loop; | |
421 | ||
422 | if (SSA_NAME_IS_DEFAULT_DEF (chrec)) | |
423 | return false; | |
424 | ||
425 | def = SSA_NAME_DEF_STMT (chrec); | |
426 | def_loop = loop_containing_stmt (def); | |
0fc822d0 | 427 | loop = get_loop (cfun, loop_nb); |
9baba81b SP |
428 | |
429 | if (def_loop == NULL) | |
430 | return false; | |
431 | ||
432 | if (loop == def_loop || flow_loop_nested_p (loop, def_loop)) | |
433 | return true; | |
434 | ||
435 | return false; | |
436 | } | |
437 | ||
5039610b SL |
438 | n = TREE_OPERAND_LENGTH (chrec); |
439 | for (i = 0; i < n; i++) | |
b8698a0f | 440 | if (chrec_contains_symbols_defined_in_loop (TREE_OPERAND (chrec, i), |
5039610b SL |
441 | loop_nb)) |
442 | return true; | |
443 | return false; | |
9baba81b SP |
444 | } |
445 | ||
446 | /* Return true when PHI is a loop-phi-node. */ | |
447 | ||
448 | static bool | |
726a989a | 449 | loop_phi_node_p (gimple phi) |
9baba81b SP |
450 | { |
451 | /* The implementation of this function is based on the following | |
452 | property: "all the loop-phi-nodes of a loop are contained in the | |
453 | loop's header basic block". */ | |
454 | ||
726a989a | 455 | return loop_containing_stmt (phi)->header == gimple_bb (phi); |
9baba81b SP |
456 | } |
457 | ||
458 | /* Compute the scalar evolution for EVOLUTION_FN after crossing LOOP. | |
459 | In general, in the case of multivariate evolutions we want to get | |
460 | the evolution in different loops. LOOP specifies the level for | |
461 | which to get the evolution. | |
b8698a0f | 462 | |
9baba81b | 463 | Example: |
b8698a0f | 464 | |
9baba81b SP |
465 | | for (j = 0; j < 100; j++) |
466 | | { | |
467 | | for (k = 0; k < 100; k++) | |
468 | | { | |
b8698a0f | 469 | | i = k + j; - Here the value of i is a function of j, k. |
9baba81b | 470 | | } |
b8698a0f | 471 | | ... = i - Here the value of i is a function of j. |
9baba81b | 472 | | } |
b8698a0f L |
473 | | ... = i - Here the value of i is a scalar. |
474 | ||
475 | Example: | |
476 | ||
9baba81b SP |
477 | | i_0 = ... |
478 | | loop_1 10 times | |
479 | | i_1 = phi (i_0, i_2) | |
480 | | i_2 = i_1 + 2 | |
481 | | endloop | |
b8698a0f | 482 | |
9baba81b SP |
483 | This loop has the same effect as: |
484 | LOOP_1 has the same effect as: | |
b8698a0f | 485 | |
9baba81b | 486 | | i_1 = i_0 + 20 |
b8698a0f L |
487 | |
488 | The overall effect of the loop, "i_0 + 20" in the previous example, | |
489 | is obtained by passing in the parameters: LOOP = 1, | |
9baba81b SP |
490 | EVOLUTION_FN = {i_0, +, 2}_1. |
491 | */ | |
b8698a0f | 492 | |
42e6eec5 | 493 | tree |
9baba81b SP |
494 | compute_overall_effect_of_inner_loop (struct loop *loop, tree evolution_fn) |
495 | { | |
496 | bool val = false; | |
497 | ||
498 | if (evolution_fn == chrec_dont_know) | |
499 | return chrec_dont_know; | |
500 | ||
501 | else if (TREE_CODE (evolution_fn) == POLYNOMIAL_CHREC) | |
502 | { | |
677cc14d ZD |
503 | struct loop *inner_loop = get_chrec_loop (evolution_fn); |
504 | ||
505 | if (inner_loop == loop | |
506 | || flow_loop_nested_p (loop, inner_loop)) | |
9baba81b | 507 | { |
a14865db | 508 | tree nb_iter = number_of_latch_executions (inner_loop); |
9baba81b SP |
509 | |
510 | if (nb_iter == chrec_dont_know) | |
511 | return chrec_dont_know; | |
512 | else | |
513 | { | |
514 | tree res; | |
515 | ||
9baba81b SP |
516 | /* evolution_fn is the evolution function in LOOP. Get |
517 | its value in the nb_iter-th iteration. */ | |
518 | res = chrec_apply (inner_loop->num, evolution_fn, nb_iter); | |
42e6eec5 SP |
519 | |
520 | if (chrec_contains_symbols_defined_in_loop (res, loop->num)) | |
521 | res = instantiate_parameters (loop, res); | |
522 | ||
8c27b7d4 | 523 | /* Continue the computation until ending on a parent of LOOP. */ |
9baba81b SP |
524 | return compute_overall_effect_of_inner_loop (loop, res); |
525 | } | |
526 | } | |
527 | else | |
528 | return evolution_fn; | |
529 | } | |
b8698a0f | 530 | |
9baba81b SP |
531 | /* If the evolution function is an invariant, there is nothing to do. */ |
532 | else if (no_evolution_in_loop_p (evolution_fn, loop->num, &val) && val) | |
533 | return evolution_fn; | |
b8698a0f | 534 | |
9baba81b SP |
535 | else |
536 | return chrec_dont_know; | |
537 | } | |
538 | ||
9baba81b SP |
539 | /* Associate CHREC to SCALAR. */ |
540 | ||
541 | static void | |
a213b219 | 542 | set_scalar_evolution (basic_block instantiated_below, tree scalar, tree chrec) |
9baba81b SP |
543 | { |
544 | tree *scalar_info; | |
b8698a0f | 545 | |
9baba81b SP |
546 | if (TREE_CODE (scalar) != SSA_NAME) |
547 | return; | |
548 | ||
a213b219 | 549 | scalar_info = find_var_scev_info (instantiated_below, scalar); |
b8698a0f | 550 | |
9baba81b SP |
551 | if (dump_file) |
552 | { | |
dfedbe40 | 553 | if (dump_flags & TDF_SCEV) |
9baba81b SP |
554 | { |
555 | fprintf (dump_file, "(set_scalar_evolution \n"); | |
a213b219 SP |
556 | fprintf (dump_file, " instantiated_below = %d \n", |
557 | instantiated_below->index); | |
9baba81b SP |
558 | fprintf (dump_file, " (scalar = "); |
559 | print_generic_expr (dump_file, scalar, 0); | |
560 | fprintf (dump_file, ")\n (scalar_evolution = "); | |
561 | print_generic_expr (dump_file, chrec, 0); | |
562 | fprintf (dump_file, "))\n"); | |
563 | } | |
564 | if (dump_flags & TDF_STATS) | |
565 | nb_set_scev++; | |
566 | } | |
b8698a0f | 567 | |
9baba81b SP |
568 | *scalar_info = chrec; |
569 | } | |
570 | ||
a213b219 SP |
571 | /* Retrieve the chrec associated to SCALAR instantiated below |
572 | INSTANTIATED_BELOW block. */ | |
9baba81b SP |
573 | |
574 | static tree | |
a213b219 | 575 | get_scalar_evolution (basic_block instantiated_below, tree scalar) |
9baba81b SP |
576 | { |
577 | tree res; | |
b8698a0f | 578 | |
9baba81b SP |
579 | if (dump_file) |
580 | { | |
dfedbe40 | 581 | if (dump_flags & TDF_SCEV) |
9baba81b SP |
582 | { |
583 | fprintf (dump_file, "(get_scalar_evolution \n"); | |
584 | fprintf (dump_file, " (scalar = "); | |
585 | print_generic_expr (dump_file, scalar, 0); | |
586 | fprintf (dump_file, ")\n"); | |
587 | } | |
588 | if (dump_flags & TDF_STATS) | |
589 | nb_get_scev++; | |
590 | } | |
b8698a0f | 591 | |
9baba81b SP |
592 | switch (TREE_CODE (scalar)) |
593 | { | |
594 | case SSA_NAME: | |
a213b219 | 595 | res = *find_var_scev_info (instantiated_below, scalar); |
9baba81b SP |
596 | break; |
597 | ||
598 | case REAL_CST: | |
325217ed | 599 | case FIXED_CST: |
9baba81b SP |
600 | case INTEGER_CST: |
601 | res = scalar; | |
602 | break; | |
603 | ||
604 | default: | |
605 | res = chrec_not_analyzed_yet; | |
606 | break; | |
607 | } | |
b8698a0f | 608 | |
dfedbe40 | 609 | if (dump_file && (dump_flags & TDF_SCEV)) |
9baba81b SP |
610 | { |
611 | fprintf (dump_file, " (scalar_evolution = "); | |
612 | print_generic_expr (dump_file, res, 0); | |
613 | fprintf (dump_file, "))\n"); | |
614 | } | |
b8698a0f | 615 | |
9baba81b SP |
616 | return res; |
617 | } | |
618 | ||
619 | /* Helper function for add_to_evolution. Returns the evolution | |
620 | function for an assignment of the form "a = b + c", where "a" and | |
621 | "b" are on the strongly connected component. CHREC_BEFORE is the | |
622 | information that we already have collected up to this point. | |
b8698a0f L |
623 | TO_ADD is the evolution of "c". |
624 | ||
9baba81b SP |
625 | When CHREC_BEFORE has an evolution part in LOOP_NB, add to this |
626 | evolution the expression TO_ADD, otherwise construct an evolution | |
627 | part for this loop. */ | |
628 | ||
629 | static tree | |
e2157b49 | 630 | add_to_evolution_1 (unsigned loop_nb, tree chrec_before, tree to_add, |
726a989a | 631 | gimple at_stmt) |
9baba81b | 632 | { |
e2157b49 | 633 | tree type, left, right; |
0fc822d0 | 634 | struct loop *loop = get_loop (cfun, loop_nb), *chloop; |
e2157b49 | 635 | |
9baba81b SP |
636 | switch (TREE_CODE (chrec_before)) |
637 | { | |
638 | case POLYNOMIAL_CHREC: | |
677cc14d ZD |
639 | chloop = get_chrec_loop (chrec_before); |
640 | if (chloop == loop | |
641 | || flow_loop_nested_p (chloop, loop)) | |
9baba81b SP |
642 | { |
643 | unsigned var; | |
e2157b49 SP |
644 | |
645 | type = chrec_type (chrec_before); | |
b8698a0f | 646 | |
9baba81b | 647 | /* When there is no evolution part in this loop, build it. */ |
677cc14d | 648 | if (chloop != loop) |
9baba81b SP |
649 | { |
650 | var = loop_nb; | |
651 | left = chrec_before; | |
7e0923cd SP |
652 | right = SCALAR_FLOAT_TYPE_P (type) |
653 | ? build_real (type, dconst0) | |
654 | : build_int_cst (type, 0); | |
9baba81b SP |
655 | } |
656 | else | |
657 | { | |
658 | var = CHREC_VARIABLE (chrec_before); | |
659 | left = CHREC_LEFT (chrec_before); | |
660 | right = CHREC_RIGHT (chrec_before); | |
661 | } | |
662 | ||
e2157b49 | 663 | to_add = chrec_convert (type, to_add, at_stmt); |
5be014d5 AP |
664 | right = chrec_convert_rhs (type, right, at_stmt); |
665 | right = chrec_fold_plus (chrec_type (right), right, to_add); | |
e2157b49 | 666 | return build_polynomial_chrec (var, left, right); |
9baba81b SP |
667 | } |
668 | else | |
e2157b49 | 669 | { |
677cc14d ZD |
670 | gcc_assert (flow_loop_nested_p (loop, chloop)); |
671 | ||
e2157b49 SP |
672 | /* Search the evolution in LOOP_NB. */ |
673 | left = add_to_evolution_1 (loop_nb, CHREC_LEFT (chrec_before), | |
674 | to_add, at_stmt); | |
675 | right = CHREC_RIGHT (chrec_before); | |
5be014d5 | 676 | right = chrec_convert_rhs (chrec_type (left), right, at_stmt); |
e2157b49 SP |
677 | return build_polynomial_chrec (CHREC_VARIABLE (chrec_before), |
678 | left, right); | |
679 | } | |
b8698a0f | 680 | |
9baba81b SP |
681 | default: |
682 | /* These nodes do not depend on a loop. */ | |
683 | if (chrec_before == chrec_dont_know) | |
684 | return chrec_dont_know; | |
e2157b49 SP |
685 | |
686 | left = chrec_before; | |
5be014d5 | 687 | right = chrec_convert_rhs (chrec_type (left), to_add, at_stmt); |
e2157b49 | 688 | return build_polynomial_chrec (loop_nb, left, right); |
9baba81b SP |
689 | } |
690 | } | |
691 | ||
692 | /* Add TO_ADD to the evolution part of CHREC_BEFORE in the dimension | |
b8698a0f L |
693 | of LOOP_NB. |
694 | ||
9baba81b SP |
695 | Description (provided for completeness, for those who read code in |
696 | a plane, and for my poor 62 bytes brain that would have forgotten | |
697 | all this in the next two or three months): | |
b8698a0f | 698 | |
9baba81b SP |
699 | The algorithm of translation of programs from the SSA representation |
700 | into the chrecs syntax is based on a pattern matching. After having | |
701 | reconstructed the overall tree expression for a loop, there are only | |
702 | two cases that can arise: | |
b8698a0f | 703 | |
9baba81b SP |
704 | 1. a = loop-phi (init, a + expr) |
705 | 2. a = loop-phi (init, expr) | |
b8698a0f | 706 | |
9baba81b SP |
707 | where EXPR is either a scalar constant with respect to the analyzed |
708 | loop (this is a degree 0 polynomial), or an expression containing | |
709 | other loop-phi definitions (these are higher degree polynomials). | |
b8698a0f | 710 | |
9baba81b | 711 | Examples: |
b8698a0f L |
712 | |
713 | 1. | |
9baba81b SP |
714 | | init = ... |
715 | | loop_1 | |
716 | | a = phi (init, a + 5) | |
717 | | endloop | |
b8698a0f L |
718 | |
719 | 2. | |
9baba81b SP |
720 | | inita = ... |
721 | | initb = ... | |
722 | | loop_1 | |
723 | | a = phi (inita, 2 * b + 3) | |
724 | | b = phi (initb, b + 1) | |
725 | | endloop | |
b8698a0f L |
726 | |
727 | For the first case, the semantics of the SSA representation is: | |
728 | ||
9baba81b | 729 | | a (x) = init + \sum_{j = 0}^{x - 1} expr (j) |
b8698a0f | 730 | |
9baba81b SP |
731 | that is, there is a loop index "x" that determines the scalar value |
732 | of the variable during the loop execution. During the first | |
733 | iteration, the value is that of the initial condition INIT, while | |
734 | during the subsequent iterations, it is the sum of the initial | |
735 | condition with the sum of all the values of EXPR from the initial | |
b8698a0f L |
736 | iteration to the before last considered iteration. |
737 | ||
9baba81b | 738 | For the second case, the semantics of the SSA program is: |
b8698a0f | 739 | |
9baba81b SP |
740 | | a (x) = init, if x = 0; |
741 | | expr (x - 1), otherwise. | |
b8698a0f | 742 | |
9baba81b | 743 | The second case corresponds to the PEELED_CHREC, whose syntax is |
b8698a0f L |
744 | close to the syntax of a loop-phi-node: |
745 | ||
9baba81b | 746 | | phi (init, expr) vs. (init, expr)_x |
b8698a0f | 747 | |
9baba81b | 748 | The proof of the translation algorithm for the first case is a |
b8698a0f L |
749 | proof by structural induction based on the degree of EXPR. |
750 | ||
9baba81b SP |
751 | Degree 0: |
752 | When EXPR is a constant with respect to the analyzed loop, or in | |
753 | other words when EXPR is a polynomial of degree 0, the evolution of | |
754 | the variable A in the loop is an affine function with an initial | |
755 | condition INIT, and a step EXPR. In order to show this, we start | |
756 | from the semantics of the SSA representation: | |
b8698a0f | 757 | |
9baba81b | 758 | f (x) = init + \sum_{j = 0}^{x - 1} expr (j) |
b8698a0f | 759 | |
9baba81b | 760 | and since "expr (j)" is a constant with respect to "j", |
b8698a0f L |
761 | |
762 | f (x) = init + x * expr | |
763 | ||
9baba81b SP |
764 | Finally, based on the semantics of the pure sum chrecs, by |
765 | identification we get the corresponding chrecs syntax: | |
b8698a0f L |
766 | |
767 | f (x) = init * \binom{x}{0} + expr * \binom{x}{1} | |
9baba81b | 768 | f (x) -> {init, +, expr}_x |
b8698a0f | 769 | |
9baba81b SP |
770 | Higher degree: |
771 | Suppose that EXPR is a polynomial of degree N with respect to the | |
772 | analyzed loop_x for which we have already determined that it is | |
773 | written under the chrecs syntax: | |
b8698a0f | 774 | |
9baba81b | 775 | | expr (x) -> {b_0, +, b_1, +, ..., +, b_{n-1}} (x) |
b8698a0f | 776 | |
9baba81b | 777 | We start from the semantics of the SSA program: |
b8698a0f | 778 | |
9baba81b SP |
779 | | f (x) = init + \sum_{j = 0}^{x - 1} expr (j) |
780 | | | |
b8698a0f | 781 | | f (x) = init + \sum_{j = 0}^{x - 1} |
9baba81b SP |
782 | | (b_0 * \binom{j}{0} + ... + b_{n-1} * \binom{j}{n-1}) |
783 | | | |
b8698a0f L |
784 | | f (x) = init + \sum_{j = 0}^{x - 1} |
785 | | \sum_{k = 0}^{n - 1} (b_k * \binom{j}{k}) | |
9baba81b | 786 | | |
b8698a0f L |
787 | | f (x) = init + \sum_{k = 0}^{n - 1} |
788 | | (b_k * \sum_{j = 0}^{x - 1} \binom{j}{k}) | |
9baba81b | 789 | | |
b8698a0f L |
790 | | f (x) = init + \sum_{k = 0}^{n - 1} |
791 | | (b_k * \binom{x}{k + 1}) | |
9baba81b | 792 | | |
b8698a0f L |
793 | | f (x) = init + b_0 * \binom{x}{1} + ... |
794 | | + b_{n-1} * \binom{x}{n} | |
9baba81b | 795 | | |
b8698a0f L |
796 | | f (x) = init * \binom{x}{0} + b_0 * \binom{x}{1} + ... |
797 | | + b_{n-1} * \binom{x}{n} | |
9baba81b | 798 | | |
b8698a0f | 799 | |
9baba81b | 800 | And finally from the definition of the chrecs syntax, we identify: |
b8698a0f L |
801 | | f (x) -> {init, +, b_0, +, ..., +, b_{n-1}}_x |
802 | ||
9baba81b SP |
803 | This shows the mechanism that stands behind the add_to_evolution |
804 | function. An important point is that the use of symbolic | |
805 | parameters avoids the need of an analysis schedule. | |
b8698a0f | 806 | |
9baba81b | 807 | Example: |
b8698a0f | 808 | |
9baba81b SP |
809 | | inita = ... |
810 | | initb = ... | |
b8698a0f | 811 | | loop_1 |
9baba81b SP |
812 | | a = phi (inita, a + 2 + b) |
813 | | b = phi (initb, b + 1) | |
814 | | endloop | |
b8698a0f | 815 | |
9baba81b | 816 | When analyzing "a", the algorithm keeps "b" symbolically: |
b8698a0f | 817 | |
9baba81b | 818 | | a -> {inita, +, 2 + b}_1 |
b8698a0f | 819 | |
9baba81b | 820 | Then, after instantiation, the analyzer ends on the evolution: |
b8698a0f | 821 | |
9baba81b SP |
822 | | a -> {inita, +, 2 + initb, +, 1}_1 |
823 | ||
824 | */ | |
825 | ||
b8698a0f | 826 | static tree |
e2157b49 | 827 | add_to_evolution (unsigned loop_nb, tree chrec_before, enum tree_code code, |
726a989a | 828 | tree to_add, gimple at_stmt) |
9baba81b SP |
829 | { |
830 | tree type = chrec_type (to_add); | |
831 | tree res = NULL_TREE; | |
b8698a0f | 832 | |
9baba81b SP |
833 | if (to_add == NULL_TREE) |
834 | return chrec_before; | |
b8698a0f | 835 | |
9baba81b SP |
836 | /* TO_ADD is either a scalar, or a parameter. TO_ADD is not |
837 | instantiated at this point. */ | |
838 | if (TREE_CODE (to_add) == POLYNOMIAL_CHREC) | |
839 | /* This should not happen. */ | |
840 | return chrec_dont_know; | |
b8698a0f | 841 | |
dfedbe40 | 842 | if (dump_file && (dump_flags & TDF_SCEV)) |
9baba81b SP |
843 | { |
844 | fprintf (dump_file, "(add_to_evolution \n"); | |
845 | fprintf (dump_file, " (loop_nb = %d)\n", loop_nb); | |
846 | fprintf (dump_file, " (chrec_before = "); | |
847 | print_generic_expr (dump_file, chrec_before, 0); | |
848 | fprintf (dump_file, ")\n (to_add = "); | |
849 | print_generic_expr (dump_file, to_add, 0); | |
850 | fprintf (dump_file, ")\n"); | |
851 | } | |
852 | ||
853 | if (code == MINUS_EXPR) | |
9d2b0e12 VR |
854 | to_add = chrec_fold_multiply (type, to_add, SCALAR_FLOAT_TYPE_P (type) |
855 | ? build_real (type, dconstm1) | |
856 | : build_int_cst_type (type, -1)); | |
9baba81b | 857 | |
e2157b49 | 858 | res = add_to_evolution_1 (loop_nb, chrec_before, to_add, at_stmt); |
9baba81b | 859 | |
dfedbe40 | 860 | if (dump_file && (dump_flags & TDF_SCEV)) |
9baba81b SP |
861 | { |
862 | fprintf (dump_file, " (res = "); | |
863 | print_generic_expr (dump_file, res, 0); | |
864 | fprintf (dump_file, "))\n"); | |
865 | } | |
866 | ||
867 | return res; | |
868 | } | |
869 | ||
9baba81b SP |
870 | \f |
871 | ||
872 | /* This section selects the loops that will be good candidates for the | |
873 | scalar evolution analysis. For the moment, greedily select all the | |
874 | loop nests we could analyze. */ | |
875 | ||
9baba81b SP |
876 | /* For a loop with a single exit edge, return the COND_EXPR that |
877 | guards the exit edge. If the expression is too difficult to | |
878 | analyze, then give up. */ | |
879 | ||
538dd0b7 | 880 | gcond * |
22ea9ec0 | 881 | get_loop_exit_condition (const struct loop *loop) |
9baba81b | 882 | { |
538dd0b7 | 883 | gcond *res = NULL; |
ac8f6c69 | 884 | edge exit_edge = single_exit (loop); |
b8698a0f | 885 | |
dfedbe40 | 886 | if (dump_file && (dump_flags & TDF_SCEV)) |
9baba81b | 887 | fprintf (dump_file, "(get_loop_exit_condition \n "); |
b8698a0f | 888 | |
82b85a85 | 889 | if (exit_edge) |
9baba81b | 890 | { |
726a989a | 891 | gimple stmt; |
b8698a0f | 892 | |
726a989a | 893 | stmt = last_stmt (exit_edge->src); |
538dd0b7 DM |
894 | if (gcond *cond_stmt = dyn_cast <gcond *> (stmt)) |
895 | res = cond_stmt; | |
9baba81b | 896 | } |
b8698a0f | 897 | |
dfedbe40 | 898 | if (dump_file && (dump_flags & TDF_SCEV)) |
9baba81b | 899 | { |
726a989a | 900 | print_gimple_stmt (dump_file, res, 0, 0); |
9baba81b SP |
901 | fprintf (dump_file, ")\n"); |
902 | } | |
b8698a0f | 903 | |
9baba81b SP |
904 | return res; |
905 | } | |
906 | ||
9baba81b SP |
907 | \f |
908 | /* Depth first search algorithm. */ | |
909 | ||
c59dabbe SP |
910 | typedef enum t_bool { |
911 | t_false, | |
912 | t_true, | |
913 | t_dont_know | |
914 | } t_bool; | |
915 | ||
916 | ||
538dd0b7 DM |
917 | static t_bool follow_ssa_edge (struct loop *loop, gimple, gphi *, |
918 | tree *, int); | |
9baba81b | 919 | |
726a989a | 920 | /* Follow the ssa edge into the binary expression RHS0 CODE RHS1. |
9baba81b SP |
921 | Return true if the strongly connected component has been found. */ |
922 | ||
c59dabbe | 923 | static t_bool |
726a989a RB |
924 | follow_ssa_edge_binary (struct loop *loop, gimple at_stmt, |
925 | tree type, tree rhs0, enum tree_code code, tree rhs1, | |
538dd0b7 DM |
926 | gphi *halting_phi, tree *evolution_of_loop, |
927 | int limit) | |
9baba81b | 928 | { |
c59dabbe | 929 | t_bool res = t_false; |
b2a93c0a | 930 | tree evol; |
726a989a | 931 | |
5be014d5 | 932 | switch (code) |
9baba81b | 933 | { |
5be014d5 | 934 | case POINTER_PLUS_EXPR: |
9baba81b | 935 | case PLUS_EXPR: |
9baba81b SP |
936 | if (TREE_CODE (rhs0) == SSA_NAME) |
937 | { | |
938 | if (TREE_CODE (rhs1) == SSA_NAME) | |
939 | { | |
b8698a0f | 940 | /* Match an assignment under the form: |
9baba81b | 941 | "a = b + c". */ |
b8698a0f | 942 | |
9e824336 ZD |
943 | /* We want only assignments of form "name + name" contribute to |
944 | LIMIT, as the other cases do not necessarily contribute to | |
945 | the complexity of the expression. */ | |
946 | limit++; | |
947 | ||
b2a93c0a | 948 | evol = *evolution_of_loop; |
b8698a0f | 949 | res = follow_ssa_edge |
726a989a | 950 | (loop, SSA_NAME_DEF_STMT (rhs0), halting_phi, &evol, limit); |
b8698a0f | 951 | |
c59dabbe | 952 | if (res == t_true) |
b8698a0f L |
953 | *evolution_of_loop = add_to_evolution |
954 | (loop->num, | |
955 | chrec_convert (type, evol, at_stmt), | |
5be014d5 | 956 | code, rhs1, at_stmt); |
b8698a0f | 957 | |
c59dabbe | 958 | else if (res == t_false) |
9baba81b | 959 | { |
b8698a0f L |
960 | res = follow_ssa_edge |
961 | (loop, SSA_NAME_DEF_STMT (rhs1), halting_phi, | |
c59dabbe | 962 | evolution_of_loop, limit); |
b8698a0f | 963 | |
c59dabbe | 964 | if (res == t_true) |
b8698a0f L |
965 | *evolution_of_loop = add_to_evolution |
966 | (loop->num, | |
967 | chrec_convert (type, *evolution_of_loop, at_stmt), | |
5be014d5 | 968 | code, rhs0, at_stmt); |
c59dabbe SP |
969 | |
970 | else if (res == t_dont_know) | |
971 | *evolution_of_loop = chrec_dont_know; | |
9baba81b | 972 | } |
c59dabbe SP |
973 | |
974 | else if (res == t_dont_know) | |
975 | *evolution_of_loop = chrec_dont_know; | |
9baba81b | 976 | } |
b8698a0f | 977 | |
9baba81b SP |
978 | else |
979 | { | |
b8698a0f | 980 | /* Match an assignment under the form: |
9baba81b | 981 | "a = b + ...". */ |
b8698a0f L |
982 | res = follow_ssa_edge |
983 | (loop, SSA_NAME_DEF_STMT (rhs0), halting_phi, | |
c59dabbe SP |
984 | evolution_of_loop, limit); |
985 | if (res == t_true) | |
b8698a0f | 986 | *evolution_of_loop = add_to_evolution |
726a989a | 987 | (loop->num, chrec_convert (type, *evolution_of_loop, |
1e8552eb | 988 | at_stmt), |
5be014d5 | 989 | code, rhs1, at_stmt); |
c59dabbe SP |
990 | |
991 | else if (res == t_dont_know) | |
992 | *evolution_of_loop = chrec_dont_know; | |
9baba81b SP |
993 | } |
994 | } | |
b8698a0f | 995 | |
9baba81b SP |
996 | else if (TREE_CODE (rhs1) == SSA_NAME) |
997 | { | |
b8698a0f | 998 | /* Match an assignment under the form: |
9baba81b | 999 | "a = ... + c". */ |
b8698a0f L |
1000 | res = follow_ssa_edge |
1001 | (loop, SSA_NAME_DEF_STMT (rhs1), halting_phi, | |
c59dabbe SP |
1002 | evolution_of_loop, limit); |
1003 | if (res == t_true) | |
b8698a0f | 1004 | *evolution_of_loop = add_to_evolution |
726a989a | 1005 | (loop->num, chrec_convert (type, *evolution_of_loop, |
1e8552eb | 1006 | at_stmt), |
5be014d5 | 1007 | code, rhs0, at_stmt); |
c59dabbe SP |
1008 | |
1009 | else if (res == t_dont_know) | |
1010 | *evolution_of_loop = chrec_dont_know; | |
9baba81b SP |
1011 | } |
1012 | ||
1013 | else | |
b8698a0f | 1014 | /* Otherwise, match an assignment under the form: |
9baba81b SP |
1015 | "a = ... + ...". */ |
1016 | /* And there is nothing to do. */ | |
c59dabbe | 1017 | res = t_false; |
9baba81b | 1018 | break; |
b8698a0f | 1019 | |
9baba81b SP |
1020 | case MINUS_EXPR: |
1021 | /* This case is under the form "opnd0 = rhs0 - rhs1". */ | |
9baba81b | 1022 | if (TREE_CODE (rhs0) == SSA_NAME) |
9baba81b | 1023 | { |
b8698a0f | 1024 | /* Match an assignment under the form: |
f8e9d512 | 1025 | "a = b - ...". */ |
9e824336 ZD |
1026 | |
1027 | /* We want only assignments of form "name - name" contribute to | |
1028 | LIMIT, as the other cases do not necessarily contribute to | |
1029 | the complexity of the expression. */ | |
1030 | if (TREE_CODE (rhs1) == SSA_NAME) | |
1031 | limit++; | |
1032 | ||
b8698a0f | 1033 | res = follow_ssa_edge (loop, SSA_NAME_DEF_STMT (rhs0), halting_phi, |
c59dabbe SP |
1034 | evolution_of_loop, limit); |
1035 | if (res == t_true) | |
b8698a0f | 1036 | *evolution_of_loop = add_to_evolution |
726a989a | 1037 | (loop->num, chrec_convert (type, *evolution_of_loop, at_stmt), |
e2157b49 | 1038 | MINUS_EXPR, rhs1, at_stmt); |
c59dabbe SP |
1039 | |
1040 | else if (res == t_dont_know) | |
1041 | *evolution_of_loop = chrec_dont_know; | |
9baba81b | 1042 | } |
9baba81b | 1043 | else |
b8698a0f | 1044 | /* Otherwise, match an assignment under the form: |
9baba81b SP |
1045 | "a = ... - ...". */ |
1046 | /* And there is nothing to do. */ | |
c59dabbe | 1047 | res = t_false; |
9baba81b | 1048 | break; |
726a989a RB |
1049 | |
1050 | default: | |
1051 | res = t_false; | |
1052 | } | |
1053 | ||
1054 | return res; | |
1055 | } | |
b8698a0f | 1056 | |
726a989a RB |
1057 | /* Follow the ssa edge into the expression EXPR. |
1058 | Return true if the strongly connected component has been found. */ | |
1059 | ||
1060 | static t_bool | |
b8698a0f | 1061 | follow_ssa_edge_expr (struct loop *loop, gimple at_stmt, tree expr, |
538dd0b7 DM |
1062 | gphi *halting_phi, tree *evolution_of_loop, |
1063 | int limit) | |
726a989a | 1064 | { |
5aefc6a0 EB |
1065 | enum tree_code code = TREE_CODE (expr); |
1066 | tree type = TREE_TYPE (expr), rhs0, rhs1; | |
1067 | t_bool res; | |
1068 | ||
726a989a | 1069 | /* The EXPR is one of the following cases: |
b8698a0f | 1070 | - an SSA_NAME, |
726a989a | 1071 | - an INTEGER_CST, |
b8698a0f L |
1072 | - a PLUS_EXPR, |
1073 | - a POINTER_PLUS_EXPR, | |
726a989a RB |
1074 | - a MINUS_EXPR, |
1075 | - an ASSERT_EXPR, | |
1076 | - other cases are not yet handled. */ | |
5aefc6a0 | 1077 | |
726a989a RB |
1078 | switch (code) |
1079 | { | |
5aefc6a0 | 1080 | CASE_CONVERT: |
726a989a RB |
1081 | /* This assignment is under the form "a_1 = (cast) rhs. */ |
1082 | res = follow_ssa_edge_expr (loop, at_stmt, TREE_OPERAND (expr, 0), | |
1083 | halting_phi, evolution_of_loop, limit); | |
1084 | *evolution_of_loop = chrec_convert (type, *evolution_of_loop, at_stmt); | |
1085 | break; | |
1086 | ||
1087 | case INTEGER_CST: | |
1088 | /* This assignment is under the form "a_1 = 7". */ | |
1089 | res = t_false; | |
1090 | break; | |
5aefc6a0 | 1091 | |
726a989a RB |
1092 | case SSA_NAME: |
1093 | /* This assignment is under the form: "a_1 = b_2". */ | |
b8698a0f | 1094 | res = follow_ssa_edge |
726a989a RB |
1095 | (loop, SSA_NAME_DEF_STMT (expr), halting_phi, evolution_of_loop, limit); |
1096 | break; | |
5aefc6a0 | 1097 | |
726a989a RB |
1098 | case POINTER_PLUS_EXPR: |
1099 | case PLUS_EXPR: | |
1100 | case MINUS_EXPR: | |
1101 | /* This case is under the form "rhs0 +- rhs1". */ | |
1102 | rhs0 = TREE_OPERAND (expr, 0); | |
1103 | rhs1 = TREE_OPERAND (expr, 1); | |
5aefc6a0 EB |
1104 | type = TREE_TYPE (rhs0); |
1105 | STRIP_USELESS_TYPE_CONVERSION (rhs0); | |
1106 | STRIP_USELESS_TYPE_CONVERSION (rhs1); | |
1107 | res = follow_ssa_edge_binary (loop, at_stmt, type, rhs0, code, rhs1, | |
1108 | halting_phi, evolution_of_loop, limit); | |
1109 | break; | |
726a989a | 1110 | |
70f34814 RG |
1111 | case ADDR_EXPR: |
1112 | /* Handle &MEM[ptr + CST] which is equivalent to POINTER_PLUS_EXPR. */ | |
1113 | if (TREE_CODE (TREE_OPERAND (expr, 0)) == MEM_REF) | |
1114 | { | |
1115 | expr = TREE_OPERAND (expr, 0); | |
1116 | rhs0 = TREE_OPERAND (expr, 0); | |
1117 | rhs1 = TREE_OPERAND (expr, 1); | |
1118 | type = TREE_TYPE (rhs0); | |
1119 | STRIP_USELESS_TYPE_CONVERSION (rhs0); | |
1120 | STRIP_USELESS_TYPE_CONVERSION (rhs1); | |
1121 | res = follow_ssa_edge_binary (loop, at_stmt, type, | |
1122 | rhs0, POINTER_PLUS_EXPR, rhs1, | |
1123 | halting_phi, evolution_of_loop, limit); | |
1124 | } | |
1125 | else | |
1126 | res = t_false; | |
1127 | break; | |
1128 | ||
0bca51f0 | 1129 | case ASSERT_EXPR: |
5aefc6a0 EB |
1130 | /* This assignment is of the form: "a_1 = ASSERT_EXPR <a_2, ...>" |
1131 | It must be handled as a copy assignment of the form a_1 = a_2. */ | |
1132 | rhs0 = ASSERT_EXPR_VAR (expr); | |
1133 | if (TREE_CODE (rhs0) == SSA_NAME) | |
1134 | res = follow_ssa_edge (loop, SSA_NAME_DEF_STMT (rhs0), | |
1135 | halting_phi, evolution_of_loop, limit); | |
1136 | else | |
1137 | res = t_false; | |
1138 | break; | |
0bca51f0 | 1139 | |
9baba81b | 1140 | default: |
c59dabbe | 1141 | res = t_false; |
9baba81b SP |
1142 | break; |
1143 | } | |
5aefc6a0 | 1144 | |
9baba81b SP |
1145 | return res; |
1146 | } | |
1147 | ||
726a989a RB |
1148 | /* Follow the ssa edge into the right hand side of an assignment STMT. |
1149 | Return true if the strongly connected component has been found. */ | |
1150 | ||
1151 | static t_bool | |
1152 | follow_ssa_edge_in_rhs (struct loop *loop, gimple stmt, | |
538dd0b7 DM |
1153 | gphi *halting_phi, tree *evolution_of_loop, |
1154 | int limit) | |
726a989a | 1155 | { |
726a989a | 1156 | enum tree_code code = gimple_assign_rhs_code (stmt); |
5aefc6a0 EB |
1157 | tree type = gimple_expr_type (stmt), rhs1, rhs2; |
1158 | t_bool res; | |
726a989a | 1159 | |
5aefc6a0 | 1160 | switch (code) |
726a989a | 1161 | { |
5aefc6a0 EB |
1162 | CASE_CONVERT: |
1163 | /* This assignment is under the form "a_1 = (cast) rhs. */ | |
1164 | res = follow_ssa_edge_expr (loop, stmt, gimple_assign_rhs1 (stmt), | |
1165 | halting_phi, evolution_of_loop, limit); | |
1166 | *evolution_of_loop = chrec_convert (type, *evolution_of_loop, stmt); | |
1167 | break; | |
1168 | ||
1169 | case POINTER_PLUS_EXPR: | |
1170 | case PLUS_EXPR: | |
1171 | case MINUS_EXPR: | |
1172 | rhs1 = gimple_assign_rhs1 (stmt); | |
1173 | rhs2 = gimple_assign_rhs2 (stmt); | |
1174 | type = TREE_TYPE (rhs1); | |
1175 | res = follow_ssa_edge_binary (loop, stmt, type, rhs1, code, rhs2, | |
218d1c24 | 1176 | halting_phi, evolution_of_loop, limit); |
5aefc6a0 | 1177 | break; |
218d1c24 | 1178 | |
726a989a | 1179 | default: |
5aefc6a0 EB |
1180 | if (get_gimple_rhs_class (code) == GIMPLE_SINGLE_RHS) |
1181 | res = follow_ssa_edge_expr (loop, stmt, gimple_assign_rhs1 (stmt), | |
1182 | halting_phi, evolution_of_loop, limit); | |
1183 | else | |
1184 | res = t_false; | |
1185 | break; | |
726a989a | 1186 | } |
5aefc6a0 EB |
1187 | |
1188 | return res; | |
726a989a RB |
1189 | } |
1190 | ||
9baba81b SP |
1191 | /* Checks whether the I-th argument of a PHI comes from a backedge. */ |
1192 | ||
1193 | static bool | |
538dd0b7 | 1194 | backedge_phi_arg_p (gphi *phi, int i) |
9baba81b | 1195 | { |
726a989a | 1196 | const_edge e = gimple_phi_arg_edge (phi, i); |
9baba81b SP |
1197 | |
1198 | /* We would in fact like to test EDGE_DFS_BACK here, but we do not care | |
1199 | about updating it anywhere, and this should work as well most of the | |
1200 | time. */ | |
1201 | if (e->flags & EDGE_IRREDUCIBLE_LOOP) | |
1202 | return true; | |
1203 | ||
1204 | return false; | |
1205 | } | |
1206 | ||
1207 | /* Helper function for one branch of the condition-phi-node. Return | |
1208 | true if the strongly connected component has been found following | |
1209 | this path. */ | |
1210 | ||
c59dabbe | 1211 | static inline t_bool |
9baba81b | 1212 | follow_ssa_edge_in_condition_phi_branch (int i, |
b8698a0f | 1213 | struct loop *loop, |
538dd0b7 DM |
1214 | gphi *condition_phi, |
1215 | gphi *halting_phi, | |
9baba81b | 1216 | tree *evolution_of_branch, |
c59dabbe | 1217 | tree init_cond, int limit) |
9baba81b SP |
1218 | { |
1219 | tree branch = PHI_ARG_DEF (condition_phi, i); | |
1220 | *evolution_of_branch = chrec_dont_know; | |
1221 | ||
1222 | /* Do not follow back edges (they must belong to an irreducible loop, which | |
1223 | we really do not want to worry about). */ | |
1224 | if (backedge_phi_arg_p (condition_phi, i)) | |
c59dabbe | 1225 | return t_false; |
9baba81b SP |
1226 | |
1227 | if (TREE_CODE (branch) == SSA_NAME) | |
1228 | { | |
1229 | *evolution_of_branch = init_cond; | |
b8698a0f | 1230 | return follow_ssa_edge (loop, SSA_NAME_DEF_STMT (branch), halting_phi, |
c59dabbe | 1231 | evolution_of_branch, limit); |
9baba81b SP |
1232 | } |
1233 | ||
b8698a0f | 1234 | /* This case occurs when one of the condition branches sets |
89dbed81 | 1235 | the variable to a constant: i.e. a phi-node like |
b8698a0f L |
1236 | "a_2 = PHI <a_7(5), 2(6)>;". |
1237 | ||
1238 | FIXME: This case have to be refined correctly: | |
9baba81b SP |
1239 | in some cases it is possible to say something better than |
1240 | chrec_dont_know, for example using a wrap-around notation. */ | |
c59dabbe | 1241 | return t_false; |
9baba81b SP |
1242 | } |
1243 | ||
1244 | /* This function merges the branches of a condition-phi-node in a | |
1245 | loop. */ | |
1246 | ||
c59dabbe | 1247 | static t_bool |
9baba81b | 1248 | follow_ssa_edge_in_condition_phi (struct loop *loop, |
538dd0b7 DM |
1249 | gphi *condition_phi, |
1250 | gphi *halting_phi, | |
c59dabbe | 1251 | tree *evolution_of_loop, int limit) |
9baba81b | 1252 | { |
726a989a | 1253 | int i, n; |
9baba81b SP |
1254 | tree init = *evolution_of_loop; |
1255 | tree evolution_of_branch; | |
c59dabbe SP |
1256 | t_bool res = follow_ssa_edge_in_condition_phi_branch (0, loop, condition_phi, |
1257 | halting_phi, | |
1258 | &evolution_of_branch, | |
1259 | init, limit); | |
1260 | if (res == t_false || res == t_dont_know) | |
1261 | return res; | |
9baba81b | 1262 | |
9baba81b SP |
1263 | *evolution_of_loop = evolution_of_branch; |
1264 | ||
726a989a | 1265 | n = gimple_phi_num_args (condition_phi); |
726a989a | 1266 | for (i = 1; i < n; i++) |
9baba81b | 1267 | { |
e0afb98a SP |
1268 | /* Quickly give up when the evolution of one of the branches is |
1269 | not known. */ | |
1270 | if (*evolution_of_loop == chrec_dont_know) | |
c59dabbe | 1271 | return t_true; |
e0afb98a | 1272 | |
788d3075 RG |
1273 | /* Increase the limit by the PHI argument number to avoid exponential |
1274 | time and memory complexity. */ | |
c59dabbe SP |
1275 | res = follow_ssa_edge_in_condition_phi_branch (i, loop, condition_phi, |
1276 | halting_phi, | |
1277 | &evolution_of_branch, | |
788d3075 | 1278 | init, limit + i); |
c59dabbe SP |
1279 | if (res == t_false || res == t_dont_know) |
1280 | return res; | |
9baba81b SP |
1281 | |
1282 | *evolution_of_loop = chrec_merge (*evolution_of_loop, | |
1283 | evolution_of_branch); | |
1284 | } | |
b8698a0f | 1285 | |
c59dabbe | 1286 | return t_true; |
9baba81b SP |
1287 | } |
1288 | ||
1289 | /* Follow an SSA edge in an inner loop. It computes the overall | |
1290 | effect of the loop, and following the symbolic initial conditions, | |
1291 | it follows the edges in the parent loop. The inner loop is | |
1292 | considered as a single statement. */ | |
1293 | ||
c59dabbe | 1294 | static t_bool |
9baba81b | 1295 | follow_ssa_edge_inner_loop_phi (struct loop *outer_loop, |
538dd0b7 DM |
1296 | gphi *loop_phi_node, |
1297 | gphi *halting_phi, | |
c59dabbe | 1298 | tree *evolution_of_loop, int limit) |
9baba81b SP |
1299 | { |
1300 | struct loop *loop = loop_containing_stmt (loop_phi_node); | |
1301 | tree ev = analyze_scalar_evolution (loop, PHI_RESULT (loop_phi_node)); | |
1302 | ||
1303 | /* Sometimes, the inner loop is too difficult to analyze, and the | |
1304 | result of the analysis is a symbolic parameter. */ | |
1305 | if (ev == PHI_RESULT (loop_phi_node)) | |
1306 | { | |
c59dabbe | 1307 | t_bool res = t_false; |
726a989a | 1308 | int i, n = gimple_phi_num_args (loop_phi_node); |
9baba81b | 1309 | |
726a989a | 1310 | for (i = 0; i < n; i++) |
9baba81b SP |
1311 | { |
1312 | tree arg = PHI_ARG_DEF (loop_phi_node, i); | |
1313 | basic_block bb; | |
1314 | ||
1315 | /* Follow the edges that exit the inner loop. */ | |
726a989a | 1316 | bb = gimple_phi_arg_edge (loop_phi_node, i)->src; |
9baba81b | 1317 | if (!flow_bb_inside_loop_p (loop, bb)) |
726a989a RB |
1318 | res = follow_ssa_edge_expr (outer_loop, loop_phi_node, |
1319 | arg, halting_phi, | |
1320 | evolution_of_loop, limit); | |
c59dabbe SP |
1321 | if (res == t_true) |
1322 | break; | |
9baba81b SP |
1323 | } |
1324 | ||
1325 | /* If the path crosses this loop-phi, give up. */ | |
c59dabbe | 1326 | if (res == t_true) |
9baba81b SP |
1327 | *evolution_of_loop = chrec_dont_know; |
1328 | ||
1329 | return res; | |
1330 | } | |
1331 | ||
1332 | /* Otherwise, compute the overall effect of the inner loop. */ | |
1333 | ev = compute_overall_effect_of_inner_loop (loop, ev); | |
726a989a RB |
1334 | return follow_ssa_edge_expr (outer_loop, loop_phi_node, ev, halting_phi, |
1335 | evolution_of_loop, limit); | |
9baba81b SP |
1336 | } |
1337 | ||
1338 | /* Follow an SSA edge from a loop-phi-node to itself, constructing a | |
1339 | path that is analyzed on the return walk. */ | |
1340 | ||
c59dabbe | 1341 | static t_bool |
538dd0b7 | 1342 | follow_ssa_edge (struct loop *loop, gimple def, gphi *halting_phi, |
c59dabbe | 1343 | tree *evolution_of_loop, int limit) |
9baba81b SP |
1344 | { |
1345 | struct loop *def_loop; | |
b8698a0f | 1346 | |
726a989a | 1347 | if (gimple_nop_p (def)) |
c59dabbe | 1348 | return t_false; |
b8698a0f | 1349 | |
c59dabbe | 1350 | /* Give up if the path is longer than the MAX that we allow. */ |
14dd9aab | 1351 | if (limit > PARAM_VALUE (PARAM_SCEV_MAX_EXPR_COMPLEXITY)) |
c59dabbe | 1352 | return t_dont_know; |
b8698a0f | 1353 | |
9baba81b | 1354 | def_loop = loop_containing_stmt (def); |
b8698a0f | 1355 | |
726a989a | 1356 | switch (gimple_code (def)) |
9baba81b | 1357 | { |
726a989a | 1358 | case GIMPLE_PHI: |
9baba81b SP |
1359 | if (!loop_phi_node_p (def)) |
1360 | /* DEF is a condition-phi-node. Follow the branches, and | |
1361 | record their evolutions. Finally, merge the collected | |
1362 | information and set the approximation to the main | |
1363 | variable. */ | |
b8698a0f | 1364 | return follow_ssa_edge_in_condition_phi |
538dd0b7 DM |
1365 | (loop, as_a <gphi *> (def), halting_phi, evolution_of_loop, |
1366 | limit); | |
9baba81b SP |
1367 | |
1368 | /* When the analyzed phi is the halting_phi, the | |
1369 | depth-first search is over: we have found a path from | |
1370 | the halting_phi to itself in the loop. */ | |
1371 | if (def == halting_phi) | |
c59dabbe | 1372 | return t_true; |
b8698a0f | 1373 | |
9baba81b | 1374 | /* Otherwise, the evolution of the HALTING_PHI depends |
89dbed81 | 1375 | on the evolution of another loop-phi-node, i.e. the |
9baba81b SP |
1376 | evolution function is a higher degree polynomial. */ |
1377 | if (def_loop == loop) | |
c59dabbe | 1378 | return t_false; |
b8698a0f | 1379 | |
9baba81b SP |
1380 | /* Inner loop. */ |
1381 | if (flow_loop_nested_p (loop, def_loop)) | |
b8698a0f | 1382 | return follow_ssa_edge_inner_loop_phi |
538dd0b7 DM |
1383 | (loop, as_a <gphi *> (def), halting_phi, evolution_of_loop, |
1384 | limit + 1); | |
9baba81b SP |
1385 | |
1386 | /* Outer loop. */ | |
c59dabbe | 1387 | return t_false; |
9baba81b | 1388 | |
726a989a | 1389 | case GIMPLE_ASSIGN: |
b8698a0f | 1390 | return follow_ssa_edge_in_rhs (loop, def, halting_phi, |
c59dabbe | 1391 | evolution_of_loop, limit); |
b8698a0f | 1392 | |
9baba81b SP |
1393 | default: |
1394 | /* At this level of abstraction, the program is just a set | |
726a989a | 1395 | of GIMPLE_ASSIGNs and PHI_NODEs. In principle there is no |
9baba81b | 1396 | other node to be handled. */ |
c59dabbe | 1397 | return t_false; |
9baba81b SP |
1398 | } |
1399 | } | |
1400 | ||
1401 | \f | |
b83b5507 BC |
1402 | /* Simplify PEELED_CHREC represented by (init_cond, arg) in LOOP. |
1403 | Handle below case and return the corresponding POLYNOMIAL_CHREC: | |
1404 | ||
1405 | # i_17 = PHI <i_13(5), 0(3)> | |
1406 | # _20 = PHI <_5(5), start_4(D)(3)> | |
1407 | ... | |
1408 | i_13 = i_17 + 1; | |
1409 | _5 = start_4(D) + i_13; | |
1410 | ||
1411 | Though variable _20 appears as a PEELED_CHREC in the form of | |
1412 | (start_4, _5)_LOOP, it's a POLYNOMIAL_CHREC like {start_4, 1}_LOOP. | |
1413 | ||
1414 | See PR41488. */ | |
1415 | ||
1416 | static tree | |
1417 | simplify_peeled_chrec (struct loop *loop, tree arg, tree init_cond) | |
1418 | { | |
1419 | aff_tree aff1, aff2; | |
1420 | tree ev, left, right, type, step_val; | |
39c8aaa4 | 1421 | hash_map<tree, name_expansion *> *peeled_chrec_map = NULL; |
b83b5507 BC |
1422 | |
1423 | ev = instantiate_parameters (loop, analyze_scalar_evolution (loop, arg)); | |
1424 | if (ev == NULL_TREE || TREE_CODE (ev) != POLYNOMIAL_CHREC) | |
1425 | return chrec_dont_know; | |
1426 | ||
1427 | left = CHREC_LEFT (ev); | |
1428 | right = CHREC_RIGHT (ev); | |
1429 | type = TREE_TYPE (left); | |
1430 | step_val = chrec_fold_plus (type, init_cond, right); | |
1431 | ||
1432 | /* Transform (init, {left, right}_LOOP)_LOOP to {init, right}_LOOP | |
1433 | if "left" equals to "init + right". */ | |
1434 | if (operand_equal_p (left, step_val, 0)) | |
1435 | { | |
1436 | if (dump_file && (dump_flags & TDF_SCEV)) | |
1437 | fprintf (dump_file, "Simplify PEELED_CHREC into POLYNOMIAL_CHREC.\n"); | |
1438 | ||
1439 | return build_polynomial_chrec (loop->num, init_cond, right); | |
1440 | } | |
1441 | ||
1442 | /* Try harder to check if they are equal. */ | |
1443 | tree_to_aff_combination_expand (left, type, &aff1, &peeled_chrec_map); | |
1444 | tree_to_aff_combination_expand (step_val, type, &aff2, &peeled_chrec_map); | |
1445 | free_affine_expand_cache (&peeled_chrec_map); | |
807e902e | 1446 | aff_combination_scale (&aff2, -1); |
b83b5507 BC |
1447 | aff_combination_add (&aff1, &aff2); |
1448 | ||
1449 | /* Transform (init, {left, right}_LOOP)_LOOP to {init, right}_LOOP | |
1450 | if "left" equals to "init + right". */ | |
1451 | if (aff_combination_zero_p (&aff1)) | |
1452 | { | |
1453 | if (dump_file && (dump_flags & TDF_SCEV)) | |
1454 | fprintf (dump_file, "Simplify PEELED_CHREC into POLYNOMIAL_CHREC.\n"); | |
1455 | ||
1456 | return build_polynomial_chrec (loop->num, init_cond, right); | |
1457 | } | |
1458 | return chrec_dont_know; | |
1459 | } | |
9baba81b SP |
1460 | |
1461 | /* Given a LOOP_PHI_NODE, this function determines the evolution | |
1462 | function from LOOP_PHI_NODE to LOOP_PHI_NODE in the loop. */ | |
1463 | ||
1464 | static tree | |
538dd0b7 | 1465 | analyze_evolution_in_loop (gphi *loop_phi_node, |
9baba81b SP |
1466 | tree init_cond) |
1467 | { | |
726a989a | 1468 | int i, n = gimple_phi_num_args (loop_phi_node); |
9baba81b SP |
1469 | tree evolution_function = chrec_not_analyzed_yet; |
1470 | struct loop *loop = loop_containing_stmt (loop_phi_node); | |
1471 | basic_block bb; | |
b83b5507 | 1472 | static bool simplify_peeled_chrec_p = true; |
b8698a0f | 1473 | |
dfedbe40 | 1474 | if (dump_file && (dump_flags & TDF_SCEV)) |
9baba81b SP |
1475 | { |
1476 | fprintf (dump_file, "(analyze_evolution_in_loop \n"); | |
1477 | fprintf (dump_file, " (loop_phi_node = "); | |
726a989a | 1478 | print_gimple_stmt (dump_file, loop_phi_node, 0, 0); |
9baba81b SP |
1479 | fprintf (dump_file, ")\n"); |
1480 | } | |
b8698a0f | 1481 | |
726a989a | 1482 | for (i = 0; i < n; i++) |
9baba81b SP |
1483 | { |
1484 | tree arg = PHI_ARG_DEF (loop_phi_node, i); | |
726a989a RB |
1485 | gimple ssa_chain; |
1486 | tree ev_fn; | |
874caa00 | 1487 | t_bool res; |
9baba81b SP |
1488 | |
1489 | /* Select the edges that enter the loop body. */ | |
726a989a | 1490 | bb = gimple_phi_arg_edge (loop_phi_node, i)->src; |
9baba81b SP |
1491 | if (!flow_bb_inside_loop_p (loop, bb)) |
1492 | continue; | |
f29deac9 | 1493 | |
9baba81b SP |
1494 | if (TREE_CODE (arg) == SSA_NAME) |
1495 | { | |
f29deac9 SP |
1496 | bool val = false; |
1497 | ||
9baba81b SP |
1498 | ssa_chain = SSA_NAME_DEF_STMT (arg); |
1499 | ||
1500 | /* Pass in the initial condition to the follow edge function. */ | |
1501 | ev_fn = init_cond; | |
c59dabbe | 1502 | res = follow_ssa_edge (loop, ssa_chain, loop_phi_node, &ev_fn, 0); |
f29deac9 SP |
1503 | |
1504 | /* If ev_fn has no evolution in the inner loop, and the | |
1505 | init_cond is not equal to ev_fn, then we have an | |
1506 | ambiguity between two possible values, as we cannot know | |
1507 | the number of iterations at this point. */ | |
1508 | if (TREE_CODE (ev_fn) != POLYNOMIAL_CHREC | |
1509 | && no_evolution_in_loop_p (ev_fn, loop->num, &val) && val | |
1510 | && !operand_equal_p (init_cond, ev_fn, 0)) | |
1511 | ev_fn = chrec_dont_know; | |
9baba81b SP |
1512 | } |
1513 | else | |
874caa00 | 1514 | res = t_false; |
f29deac9 | 1515 | |
9baba81b SP |
1516 | /* When it is impossible to go back on the same |
1517 | loop_phi_node by following the ssa edges, the | |
89dbed81 | 1518 | evolution is represented by a peeled chrec, i.e. the |
9baba81b | 1519 | first iteration, EV_FN has the value INIT_COND, then |
b8698a0f | 1520 | all the other iterations it has the value of ARG. |
9baba81b | 1521 | For the moment, PEELED_CHREC nodes are not built. */ |
874caa00 | 1522 | if (res != t_true) |
b83b5507 BC |
1523 | { |
1524 | ev_fn = chrec_dont_know; | |
1525 | /* Try to recognize POLYNOMIAL_CHREC which appears in | |
1526 | the form of PEELED_CHREC, but guard the process with | |
1527 | a bool variable to keep the analyzer from infinite | |
1528 | recurrence for real PEELED_RECs. */ | |
1529 | if (simplify_peeled_chrec_p && TREE_CODE (arg) == SSA_NAME) | |
1530 | { | |
1531 | simplify_peeled_chrec_p = false; | |
1532 | ev_fn = simplify_peeled_chrec (loop, arg, init_cond); | |
1533 | simplify_peeled_chrec_p = true; | |
1534 | } | |
1535 | } | |
b8698a0f | 1536 | |
9baba81b | 1537 | /* When there are multiple back edges of the loop (which in fact never |
8c27b7d4 | 1538 | happens currently, but nevertheless), merge their evolutions. */ |
9baba81b SP |
1539 | evolution_function = chrec_merge (evolution_function, ev_fn); |
1540 | } | |
b8698a0f | 1541 | |
dfedbe40 | 1542 | if (dump_file && (dump_flags & TDF_SCEV)) |
9baba81b SP |
1543 | { |
1544 | fprintf (dump_file, " (evolution_function = "); | |
1545 | print_generic_expr (dump_file, evolution_function, 0); | |
1546 | fprintf (dump_file, "))\n"); | |
1547 | } | |
b8698a0f | 1548 | |
9baba81b SP |
1549 | return evolution_function; |
1550 | } | |
1551 | ||
1552 | /* Given a loop-phi-node, return the initial conditions of the | |
1553 | variable on entry of the loop. When the CCP has propagated | |
1554 | constants into the loop-phi-node, the initial condition is | |
1555 | instantiated, otherwise the initial condition is kept symbolic. | |
1556 | This analyzer does not analyze the evolution outside the current | |
1557 | loop, and leaves this task to the on-demand tree reconstructor. */ | |
1558 | ||
b8698a0f | 1559 | static tree |
538dd0b7 | 1560 | analyze_initial_condition (gphi *loop_phi_node) |
9baba81b | 1561 | { |
726a989a | 1562 | int i, n; |
9baba81b | 1563 | tree init_cond = chrec_not_analyzed_yet; |
726a989a | 1564 | struct loop *loop = loop_containing_stmt (loop_phi_node); |
b8698a0f | 1565 | |
dfedbe40 | 1566 | if (dump_file && (dump_flags & TDF_SCEV)) |
9baba81b SP |
1567 | { |
1568 | fprintf (dump_file, "(analyze_initial_condition \n"); | |
1569 | fprintf (dump_file, " (loop_phi_node = \n"); | |
726a989a | 1570 | print_gimple_stmt (dump_file, loop_phi_node, 0, 0); |
9baba81b SP |
1571 | fprintf (dump_file, ")\n"); |
1572 | } | |
b8698a0f | 1573 | |
726a989a RB |
1574 | n = gimple_phi_num_args (loop_phi_node); |
1575 | for (i = 0; i < n; i++) | |
9baba81b SP |
1576 | { |
1577 | tree branch = PHI_ARG_DEF (loop_phi_node, i); | |
726a989a | 1578 | basic_block bb = gimple_phi_arg_edge (loop_phi_node, i)->src; |
b8698a0f | 1579 | |
9baba81b SP |
1580 | /* When the branch is oriented to the loop's body, it does |
1581 | not contribute to the initial condition. */ | |
1582 | if (flow_bb_inside_loop_p (loop, bb)) | |
1583 | continue; | |
1584 | ||
1585 | if (init_cond == chrec_not_analyzed_yet) | |
1586 | { | |
1587 | init_cond = branch; | |
1588 | continue; | |
1589 | } | |
1590 | ||
1591 | if (TREE_CODE (branch) == SSA_NAME) | |
1592 | { | |
1593 | init_cond = chrec_dont_know; | |
1594 | break; | |
1595 | } | |
1596 | ||
1597 | init_cond = chrec_merge (init_cond, branch); | |
1598 | } | |
1599 | ||
1600 | /* Ooops -- a loop without an entry??? */ | |
1601 | if (init_cond == chrec_not_analyzed_yet) | |
1602 | init_cond = chrec_dont_know; | |
1603 | ||
bf1cbdc6 RG |
1604 | /* During early loop unrolling we do not have fully constant propagated IL. |
1605 | Handle degenerate PHIs here to not miss important unrollings. */ | |
1606 | if (TREE_CODE (init_cond) == SSA_NAME) | |
1607 | { | |
1608 | gimple def = SSA_NAME_DEF_STMT (init_cond); | |
538dd0b7 DM |
1609 | if (gphi *phi = dyn_cast <gphi *> (def)) |
1610 | { | |
1611 | tree res = degenerate_phi_result (phi); | |
1612 | if (res != NULL_TREE | |
1613 | /* Only allow invariants here, otherwise we may break | |
1614 | loop-closed SSA form. */ | |
1615 | && is_gimple_min_invariant (res)) | |
1616 | init_cond = res; | |
1617 | } | |
bf1cbdc6 RG |
1618 | } |
1619 | ||
dfedbe40 | 1620 | if (dump_file && (dump_flags & TDF_SCEV)) |
9baba81b SP |
1621 | { |
1622 | fprintf (dump_file, " (init_cond = "); | |
1623 | print_generic_expr (dump_file, init_cond, 0); | |
1624 | fprintf (dump_file, "))\n"); | |
1625 | } | |
b8698a0f | 1626 | |
9baba81b SP |
1627 | return init_cond; |
1628 | } | |
1629 | ||
1630 | /* Analyze the scalar evolution for LOOP_PHI_NODE. */ | |
1631 | ||
b8698a0f | 1632 | static tree |
538dd0b7 | 1633 | interpret_loop_phi (struct loop *loop, gphi *loop_phi_node) |
9baba81b SP |
1634 | { |
1635 | tree res; | |
1636 | struct loop *phi_loop = loop_containing_stmt (loop_phi_node); | |
1637 | tree init_cond; | |
b8698a0f | 1638 | |
9baba81b SP |
1639 | if (phi_loop != loop) |
1640 | { | |
1641 | struct loop *subloop; | |
1642 | tree evolution_fn = analyze_scalar_evolution | |
1643 | (phi_loop, PHI_RESULT (loop_phi_node)); | |
1644 | ||
1645 | /* Dive one level deeper. */ | |
9ba025a2 | 1646 | subloop = superloop_at_depth (phi_loop, loop_depth (loop) + 1); |
9baba81b SP |
1647 | |
1648 | /* Interpret the subloop. */ | |
1649 | res = compute_overall_effect_of_inner_loop (subloop, evolution_fn); | |
1650 | return res; | |
1651 | } | |
1652 | ||
1653 | /* Otherwise really interpret the loop phi. */ | |
1654 | init_cond = analyze_initial_condition (loop_phi_node); | |
1655 | res = analyze_evolution_in_loop (loop_phi_node, init_cond); | |
1656 | ||
73c865fa RG |
1657 | /* Verify we maintained the correct initial condition throughout |
1658 | possible conversions in the SSA chain. */ | |
1659 | if (res != chrec_dont_know) | |
1660 | { | |
1661 | tree new_init = res; | |
1662 | if (CONVERT_EXPR_P (res) | |
1663 | && TREE_CODE (TREE_OPERAND (res, 0)) == POLYNOMIAL_CHREC) | |
1664 | new_init = fold_convert (TREE_TYPE (res), | |
1665 | CHREC_LEFT (TREE_OPERAND (res, 0))); | |
1666 | else if (TREE_CODE (res) == POLYNOMIAL_CHREC) | |
1667 | new_init = CHREC_LEFT (res); | |
1668 | STRIP_USELESS_TYPE_CONVERSION (new_init); | |
eb723fa3 RG |
1669 | if (TREE_CODE (new_init) == POLYNOMIAL_CHREC |
1670 | || !operand_equal_p (init_cond, new_init, 0)) | |
73c865fa RG |
1671 | return chrec_dont_know; |
1672 | } | |
1673 | ||
9baba81b SP |
1674 | return res; |
1675 | } | |
1676 | ||
1677 | /* This function merges the branches of a condition-phi-node, | |
1678 | contained in the outermost loop, and whose arguments are already | |
1679 | analyzed. */ | |
1680 | ||
1681 | static tree | |
538dd0b7 | 1682 | interpret_condition_phi (struct loop *loop, gphi *condition_phi) |
9baba81b | 1683 | { |
726a989a | 1684 | int i, n = gimple_phi_num_args (condition_phi); |
9baba81b | 1685 | tree res = chrec_not_analyzed_yet; |
b8698a0f | 1686 | |
726a989a | 1687 | for (i = 0; i < n; i++) |
9baba81b SP |
1688 | { |
1689 | tree branch_chrec; | |
b8698a0f | 1690 | |
9baba81b SP |
1691 | if (backedge_phi_arg_p (condition_phi, i)) |
1692 | { | |
1693 | res = chrec_dont_know; | |
1694 | break; | |
1695 | } | |
1696 | ||
1697 | branch_chrec = analyze_scalar_evolution | |
1698 | (loop, PHI_ARG_DEF (condition_phi, i)); | |
b8698a0f | 1699 | |
9baba81b SP |
1700 | res = chrec_merge (res, branch_chrec); |
1701 | } | |
1702 | ||
1703 | return res; | |
1704 | } | |
1705 | ||
726a989a | 1706 | /* Interpret the operation RHS1 OP RHS2. If we didn't |
29836d07 | 1707 | analyze this node before, follow the definitions until ending |
726a989a | 1708 | either on an analyzed GIMPLE_ASSIGN, or on a loop-phi-node. On the |
9baba81b SP |
1709 | return path, this function propagates evolutions (ala constant copy |
1710 | propagation). OPND1 is not a GIMPLE expression because we could | |
1711 | analyze the effect of an inner loop: see interpret_loop_phi. */ | |
1712 | ||
1713 | static tree | |
726a989a RB |
1714 | interpret_rhs_expr (struct loop *loop, gimple at_stmt, |
1715 | tree type, tree rhs1, enum tree_code code, tree rhs2) | |
9baba81b | 1716 | { |
726a989a | 1717 | tree res, chrec1, chrec2; |
195b4c50 | 1718 | gimple def; |
726a989a RB |
1719 | |
1720 | if (get_gimple_rhs_class (code) == GIMPLE_SINGLE_RHS) | |
1721 | { | |
1722 | if (is_gimple_min_invariant (rhs1)) | |
1723 | return chrec_convert (type, rhs1, at_stmt); | |
1724 | ||
1725 | if (code == SSA_NAME) | |
1726 | return chrec_convert (type, analyze_scalar_evolution (loop, rhs1), | |
1727 | at_stmt); | |
1e8552eb | 1728 | |
726a989a RB |
1729 | if (code == ASSERT_EXPR) |
1730 | { | |
1731 | rhs1 = ASSERT_EXPR_VAR (rhs1); | |
1732 | return chrec_convert (type, analyze_scalar_evolution (loop, rhs1), | |
1733 | at_stmt); | |
1734 | } | |
726a989a | 1735 | } |
1e8552eb | 1736 | |
726a989a | 1737 | switch (code) |
9baba81b | 1738 | { |
6a02a719 | 1739 | case ADDR_EXPR: |
bef28ced JL |
1740 | if (TREE_CODE (TREE_OPERAND (rhs1, 0)) == MEM_REF |
1741 | || handled_component_p (TREE_OPERAND (rhs1, 0))) | |
1742 | { | |
ef4bddc2 | 1743 | machine_mode mode; |
bef28ced JL |
1744 | HOST_WIDE_INT bitsize, bitpos; |
1745 | int unsignedp; | |
1746 | int volatilep = 0; | |
1747 | tree base, offset; | |
1748 | tree chrec3; | |
1749 | tree unitpos; | |
1750 | ||
1751 | base = get_inner_reference (TREE_OPERAND (rhs1, 0), | |
1752 | &bitsize, &bitpos, &offset, | |
b3ecff82 | 1753 | &mode, &unsignedp, &volatilep, false); |
bef28ced JL |
1754 | |
1755 | if (TREE_CODE (base) == MEM_REF) | |
1756 | { | |
1757 | rhs2 = TREE_OPERAND (base, 1); | |
1758 | rhs1 = TREE_OPERAND (base, 0); | |
1759 | ||
1760 | chrec1 = analyze_scalar_evolution (loop, rhs1); | |
1761 | chrec2 = analyze_scalar_evolution (loop, rhs2); | |
1762 | chrec1 = chrec_convert (type, chrec1, at_stmt); | |
1763 | chrec2 = chrec_convert (TREE_TYPE (rhs2), chrec2, at_stmt); | |
0547c9b6 RB |
1764 | chrec1 = instantiate_parameters (loop, chrec1); |
1765 | chrec2 = instantiate_parameters (loop, chrec2); | |
bef28ced JL |
1766 | res = chrec_fold_plus (type, chrec1, chrec2); |
1767 | } | |
1768 | else | |
1769 | { | |
1770 | chrec1 = analyze_scalar_evolution_for_address_of (loop, base); | |
1771 | chrec1 = chrec_convert (type, chrec1, at_stmt); | |
1772 | res = chrec1; | |
1773 | } | |
6a02a719 | 1774 | |
bef28ced JL |
1775 | if (offset != NULL_TREE) |
1776 | { | |
1777 | chrec2 = analyze_scalar_evolution (loop, offset); | |
1778 | chrec2 = chrec_convert (TREE_TYPE (offset), chrec2, at_stmt); | |
0547c9b6 | 1779 | chrec2 = instantiate_parameters (loop, chrec2); |
bef28ced JL |
1780 | res = chrec_fold_plus (type, res, chrec2); |
1781 | } | |
1782 | ||
1783 | if (bitpos != 0) | |
1784 | { | |
1785 | gcc_assert ((bitpos % BITS_PER_UNIT) == 0); | |
1786 | ||
18dae016 | 1787 | unitpos = size_int (bitpos / BITS_PER_UNIT); |
bef28ced JL |
1788 | chrec3 = analyze_scalar_evolution (loop, unitpos); |
1789 | chrec3 = chrec_convert (TREE_TYPE (unitpos), chrec3, at_stmt); | |
0547c9b6 | 1790 | chrec3 = instantiate_parameters (loop, chrec3); |
bef28ced JL |
1791 | res = chrec_fold_plus (type, res, chrec3); |
1792 | } | |
1793 | } | |
1794 | else | |
1795 | res = chrec_dont_know; | |
1796 | break; | |
6a02a719 | 1797 | |
5be014d5 | 1798 | case POINTER_PLUS_EXPR: |
726a989a RB |
1799 | chrec1 = analyze_scalar_evolution (loop, rhs1); |
1800 | chrec2 = analyze_scalar_evolution (loop, rhs2); | |
1801 | chrec1 = chrec_convert (type, chrec1, at_stmt); | |
0d82a1c8 | 1802 | chrec2 = chrec_convert (TREE_TYPE (rhs2), chrec2, at_stmt); |
0547c9b6 RB |
1803 | chrec1 = instantiate_parameters (loop, chrec1); |
1804 | chrec2 = instantiate_parameters (loop, chrec2); | |
726a989a | 1805 | res = chrec_fold_plus (type, chrec1, chrec2); |
5be014d5 AP |
1806 | break; |
1807 | ||
9baba81b | 1808 | case PLUS_EXPR: |
726a989a RB |
1809 | chrec1 = analyze_scalar_evolution (loop, rhs1); |
1810 | chrec2 = analyze_scalar_evolution (loop, rhs2); | |
1811 | chrec1 = chrec_convert (type, chrec1, at_stmt); | |
1812 | chrec2 = chrec_convert (type, chrec2, at_stmt); | |
0547c9b6 RB |
1813 | chrec1 = instantiate_parameters (loop, chrec1); |
1814 | chrec2 = instantiate_parameters (loop, chrec2); | |
726a989a | 1815 | res = chrec_fold_plus (type, chrec1, chrec2); |
9baba81b | 1816 | break; |
b8698a0f | 1817 | |
9baba81b | 1818 | case MINUS_EXPR: |
726a989a RB |
1819 | chrec1 = analyze_scalar_evolution (loop, rhs1); |
1820 | chrec2 = analyze_scalar_evolution (loop, rhs2); | |
1821 | chrec1 = chrec_convert (type, chrec1, at_stmt); | |
1822 | chrec2 = chrec_convert (type, chrec2, at_stmt); | |
0547c9b6 RB |
1823 | chrec1 = instantiate_parameters (loop, chrec1); |
1824 | chrec2 = instantiate_parameters (loop, chrec2); | |
726a989a | 1825 | res = chrec_fold_minus (type, chrec1, chrec2); |
9baba81b SP |
1826 | break; |
1827 | ||
1828 | case NEGATE_EXPR: | |
726a989a RB |
1829 | chrec1 = analyze_scalar_evolution (loop, rhs1); |
1830 | chrec1 = chrec_convert (type, chrec1, at_stmt); | |
9a75ede0 | 1831 | /* TYPE may be integer, real or complex, so use fold_convert. */ |
0547c9b6 | 1832 | chrec1 = instantiate_parameters (loop, chrec1); |
726a989a | 1833 | res = chrec_fold_multiply (type, chrec1, |
9a75ede0 | 1834 | fold_convert (type, integer_minus_one_node)); |
9baba81b SP |
1835 | break; |
1836 | ||
418df9d7 JJ |
1837 | case BIT_NOT_EXPR: |
1838 | /* Handle ~X as -1 - X. */ | |
1839 | chrec1 = analyze_scalar_evolution (loop, rhs1); | |
1840 | chrec1 = chrec_convert (type, chrec1, at_stmt); | |
0547c9b6 | 1841 | chrec1 = instantiate_parameters (loop, chrec1); |
418df9d7 JJ |
1842 | res = chrec_fold_minus (type, |
1843 | fold_convert (type, integer_minus_one_node), | |
1844 | chrec1); | |
1845 | break; | |
1846 | ||
9baba81b | 1847 | case MULT_EXPR: |
726a989a RB |
1848 | chrec1 = analyze_scalar_evolution (loop, rhs1); |
1849 | chrec2 = analyze_scalar_evolution (loop, rhs2); | |
1850 | chrec1 = chrec_convert (type, chrec1, at_stmt); | |
1851 | chrec2 = chrec_convert (type, chrec2, at_stmt); | |
0547c9b6 RB |
1852 | chrec1 = instantiate_parameters (loop, chrec1); |
1853 | chrec2 = instantiate_parameters (loop, chrec2); | |
726a989a | 1854 | res = chrec_fold_multiply (type, chrec1, chrec2); |
0bca51f0 | 1855 | break; |
b8698a0f | 1856 | |
1043771b | 1857 | CASE_CONVERT: |
195b4c50 RG |
1858 | /* In case we have a truncation of a widened operation that in |
1859 | the truncated type has undefined overflow behavior analyze | |
1860 | the operation done in an unsigned type of the same precision | |
1861 | as the final truncation. We cannot derive a scalar evolution | |
1862 | for the widened operation but for the truncated result. */ | |
1863 | if (TREE_CODE (type) == INTEGER_TYPE | |
1864 | && TREE_CODE (TREE_TYPE (rhs1)) == INTEGER_TYPE | |
1865 | && TYPE_PRECISION (type) < TYPE_PRECISION (TREE_TYPE (rhs1)) | |
1866 | && TYPE_OVERFLOW_UNDEFINED (type) | |
1867 | && TREE_CODE (rhs1) == SSA_NAME | |
1868 | && (def = SSA_NAME_DEF_STMT (rhs1)) | |
1869 | && is_gimple_assign (def) | |
1870 | && TREE_CODE_CLASS (gimple_assign_rhs_code (def)) == tcc_binary | |
1871 | && TREE_CODE (gimple_assign_rhs2 (def)) == INTEGER_CST) | |
1872 | { | |
1873 | tree utype = unsigned_type_for (type); | |
1874 | chrec1 = interpret_rhs_expr (loop, at_stmt, utype, | |
1875 | gimple_assign_rhs1 (def), | |
1876 | gimple_assign_rhs_code (def), | |
1877 | gimple_assign_rhs2 (def)); | |
1878 | } | |
1879 | else | |
1880 | chrec1 = analyze_scalar_evolution (loop, rhs1); | |
726a989a | 1881 | res = chrec_convert (type, chrec1, at_stmt); |
9baba81b | 1882 | break; |
b8698a0f | 1883 | |
9baba81b SP |
1884 | default: |
1885 | res = chrec_dont_know; | |
1886 | break; | |
1887 | } | |
b8698a0f | 1888 | |
9baba81b SP |
1889 | return res; |
1890 | } | |
1891 | ||
726a989a RB |
1892 | /* Interpret the expression EXPR. */ |
1893 | ||
1894 | static tree | |
1895 | interpret_expr (struct loop *loop, gimple at_stmt, tree expr) | |
1896 | { | |
1897 | enum tree_code code; | |
1898 | tree type = TREE_TYPE (expr), op0, op1; | |
1899 | ||
1900 | if (automatically_generated_chrec_p (expr)) | |
1901 | return expr; | |
1902 | ||
4e71066d RG |
1903 | if (TREE_CODE (expr) == POLYNOMIAL_CHREC |
1904 | || get_gimple_rhs_class (TREE_CODE (expr)) == GIMPLE_TERNARY_RHS) | |
726a989a RB |
1905 | return chrec_dont_know; |
1906 | ||
1907 | extract_ops_from_tree (expr, &code, &op0, &op1); | |
1908 | ||
1909 | return interpret_rhs_expr (loop, at_stmt, type, | |
1910 | op0, code, op1); | |
1911 | } | |
1912 | ||
1913 | /* Interpret the rhs of the assignment STMT. */ | |
1914 | ||
1915 | static tree | |
1916 | interpret_gimple_assign (struct loop *loop, gimple stmt) | |
1917 | { | |
1918 | tree type = TREE_TYPE (gimple_assign_lhs (stmt)); | |
1919 | enum tree_code code = gimple_assign_rhs_code (stmt); | |
1920 | ||
1921 | return interpret_rhs_expr (loop, stmt, type, | |
1922 | gimple_assign_rhs1 (stmt), code, | |
1923 | gimple_assign_rhs2 (stmt)); | |
1924 | } | |
1925 | ||
9baba81b SP |
1926 | \f |
1927 | ||
b8698a0f | 1928 | /* This section contains all the entry points: |
9baba81b SP |
1929 | - number_of_iterations_in_loop, |
1930 | - analyze_scalar_evolution, | |
1931 | - instantiate_parameters. | |
1932 | */ | |
1933 | ||
1934 | /* Compute and return the evolution function in WRTO_LOOP, the nearest | |
1935 | common ancestor of DEF_LOOP and USE_LOOP. */ | |
1936 | ||
b8698a0f L |
1937 | static tree |
1938 | compute_scalar_evolution_in_loop (struct loop *wrto_loop, | |
1939 | struct loop *def_loop, | |
9baba81b SP |
1940 | tree ev) |
1941 | { | |
492e5456 | 1942 | bool val; |
9baba81b | 1943 | tree res; |
492e5456 | 1944 | |
9baba81b SP |
1945 | if (def_loop == wrto_loop) |
1946 | return ev; | |
1947 | ||
9ba025a2 | 1948 | def_loop = superloop_at_depth (def_loop, loop_depth (wrto_loop) + 1); |
9baba81b SP |
1949 | res = compute_overall_effect_of_inner_loop (def_loop, ev); |
1950 | ||
492e5456 SP |
1951 | if (no_evolution_in_loop_p (res, wrto_loop->num, &val) && val) |
1952 | return res; | |
1953 | ||
9baba81b SP |
1954 | return analyze_scalar_evolution_1 (wrto_loop, res, chrec_not_analyzed_yet); |
1955 | } | |
1956 | ||
1957 | /* Helper recursive function. */ | |
1958 | ||
1959 | static tree | |
1960 | analyze_scalar_evolution_1 (struct loop *loop, tree var, tree res) | |
1961 | { | |
726a989a RB |
1962 | tree type = TREE_TYPE (var); |
1963 | gimple def; | |
9baba81b SP |
1964 | basic_block bb; |
1965 | struct loop *def_loop; | |
1966 | ||
42d375ed | 1967 | if (loop == NULL || TREE_CODE (type) == VECTOR_TYPE) |
9baba81b SP |
1968 | return chrec_dont_know; |
1969 | ||
1970 | if (TREE_CODE (var) != SSA_NAME) | |
726a989a | 1971 | return interpret_expr (loop, NULL, var); |
9baba81b SP |
1972 | |
1973 | def = SSA_NAME_DEF_STMT (var); | |
726a989a | 1974 | bb = gimple_bb (def); |
9baba81b SP |
1975 | def_loop = bb ? bb->loop_father : NULL; |
1976 | ||
1977 | if (bb == NULL | |
1978 | || !flow_bb_inside_loop_p (loop, bb)) | |
1979 | { | |
1980 | /* Keep the symbolic form. */ | |
1981 | res = var; | |
1982 | goto set_and_end; | |
1983 | } | |
1984 | ||
1985 | if (res != chrec_not_analyzed_yet) | |
1986 | { | |
1987 | if (loop != bb->loop_father) | |
b8698a0f | 1988 | res = compute_scalar_evolution_in_loop |
9baba81b SP |
1989 | (find_common_loop (loop, bb->loop_father), bb->loop_father, res); |
1990 | ||
1991 | goto set_and_end; | |
1992 | } | |
1993 | ||
1994 | if (loop != def_loop) | |
1995 | { | |
1996 | res = analyze_scalar_evolution_1 (def_loop, var, chrec_not_analyzed_yet); | |
1997 | res = compute_scalar_evolution_in_loop (loop, def_loop, res); | |
1998 | ||
1999 | goto set_and_end; | |
2000 | } | |
2001 | ||
726a989a | 2002 | switch (gimple_code (def)) |
9baba81b | 2003 | { |
726a989a RB |
2004 | case GIMPLE_ASSIGN: |
2005 | res = interpret_gimple_assign (loop, def); | |
9baba81b SP |
2006 | break; |
2007 | ||
726a989a | 2008 | case GIMPLE_PHI: |
9baba81b | 2009 | if (loop_phi_node_p (def)) |
538dd0b7 | 2010 | res = interpret_loop_phi (loop, as_a <gphi *> (def)); |
9baba81b | 2011 | else |
538dd0b7 | 2012 | res = interpret_condition_phi (loop, as_a <gphi *> (def)); |
9baba81b SP |
2013 | break; |
2014 | ||
2015 | default: | |
2016 | res = chrec_dont_know; | |
2017 | break; | |
2018 | } | |
2019 | ||
2020 | set_and_end: | |
2021 | ||
2022 | /* Keep the symbolic form. */ | |
2023 | if (res == chrec_dont_know) | |
2024 | res = var; | |
2025 | ||
2026 | if (loop == def_loop) | |
a213b219 | 2027 | set_scalar_evolution (block_before_loop (loop), var, res); |
9baba81b SP |
2028 | |
2029 | return res; | |
2030 | } | |
2031 | ||
52bdd655 SP |
2032 | /* Analyzes and returns the scalar evolution of the ssa_name VAR in |
2033 | LOOP. LOOP is the loop in which the variable is used. | |
b8698a0f | 2034 | |
9baba81b SP |
2035 | Example of use: having a pointer VAR to a SSA_NAME node, STMT a |
2036 | pointer to the statement that uses this variable, in order to | |
2037 | determine the evolution function of the variable, use the following | |
2038 | calls: | |
b8698a0f | 2039 | |
52bdd655 SP |
2040 | loop_p loop = loop_containing_stmt (stmt); |
2041 | tree chrec_with_symbols = analyze_scalar_evolution (loop, var); | |
3f227a8c | 2042 | tree chrec_instantiated = instantiate_parameters (loop, chrec_with_symbols); |
9baba81b SP |
2043 | */ |
2044 | ||
b8698a0f | 2045 | tree |
9baba81b SP |
2046 | analyze_scalar_evolution (struct loop *loop, tree var) |
2047 | { | |
2048 | tree res; | |
2049 | ||
dfedbe40 | 2050 | if (dump_file && (dump_flags & TDF_SCEV)) |
9baba81b SP |
2051 | { |
2052 | fprintf (dump_file, "(analyze_scalar_evolution \n"); | |
2053 | fprintf (dump_file, " (loop_nb = %d)\n", loop->num); | |
2054 | fprintf (dump_file, " (scalar = "); | |
2055 | print_generic_expr (dump_file, var, 0); | |
2056 | fprintf (dump_file, ")\n"); | |
2057 | } | |
2058 | ||
a213b219 SP |
2059 | res = get_scalar_evolution (block_before_loop (loop), var); |
2060 | res = analyze_scalar_evolution_1 (loop, var, res); | |
9baba81b | 2061 | |
dfedbe40 | 2062 | if (dump_file && (dump_flags & TDF_SCEV)) |
9baba81b SP |
2063 | fprintf (dump_file, ")\n"); |
2064 | ||
2065 | return res; | |
2066 | } | |
2067 | ||
bef28ced JL |
2068 | /* Analyzes and returns the scalar evolution of VAR address in LOOP. */ |
2069 | ||
2070 | static tree | |
2071 | analyze_scalar_evolution_for_address_of (struct loop *loop, tree var) | |
2072 | { | |
2073 | return analyze_scalar_evolution (loop, build_fold_addr_expr (var)); | |
2074 | } | |
2075 | ||
9baba81b | 2076 | /* Analyze scalar evolution of use of VERSION in USE_LOOP with respect to |
f017bf5e | 2077 | WRTO_LOOP (which should be a superloop of USE_LOOP) |
a6f778b2 ZD |
2078 | |
2079 | FOLDED_CASTS is set to true if resolve_mixers used | |
2080 | chrec_convert_aggressive (TODO -- not really, we are way too conservative | |
b8698a0f L |
2081 | at the moment in order to keep things simple). |
2082 | ||
f017bf5e ZD |
2083 | To illustrate the meaning of USE_LOOP and WRTO_LOOP, consider the following |
2084 | example: | |
2085 | ||
2086 | for (i = 0; i < 100; i++) -- loop 1 | |
2087 | { | |
2088 | for (j = 0; j < 100; j++) -- loop 2 | |
2089 | { | |
2090 | k1 = i; | |
2091 | k2 = j; | |
2092 | ||
2093 | use2 (k1, k2); | |
2094 | ||
2095 | for (t = 0; t < 100; t++) -- loop 3 | |
2096 | use3 (k1, k2); | |
2097 | ||
2098 | } | |
2099 | use1 (k1, k2); | |
2100 | } | |
2101 | ||
2102 | Both k1 and k2 are invariants in loop3, thus | |
2103 | analyze_scalar_evolution_in_loop (loop3, loop3, k1) = k1 | |
2104 | analyze_scalar_evolution_in_loop (loop3, loop3, k2) = k2 | |
2105 | ||
2106 | As they are invariant, it does not matter whether we consider their | |
2107 | usage in loop 3 or loop 2, hence | |
2108 | analyze_scalar_evolution_in_loop (loop2, loop3, k1) = | |
2109 | analyze_scalar_evolution_in_loop (loop2, loop2, k1) = i | |
2110 | analyze_scalar_evolution_in_loop (loop2, loop3, k2) = | |
2111 | analyze_scalar_evolution_in_loop (loop2, loop2, k2) = [0,+,1]_2 | |
2112 | ||
2113 | Similarly for their evolutions with respect to loop 1. The values of K2 | |
2114 | in the use in loop 2 vary independently on loop 1, thus we cannot express | |
2115 | the evolution with respect to loop 1: | |
2116 | analyze_scalar_evolution_in_loop (loop1, loop3, k1) = | |
2117 | analyze_scalar_evolution_in_loop (loop1, loop2, k1) = [0,+,1]_1 | |
2118 | analyze_scalar_evolution_in_loop (loop1, loop3, k2) = | |
2119 | analyze_scalar_evolution_in_loop (loop1, loop2, k2) = dont_know | |
2120 | ||
2121 | The value of k2 in the use in loop 1 is known, though: | |
2122 | analyze_scalar_evolution_in_loop (loop1, loop1, k1) = [0,+,1]_1 | |
2123 | analyze_scalar_evolution_in_loop (loop1, loop1, k2) = 100 | |
2124 | */ | |
9baba81b SP |
2125 | |
2126 | static tree | |
2127 | analyze_scalar_evolution_in_loop (struct loop *wrto_loop, struct loop *use_loop, | |
a6f778b2 | 2128 | tree version, bool *folded_casts) |
9baba81b SP |
2129 | { |
2130 | bool val = false; | |
a6f778b2 | 2131 | tree ev = version, tmp; |
9baba81b | 2132 | |
b8698a0f | 2133 | /* We cannot just do |
f017bf5e ZD |
2134 | |
2135 | tmp = analyze_scalar_evolution (use_loop, version); | |
2136 | ev = resolve_mixers (wrto_loop, tmp); | |
2137 | ||
2138 | as resolve_mixers would query the scalar evolution with respect to | |
2139 | wrto_loop. For example, in the situation described in the function | |
2140 | comment, suppose that wrto_loop = loop1, use_loop = loop3 and | |
2141 | version = k2. Then | |
2142 | ||
2143 | analyze_scalar_evolution (use_loop, version) = k2 | |
2144 | ||
2145 | and resolve_mixers (loop1, k2) finds that the value of k2 in loop 1 | |
2146 | is 100, which is a wrong result, since we are interested in the | |
2147 | value in loop 3. | |
2148 | ||
2149 | Instead, we need to proceed from use_loop to wrto_loop loop by loop, | |
2150 | each time checking that there is no evolution in the inner loop. */ | |
2151 | ||
a6f778b2 ZD |
2152 | if (folded_casts) |
2153 | *folded_casts = false; | |
9baba81b SP |
2154 | while (1) |
2155 | { | |
a6f778b2 ZD |
2156 | tmp = analyze_scalar_evolution (use_loop, ev); |
2157 | ev = resolve_mixers (use_loop, tmp); | |
2158 | ||
2159 | if (folded_casts && tmp != ev) | |
2160 | *folded_casts = true; | |
9baba81b SP |
2161 | |
2162 | if (use_loop == wrto_loop) | |
2163 | return ev; | |
2164 | ||
2165 | /* If the value of the use changes in the inner loop, we cannot express | |
2166 | its value in the outer loop (we might try to return interval chrec, | |
2167 | but we do not have a user for it anyway) */ | |
2168 | if (!no_evolution_in_loop_p (ev, use_loop->num, &val) | |
2169 | || !val) | |
2170 | return chrec_dont_know; | |
2171 | ||
9ba025a2 | 2172 | use_loop = loop_outer (use_loop); |
9baba81b SP |
2173 | } |
2174 | } | |
2175 | ||
eb0bc7af | 2176 | |
fdd43ac4 RB |
2177 | /* Hashtable helpers for a temporary hash-table used when |
2178 | instantiating a CHREC or resolving mixers. For this use | |
2179 | instantiated_below is always the same. */ | |
2180 | ||
fdd43ac4 | 2181 | struct instantiate_cache_type |
eb0bc7af | 2182 | { |
a3cc13cc RB |
2183 | htab_t map; |
2184 | vec<scev_info_str> entries; | |
b8698a0f | 2185 | |
c3284718 | 2186 | instantiate_cache_type () : map (NULL), entries (vNULL) {} |
fdd43ac4 | 2187 | ~instantiate_cache_type (); |
0547c9b6 RB |
2188 | tree get (unsigned slot) { return entries[slot].chrec; } |
2189 | void set (unsigned slot, tree chrec) { entries[slot].chrec = chrec; } | |
fdd43ac4 | 2190 | }; |
eb0bc7af | 2191 | |
fdd43ac4 RB |
2192 | instantiate_cache_type::~instantiate_cache_type () |
2193 | { | |
0547c9b6 | 2194 | if (map != NULL) |
fdd43ac4 | 2195 | { |
a3cc13cc | 2196 | htab_delete (map); |
fdd43ac4 RB |
2197 | entries.release (); |
2198 | } | |
eb0bc7af ZD |
2199 | } |
2200 | ||
a3cc13cc RB |
2201 | /* Cache to avoid infinite recursion when instantiating an SSA name. |
2202 | Live during the outermost instantiate_scev or resolve_mixers call. */ | |
2203 | static instantiate_cache_type *global_cache; | |
2204 | ||
2205 | /* Computes a hash function for database element ELT. */ | |
2206 | ||
2207 | static inline hashval_t | |
2208 | hash_idx_scev_info (const void *elt_) | |
2209 | { | |
2210 | unsigned idx = ((size_t) elt_) - 2; | |
907dadbd | 2211 | return scev_info_hasher::hash (&global_cache->entries[idx]); |
a3cc13cc RB |
2212 | } |
2213 | ||
2214 | /* Compares database elements E1 and E2. */ | |
2215 | ||
2216 | static inline int | |
2217 | eq_idx_scev_info (const void *e1, const void *e2) | |
2218 | { | |
2219 | unsigned idx1 = ((size_t) e1) - 2; | |
907dadbd TS |
2220 | return scev_info_hasher::equal (&global_cache->entries[idx1], |
2221 | (const scev_info_str *) e2); | |
a3cc13cc RB |
2222 | } |
2223 | ||
0547c9b6 | 2224 | /* Returns from CACHE the slot number of the cached chrec for NAME. */ |
fdd43ac4 | 2225 | |
0547c9b6 | 2226 | static unsigned |
a3cc13cc RB |
2227 | get_instantiated_value_entry (instantiate_cache_type &cache, |
2228 | tree name, basic_block instantiate_below) | |
fdd43ac4 | 2229 | { |
0547c9b6 | 2230 | if (!cache.map) |
fdd43ac4 | 2231 | { |
a3cc13cc | 2232 | cache.map = htab_create (10, hash_idx_scev_info, eq_idx_scev_info, NULL); |
fdd43ac4 RB |
2233 | cache.entries.create (10); |
2234 | } | |
b8698a0f | 2235 | |
a3cc13cc RB |
2236 | scev_info_str e; |
2237 | e.name_version = SSA_NAME_VERSION (name); | |
2238 | e.instantiated_below = instantiate_below->index; | |
2239 | void **slot = htab_find_slot_with_hash (cache.map, &e, | |
907dadbd | 2240 | scev_info_hasher::hash (&e), INSERT); |
a3cc13cc | 2241 | if (!*slot) |
fdd43ac4 RB |
2242 | { |
2243 | e.chrec = chrec_not_analyzed_yet; | |
a3cc13cc | 2244 | *slot = (void *)(size_t)(cache.entries.length () + 2); |
fdd43ac4 | 2245 | cache.entries.safe_push (e); |
fdd43ac4 RB |
2246 | } |
2247 | ||
a3cc13cc | 2248 | return ((size_t)*slot) - 2; |
eb0bc7af ZD |
2249 | } |
2250 | ||
0547c9b6 | 2251 | |
18aed06a SP |
2252 | /* Return the closed_loop_phi node for VAR. If there is none, return |
2253 | NULL_TREE. */ | |
2254 | ||
2255 | static tree | |
2256 | loop_closed_phi_def (tree var) | |
2257 | { | |
2258 | struct loop *loop; | |
2259 | edge exit; | |
538dd0b7 DM |
2260 | gphi *phi; |
2261 | gphi_iterator psi; | |
18aed06a SP |
2262 | |
2263 | if (var == NULL_TREE | |
2264 | || TREE_CODE (var) != SSA_NAME) | |
2265 | return NULL_TREE; | |
2266 | ||
2267 | loop = loop_containing_stmt (SSA_NAME_DEF_STMT (var)); | |
ac8f6c69 | 2268 | exit = single_exit (loop); |
18aed06a SP |
2269 | if (!exit) |
2270 | return NULL_TREE; | |
2271 | ||
726a989a RB |
2272 | for (psi = gsi_start_phis (exit->dest); !gsi_end_p (psi); gsi_next (&psi)) |
2273 | { | |
538dd0b7 | 2274 | phi = psi.phi (); |
726a989a RB |
2275 | if (PHI_ARG_DEF_FROM_EDGE (phi, exit) == var) |
2276 | return PHI_RESULT (phi); | |
2277 | } | |
18aed06a SP |
2278 | |
2279 | return NULL_TREE; | |
2280 | } | |
2281 | ||
8b679c9b | 2282 | static tree instantiate_scev_r (basic_block, struct loop *, struct loop *, |
0547c9b6 | 2283 | tree, bool, int); |
320f5a78 SP |
2284 | |
2285 | /* Analyze all the parameters of the chrec, between INSTANTIATE_BELOW | |
2286 | and EVOLUTION_LOOP, that were left under a symbolic form. | |
2287 | ||
2495a183 | 2288 | CHREC is an SSA_NAME to be instantiated. |
320f5a78 SP |
2289 | |
2290 | CACHE is the cache of already instantiated values. | |
2291 | ||
2292 | FOLD_CONVERSIONS should be set to true when the conversions that | |
2293 | may wrap in signed/pointer type are folded, as long as the value of | |
2294 | the chrec is preserved. | |
2295 | ||
2296 | SIZE_EXPR is used for computing the size of the expression to be | |
2297 | instantiated, and to stop if it exceeds some limit. */ | |
2298 | ||
2299 | static tree | |
2495a183 | 2300 | instantiate_scev_name (basic_block instantiate_below, |
8b679c9b RB |
2301 | struct loop *evolution_loop, struct loop *inner_loop, |
2302 | tree chrec, | |
0547c9b6 | 2303 | bool fold_conversions, |
4a8fb1a1 | 2304 | int size_expr) |
320f5a78 | 2305 | { |
2495a183 SP |
2306 | tree res; |
2307 | struct loop *def_loop; | |
2308 | basic_block def_bb = gimple_bb (SSA_NAME_DEF_STMT (chrec)); | |
20179b0d | 2309 | |
2495a183 SP |
2310 | /* A parameter (or loop invariant and we do not want to include |
2311 | evolutions in outer loops), nothing to do. */ | |
2312 | if (!def_bb | |
2313 | || loop_depth (def_bb->loop_father) == 0 | |
2314 | || dominated_by_p (CDI_DOMINATORS, instantiate_below, def_bb)) | |
2315 | return chrec; | |
20179b0d | 2316 | |
2495a183 SP |
2317 | /* We cache the value of instantiated variable to avoid exponential |
2318 | time complexity due to reevaluations. We also store the convenient | |
2319 | value in the cache in order to prevent infinite recursion -- we do | |
2320 | not want to instantiate the SSA_NAME if it is in a mixer | |
2321 | structure. This is used for avoiding the instantiation of | |
2322 | recursively defined functions, such as: | |
320f5a78 | 2323 | |
2495a183 | 2324 | | a_2 -> {0, +, 1, +, a_2}_1 */ |
20179b0d | 2325 | |
a3cc13cc RB |
2326 | unsigned si = get_instantiated_value_entry (*global_cache, |
2327 | chrec, instantiate_below); | |
0547c9b6 RB |
2328 | if (global_cache->get (si) != chrec_not_analyzed_yet) |
2329 | return global_cache->get (si); | |
20179b0d | 2330 | |
fdd43ac4 | 2331 | /* On recursion return chrec_dont_know. */ |
0547c9b6 | 2332 | global_cache->set (si, chrec_dont_know); |
320f5a78 | 2333 | |
2495a183 SP |
2334 | def_loop = find_common_loop (evolution_loop, def_bb->loop_father); |
2335 | ||
320f5a78 SP |
2336 | /* If the analysis yields a parametric chrec, instantiate the |
2337 | result again. */ | |
2338 | res = analyze_scalar_evolution (def_loop, chrec); | |
2339 | ||
2847388e | 2340 | /* Don't instantiate default definitions. */ |
320f5a78 | 2341 | if (TREE_CODE (res) == SSA_NAME |
2847388e SP |
2342 | && SSA_NAME_IS_DEFAULT_DEF (res)) |
2343 | ; | |
2344 | ||
2345 | /* Don't instantiate loop-closed-ssa phi nodes. */ | |
2346 | else if (TREE_CODE (res) == SSA_NAME | |
2347 | && loop_depth (loop_containing_stmt (SSA_NAME_DEF_STMT (res))) | |
2348 | > loop_depth (def_loop)) | |
320f5a78 SP |
2349 | { |
2350 | if (res == chrec) | |
2351 | res = loop_closed_phi_def (chrec); | |
2352 | else | |
2353 | res = chrec; | |
2354 | ||
7472eb13 SP |
2355 | /* When there is no loop_closed_phi_def, it means that the |
2356 | variable is not used after the loop: try to still compute the | |
2357 | value of the variable when exiting the loop. */ | |
2358 | if (res == NULL_TREE) | |
2359 | { | |
2360 | loop_p loop = loop_containing_stmt (SSA_NAME_DEF_STMT (chrec)); | |
2361 | res = analyze_scalar_evolution (loop, chrec); | |
2362 | res = compute_overall_effect_of_inner_loop (loop, res); | |
8b679c9b RB |
2363 | res = instantiate_scev_r (instantiate_below, evolution_loop, |
2364 | inner_loop, res, | |
0547c9b6 | 2365 | fold_conversions, size_expr); |
7472eb13 SP |
2366 | } |
2367 | else if (!dominated_by_p (CDI_DOMINATORS, instantiate_below, | |
2368 | gimple_bb (SSA_NAME_DEF_STMT (res)))) | |
320f5a78 SP |
2369 | res = chrec_dont_know; |
2370 | } | |
2371 | ||
2372 | else if (res != chrec_dont_know) | |
8b679c9b RB |
2373 | { |
2374 | if (inner_loop | |
63fdb7be | 2375 | && def_bb->loop_father != inner_loop |
8b679c9b RB |
2376 | && !flow_loop_nested_p (def_bb->loop_father, inner_loop)) |
2377 | /* ??? We could try to compute the overall effect of the loop here. */ | |
2378 | res = chrec_dont_know; | |
2379 | else | |
2380 | res = instantiate_scev_r (instantiate_below, evolution_loop, | |
2381 | inner_loop, res, | |
0547c9b6 | 2382 | fold_conversions, size_expr); |
8b679c9b | 2383 | } |
320f5a78 SP |
2384 | |
2385 | /* Store the correct value to the cache. */ | |
0547c9b6 | 2386 | global_cache->set (si, res); |
320f5a78 | 2387 | return res; |
320f5a78 SP |
2388 | } |
2389 | ||
ec6636eb SP |
2390 | /* Analyze all the parameters of the chrec, between INSTANTIATE_BELOW |
2391 | and EVOLUTION_LOOP, that were left under a symbolic form. | |
2392 | ||
2393 | CHREC is a polynomial chain of recurrence to be instantiated. | |
2394 | ||
2395 | CACHE is the cache of already instantiated values. | |
2396 | ||
2397 | FOLD_CONVERSIONS should be set to true when the conversions that | |
2398 | may wrap in signed/pointer type are folded, as long as the value of | |
2399 | the chrec is preserved. | |
2400 | ||
2401 | SIZE_EXPR is used for computing the size of the expression to be | |
2402 | instantiated, and to stop if it exceeds some limit. */ | |
2403 | ||
2404 | static tree | |
2405 | instantiate_scev_poly (basic_block instantiate_below, | |
8b679c9b | 2406 | struct loop *evolution_loop, struct loop *, |
0547c9b6 | 2407 | tree chrec, bool fold_conversions, int size_expr) |
ec6636eb SP |
2408 | { |
2409 | tree op1; | |
9e5dc77f | 2410 | tree op0 = instantiate_scev_r (instantiate_below, evolution_loop, |
8b679c9b | 2411 | get_chrec_loop (chrec), |
0547c9b6 | 2412 | CHREC_LEFT (chrec), fold_conversions, |
ec6636eb SP |
2413 | size_expr); |
2414 | if (op0 == chrec_dont_know) | |
2415 | return chrec_dont_know; | |
2416 | ||
9e5dc77f | 2417 | op1 = instantiate_scev_r (instantiate_below, evolution_loop, |
8b679c9b | 2418 | get_chrec_loop (chrec), |
0547c9b6 | 2419 | CHREC_RIGHT (chrec), fold_conversions, |
ec6636eb SP |
2420 | size_expr); |
2421 | if (op1 == chrec_dont_know) | |
2422 | return chrec_dont_know; | |
2423 | ||
2424 | if (CHREC_LEFT (chrec) != op0 | |
2425 | || CHREC_RIGHT (chrec) != op1) | |
2426 | { | |
2427 | op1 = chrec_convert_rhs (chrec_type (op0), op1, NULL); | |
8b679c9b | 2428 | chrec = build_polynomial_chrec (CHREC_VARIABLE (chrec), op0, op1); |
ec6636eb | 2429 | } |
4bf4e169 | 2430 | |
ec6636eb SP |
2431 | return chrec; |
2432 | } | |
2433 | ||
15fda317 SP |
2434 | /* Analyze all the parameters of the chrec, between INSTANTIATE_BELOW |
2435 | and EVOLUTION_LOOP, that were left under a symbolic form. | |
2436 | ||
ffa34f4b | 2437 | "C0 CODE C1" is a binary expression of type TYPE to be instantiated. |
15fda317 SP |
2438 | |
2439 | CACHE is the cache of already instantiated values. | |
2440 | ||
2441 | FOLD_CONVERSIONS should be set to true when the conversions that | |
2442 | may wrap in signed/pointer type are folded, as long as the value of | |
2443 | the chrec is preserved. | |
2444 | ||
2445 | SIZE_EXPR is used for computing the size of the expression to be | |
2446 | instantiated, and to stop if it exceeds some limit. */ | |
2447 | ||
2448 | static tree | |
2449 | instantiate_scev_binary (basic_block instantiate_below, | |
8b679c9b RB |
2450 | struct loop *evolution_loop, struct loop *inner_loop, |
2451 | tree chrec, enum tree_code code, | |
ffa34f4b | 2452 | tree type, tree c0, tree c1, |
0547c9b6 | 2453 | bool fold_conversions, int size_expr) |
15fda317 SP |
2454 | { |
2455 | tree op1; | |
8b679c9b | 2456 | tree op0 = instantiate_scev_r (instantiate_below, evolution_loop, inner_loop, |
0547c9b6 | 2457 | c0, fold_conversions, size_expr); |
15fda317 SP |
2458 | if (op0 == chrec_dont_know) |
2459 | return chrec_dont_know; | |
2460 | ||
8b679c9b | 2461 | op1 = instantiate_scev_r (instantiate_below, evolution_loop, inner_loop, |
0547c9b6 | 2462 | c1, fold_conversions, size_expr); |
15fda317 SP |
2463 | if (op1 == chrec_dont_know) |
2464 | return chrec_dont_know; | |
2465 | ||
ffa34f4b SP |
2466 | if (c0 != op0 |
2467 | || c1 != op1) | |
15fda317 | 2468 | { |
15fda317 SP |
2469 | op0 = chrec_convert (type, op0, NULL); |
2470 | op1 = chrec_convert_rhs (type, op1, NULL); | |
2471 | ||
ffa34f4b | 2472 | switch (code) |
15fda317 SP |
2473 | { |
2474 | case POINTER_PLUS_EXPR: | |
2475 | case PLUS_EXPR: | |
2476 | return chrec_fold_plus (type, op0, op1); | |
2477 | ||
2478 | case MINUS_EXPR: | |
2479 | return chrec_fold_minus (type, op0, op1); | |
2480 | ||
2481 | case MULT_EXPR: | |
2482 | return chrec_fold_multiply (type, op0, op1); | |
2483 | ||
2484 | default: | |
2485 | gcc_unreachable (); | |
2486 | } | |
2487 | } | |
2488 | ||
ffa34f4b | 2489 | return chrec ? chrec : fold_build2 (code, type, c0, c1); |
15fda317 SP |
2490 | } |
2491 | ||
dbc08079 SP |
2492 | /* Analyze all the parameters of the chrec, between INSTANTIATE_BELOW |
2493 | and EVOLUTION_LOOP, that were left under a symbolic form. | |
2494 | ||
2495 | "CHREC" is an array reference to be instantiated. | |
2496 | ||
2497 | CACHE is the cache of already instantiated values. | |
2498 | ||
2499 | FOLD_CONVERSIONS should be set to true when the conversions that | |
2500 | may wrap in signed/pointer type are folded, as long as the value of | |
2501 | the chrec is preserved. | |
2502 | ||
2503 | SIZE_EXPR is used for computing the size of the expression to be | |
2504 | instantiated, and to stop if it exceeds some limit. */ | |
2505 | ||
2506 | static tree | |
2507 | instantiate_array_ref (basic_block instantiate_below, | |
8b679c9b | 2508 | struct loop *evolution_loop, struct loop *inner_loop, |
0547c9b6 | 2509 | tree chrec, bool fold_conversions, int size_expr) |
dbc08079 SP |
2510 | { |
2511 | tree res; | |
2512 | tree index = TREE_OPERAND (chrec, 1); | |
8b679c9b RB |
2513 | tree op1 = instantiate_scev_r (instantiate_below, evolution_loop, |
2514 | inner_loop, index, | |
0547c9b6 | 2515 | fold_conversions, size_expr); |
dbc08079 SP |
2516 | |
2517 | if (op1 == chrec_dont_know) | |
2518 | return chrec_dont_know; | |
2519 | ||
2520 | if (chrec && op1 == index) | |
2521 | return chrec; | |
2522 | ||
2523 | res = unshare_expr (chrec); | |
2524 | TREE_OPERAND (res, 1) = op1; | |
2525 | return res; | |
2526 | } | |
2527 | ||
a213b219 | 2528 | /* Analyze all the parameters of the chrec, between INSTANTIATE_BELOW |
9c382ce9 SP |
2529 | and EVOLUTION_LOOP, that were left under a symbolic form. |
2530 | ||
2531 | "CHREC" that stands for a convert expression "(TYPE) OP" is to be | |
2532 | instantiated. | |
2533 | ||
2534 | CACHE is the cache of already instantiated values. | |
2535 | ||
2536 | FOLD_CONVERSIONS should be set to true when the conversions that | |
2537 | may wrap in signed/pointer type are folded, as long as the value of | |
2538 | the chrec is preserved. | |
2539 | ||
2540 | SIZE_EXPR is used for computing the size of the expression to be | |
2541 | instantiated, and to stop if it exceeds some limit. */ | |
2542 | ||
2543 | static tree | |
2544 | instantiate_scev_convert (basic_block instantiate_below, | |
8b679c9b | 2545 | struct loop *evolution_loop, struct loop *inner_loop, |
0547c9b6 RB |
2546 | tree chrec, tree type, tree op, |
2547 | bool fold_conversions, int size_expr) | |
9c382ce9 | 2548 | { |
8b679c9b RB |
2549 | tree op0 = instantiate_scev_r (instantiate_below, evolution_loop, |
2550 | inner_loop, op, | |
0547c9b6 | 2551 | fold_conversions, size_expr); |
9c382ce9 SP |
2552 | |
2553 | if (op0 == chrec_dont_know) | |
2554 | return chrec_dont_know; | |
2555 | ||
2556 | if (fold_conversions) | |
2557 | { | |
2558 | tree tmp = chrec_convert_aggressive (type, op0); | |
2559 | if (tmp) | |
2560 | return tmp; | |
2561 | } | |
2562 | ||
2563 | if (chrec && op0 == op) | |
2564 | return chrec; | |
2565 | ||
2566 | /* If we used chrec_convert_aggressive, we can no longer assume that | |
2567 | signed chrecs do not overflow, as chrec_convert does, so avoid | |
2568 | calling it in that case. */ | |
2569 | if (fold_conversions) | |
2570 | return fold_convert (type, op0); | |
2571 | ||
2572 | return chrec_convert (type, op0, NULL); | |
2573 | } | |
2574 | ||
7ec0665d SP |
2575 | /* Analyze all the parameters of the chrec, between INSTANTIATE_BELOW |
2576 | and EVOLUTION_LOOP, that were left under a symbolic form. | |
2577 | ||
4b9d48a1 | 2578 | CHREC is a BIT_NOT_EXPR or a NEGATE_EXPR expression to be instantiated. |
7ec0665d | 2579 | Handle ~X as -1 - X. |
4b9d48a1 | 2580 | Handle -X as -1 * X. |
7ec0665d SP |
2581 | |
2582 | CACHE is the cache of already instantiated values. | |
2583 | ||
2584 | FOLD_CONVERSIONS should be set to true when the conversions that | |
2585 | may wrap in signed/pointer type are folded, as long as the value of | |
2586 | the chrec is preserved. | |
2587 | ||
2588 | SIZE_EXPR is used for computing the size of the expression to be | |
2589 | instantiated, and to stop if it exceeds some limit. */ | |
2590 | ||
2591 | static tree | |
4b9d48a1 | 2592 | instantiate_scev_not (basic_block instantiate_below, |
8b679c9b RB |
2593 | struct loop *evolution_loop, struct loop *inner_loop, |
2594 | tree chrec, | |
20179b0d | 2595 | enum tree_code code, tree type, tree op, |
0547c9b6 | 2596 | bool fold_conversions, int size_expr) |
7ec0665d | 2597 | { |
8b679c9b RB |
2598 | tree op0 = instantiate_scev_r (instantiate_below, evolution_loop, |
2599 | inner_loop, op, | |
0547c9b6 | 2600 | fold_conversions, size_expr); |
20179b0d | 2601 | |
7ec0665d SP |
2602 | if (op0 == chrec_dont_know) |
2603 | return chrec_dont_know; | |
2604 | ||
20179b0d | 2605 | if (op != op0) |
7ec0665d SP |
2606 | { |
2607 | op0 = chrec_convert (type, op0, NULL); | |
4b9d48a1 | 2608 | |
20179b0d | 2609 | switch (code) |
4b9d48a1 SP |
2610 | { |
2611 | case BIT_NOT_EXPR: | |
2612 | return chrec_fold_minus | |
2613 | (type, fold_convert (type, integer_minus_one_node), op0); | |
2614 | ||
2615 | case NEGATE_EXPR: | |
2616 | return chrec_fold_multiply | |
2617 | (type, fold_convert (type, integer_minus_one_node), op0); | |
2618 | ||
2619 | default: | |
2620 | gcc_unreachable (); | |
2621 | } | |
7ec0665d | 2622 | } |
4b9d48a1 | 2623 | |
20179b0d | 2624 | return chrec ? chrec : fold_build1 (code, type, op0); |
7ec0665d SP |
2625 | } |
2626 | ||
d814176c SP |
2627 | /* Analyze all the parameters of the chrec, between INSTANTIATE_BELOW |
2628 | and EVOLUTION_LOOP, that were left under a symbolic form. | |
2629 | ||
2630 | CHREC is an expression with 3 operands to be instantiated. | |
2631 | ||
2632 | CACHE is the cache of already instantiated values. | |
2633 | ||
2634 | FOLD_CONVERSIONS should be set to true when the conversions that | |
2635 | may wrap in signed/pointer type are folded, as long as the value of | |
2636 | the chrec is preserved. | |
2637 | ||
2638 | SIZE_EXPR is used for computing the size of the expression to be | |
2639 | instantiated, and to stop if it exceeds some limit. */ | |
2640 | ||
2641 | static tree | |
2642 | instantiate_scev_3 (basic_block instantiate_below, | |
8b679c9b RB |
2643 | struct loop *evolution_loop, struct loop *inner_loop, |
2644 | tree chrec, | |
0547c9b6 | 2645 | bool fold_conversions, int size_expr) |
d814176c SP |
2646 | { |
2647 | tree op1, op2; | |
9e5dc77f | 2648 | tree op0 = instantiate_scev_r (instantiate_below, evolution_loop, |
8b679c9b | 2649 | inner_loop, TREE_OPERAND (chrec, 0), |
0547c9b6 | 2650 | fold_conversions, size_expr); |
d814176c SP |
2651 | if (op0 == chrec_dont_know) |
2652 | return chrec_dont_know; | |
2653 | ||
9e5dc77f | 2654 | op1 = instantiate_scev_r (instantiate_below, evolution_loop, |
8b679c9b | 2655 | inner_loop, TREE_OPERAND (chrec, 1), |
0547c9b6 | 2656 | fold_conversions, size_expr); |
d814176c SP |
2657 | if (op1 == chrec_dont_know) |
2658 | return chrec_dont_know; | |
2659 | ||
9e5dc77f | 2660 | op2 = instantiate_scev_r (instantiate_below, evolution_loop, |
8b679c9b | 2661 | inner_loop, TREE_OPERAND (chrec, 2), |
0547c9b6 | 2662 | fold_conversions, size_expr); |
d814176c SP |
2663 | if (op2 == chrec_dont_know) |
2664 | return chrec_dont_know; | |
2665 | ||
2666 | if (op0 == TREE_OPERAND (chrec, 0) | |
2667 | && op1 == TREE_OPERAND (chrec, 1) | |
2668 | && op2 == TREE_OPERAND (chrec, 2)) | |
2669 | return chrec; | |
2670 | ||
2671 | return fold_build3 (TREE_CODE (chrec), | |
2672 | TREE_TYPE (chrec), op0, op1, op2); | |
2673 | } | |
2674 | ||
9c382ce9 SP |
2675 | /* Analyze all the parameters of the chrec, between INSTANTIATE_BELOW |
2676 | and EVOLUTION_LOOP, that were left under a symbolic form. | |
5b78fc3e | 2677 | |
9e5dc77f SP |
2678 | CHREC is an expression with 2 operands to be instantiated. |
2679 | ||
2680 | CACHE is the cache of already instantiated values. | |
2681 | ||
2682 | FOLD_CONVERSIONS should be set to true when the conversions that | |
2683 | may wrap in signed/pointer type are folded, as long as the value of | |
2684 | the chrec is preserved. | |
2685 | ||
2686 | SIZE_EXPR is used for computing the size of the expression to be | |
2687 | instantiated, and to stop if it exceeds some limit. */ | |
2688 | ||
2689 | static tree | |
2690 | instantiate_scev_2 (basic_block instantiate_below, | |
8b679c9b RB |
2691 | struct loop *evolution_loop, struct loop *inner_loop, |
2692 | tree chrec, | |
0547c9b6 | 2693 | bool fold_conversions, int size_expr) |
9e5dc77f SP |
2694 | { |
2695 | tree op1; | |
2696 | tree op0 = instantiate_scev_r (instantiate_below, evolution_loop, | |
8b679c9b | 2697 | inner_loop, TREE_OPERAND (chrec, 0), |
0547c9b6 | 2698 | fold_conversions, size_expr); |
9e5dc77f SP |
2699 | if (op0 == chrec_dont_know) |
2700 | return chrec_dont_know; | |
2701 | ||
2702 | op1 = instantiate_scev_r (instantiate_below, evolution_loop, | |
8b679c9b | 2703 | inner_loop, TREE_OPERAND (chrec, 1), |
0547c9b6 | 2704 | fold_conversions, size_expr); |
9e5dc77f SP |
2705 | if (op1 == chrec_dont_know) |
2706 | return chrec_dont_know; | |
2707 | ||
2708 | if (op0 == TREE_OPERAND (chrec, 0) | |
2709 | && op1 == TREE_OPERAND (chrec, 1)) | |
2710 | return chrec; | |
2711 | ||
2712 | return fold_build2 (TREE_CODE (chrec), TREE_TYPE (chrec), op0, op1); | |
2713 | } | |
2714 | ||
2715 | /* Analyze all the parameters of the chrec, between INSTANTIATE_BELOW | |
2716 | and EVOLUTION_LOOP, that were left under a symbolic form. | |
2717 | ||
2718 | CHREC is an expression with 2 operands to be instantiated. | |
5b78fc3e JS |
2719 | |
2720 | CACHE is the cache of already instantiated values. | |
2721 | ||
2722 | FOLD_CONVERSIONS should be set to true when the conversions that | |
2723 | may wrap in signed/pointer type are folded, as long as the value of | |
2724 | the chrec is preserved. | |
2725 | ||
3f227a8c JS |
2726 | SIZE_EXPR is used for computing the size of the expression to be |
2727 | instantiated, and to stop if it exceeds some limit. */ | |
9c382ce9 | 2728 | |
9baba81b | 2729 | static tree |
a213b219 | 2730 | instantiate_scev_1 (basic_block instantiate_below, |
8b679c9b RB |
2731 | struct loop *evolution_loop, struct loop *inner_loop, |
2732 | tree chrec, | |
0547c9b6 | 2733 | bool fold_conversions, int size_expr) |
9baba81b | 2734 | { |
9e5dc77f | 2735 | tree op0 = instantiate_scev_r (instantiate_below, evolution_loop, |
8b679c9b | 2736 | inner_loop, TREE_OPERAND (chrec, 0), |
0547c9b6 | 2737 | fold_conversions, size_expr); |
9e5dc77f SP |
2738 | |
2739 | if (op0 == chrec_dont_know) | |
2740 | return chrec_dont_know; | |
2741 | ||
2742 | if (op0 == TREE_OPERAND (chrec, 0)) | |
2743 | return chrec; | |
2744 | ||
2745 | return fold_build1 (TREE_CODE (chrec), TREE_TYPE (chrec), op0); | |
2746 | } | |
2747 | ||
2748 | /* Analyze all the parameters of the chrec, between INSTANTIATE_BELOW | |
2749 | and EVOLUTION_LOOP, that were left under a symbolic form. | |
2750 | ||
2751 | CHREC is the scalar evolution to instantiate. | |
2752 | ||
2753 | CACHE is the cache of already instantiated values. | |
2282a0e6 | 2754 | |
9e5dc77f SP |
2755 | FOLD_CONVERSIONS should be set to true when the conversions that |
2756 | may wrap in signed/pointer type are folded, as long as the value of | |
2757 | the chrec is preserved. | |
2758 | ||
2759 | SIZE_EXPR is used for computing the size of the expression to be | |
2760 | instantiated, and to stop if it exceeds some limit. */ | |
2761 | ||
2762 | static tree | |
2763 | instantiate_scev_r (basic_block instantiate_below, | |
8b679c9b RB |
2764 | struct loop *evolution_loop, struct loop *inner_loop, |
2765 | tree chrec, | |
0547c9b6 | 2766 | bool fold_conversions, int size_expr) |
9e5dc77f | 2767 | { |
47ae9e4c SP |
2768 | /* Give up if the expression is larger than the MAX that we allow. */ |
2769 | if (size_expr++ > PARAM_VALUE (PARAM_SCEV_MAX_EXPR_SIZE)) | |
2770 | return chrec_dont_know; | |
2771 | ||
81fada9a JJ |
2772 | if (chrec == NULL_TREE |
2773 | || automatically_generated_chrec_p (chrec) | |
d7770457 | 2774 | || is_gimple_min_invariant (chrec)) |
9baba81b SP |
2775 | return chrec; |
2776 | ||
2777 | switch (TREE_CODE (chrec)) | |
2778 | { | |
2779 | case SSA_NAME: | |
8b679c9b RB |
2780 | return instantiate_scev_name (instantiate_below, evolution_loop, |
2781 | inner_loop, chrec, | |
0547c9b6 | 2782 | fold_conversions, size_expr); |
9baba81b SP |
2783 | |
2784 | case POLYNOMIAL_CHREC: | |
8b679c9b RB |
2785 | return instantiate_scev_poly (instantiate_below, evolution_loop, |
2786 | inner_loop, chrec, | |
0547c9b6 | 2787 | fold_conversions, size_expr); |
9baba81b | 2788 | |
5be014d5 | 2789 | case POINTER_PLUS_EXPR: |
9baba81b | 2790 | case PLUS_EXPR: |
9baba81b | 2791 | case MINUS_EXPR: |
9baba81b | 2792 | case MULT_EXPR: |
8b679c9b RB |
2793 | return instantiate_scev_binary (instantiate_below, evolution_loop, |
2794 | inner_loop, chrec, | |
ffa34f4b SP |
2795 | TREE_CODE (chrec), chrec_type (chrec), |
2796 | TREE_OPERAND (chrec, 0), | |
2797 | TREE_OPERAND (chrec, 1), | |
0547c9b6 | 2798 | fold_conversions, size_expr); |
9baba81b | 2799 | |
1043771b | 2800 | CASE_CONVERT: |
8b679c9b RB |
2801 | return instantiate_scev_convert (instantiate_below, evolution_loop, |
2802 | inner_loop, chrec, | |
9c382ce9 | 2803 | TREE_TYPE (chrec), TREE_OPERAND (chrec, 0), |
0547c9b6 | 2804 | fold_conversions, size_expr); |
9baba81b | 2805 | |
4b9d48a1 | 2806 | case NEGATE_EXPR: |
418df9d7 | 2807 | case BIT_NOT_EXPR: |
8b679c9b RB |
2808 | return instantiate_scev_not (instantiate_below, evolution_loop, |
2809 | inner_loop, chrec, | |
20179b0d SP |
2810 | TREE_CODE (chrec), TREE_TYPE (chrec), |
2811 | TREE_OPERAND (chrec, 0), | |
0547c9b6 | 2812 | fold_conversions, size_expr); |
418df9d7 | 2813 | |
4c7d6755 | 2814 | case ADDR_EXPR: |
9baba81b SP |
2815 | case SCEV_NOT_KNOWN: |
2816 | return chrec_dont_know; | |
2817 | ||
2818 | case SCEV_KNOWN: | |
2819 | return chrec_known; | |
15fda317 | 2820 | |
dbc08079 | 2821 | case ARRAY_REF: |
8b679c9b RB |
2822 | return instantiate_array_ref (instantiate_below, evolution_loop, |
2823 | inner_loop, chrec, | |
0547c9b6 | 2824 | fold_conversions, size_expr); |
dbc08079 | 2825 | |
9baba81b SP |
2826 | default: |
2827 | break; | |
2828 | } | |
2829 | ||
0dfb0dc6 SP |
2830 | if (VL_EXP_CLASS_P (chrec)) |
2831 | return chrec_dont_know; | |
2832 | ||
9baba81b SP |
2833 | switch (TREE_CODE_LENGTH (TREE_CODE (chrec))) |
2834 | { | |
2835 | case 3: | |
8b679c9b RB |
2836 | return instantiate_scev_3 (instantiate_below, evolution_loop, |
2837 | inner_loop, chrec, | |
0547c9b6 | 2838 | fold_conversions, size_expr); |
9baba81b SP |
2839 | |
2840 | case 2: | |
8b679c9b RB |
2841 | return instantiate_scev_2 (instantiate_below, evolution_loop, |
2842 | inner_loop, chrec, | |
0547c9b6 | 2843 | fold_conversions, size_expr); |
7ec0665d | 2844 | |
9baba81b | 2845 | case 1: |
8b679c9b RB |
2846 | return instantiate_scev_1 (instantiate_below, evolution_loop, |
2847 | inner_loop, chrec, | |
0547c9b6 | 2848 | fold_conversions, size_expr); |
9baba81b SP |
2849 | |
2850 | case 0: | |
2851 | return chrec; | |
2852 | ||
2853 | default: | |
2854 | break; | |
2855 | } | |
2856 | ||
2857 | /* Too complicated to handle. */ | |
2858 | return chrec_dont_know; | |
2859 | } | |
e9eb809d ZD |
2860 | |
2861 | /* Analyze all the parameters of the chrec that were left under a | |
a213b219 SP |
2862 | symbolic form. INSTANTIATE_BELOW is the basic block that stops the |
2863 | recursive instantiation of parameters: a parameter is a variable | |
2864 | that is defined in a basic block that dominates INSTANTIATE_BELOW or | |
2865 | a function parameter. */ | |
e9eb809d ZD |
2866 | |
2867 | tree | |
a213b219 | 2868 | instantiate_scev (basic_block instantiate_below, struct loop *evolution_loop, |
3f227a8c | 2869 | tree chrec) |
e9eb809d | 2870 | { |
9baba81b SP |
2871 | tree res; |
2872 | ||
dfedbe40 | 2873 | if (dump_file && (dump_flags & TDF_SCEV)) |
9baba81b | 2874 | { |
3f227a8c | 2875 | fprintf (dump_file, "(instantiate_scev \n"); |
a213b219 | 2876 | fprintf (dump_file, " (instantiate_below = %d)\n", instantiate_below->index); |
3f227a8c | 2877 | fprintf (dump_file, " (evolution_loop = %d)\n", evolution_loop->num); |
9baba81b SP |
2878 | fprintf (dump_file, " (chrec = "); |
2879 | print_generic_expr (dump_file, chrec, 0); | |
2880 | fprintf (dump_file, ")\n"); | |
2881 | } | |
b8698a0f | 2882 | |
0547c9b6 RB |
2883 | bool destr = false; |
2884 | if (!global_cache) | |
2885 | { | |
2886 | global_cache = new instantiate_cache_type; | |
2887 | destr = true; | |
2888 | } | |
2889 | ||
8b679c9b | 2890 | res = instantiate_scev_r (instantiate_below, evolution_loop, |
0547c9b6 RB |
2891 | NULL, chrec, false, 0); |
2892 | ||
2893 | if (destr) | |
2894 | { | |
2895 | delete global_cache; | |
2896 | global_cache = NULL; | |
2897 | } | |
9baba81b | 2898 | |
dfedbe40 | 2899 | if (dump_file && (dump_flags & TDF_SCEV)) |
9baba81b SP |
2900 | { |
2901 | fprintf (dump_file, " (res = "); | |
2902 | print_generic_expr (dump_file, res, 0); | |
2903 | fprintf (dump_file, "))\n"); | |
2904 | } | |
eb0bc7af | 2905 | |
9baba81b SP |
2906 | return res; |
2907 | } | |
2908 | ||
2909 | /* Similar to instantiate_parameters, but does not introduce the | |
2282a0e6 ZD |
2910 | evolutions in outer loops for LOOP invariants in CHREC, and does not |
2911 | care about causing overflows, as long as they do not affect value | |
2912 | of an expression. */ | |
9baba81b | 2913 | |
3cb960c7 | 2914 | tree |
9baba81b SP |
2915 | resolve_mixers (struct loop *loop, tree chrec) |
2916 | { | |
0547c9b6 RB |
2917 | bool destr = false; |
2918 | if (!global_cache) | |
2919 | { | |
2920 | global_cache = new instantiate_cache_type; | |
2921 | destr = true; | |
2922 | } | |
2923 | ||
8b679c9b | 2924 | tree ret = instantiate_scev_r (block_before_loop (loop), loop, NULL, |
0547c9b6 RB |
2925 | chrec, true, 0); |
2926 | ||
2927 | if (destr) | |
2928 | { | |
2929 | delete global_cache; | |
2930 | global_cache = NULL; | |
2931 | } | |
2932 | ||
eb0bc7af | 2933 | return ret; |
9baba81b SP |
2934 | } |
2935 | ||
b8698a0f | 2936 | /* Entry point for the analysis of the number of iterations pass. |
9baba81b SP |
2937 | This function tries to safely approximate the number of iterations |
2938 | the loop will run. When this property is not decidable at compile | |
0a74c758 SP |
2939 | time, the result is chrec_dont_know. Otherwise the result is a |
2940 | scalar or a symbolic parameter. When the number of iterations may | |
2941 | be equal to zero and the property cannot be determined at compile | |
2942 | time, the result is a COND_EXPR that represents in a symbolic form | |
2943 | the conditions under which the number of iterations is not zero. | |
b8698a0f | 2944 | |
9baba81b | 2945 | Example of analysis: suppose that the loop has an exit condition: |
b8698a0f | 2946 | |
9baba81b | 2947 | "if (b > 49) goto end_loop;" |
b8698a0f | 2948 | |
9baba81b SP |
2949 | and that in a previous analysis we have determined that the |
2950 | variable 'b' has an evolution function: | |
b8698a0f L |
2951 | |
2952 | "EF = {23, +, 5}_2". | |
2953 | ||
9baba81b SP |
2954 | When we evaluate the function at the point 5, i.e. the value of the |
2955 | variable 'b' after 5 iterations in the loop, we have EF (5) = 48, | |
2956 | and EF (6) = 53. In this case the value of 'b' on exit is '53' and | |
2957 | the loop body has been executed 6 times. */ | |
2958 | ||
b8698a0f | 2959 | tree |
a14865db | 2960 | number_of_latch_executions (struct loop *loop) |
9baba81b | 2961 | { |
9baba81b SP |
2962 | edge exit; |
2963 | struct tree_niter_desc niter_desc; | |
0a74c758 SP |
2964 | tree may_be_zero; |
2965 | tree res; | |
9baba81b | 2966 | |
0a74c758 | 2967 | /* Determine whether the number of iterations in loop has already |
9baba81b SP |
2968 | been computed. */ |
2969 | res = loop->nb_iterations; | |
2970 | if (res) | |
2971 | return res; | |
0a74c758 SP |
2972 | |
2973 | may_be_zero = NULL_TREE; | |
9baba81b | 2974 | |
dfedbe40 | 2975 | if (dump_file && (dump_flags & TDF_SCEV)) |
0a74c758 | 2976 | fprintf (dump_file, "(number_of_iterations_in_loop = \n"); |
b8698a0f | 2977 | |
0a74c758 | 2978 | res = chrec_dont_know; |
ac8f6c69 | 2979 | exit = single_exit (loop); |
9baba81b | 2980 | |
0a74c758 SP |
2981 | if (exit && number_of_iterations_exit (loop, exit, &niter_desc, false)) |
2982 | { | |
2983 | may_be_zero = niter_desc.may_be_zero; | |
2984 | res = niter_desc.niter; | |
2985 | } | |
2986 | ||
2987 | if (res == chrec_dont_know | |
2988 | || !may_be_zero | |
2989 | || integer_zerop (may_be_zero)) | |
2990 | ; | |
2991 | else if (integer_nonzerop (may_be_zero)) | |
2992 | res = build_int_cst (TREE_TYPE (res), 0); | |
9baba81b | 2993 | |
0a74c758 SP |
2994 | else if (COMPARISON_CLASS_P (may_be_zero)) |
2995 | res = fold_build3 (COND_EXPR, TREE_TYPE (res), may_be_zero, | |
2996 | build_int_cst (TREE_TYPE (res), 0), res); | |
9baba81b SP |
2997 | else |
2998 | res = chrec_dont_know; | |
2999 | ||
dfedbe40 | 3000 | if (dump_file && (dump_flags & TDF_SCEV)) |
0a74c758 SP |
3001 | { |
3002 | fprintf (dump_file, " (set_nb_iterations_in_loop = "); | |
3003 | print_generic_expr (dump_file, res, 0); | |
3004 | fprintf (dump_file, "))\n"); | |
3005 | } | |
3006 | ||
3007 | loop->nb_iterations = res; | |
3008 | return res; | |
9baba81b | 3009 | } |
9baba81b SP |
3010 | \f |
3011 | ||
3012 | /* Counters for the stats. */ | |
3013 | ||
b8698a0f | 3014 | struct chrec_stats |
9baba81b SP |
3015 | { |
3016 | unsigned nb_chrecs; | |
3017 | unsigned nb_affine; | |
3018 | unsigned nb_affine_multivar; | |
3019 | unsigned nb_higher_poly; | |
3020 | unsigned nb_chrec_dont_know; | |
3021 | unsigned nb_undetermined; | |
3022 | }; | |
3023 | ||
3024 | /* Reset the counters. */ | |
3025 | ||
3026 | static inline void | |
3027 | reset_chrecs_counters (struct chrec_stats *stats) | |
3028 | { | |
3029 | stats->nb_chrecs = 0; | |
3030 | stats->nb_affine = 0; | |
3031 | stats->nb_affine_multivar = 0; | |
3032 | stats->nb_higher_poly = 0; | |
3033 | stats->nb_chrec_dont_know = 0; | |
3034 | stats->nb_undetermined = 0; | |
3035 | } | |
3036 | ||
3037 | /* Dump the contents of a CHREC_STATS structure. */ | |
3038 | ||
3039 | static void | |
3040 | dump_chrecs_stats (FILE *file, struct chrec_stats *stats) | |
3041 | { | |
3042 | fprintf (file, "\n(\n"); | |
3043 | fprintf (file, "-----------------------------------------\n"); | |
3044 | fprintf (file, "%d\taffine univariate chrecs\n", stats->nb_affine); | |
3045 | fprintf (file, "%d\taffine multivariate chrecs\n", stats->nb_affine_multivar); | |
b8698a0f | 3046 | fprintf (file, "%d\tdegree greater than 2 polynomials\n", |
9baba81b SP |
3047 | stats->nb_higher_poly); |
3048 | fprintf (file, "%d\tchrec_dont_know chrecs\n", stats->nb_chrec_dont_know); | |
3049 | fprintf (file, "-----------------------------------------\n"); | |
3050 | fprintf (file, "%d\ttotal chrecs\n", stats->nb_chrecs); | |
b8698a0f | 3051 | fprintf (file, "%d\twith undetermined coefficients\n", |
9baba81b SP |
3052 | stats->nb_undetermined); |
3053 | fprintf (file, "-----------------------------------------\n"); | |
b8698a0f | 3054 | fprintf (file, "%d\tchrecs in the scev database\n", |
907dadbd | 3055 | (int) scalar_evolution_info->elements ()); |
9baba81b SP |
3056 | fprintf (file, "%d\tsets in the scev database\n", nb_set_scev); |
3057 | fprintf (file, "%d\tgets in the scev database\n", nb_get_scev); | |
3058 | fprintf (file, "-----------------------------------------\n"); | |
3059 | fprintf (file, ")\n\n"); | |
3060 | } | |
3061 | ||
3062 | /* Gather statistics about CHREC. */ | |
3063 | ||
3064 | static void | |
3065 | gather_chrec_stats (tree chrec, struct chrec_stats *stats) | |
3066 | { | |
3067 | if (dump_file && (dump_flags & TDF_STATS)) | |
3068 | { | |
3069 | fprintf (dump_file, "(classify_chrec "); | |
3070 | print_generic_expr (dump_file, chrec, 0); | |
3071 | fprintf (dump_file, "\n"); | |
3072 | } | |
b8698a0f | 3073 | |
9baba81b | 3074 | stats->nb_chrecs++; |
b8698a0f | 3075 | |
9baba81b SP |
3076 | if (chrec == NULL_TREE) |
3077 | { | |
3078 | stats->nb_undetermined++; | |
3079 | return; | |
3080 | } | |
b8698a0f | 3081 | |
9baba81b SP |
3082 | switch (TREE_CODE (chrec)) |
3083 | { | |
3084 | case POLYNOMIAL_CHREC: | |
3085 | if (evolution_function_is_affine_p (chrec)) | |
3086 | { | |
3087 | if (dump_file && (dump_flags & TDF_STATS)) | |
3088 | fprintf (dump_file, " affine_univariate\n"); | |
3089 | stats->nb_affine++; | |
3090 | } | |
a50411de | 3091 | else if (evolution_function_is_affine_multivariate_p (chrec, 0)) |
9baba81b SP |
3092 | { |
3093 | if (dump_file && (dump_flags & TDF_STATS)) | |
3094 | fprintf (dump_file, " affine_multivariate\n"); | |
3095 | stats->nb_affine_multivar++; | |
3096 | } | |
3097 | else | |
3098 | { | |
3099 | if (dump_file && (dump_flags & TDF_STATS)) | |
3100 | fprintf (dump_file, " higher_degree_polynomial\n"); | |
3101 | stats->nb_higher_poly++; | |
3102 | } | |
b8698a0f | 3103 | |
9baba81b SP |
3104 | break; |
3105 | ||
3106 | default: | |
3107 | break; | |
3108 | } | |
b8698a0f | 3109 | |
9baba81b SP |
3110 | if (chrec_contains_undetermined (chrec)) |
3111 | { | |
3112 | if (dump_file && (dump_flags & TDF_STATS)) | |
3113 | fprintf (dump_file, " undetermined\n"); | |
3114 | stats->nb_undetermined++; | |
3115 | } | |
b8698a0f | 3116 | |
9baba81b SP |
3117 | if (dump_file && (dump_flags & TDF_STATS)) |
3118 | fprintf (dump_file, ")\n"); | |
3119 | } | |
3120 | ||
9baba81b SP |
3121 | /* Classify the chrecs of the whole database. */ |
3122 | ||
b8698a0f | 3123 | void |
9baba81b SP |
3124 | gather_stats_on_scev_database (void) |
3125 | { | |
3126 | struct chrec_stats stats; | |
b8698a0f | 3127 | |
9baba81b SP |
3128 | if (!dump_file) |
3129 | return; | |
b8698a0f | 3130 | |
9baba81b | 3131 | reset_chrecs_counters (&stats); |
b8698a0f | 3132 | |
907dadbd TS |
3133 | hash_table<scev_info_hasher>::iterator iter; |
3134 | scev_info_str *elt; | |
3135 | FOR_EACH_HASH_TABLE_ELEMENT (*scalar_evolution_info, elt, scev_info_str *, | |
3136 | iter) | |
3137 | gather_chrec_stats (elt->chrec, &stats); | |
9baba81b SP |
3138 | |
3139 | dump_chrecs_stats (dump_file, &stats); | |
3140 | } | |
3141 | ||
3142 | \f | |
3143 | ||
3144 | /* Initializer. */ | |
3145 | ||
3146 | static void | |
3147 | initialize_scalar_evolutions_analyzer (void) | |
3148 | { | |
3149 | /* The elements below are unique. */ | |
3150 | if (chrec_dont_know == NULL_TREE) | |
3151 | { | |
3152 | chrec_not_analyzed_yet = NULL_TREE; | |
3153 | chrec_dont_know = make_node (SCEV_NOT_KNOWN); | |
3154 | chrec_known = make_node (SCEV_KNOWN); | |
d5ab5675 ZD |
3155 | TREE_TYPE (chrec_dont_know) = void_type_node; |
3156 | TREE_TYPE (chrec_known) = void_type_node; | |
9baba81b SP |
3157 | } |
3158 | } | |
3159 | ||
3160 | /* Initialize the analysis of scalar evolutions for LOOPS. */ | |
3161 | ||
3162 | void | |
d73be268 | 3163 | scev_initialize (void) |
9baba81b | 3164 | { |
42fd6772 | 3165 | struct loop *loop; |
9baba81b | 3166 | |
907dadbd | 3167 | scalar_evolution_info = hash_table<scev_info_hasher>::create_ggc (100); |
b8698a0f | 3168 | |
9baba81b SP |
3169 | initialize_scalar_evolutions_analyzer (); |
3170 | ||
f0bd40b1 | 3171 | FOR_EACH_LOOP (loop, 0) |
42fd6772 ZD |
3172 | { |
3173 | loop->nb_iterations = NULL_TREE; | |
3174 | } | |
9baba81b SP |
3175 | } |
3176 | ||
e3a8f1fa JH |
3177 | /* Return true if SCEV is initialized. */ |
3178 | ||
3179 | bool | |
3180 | scev_initialized_p (void) | |
3181 | { | |
3182 | return scalar_evolution_info != NULL; | |
3183 | } | |
3184 | ||
a7bf45de SP |
3185 | /* Cleans up the information cached by the scalar evolutions analysis |
3186 | in the hash table. */ | |
3187 | ||
3188 | void | |
3189 | scev_reset_htab (void) | |
3190 | { | |
3191 | if (!scalar_evolution_info) | |
3192 | return; | |
3193 | ||
907dadbd | 3194 | scalar_evolution_info->empty (); |
a7bf45de SP |
3195 | } |
3196 | ||
3197 | /* Cleans up the information cached by the scalar evolutions analysis | |
3198 | in the hash table and in the loop->nb_iterations. */ | |
9baba81b SP |
3199 | |
3200 | void | |
3201 | scev_reset (void) | |
3202 | { | |
9baba81b SP |
3203 | struct loop *loop; |
3204 | ||
a7bf45de SP |
3205 | scev_reset_htab (); |
3206 | ||
f0bd40b1 | 3207 | FOR_EACH_LOOP (loop, 0) |
9baba81b | 3208 | { |
42fd6772 | 3209 | loop->nb_iterations = NULL_TREE; |
9baba81b | 3210 | } |
e9eb809d ZD |
3211 | } |
3212 | ||
f017bf5e ZD |
3213 | /* Checks whether use of OP in USE_LOOP behaves as a simple affine iv with |
3214 | respect to WRTO_LOOP and returns its base and step in IV if possible | |
3215 | (see analyze_scalar_evolution_in_loop for more details on USE_LOOP | |
3216 | and WRTO_LOOP). If ALLOW_NONCONSTANT_STEP is true, we want step to be | |
3217 | invariant in LOOP. Otherwise we require it to be an integer constant. | |
b8698a0f | 3218 | |
f017bf5e ZD |
3219 | IV->no_overflow is set to true if we are sure the iv cannot overflow (e.g. |
3220 | because it is computed in signed arithmetics). Consequently, adding an | |
3221 | induction variable | |
b8698a0f | 3222 | |
f017bf5e ZD |
3223 | for (i = IV->base; ; i += IV->step) |
3224 | ||
3225 | is only safe if IV->no_overflow is false, or TYPE_OVERFLOW_UNDEFINED is | |
3226 | false for the type of the induction variable, or you can prove that i does | |
3227 | not wrap by some other argument. Otherwise, this might introduce undefined | |
3228 | behavior, and | |
b8698a0f | 3229 | |
f017bf5e ZD |
3230 | for (i = iv->base; ; i = (type) ((unsigned type) i + (unsigned type) iv->step)) |
3231 | ||
3232 | must be used instead. */ | |
e9eb809d ZD |
3233 | |
3234 | bool | |
f017bf5e ZD |
3235 | simple_iv (struct loop *wrto_loop, struct loop *use_loop, tree op, |
3236 | affine_iv *iv, bool allow_nonconstant_step) | |
e9eb809d | 3237 | { |
9baba81b | 3238 | tree type, ev; |
a6f778b2 | 3239 | bool folded_casts; |
9baba81b | 3240 | |
a6f778b2 ZD |
3241 | iv->base = NULL_TREE; |
3242 | iv->step = NULL_TREE; | |
3243 | iv->no_overflow = false; | |
9baba81b SP |
3244 | |
3245 | type = TREE_TYPE (op); | |
1ee0d660 EB |
3246 | if (!POINTER_TYPE_P (type) |
3247 | && !INTEGRAL_TYPE_P (type)) | |
9baba81b SP |
3248 | return false; |
3249 | ||
f017bf5e | 3250 | ev = analyze_scalar_evolution_in_loop (wrto_loop, use_loop, op, |
a6f778b2 | 3251 | &folded_casts); |
f017bf5e ZD |
3252 | if (chrec_contains_undetermined (ev) |
3253 | || chrec_contains_symbols_defined_in_loop (ev, wrto_loop->num)) | |
9baba81b SP |
3254 | return false; |
3255 | ||
f017bf5e | 3256 | if (tree_does_not_contain_chrecs (ev)) |
9baba81b | 3257 | { |
a6f778b2 | 3258 | iv->base = ev; |
6e42ce54 | 3259 | iv->step = build_int_cst (TREE_TYPE (ev), 0); |
a6f778b2 | 3260 | iv->no_overflow = true; |
9baba81b SP |
3261 | return true; |
3262 | } | |
3263 | ||
3264 | if (TREE_CODE (ev) != POLYNOMIAL_CHREC | |
f017bf5e | 3265 | || CHREC_VARIABLE (ev) != (unsigned) wrto_loop->num) |
9baba81b SP |
3266 | return false; |
3267 | ||
a6f778b2 | 3268 | iv->step = CHREC_RIGHT (ev); |
f017bf5e ZD |
3269 | if ((!allow_nonconstant_step && TREE_CODE (iv->step) != INTEGER_CST) |
3270 | || tree_contains_chrecs (iv->step, NULL)) | |
9baba81b | 3271 | return false; |
9be872b7 | 3272 | |
a6f778b2 | 3273 | iv->base = CHREC_LEFT (ev); |
f017bf5e | 3274 | if (tree_contains_chrecs (iv->base, NULL)) |
9baba81b SP |
3275 | return false; |
3276 | ||
20bd649a MP |
3277 | iv->no_overflow = (!folded_casts && ANY_INTEGRAL_TYPE_P (type) |
3278 | && TYPE_OVERFLOW_UNDEFINED (type)); | |
eeef0e45 | 3279 | |
9baba81b SP |
3280 | return true; |
3281 | } | |
3282 | ||
9baba81b SP |
3283 | /* Finalize the scalar evolution analysis. */ |
3284 | ||
3285 | void | |
3286 | scev_finalize (void) | |
3287 | { | |
d51157de ZD |
3288 | if (!scalar_evolution_info) |
3289 | return; | |
907dadbd | 3290 | scalar_evolution_info->empty (); |
c7b852c8 | 3291 | scalar_evolution_info = NULL; |
9baba81b SP |
3292 | } |
3293 | ||
771f882e ZD |
3294 | /* Returns true if the expression EXPR is considered to be too expensive |
3295 | for scev_const_prop. */ | |
3296 | ||
3297 | bool | |
3298 | expression_expensive_p (tree expr) | |
3299 | { | |
3300 | enum tree_code code; | |
3301 | ||
3302 | if (is_gimple_val (expr)) | |
3303 | return false; | |
3304 | ||
3305 | code = TREE_CODE (expr); | |
3306 | if (code == TRUNC_DIV_EXPR | |
3307 | || code == CEIL_DIV_EXPR | |
3308 | || code == FLOOR_DIV_EXPR | |
3309 | || code == ROUND_DIV_EXPR | |
3310 | || code == TRUNC_MOD_EXPR | |
3311 | || code == CEIL_MOD_EXPR | |
3312 | || code == FLOOR_MOD_EXPR | |
3313 | || code == ROUND_MOD_EXPR | |
3314 | || code == EXACT_DIV_EXPR) | |
3315 | { | |
3316 | /* Division by power of two is usually cheap, so we allow it. | |
3317 | Forbid anything else. */ | |
3318 | if (!integer_pow2p (TREE_OPERAND (expr, 1))) | |
3319 | return true; | |
3320 | } | |
3321 | ||
3322 | switch (TREE_CODE_CLASS (code)) | |
3323 | { | |
3324 | case tcc_binary: | |
3325 | case tcc_comparison: | |
3326 | if (expression_expensive_p (TREE_OPERAND (expr, 1))) | |
3327 | return true; | |
3328 | ||
3329 | /* Fallthru. */ | |
3330 | case tcc_unary: | |
3331 | return expression_expensive_p (TREE_OPERAND (expr, 0)); | |
3332 | ||
3333 | default: | |
3334 | return true; | |
3335 | } | |
3336 | } | |
3337 | ||
684aaf29 | 3338 | /* Replace ssa names for that scev can prove they are constant by the |
3ac01fde ZD |
3339 | appropriate constants. Also perform final value replacement in loops, |
3340 | in case the replacement expressions are cheap. | |
b8698a0f | 3341 | |
684aaf29 ZD |
3342 | We only consider SSA names defined by phi nodes; rest is left to the |
3343 | ordinary constant propagation pass. */ | |
3344 | ||
c2924966 | 3345 | unsigned int |
684aaf29 ZD |
3346 | scev_const_prop (void) |
3347 | { | |
3348 | basic_block bb; | |
726a989a | 3349 | tree name, type, ev; |
538dd0b7 DM |
3350 | gphi *phi; |
3351 | gassign *ass; | |
3ac01fde | 3352 | struct loop *loop, *ex_loop; |
684aaf29 | 3353 | bitmap ssa_names_to_remove = NULL; |
3ac01fde | 3354 | unsigned i; |
538dd0b7 | 3355 | gphi_iterator psi; |
684aaf29 | 3356 | |
0fc822d0 | 3357 | if (number_of_loops (cfun) <= 1) |
c2924966 | 3358 | return 0; |
684aaf29 | 3359 | |
11cd3bed | 3360 | FOR_EACH_BB_FN (bb, cfun) |
684aaf29 ZD |
3361 | { |
3362 | loop = bb->loop_father; | |
3363 | ||
726a989a | 3364 | for (psi = gsi_start_phis (bb); !gsi_end_p (psi); gsi_next (&psi)) |
684aaf29 | 3365 | { |
538dd0b7 | 3366 | phi = psi.phi (); |
684aaf29 ZD |
3367 | name = PHI_RESULT (phi); |
3368 | ||
ea057359 | 3369 | if (virtual_operand_p (name)) |
684aaf29 ZD |
3370 | continue; |
3371 | ||
3372 | type = TREE_TYPE (name); | |
3373 | ||
3374 | if (!POINTER_TYPE_P (type) | |
3375 | && !INTEGRAL_TYPE_P (type)) | |
3376 | continue; | |
3377 | ||
3378 | ev = resolve_mixers (loop, analyze_scalar_evolution (loop, name)); | |
3379 | if (!is_gimple_min_invariant (ev) | |
3380 | || !may_propagate_copy (name, ev)) | |
3381 | continue; | |
3382 | ||
3383 | /* Replace the uses of the name. */ | |
18aed06a SP |
3384 | if (name != ev) |
3385 | replace_uses_by (name, ev); | |
684aaf29 ZD |
3386 | |
3387 | if (!ssa_names_to_remove) | |
3388 | ssa_names_to_remove = BITMAP_ALLOC (NULL); | |
3389 | bitmap_set_bit (ssa_names_to_remove, SSA_NAME_VERSION (name)); | |
3390 | } | |
3391 | } | |
3392 | ||
9b3b55a1 DN |
3393 | /* Remove the ssa names that were replaced by constants. We do not |
3394 | remove them directly in the previous cycle, since this | |
3395 | invalidates scev cache. */ | |
684aaf29 ZD |
3396 | if (ssa_names_to_remove) |
3397 | { | |
3398 | bitmap_iterator bi; | |
684aaf29 ZD |
3399 | |
3400 | EXECUTE_IF_SET_IN_BITMAP (ssa_names_to_remove, 0, i, bi) | |
3401 | { | |
726a989a | 3402 | gimple_stmt_iterator psi; |
684aaf29 | 3403 | name = ssa_name (i); |
538dd0b7 | 3404 | phi = as_a <gphi *> (SSA_NAME_DEF_STMT (name)); |
684aaf29 | 3405 | |
726a989a RB |
3406 | gcc_assert (gimple_code (phi) == GIMPLE_PHI); |
3407 | psi = gsi_for_stmt (phi); | |
3408 | remove_phi_node (&psi, true); | |
684aaf29 ZD |
3409 | } |
3410 | ||
3411 | BITMAP_FREE (ssa_names_to_remove); | |
3412 | scev_reset (); | |
3413 | } | |
3ac01fde ZD |
3414 | |
3415 | /* Now the regular final value replacement. */ | |
f0bd40b1 | 3416 | FOR_EACH_LOOP (loop, LI_FROM_INNERMOST) |
3ac01fde ZD |
3417 | { |
3418 | edge exit; | |
726a989a | 3419 | tree def, rslt, niter; |
19e51b40 | 3420 | gimple_stmt_iterator gsi; |
3ac01fde | 3421 | |
3ac01fde ZD |
3422 | /* If we do not know exact number of iterations of the loop, we cannot |
3423 | replace the final value. */ | |
ac8f6c69 | 3424 | exit = single_exit (loop); |
a6f778b2 ZD |
3425 | if (!exit) |
3426 | continue; | |
3427 | ||
a14865db | 3428 | niter = number_of_latch_executions (loop); |
b3ce5b6e | 3429 | if (niter == chrec_dont_know) |
3ac01fde | 3430 | continue; |
925196ed ZD |
3431 | |
3432 | /* Ensure that it is possible to insert new statements somewhere. */ | |
3433 | if (!single_pred_p (exit->dest)) | |
3434 | split_loop_exit_edge (exit); | |
19e51b40 | 3435 | gsi = gsi_after_labels (exit->dest); |
925196ed | 3436 | |
9ba025a2 ZD |
3437 | ex_loop = superloop_at_depth (loop, |
3438 | loop_depth (exit->dest->loop_father) + 1); | |
3ac01fde | 3439 | |
726a989a | 3440 | for (psi = gsi_start_phis (exit->dest); !gsi_end_p (psi); ) |
3ac01fde | 3441 | { |
538dd0b7 | 3442 | phi = psi.phi (); |
925196ed | 3443 | rslt = PHI_RESULT (phi); |
3ac01fde | 3444 | def = PHI_ARG_DEF_FROM_EDGE (phi, exit); |
ea057359 | 3445 | if (virtual_operand_p (def)) |
726a989a RB |
3446 | { |
3447 | gsi_next (&psi); | |
3448 | continue; | |
3449 | } | |
3ac01fde ZD |
3450 | |
3451 | if (!POINTER_TYPE_P (TREE_TYPE (def)) | |
3452 | && !INTEGRAL_TYPE_P (TREE_TYPE (def))) | |
726a989a RB |
3453 | { |
3454 | gsi_next (&psi); | |
3455 | continue; | |
3456 | } | |
3ac01fde | 3457 | |
19e51b40 JJ |
3458 | bool folded_casts; |
3459 | def = analyze_scalar_evolution_in_loop (ex_loop, loop, def, | |
3460 | &folded_casts); | |
925196ed | 3461 | def = compute_overall_effect_of_inner_loop (ex_loop, def); |
3ac01fde | 3462 | if (!tree_does_not_contain_chrecs (def) |
e5db3515 ZD |
3463 | || chrec_contains_symbols_defined_in_loop (def, ex_loop->num) |
3464 | /* Moving the computation from the loop may prolong life range | |
3465 | of some ssa names, which may cause problems if they appear | |
3466 | on abnormal edges. */ | |
771f882e ZD |
3467 | || contains_abnormal_ssa_name_p (def) |
3468 | /* Do not emit expensive expressions. The rationale is that | |
3469 | when someone writes a code like | |
3470 | ||
3471 | while (n > 45) n -= 45; | |
3472 | ||
3473 | he probably knows that n is not large, and does not want it | |
3474 | to be turned into n %= 45. */ | |
3475 | || expression_expensive_p (def)) | |
726a989a | 3476 | { |
3571dde6 MP |
3477 | if (dump_file && (dump_flags & TDF_DETAILS)) |
3478 | { | |
3479 | fprintf (dump_file, "not replacing:\n "); | |
3480 | print_gimple_stmt (dump_file, phi, 0, 0); | |
3481 | fprintf (dump_file, "\n"); | |
3482 | } | |
726a989a RB |
3483 | gsi_next (&psi); |
3484 | continue; | |
3485 | } | |
3ac01fde | 3486 | |
9b3b55a1 | 3487 | /* Eliminate the PHI node and replace it by a computation outside |
925196ed | 3488 | the loop. */ |
3571dde6 MP |
3489 | if (dump_file) |
3490 | { | |
3491 | fprintf (dump_file, "\nfinal value replacement:\n "); | |
3492 | print_gimple_stmt (dump_file, phi, 0, 0); | |
3493 | fprintf (dump_file, " with\n "); | |
3494 | } | |
925196ed | 3495 | def = unshare_expr (def); |
726a989a RB |
3496 | remove_phi_node (&psi, false); |
3497 | ||
19e51b40 JJ |
3498 | /* If def's type has undefined overflow and there were folded |
3499 | casts, rewrite all stmts added for def into arithmetics | |
3500 | with defined overflow behavior. */ | |
20bd649a MP |
3501 | if (folded_casts && ANY_INTEGRAL_TYPE_P (TREE_TYPE (def)) |
3502 | && TYPE_OVERFLOW_UNDEFINED (TREE_TYPE (def))) | |
19e51b40 JJ |
3503 | { |
3504 | gimple_seq stmts; | |
3505 | gimple_stmt_iterator gsi2; | |
3506 | def = force_gimple_operand (def, &stmts, true, NULL_TREE); | |
3507 | gsi2 = gsi_start (stmts); | |
3508 | while (!gsi_end_p (gsi2)) | |
3509 | { | |
3510 | gimple stmt = gsi_stmt (gsi2); | |
3511 | gimple_stmt_iterator gsi3 = gsi2; | |
3512 | gsi_next (&gsi2); | |
3513 | gsi_remove (&gsi3, false); | |
3514 | if (is_gimple_assign (stmt) | |
3515 | && arith_code_with_undefined_signed_overflow | |
3516 | (gimple_assign_rhs_code (stmt))) | |
3517 | gsi_insert_seq_before (&gsi, | |
3518 | rewrite_to_defined_overflow (stmt), | |
3519 | GSI_SAME_STMT); | |
3520 | else | |
3521 | gsi_insert_before (&gsi, stmt, GSI_SAME_STMT); | |
3522 | } | |
3523 | } | |
3524 | else | |
3525 | def = force_gimple_operand_gsi (&gsi, def, false, NULL_TREE, | |
3526 | true, GSI_SAME_STMT); | |
3527 | ||
726a989a | 3528 | ass = gimple_build_assign (rslt, def); |
19e51b40 | 3529 | gsi_insert_before (&gsi, ass, GSI_SAME_STMT); |
3571dde6 MP |
3530 | if (dump_file) |
3531 | { | |
3532 | print_gimple_stmt (dump_file, ass, 0, 0); | |
3533 | fprintf (dump_file, "\n"); | |
3534 | } | |
3ac01fde ZD |
3535 | } |
3536 | } | |
c2924966 | 3537 | return 0; |
684aaf29 | 3538 | } |
9e2f83a5 ZD |
3539 | |
3540 | #include "gt-tree-scalar-evolution.h" |