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e9eb809d | 1 | /* Scalar evolution detector. |
23a5b65a | 2 | Copyright (C) 2003-2014 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" | |
cf2d1b38 | 259 | #include "tree.h" |
d8a2d370 | 260 | #include "expr.h" |
cf835838 | 261 | #include "gimple-pretty-print.h" |
2fb9a547 AM |
262 | #include "basic-block.h" |
263 | #include "tree-ssa-alias.h" | |
264 | #include "internal-fn.h" | |
265 | #include "gimple-expr.h" | |
266 | #include "is-a.h" | |
18f429e2 | 267 | #include "gimple.h" |
45b0be94 | 268 | #include "gimplify.h" |
5be5c238 | 269 | #include "gimple-iterator.h" |
18f429e2 | 270 | #include "gimplify-me.h" |
442b4905 AM |
271 | #include "gimple-ssa.h" |
272 | #include "tree-cfg.h" | |
273 | #include "tree-phinodes.h" | |
d8a2d370 | 274 | #include "stringpool.h" |
442b4905 | 275 | #include "tree-ssanames.h" |
e28030cf AM |
276 | #include "tree-ssa-loop-ivopts.h" |
277 | #include "tree-ssa-loop-manip.h" | |
278 | #include "tree-ssa-loop-niter.h" | |
442b4905 | 279 | #include "tree-ssa-loop.h" |
7a300452 | 280 | #include "tree-ssa.h" |
e9eb809d ZD |
281 | #include "cfgloop.h" |
282 | #include "tree-chrec.h" | |
b83b5507 BC |
283 | #include "pointer-set.h" |
284 | #include "tree-affine.h" | |
e9eb809d | 285 | #include "tree-scalar-evolution.h" |
7ee2468b | 286 | #include "dumpfile.h" |
c59dabbe | 287 | #include "params.h" |
744730a4 | 288 | #include "tree-ssa-propagate.h" |
9baba81b SP |
289 | |
290 | static tree analyze_scalar_evolution_1 (struct loop *, tree, tree); | |
bef28ced JL |
291 | static tree analyze_scalar_evolution_for_address_of (struct loop *loop, |
292 | tree var); | |
9baba81b | 293 | |
a3cc13cc RB |
294 | /* The cached information about an SSA name with version NAME_VERSION, |
295 | claiming that below basic block with index INSTANTIATED_BELOW, the | |
296 | value of the SSA name can be expressed as CHREC. */ | |
9baba81b | 297 | |
d1b38208 | 298 | struct GTY(()) scev_info_str { |
a3cc13cc RB |
299 | unsigned int name_version; |
300 | int instantiated_below; | |
9baba81b SP |
301 | tree chrec; |
302 | }; | |
303 | ||
304 | /* Counters for the scev database. */ | |
305 | static unsigned nb_set_scev = 0; | |
306 | static unsigned nb_get_scev = 0; | |
307 | ||
308 | /* The following trees are unique elements. Thus the comparison of | |
309 | another element to these elements should be done on the pointer to | |
310 | these trees, and not on their value. */ | |
311 | ||
312 | /* The SSA_NAMEs that are not yet analyzed are qualified with NULL_TREE. */ | |
313 | tree chrec_not_analyzed_yet; | |
314 | ||
315 | /* Reserved to the cases where the analyzer has detected an | |
316 | undecidable property at compile time. */ | |
317 | tree chrec_dont_know; | |
318 | ||
319 | /* When the analyzer has detected that a property will never | |
320 | happen, then it qualifies it with chrec_known. */ | |
321 | tree chrec_known; | |
322 | ||
9e2f83a5 | 323 | static GTY ((param_is (struct scev_info_str))) htab_t scalar_evolution_info; |
9baba81b SP |
324 | |
325 | \f | |
a213b219 | 326 | /* Constructs a new SCEV_INFO_STR structure for VAR and INSTANTIATED_BELOW. */ |
9baba81b SP |
327 | |
328 | static inline struct scev_info_str * | |
a213b219 | 329 | new_scev_info_str (basic_block instantiated_below, tree var) |
9baba81b SP |
330 | { |
331 | struct scev_info_str *res; | |
b8698a0f | 332 | |
a9429e29 | 333 | res = ggc_alloc_scev_info_str (); |
a3cc13cc | 334 | res->name_version = SSA_NAME_VERSION (var); |
9baba81b | 335 | res->chrec = chrec_not_analyzed_yet; |
a3cc13cc | 336 | res->instantiated_below = instantiated_below->index; |
a213b219 | 337 | |
9baba81b SP |
338 | return res; |
339 | } | |
340 | ||
341 | /* Computes a hash function for database element ELT. */ | |
342 | ||
4a8fb1a1 | 343 | static inline hashval_t |
a3cc13cc | 344 | hash_scev_info (const void *elt_) |
9baba81b | 345 | { |
a3cc13cc RB |
346 | const struct scev_info_str *elt = (const struct scev_info_str *) elt_; |
347 | return elt->name_version ^ elt->instantiated_below; | |
9baba81b SP |
348 | } |
349 | ||
350 | /* Compares database elements E1 and E2. */ | |
351 | ||
4a8fb1a1 | 352 | static inline int |
9baba81b SP |
353 | eq_scev_info (const void *e1, const void *e2) |
354 | { | |
cceb1885 GDR |
355 | const struct scev_info_str *elt1 = (const struct scev_info_str *) e1; |
356 | const struct scev_info_str *elt2 = (const struct scev_info_str *) e2; | |
9baba81b | 357 | |
a3cc13cc | 358 | return (elt1->name_version == elt2->name_version |
a213b219 | 359 | && elt1->instantiated_below == elt2->instantiated_below); |
9baba81b SP |
360 | } |
361 | ||
362 | /* Deletes database element E. */ | |
363 | ||
364 | static void | |
365 | del_scev_info (void *e) | |
366 | { | |
9e2f83a5 | 367 | ggc_free (e); |
9baba81b SP |
368 | } |
369 | ||
4a8fb1a1 | 370 | |
a213b219 SP |
371 | /* Get the scalar evolution of VAR for INSTANTIATED_BELOW basic block. |
372 | A first query on VAR returns chrec_not_analyzed_yet. */ | |
9baba81b SP |
373 | |
374 | static tree * | |
a213b219 | 375 | find_var_scev_info (basic_block instantiated_below, tree var) |
9baba81b SP |
376 | { |
377 | struct scev_info_str *res; | |
378 | struct scev_info_str tmp; | |
379 | PTR *slot; | |
380 | ||
a3cc13cc RB |
381 | tmp.name_version = SSA_NAME_VERSION (var); |
382 | tmp.instantiated_below = instantiated_below->index; | |
9baba81b SP |
383 | slot = htab_find_slot (scalar_evolution_info, &tmp, INSERT); |
384 | ||
385 | if (!*slot) | |
a213b219 | 386 | *slot = new_scev_info_str (instantiated_below, var); |
cceb1885 | 387 | res = (struct scev_info_str *) *slot; |
9baba81b SP |
388 | |
389 | return &res->chrec; | |
390 | } | |
391 | ||
9baba81b SP |
392 | /* Return true when CHREC contains symbolic names defined in |
393 | LOOP_NB. */ | |
394 | ||
b8698a0f | 395 | bool |
ed7a4b4b | 396 | chrec_contains_symbols_defined_in_loop (const_tree chrec, unsigned loop_nb) |
9baba81b | 397 | { |
5039610b SL |
398 | int i, n; |
399 | ||
9baba81b SP |
400 | if (chrec == NULL_TREE) |
401 | return false; | |
402 | ||
ad6003f2 | 403 | if (is_gimple_min_invariant (chrec)) |
9baba81b SP |
404 | return false; |
405 | ||
9baba81b SP |
406 | if (TREE_CODE (chrec) == SSA_NAME) |
407 | { | |
492e5456 SP |
408 | gimple def; |
409 | loop_p def_loop, loop; | |
410 | ||
411 | if (SSA_NAME_IS_DEFAULT_DEF (chrec)) | |
412 | return false; | |
413 | ||
414 | def = SSA_NAME_DEF_STMT (chrec); | |
415 | def_loop = loop_containing_stmt (def); | |
0fc822d0 | 416 | loop = get_loop (cfun, loop_nb); |
9baba81b SP |
417 | |
418 | if (def_loop == NULL) | |
419 | return false; | |
420 | ||
421 | if (loop == def_loop || flow_loop_nested_p (loop, def_loop)) | |
422 | return true; | |
423 | ||
424 | return false; | |
425 | } | |
426 | ||
5039610b SL |
427 | n = TREE_OPERAND_LENGTH (chrec); |
428 | for (i = 0; i < n; i++) | |
b8698a0f | 429 | if (chrec_contains_symbols_defined_in_loop (TREE_OPERAND (chrec, i), |
5039610b SL |
430 | loop_nb)) |
431 | return true; | |
432 | return false; | |
9baba81b SP |
433 | } |
434 | ||
435 | /* Return true when PHI is a loop-phi-node. */ | |
436 | ||
437 | static bool | |
726a989a | 438 | loop_phi_node_p (gimple phi) |
9baba81b SP |
439 | { |
440 | /* The implementation of this function is based on the following | |
441 | property: "all the loop-phi-nodes of a loop are contained in the | |
442 | loop's header basic block". */ | |
443 | ||
726a989a | 444 | return loop_containing_stmt (phi)->header == gimple_bb (phi); |
9baba81b SP |
445 | } |
446 | ||
447 | /* Compute the scalar evolution for EVOLUTION_FN after crossing LOOP. | |
448 | In general, in the case of multivariate evolutions we want to get | |
449 | the evolution in different loops. LOOP specifies the level for | |
450 | which to get the evolution. | |
b8698a0f | 451 | |
9baba81b | 452 | Example: |
b8698a0f | 453 | |
9baba81b SP |
454 | | for (j = 0; j < 100; j++) |
455 | | { | |
456 | | for (k = 0; k < 100; k++) | |
457 | | { | |
b8698a0f | 458 | | i = k + j; - Here the value of i is a function of j, k. |
9baba81b | 459 | | } |
b8698a0f | 460 | | ... = i - Here the value of i is a function of j. |
9baba81b | 461 | | } |
b8698a0f L |
462 | | ... = i - Here the value of i is a scalar. |
463 | ||
464 | Example: | |
465 | ||
9baba81b SP |
466 | | i_0 = ... |
467 | | loop_1 10 times | |
468 | | i_1 = phi (i_0, i_2) | |
469 | | i_2 = i_1 + 2 | |
470 | | endloop | |
b8698a0f | 471 | |
9baba81b SP |
472 | This loop has the same effect as: |
473 | LOOP_1 has the same effect as: | |
b8698a0f | 474 | |
9baba81b | 475 | | i_1 = i_0 + 20 |
b8698a0f L |
476 | |
477 | The overall effect of the loop, "i_0 + 20" in the previous example, | |
478 | is obtained by passing in the parameters: LOOP = 1, | |
9baba81b SP |
479 | EVOLUTION_FN = {i_0, +, 2}_1. |
480 | */ | |
b8698a0f | 481 | |
42e6eec5 | 482 | tree |
9baba81b SP |
483 | compute_overall_effect_of_inner_loop (struct loop *loop, tree evolution_fn) |
484 | { | |
485 | bool val = false; | |
486 | ||
487 | if (evolution_fn == chrec_dont_know) | |
488 | return chrec_dont_know; | |
489 | ||
490 | else if (TREE_CODE (evolution_fn) == POLYNOMIAL_CHREC) | |
491 | { | |
677cc14d ZD |
492 | struct loop *inner_loop = get_chrec_loop (evolution_fn); |
493 | ||
494 | if (inner_loop == loop | |
495 | || flow_loop_nested_p (loop, inner_loop)) | |
9baba81b | 496 | { |
a14865db | 497 | tree nb_iter = number_of_latch_executions (inner_loop); |
9baba81b SP |
498 | |
499 | if (nb_iter == chrec_dont_know) | |
500 | return chrec_dont_know; | |
501 | else | |
502 | { | |
503 | tree res; | |
504 | ||
9baba81b SP |
505 | /* evolution_fn is the evolution function in LOOP. Get |
506 | its value in the nb_iter-th iteration. */ | |
507 | res = chrec_apply (inner_loop->num, evolution_fn, nb_iter); | |
42e6eec5 SP |
508 | |
509 | if (chrec_contains_symbols_defined_in_loop (res, loop->num)) | |
510 | res = instantiate_parameters (loop, res); | |
511 | ||
8c27b7d4 | 512 | /* Continue the computation until ending on a parent of LOOP. */ |
9baba81b SP |
513 | return compute_overall_effect_of_inner_loop (loop, res); |
514 | } | |
515 | } | |
516 | else | |
517 | return evolution_fn; | |
518 | } | |
b8698a0f | 519 | |
9baba81b SP |
520 | /* If the evolution function is an invariant, there is nothing to do. */ |
521 | else if (no_evolution_in_loop_p (evolution_fn, loop->num, &val) && val) | |
522 | return evolution_fn; | |
b8698a0f | 523 | |
9baba81b SP |
524 | else |
525 | return chrec_dont_know; | |
526 | } | |
527 | ||
9baba81b SP |
528 | /* Associate CHREC to SCALAR. */ |
529 | ||
530 | static void | |
a213b219 | 531 | set_scalar_evolution (basic_block instantiated_below, tree scalar, tree chrec) |
9baba81b SP |
532 | { |
533 | tree *scalar_info; | |
b8698a0f | 534 | |
9baba81b SP |
535 | if (TREE_CODE (scalar) != SSA_NAME) |
536 | return; | |
537 | ||
a213b219 | 538 | scalar_info = find_var_scev_info (instantiated_below, scalar); |
b8698a0f | 539 | |
9baba81b SP |
540 | if (dump_file) |
541 | { | |
dfedbe40 | 542 | if (dump_flags & TDF_SCEV) |
9baba81b SP |
543 | { |
544 | fprintf (dump_file, "(set_scalar_evolution \n"); | |
a213b219 SP |
545 | fprintf (dump_file, " instantiated_below = %d \n", |
546 | instantiated_below->index); | |
9baba81b SP |
547 | fprintf (dump_file, " (scalar = "); |
548 | print_generic_expr (dump_file, scalar, 0); | |
549 | fprintf (dump_file, ")\n (scalar_evolution = "); | |
550 | print_generic_expr (dump_file, chrec, 0); | |
551 | fprintf (dump_file, "))\n"); | |
552 | } | |
553 | if (dump_flags & TDF_STATS) | |
554 | nb_set_scev++; | |
555 | } | |
b8698a0f | 556 | |
9baba81b SP |
557 | *scalar_info = chrec; |
558 | } | |
559 | ||
a213b219 SP |
560 | /* Retrieve the chrec associated to SCALAR instantiated below |
561 | INSTANTIATED_BELOW block. */ | |
9baba81b SP |
562 | |
563 | static tree | |
a213b219 | 564 | get_scalar_evolution (basic_block instantiated_below, tree scalar) |
9baba81b SP |
565 | { |
566 | tree res; | |
b8698a0f | 567 | |
9baba81b SP |
568 | if (dump_file) |
569 | { | |
dfedbe40 | 570 | if (dump_flags & TDF_SCEV) |
9baba81b SP |
571 | { |
572 | fprintf (dump_file, "(get_scalar_evolution \n"); | |
573 | fprintf (dump_file, " (scalar = "); | |
574 | print_generic_expr (dump_file, scalar, 0); | |
575 | fprintf (dump_file, ")\n"); | |
576 | } | |
577 | if (dump_flags & TDF_STATS) | |
578 | nb_get_scev++; | |
579 | } | |
b8698a0f | 580 | |
9baba81b SP |
581 | switch (TREE_CODE (scalar)) |
582 | { | |
583 | case SSA_NAME: | |
a213b219 | 584 | res = *find_var_scev_info (instantiated_below, scalar); |
9baba81b SP |
585 | break; |
586 | ||
587 | case REAL_CST: | |
325217ed | 588 | case FIXED_CST: |
9baba81b SP |
589 | case INTEGER_CST: |
590 | res = scalar; | |
591 | break; | |
592 | ||
593 | default: | |
594 | res = chrec_not_analyzed_yet; | |
595 | break; | |
596 | } | |
b8698a0f | 597 | |
dfedbe40 | 598 | if (dump_file && (dump_flags & TDF_SCEV)) |
9baba81b SP |
599 | { |
600 | fprintf (dump_file, " (scalar_evolution = "); | |
601 | print_generic_expr (dump_file, res, 0); | |
602 | fprintf (dump_file, "))\n"); | |
603 | } | |
b8698a0f | 604 | |
9baba81b SP |
605 | return res; |
606 | } | |
607 | ||
608 | /* Helper function for add_to_evolution. Returns the evolution | |
609 | function for an assignment of the form "a = b + c", where "a" and | |
610 | "b" are on the strongly connected component. CHREC_BEFORE is the | |
611 | information that we already have collected up to this point. | |
b8698a0f L |
612 | TO_ADD is the evolution of "c". |
613 | ||
9baba81b SP |
614 | When CHREC_BEFORE has an evolution part in LOOP_NB, add to this |
615 | evolution the expression TO_ADD, otherwise construct an evolution | |
616 | part for this loop. */ | |
617 | ||
618 | static tree | |
e2157b49 | 619 | add_to_evolution_1 (unsigned loop_nb, tree chrec_before, tree to_add, |
726a989a | 620 | gimple at_stmt) |
9baba81b | 621 | { |
e2157b49 | 622 | tree type, left, right; |
0fc822d0 | 623 | struct loop *loop = get_loop (cfun, loop_nb), *chloop; |
e2157b49 | 624 | |
9baba81b SP |
625 | switch (TREE_CODE (chrec_before)) |
626 | { | |
627 | case POLYNOMIAL_CHREC: | |
677cc14d ZD |
628 | chloop = get_chrec_loop (chrec_before); |
629 | if (chloop == loop | |
630 | || flow_loop_nested_p (chloop, loop)) | |
9baba81b SP |
631 | { |
632 | unsigned var; | |
e2157b49 SP |
633 | |
634 | type = chrec_type (chrec_before); | |
b8698a0f | 635 | |
9baba81b | 636 | /* When there is no evolution part in this loop, build it. */ |
677cc14d | 637 | if (chloop != loop) |
9baba81b SP |
638 | { |
639 | var = loop_nb; | |
640 | left = chrec_before; | |
7e0923cd SP |
641 | right = SCALAR_FLOAT_TYPE_P (type) |
642 | ? build_real (type, dconst0) | |
643 | : build_int_cst (type, 0); | |
9baba81b SP |
644 | } |
645 | else | |
646 | { | |
647 | var = CHREC_VARIABLE (chrec_before); | |
648 | left = CHREC_LEFT (chrec_before); | |
649 | right = CHREC_RIGHT (chrec_before); | |
650 | } | |
651 | ||
e2157b49 | 652 | to_add = chrec_convert (type, to_add, at_stmt); |
5be014d5 AP |
653 | right = chrec_convert_rhs (type, right, at_stmt); |
654 | right = chrec_fold_plus (chrec_type (right), right, to_add); | |
e2157b49 | 655 | return build_polynomial_chrec (var, left, right); |
9baba81b SP |
656 | } |
657 | else | |
e2157b49 | 658 | { |
677cc14d ZD |
659 | gcc_assert (flow_loop_nested_p (loop, chloop)); |
660 | ||
e2157b49 SP |
661 | /* Search the evolution in LOOP_NB. */ |
662 | left = add_to_evolution_1 (loop_nb, CHREC_LEFT (chrec_before), | |
663 | to_add, at_stmt); | |
664 | right = CHREC_RIGHT (chrec_before); | |
5be014d5 | 665 | right = chrec_convert_rhs (chrec_type (left), right, at_stmt); |
e2157b49 SP |
666 | return build_polynomial_chrec (CHREC_VARIABLE (chrec_before), |
667 | left, right); | |
668 | } | |
b8698a0f | 669 | |
9baba81b SP |
670 | default: |
671 | /* These nodes do not depend on a loop. */ | |
672 | if (chrec_before == chrec_dont_know) | |
673 | return chrec_dont_know; | |
e2157b49 SP |
674 | |
675 | left = chrec_before; | |
5be014d5 | 676 | right = chrec_convert_rhs (chrec_type (left), to_add, at_stmt); |
e2157b49 | 677 | return build_polynomial_chrec (loop_nb, left, right); |
9baba81b SP |
678 | } |
679 | } | |
680 | ||
681 | /* Add TO_ADD to the evolution part of CHREC_BEFORE in the dimension | |
b8698a0f L |
682 | of LOOP_NB. |
683 | ||
9baba81b SP |
684 | Description (provided for completeness, for those who read code in |
685 | a plane, and for my poor 62 bytes brain that would have forgotten | |
686 | all this in the next two or three months): | |
b8698a0f | 687 | |
9baba81b SP |
688 | The algorithm of translation of programs from the SSA representation |
689 | into the chrecs syntax is based on a pattern matching. After having | |
690 | reconstructed the overall tree expression for a loop, there are only | |
691 | two cases that can arise: | |
b8698a0f | 692 | |
9baba81b SP |
693 | 1. a = loop-phi (init, a + expr) |
694 | 2. a = loop-phi (init, expr) | |
b8698a0f | 695 | |
9baba81b SP |
696 | where EXPR is either a scalar constant with respect to the analyzed |
697 | loop (this is a degree 0 polynomial), or an expression containing | |
698 | other loop-phi definitions (these are higher degree polynomials). | |
b8698a0f | 699 | |
9baba81b | 700 | Examples: |
b8698a0f L |
701 | |
702 | 1. | |
9baba81b SP |
703 | | init = ... |
704 | | loop_1 | |
705 | | a = phi (init, a + 5) | |
706 | | endloop | |
b8698a0f L |
707 | |
708 | 2. | |
9baba81b SP |
709 | | inita = ... |
710 | | initb = ... | |
711 | | loop_1 | |
712 | | a = phi (inita, 2 * b + 3) | |
713 | | b = phi (initb, b + 1) | |
714 | | endloop | |
b8698a0f L |
715 | |
716 | For the first case, the semantics of the SSA representation is: | |
717 | ||
9baba81b | 718 | | a (x) = init + \sum_{j = 0}^{x - 1} expr (j) |
b8698a0f | 719 | |
9baba81b SP |
720 | that is, there is a loop index "x" that determines the scalar value |
721 | of the variable during the loop execution. During the first | |
722 | iteration, the value is that of the initial condition INIT, while | |
723 | during the subsequent iterations, it is the sum of the initial | |
724 | condition with the sum of all the values of EXPR from the initial | |
b8698a0f L |
725 | iteration to the before last considered iteration. |
726 | ||
9baba81b | 727 | For the second case, the semantics of the SSA program is: |
b8698a0f | 728 | |
9baba81b SP |
729 | | a (x) = init, if x = 0; |
730 | | expr (x - 1), otherwise. | |
b8698a0f | 731 | |
9baba81b | 732 | The second case corresponds to the PEELED_CHREC, whose syntax is |
b8698a0f L |
733 | close to the syntax of a loop-phi-node: |
734 | ||
9baba81b | 735 | | phi (init, expr) vs. (init, expr)_x |
b8698a0f | 736 | |
9baba81b | 737 | The proof of the translation algorithm for the first case is a |
b8698a0f L |
738 | proof by structural induction based on the degree of EXPR. |
739 | ||
9baba81b SP |
740 | Degree 0: |
741 | When EXPR is a constant with respect to the analyzed loop, or in | |
742 | other words when EXPR is a polynomial of degree 0, the evolution of | |
743 | the variable A in the loop is an affine function with an initial | |
744 | condition INIT, and a step EXPR. In order to show this, we start | |
745 | from the semantics of the SSA representation: | |
b8698a0f | 746 | |
9baba81b | 747 | f (x) = init + \sum_{j = 0}^{x - 1} expr (j) |
b8698a0f | 748 | |
9baba81b | 749 | and since "expr (j)" is a constant with respect to "j", |
b8698a0f L |
750 | |
751 | f (x) = init + x * expr | |
752 | ||
9baba81b SP |
753 | Finally, based on the semantics of the pure sum chrecs, by |
754 | identification we get the corresponding chrecs syntax: | |
b8698a0f L |
755 | |
756 | f (x) = init * \binom{x}{0} + expr * \binom{x}{1} | |
9baba81b | 757 | f (x) -> {init, +, expr}_x |
b8698a0f | 758 | |
9baba81b SP |
759 | Higher degree: |
760 | Suppose that EXPR is a polynomial of degree N with respect to the | |
761 | analyzed loop_x for which we have already determined that it is | |
762 | written under the chrecs syntax: | |
b8698a0f | 763 | |
9baba81b | 764 | | expr (x) -> {b_0, +, b_1, +, ..., +, b_{n-1}} (x) |
b8698a0f | 765 | |
9baba81b | 766 | We start from the semantics of the SSA program: |
b8698a0f | 767 | |
9baba81b SP |
768 | | f (x) = init + \sum_{j = 0}^{x - 1} expr (j) |
769 | | | |
b8698a0f | 770 | | f (x) = init + \sum_{j = 0}^{x - 1} |
9baba81b SP |
771 | | (b_0 * \binom{j}{0} + ... + b_{n-1} * \binom{j}{n-1}) |
772 | | | |
b8698a0f L |
773 | | f (x) = init + \sum_{j = 0}^{x - 1} |
774 | | \sum_{k = 0}^{n - 1} (b_k * \binom{j}{k}) | |
9baba81b | 775 | | |
b8698a0f L |
776 | | f (x) = init + \sum_{k = 0}^{n - 1} |
777 | | (b_k * \sum_{j = 0}^{x - 1} \binom{j}{k}) | |
9baba81b | 778 | | |
b8698a0f L |
779 | | f (x) = init + \sum_{k = 0}^{n - 1} |
780 | | (b_k * \binom{x}{k + 1}) | |
9baba81b | 781 | | |
b8698a0f L |
782 | | f (x) = init + b_0 * \binom{x}{1} + ... |
783 | | + b_{n-1} * \binom{x}{n} | |
9baba81b | 784 | | |
b8698a0f L |
785 | | f (x) = init * \binom{x}{0} + b_0 * \binom{x}{1} + ... |
786 | | + b_{n-1} * \binom{x}{n} | |
9baba81b | 787 | | |
b8698a0f | 788 | |
9baba81b | 789 | And finally from the definition of the chrecs syntax, we identify: |
b8698a0f L |
790 | | f (x) -> {init, +, b_0, +, ..., +, b_{n-1}}_x |
791 | ||
9baba81b SP |
792 | This shows the mechanism that stands behind the add_to_evolution |
793 | function. An important point is that the use of symbolic | |
794 | parameters avoids the need of an analysis schedule. | |
b8698a0f | 795 | |
9baba81b | 796 | Example: |
b8698a0f | 797 | |
9baba81b SP |
798 | | inita = ... |
799 | | initb = ... | |
b8698a0f | 800 | | loop_1 |
9baba81b SP |
801 | | a = phi (inita, a + 2 + b) |
802 | | b = phi (initb, b + 1) | |
803 | | endloop | |
b8698a0f | 804 | |
9baba81b | 805 | When analyzing "a", the algorithm keeps "b" symbolically: |
b8698a0f | 806 | |
9baba81b | 807 | | a -> {inita, +, 2 + b}_1 |
b8698a0f | 808 | |
9baba81b | 809 | Then, after instantiation, the analyzer ends on the evolution: |
b8698a0f | 810 | |
9baba81b SP |
811 | | a -> {inita, +, 2 + initb, +, 1}_1 |
812 | ||
813 | */ | |
814 | ||
b8698a0f | 815 | static tree |
e2157b49 | 816 | add_to_evolution (unsigned loop_nb, tree chrec_before, enum tree_code code, |
726a989a | 817 | tree to_add, gimple at_stmt) |
9baba81b SP |
818 | { |
819 | tree type = chrec_type (to_add); | |
820 | tree res = NULL_TREE; | |
b8698a0f | 821 | |
9baba81b SP |
822 | if (to_add == NULL_TREE) |
823 | return chrec_before; | |
b8698a0f | 824 | |
9baba81b SP |
825 | /* TO_ADD is either a scalar, or a parameter. TO_ADD is not |
826 | instantiated at this point. */ | |
827 | if (TREE_CODE (to_add) == POLYNOMIAL_CHREC) | |
828 | /* This should not happen. */ | |
829 | return chrec_dont_know; | |
b8698a0f | 830 | |
dfedbe40 | 831 | if (dump_file && (dump_flags & TDF_SCEV)) |
9baba81b SP |
832 | { |
833 | fprintf (dump_file, "(add_to_evolution \n"); | |
834 | fprintf (dump_file, " (loop_nb = %d)\n", loop_nb); | |
835 | fprintf (dump_file, " (chrec_before = "); | |
836 | print_generic_expr (dump_file, chrec_before, 0); | |
837 | fprintf (dump_file, ")\n (to_add = "); | |
838 | print_generic_expr (dump_file, to_add, 0); | |
839 | fprintf (dump_file, ")\n"); | |
840 | } | |
841 | ||
842 | if (code == MINUS_EXPR) | |
9d2b0e12 VR |
843 | to_add = chrec_fold_multiply (type, to_add, SCALAR_FLOAT_TYPE_P (type) |
844 | ? build_real (type, dconstm1) | |
845 | : build_int_cst_type (type, -1)); | |
9baba81b | 846 | |
e2157b49 | 847 | res = add_to_evolution_1 (loop_nb, chrec_before, to_add, at_stmt); |
9baba81b | 848 | |
dfedbe40 | 849 | if (dump_file && (dump_flags & TDF_SCEV)) |
9baba81b SP |
850 | { |
851 | fprintf (dump_file, " (res = "); | |
852 | print_generic_expr (dump_file, res, 0); | |
853 | fprintf (dump_file, "))\n"); | |
854 | } | |
855 | ||
856 | return res; | |
857 | } | |
858 | ||
9baba81b SP |
859 | \f |
860 | ||
861 | /* This section selects the loops that will be good candidates for the | |
862 | scalar evolution analysis. For the moment, greedily select all the | |
863 | loop nests we could analyze. */ | |
864 | ||
9baba81b SP |
865 | /* For a loop with a single exit edge, return the COND_EXPR that |
866 | guards the exit edge. If the expression is too difficult to | |
867 | analyze, then give up. */ | |
868 | ||
b8698a0f | 869 | gimple |
22ea9ec0 | 870 | get_loop_exit_condition (const struct loop *loop) |
9baba81b | 871 | { |
726a989a | 872 | gimple res = NULL; |
ac8f6c69 | 873 | edge exit_edge = single_exit (loop); |
b8698a0f | 874 | |
dfedbe40 | 875 | if (dump_file && (dump_flags & TDF_SCEV)) |
9baba81b | 876 | fprintf (dump_file, "(get_loop_exit_condition \n "); |
b8698a0f | 877 | |
82b85a85 | 878 | if (exit_edge) |
9baba81b | 879 | { |
726a989a | 880 | gimple stmt; |
b8698a0f | 881 | |
726a989a RB |
882 | stmt = last_stmt (exit_edge->src); |
883 | if (gimple_code (stmt) == GIMPLE_COND) | |
884 | res = stmt; | |
9baba81b | 885 | } |
b8698a0f | 886 | |
dfedbe40 | 887 | if (dump_file && (dump_flags & TDF_SCEV)) |
9baba81b | 888 | { |
726a989a | 889 | print_gimple_stmt (dump_file, res, 0, 0); |
9baba81b SP |
890 | fprintf (dump_file, ")\n"); |
891 | } | |
b8698a0f | 892 | |
9baba81b SP |
893 | return res; |
894 | } | |
895 | ||
9baba81b SP |
896 | \f |
897 | /* Depth first search algorithm. */ | |
898 | ||
c59dabbe SP |
899 | typedef enum t_bool { |
900 | t_false, | |
901 | t_true, | |
902 | t_dont_know | |
903 | } t_bool; | |
904 | ||
905 | ||
726a989a | 906 | static t_bool follow_ssa_edge (struct loop *loop, gimple, gimple, tree *, int); |
9baba81b | 907 | |
726a989a | 908 | /* Follow the ssa edge into the binary expression RHS0 CODE RHS1. |
9baba81b SP |
909 | Return true if the strongly connected component has been found. */ |
910 | ||
c59dabbe | 911 | static t_bool |
726a989a RB |
912 | follow_ssa_edge_binary (struct loop *loop, gimple at_stmt, |
913 | tree type, tree rhs0, enum tree_code code, tree rhs1, | |
914 | gimple halting_phi, tree *evolution_of_loop, int limit) | |
9baba81b | 915 | { |
c59dabbe | 916 | t_bool res = t_false; |
b2a93c0a | 917 | tree evol; |
726a989a | 918 | |
5be014d5 | 919 | switch (code) |
9baba81b | 920 | { |
5be014d5 | 921 | case POINTER_PLUS_EXPR: |
9baba81b | 922 | case PLUS_EXPR: |
9baba81b SP |
923 | if (TREE_CODE (rhs0) == SSA_NAME) |
924 | { | |
925 | if (TREE_CODE (rhs1) == SSA_NAME) | |
926 | { | |
b8698a0f | 927 | /* Match an assignment under the form: |
9baba81b | 928 | "a = b + c". */ |
b8698a0f | 929 | |
9e824336 ZD |
930 | /* We want only assignments of form "name + name" contribute to |
931 | LIMIT, as the other cases do not necessarily contribute to | |
932 | the complexity of the expression. */ | |
933 | limit++; | |
934 | ||
b2a93c0a | 935 | evol = *evolution_of_loop; |
b8698a0f | 936 | res = follow_ssa_edge |
726a989a | 937 | (loop, SSA_NAME_DEF_STMT (rhs0), halting_phi, &evol, limit); |
b8698a0f | 938 | |
c59dabbe | 939 | if (res == t_true) |
b8698a0f L |
940 | *evolution_of_loop = add_to_evolution |
941 | (loop->num, | |
942 | chrec_convert (type, evol, at_stmt), | |
5be014d5 | 943 | code, rhs1, at_stmt); |
b8698a0f | 944 | |
c59dabbe | 945 | else if (res == t_false) |
9baba81b | 946 | { |
b8698a0f L |
947 | res = follow_ssa_edge |
948 | (loop, SSA_NAME_DEF_STMT (rhs1), halting_phi, | |
c59dabbe | 949 | evolution_of_loop, limit); |
b8698a0f | 950 | |
c59dabbe | 951 | if (res == t_true) |
b8698a0f L |
952 | *evolution_of_loop = add_to_evolution |
953 | (loop->num, | |
954 | chrec_convert (type, *evolution_of_loop, at_stmt), | |
5be014d5 | 955 | code, rhs0, at_stmt); |
c59dabbe SP |
956 | |
957 | else if (res == t_dont_know) | |
958 | *evolution_of_loop = chrec_dont_know; | |
9baba81b | 959 | } |
c59dabbe SP |
960 | |
961 | else if (res == t_dont_know) | |
962 | *evolution_of_loop = chrec_dont_know; | |
9baba81b | 963 | } |
b8698a0f | 964 | |
9baba81b SP |
965 | else |
966 | { | |
b8698a0f | 967 | /* Match an assignment under the form: |
9baba81b | 968 | "a = b + ...". */ |
b8698a0f L |
969 | res = follow_ssa_edge |
970 | (loop, SSA_NAME_DEF_STMT (rhs0), halting_phi, | |
c59dabbe SP |
971 | evolution_of_loop, limit); |
972 | if (res == t_true) | |
b8698a0f | 973 | *evolution_of_loop = add_to_evolution |
726a989a | 974 | (loop->num, chrec_convert (type, *evolution_of_loop, |
1e8552eb | 975 | at_stmt), |
5be014d5 | 976 | code, rhs1, at_stmt); |
c59dabbe SP |
977 | |
978 | else if (res == t_dont_know) | |
979 | *evolution_of_loop = chrec_dont_know; | |
9baba81b SP |
980 | } |
981 | } | |
b8698a0f | 982 | |
9baba81b SP |
983 | else if (TREE_CODE (rhs1) == SSA_NAME) |
984 | { | |
b8698a0f | 985 | /* Match an assignment under the form: |
9baba81b | 986 | "a = ... + c". */ |
b8698a0f L |
987 | res = follow_ssa_edge |
988 | (loop, SSA_NAME_DEF_STMT (rhs1), halting_phi, | |
c59dabbe SP |
989 | evolution_of_loop, limit); |
990 | if (res == t_true) | |
b8698a0f | 991 | *evolution_of_loop = add_to_evolution |
726a989a | 992 | (loop->num, chrec_convert (type, *evolution_of_loop, |
1e8552eb | 993 | at_stmt), |
5be014d5 | 994 | code, rhs0, at_stmt); |
c59dabbe SP |
995 | |
996 | else if (res == t_dont_know) | |
997 | *evolution_of_loop = chrec_dont_know; | |
9baba81b SP |
998 | } |
999 | ||
1000 | else | |
b8698a0f | 1001 | /* Otherwise, match an assignment under the form: |
9baba81b SP |
1002 | "a = ... + ...". */ |
1003 | /* And there is nothing to do. */ | |
c59dabbe | 1004 | res = t_false; |
9baba81b | 1005 | break; |
b8698a0f | 1006 | |
9baba81b SP |
1007 | case MINUS_EXPR: |
1008 | /* This case is under the form "opnd0 = rhs0 - rhs1". */ | |
9baba81b | 1009 | if (TREE_CODE (rhs0) == SSA_NAME) |
9baba81b | 1010 | { |
b8698a0f | 1011 | /* Match an assignment under the form: |
f8e9d512 | 1012 | "a = b - ...". */ |
9e824336 ZD |
1013 | |
1014 | /* We want only assignments of form "name - name" contribute to | |
1015 | LIMIT, as the other cases do not necessarily contribute to | |
1016 | the complexity of the expression. */ | |
1017 | if (TREE_CODE (rhs1) == SSA_NAME) | |
1018 | limit++; | |
1019 | ||
b8698a0f | 1020 | res = follow_ssa_edge (loop, SSA_NAME_DEF_STMT (rhs0), halting_phi, |
c59dabbe SP |
1021 | evolution_of_loop, limit); |
1022 | if (res == t_true) | |
b8698a0f | 1023 | *evolution_of_loop = add_to_evolution |
726a989a | 1024 | (loop->num, chrec_convert (type, *evolution_of_loop, at_stmt), |
e2157b49 | 1025 | MINUS_EXPR, rhs1, at_stmt); |
c59dabbe SP |
1026 | |
1027 | else if (res == t_dont_know) | |
1028 | *evolution_of_loop = chrec_dont_know; | |
9baba81b | 1029 | } |
9baba81b | 1030 | else |
b8698a0f | 1031 | /* Otherwise, match an assignment under the form: |
9baba81b SP |
1032 | "a = ... - ...". */ |
1033 | /* And there is nothing to do. */ | |
c59dabbe | 1034 | res = t_false; |
9baba81b | 1035 | break; |
726a989a RB |
1036 | |
1037 | default: | |
1038 | res = t_false; | |
1039 | } | |
1040 | ||
1041 | return res; | |
1042 | } | |
b8698a0f | 1043 | |
726a989a RB |
1044 | /* Follow the ssa edge into the expression EXPR. |
1045 | Return true if the strongly connected component has been found. */ | |
1046 | ||
1047 | static t_bool | |
b8698a0f | 1048 | follow_ssa_edge_expr (struct loop *loop, gimple at_stmt, tree expr, |
726a989a RB |
1049 | gimple halting_phi, tree *evolution_of_loop, int limit) |
1050 | { | |
5aefc6a0 EB |
1051 | enum tree_code code = TREE_CODE (expr); |
1052 | tree type = TREE_TYPE (expr), rhs0, rhs1; | |
1053 | t_bool res; | |
1054 | ||
726a989a | 1055 | /* The EXPR is one of the following cases: |
b8698a0f | 1056 | - an SSA_NAME, |
726a989a | 1057 | - an INTEGER_CST, |
b8698a0f L |
1058 | - a PLUS_EXPR, |
1059 | - a POINTER_PLUS_EXPR, | |
726a989a RB |
1060 | - a MINUS_EXPR, |
1061 | - an ASSERT_EXPR, | |
1062 | - other cases are not yet handled. */ | |
5aefc6a0 | 1063 | |
726a989a RB |
1064 | switch (code) |
1065 | { | |
5aefc6a0 | 1066 | CASE_CONVERT: |
726a989a RB |
1067 | /* This assignment is under the form "a_1 = (cast) rhs. */ |
1068 | res = follow_ssa_edge_expr (loop, at_stmt, TREE_OPERAND (expr, 0), | |
1069 | halting_phi, evolution_of_loop, limit); | |
1070 | *evolution_of_loop = chrec_convert (type, *evolution_of_loop, at_stmt); | |
1071 | break; | |
1072 | ||
1073 | case INTEGER_CST: | |
1074 | /* This assignment is under the form "a_1 = 7". */ | |
1075 | res = t_false; | |
1076 | break; | |
5aefc6a0 | 1077 | |
726a989a RB |
1078 | case SSA_NAME: |
1079 | /* This assignment is under the form: "a_1 = b_2". */ | |
b8698a0f | 1080 | res = follow_ssa_edge |
726a989a RB |
1081 | (loop, SSA_NAME_DEF_STMT (expr), halting_phi, evolution_of_loop, limit); |
1082 | break; | |
5aefc6a0 | 1083 | |
726a989a RB |
1084 | case POINTER_PLUS_EXPR: |
1085 | case PLUS_EXPR: | |
1086 | case MINUS_EXPR: | |
1087 | /* This case is under the form "rhs0 +- rhs1". */ | |
1088 | rhs0 = TREE_OPERAND (expr, 0); | |
1089 | rhs1 = TREE_OPERAND (expr, 1); | |
5aefc6a0 EB |
1090 | type = TREE_TYPE (rhs0); |
1091 | STRIP_USELESS_TYPE_CONVERSION (rhs0); | |
1092 | STRIP_USELESS_TYPE_CONVERSION (rhs1); | |
1093 | res = follow_ssa_edge_binary (loop, at_stmt, type, rhs0, code, rhs1, | |
1094 | halting_phi, evolution_of_loop, limit); | |
1095 | break; | |
726a989a | 1096 | |
70f34814 RG |
1097 | case ADDR_EXPR: |
1098 | /* Handle &MEM[ptr + CST] which is equivalent to POINTER_PLUS_EXPR. */ | |
1099 | if (TREE_CODE (TREE_OPERAND (expr, 0)) == MEM_REF) | |
1100 | { | |
1101 | expr = TREE_OPERAND (expr, 0); | |
1102 | rhs0 = TREE_OPERAND (expr, 0); | |
1103 | rhs1 = TREE_OPERAND (expr, 1); | |
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, | |
1108 | rhs0, POINTER_PLUS_EXPR, rhs1, | |
1109 | halting_phi, evolution_of_loop, limit); | |
1110 | } | |
1111 | else | |
1112 | res = t_false; | |
1113 | break; | |
1114 | ||
0bca51f0 | 1115 | case ASSERT_EXPR: |
5aefc6a0 EB |
1116 | /* This assignment is of the form: "a_1 = ASSERT_EXPR <a_2, ...>" |
1117 | It must be handled as a copy assignment of the form a_1 = a_2. */ | |
1118 | rhs0 = ASSERT_EXPR_VAR (expr); | |
1119 | if (TREE_CODE (rhs0) == SSA_NAME) | |
1120 | res = follow_ssa_edge (loop, SSA_NAME_DEF_STMT (rhs0), | |
1121 | halting_phi, evolution_of_loop, limit); | |
1122 | else | |
1123 | res = t_false; | |
1124 | break; | |
0bca51f0 | 1125 | |
9baba81b | 1126 | default: |
c59dabbe | 1127 | res = t_false; |
9baba81b SP |
1128 | break; |
1129 | } | |
5aefc6a0 | 1130 | |
9baba81b SP |
1131 | return res; |
1132 | } | |
1133 | ||
726a989a RB |
1134 | /* Follow the ssa edge into the right hand side of an assignment STMT. |
1135 | Return true if the strongly connected component has been found. */ | |
1136 | ||
1137 | static t_bool | |
1138 | follow_ssa_edge_in_rhs (struct loop *loop, gimple stmt, | |
1139 | gimple halting_phi, tree *evolution_of_loop, int limit) | |
1140 | { | |
726a989a | 1141 | enum tree_code code = gimple_assign_rhs_code (stmt); |
5aefc6a0 EB |
1142 | tree type = gimple_expr_type (stmt), rhs1, rhs2; |
1143 | t_bool res; | |
726a989a | 1144 | |
5aefc6a0 | 1145 | switch (code) |
726a989a | 1146 | { |
5aefc6a0 EB |
1147 | CASE_CONVERT: |
1148 | /* This assignment is under the form "a_1 = (cast) rhs. */ | |
1149 | res = follow_ssa_edge_expr (loop, stmt, gimple_assign_rhs1 (stmt), | |
1150 | halting_phi, evolution_of_loop, limit); | |
1151 | *evolution_of_loop = chrec_convert (type, *evolution_of_loop, stmt); | |
1152 | break; | |
1153 | ||
1154 | case POINTER_PLUS_EXPR: | |
1155 | case PLUS_EXPR: | |
1156 | case MINUS_EXPR: | |
1157 | rhs1 = gimple_assign_rhs1 (stmt); | |
1158 | rhs2 = gimple_assign_rhs2 (stmt); | |
1159 | type = TREE_TYPE (rhs1); | |
1160 | res = follow_ssa_edge_binary (loop, stmt, type, rhs1, code, rhs2, | |
218d1c24 | 1161 | halting_phi, evolution_of_loop, limit); |
5aefc6a0 | 1162 | break; |
218d1c24 | 1163 | |
726a989a | 1164 | default: |
5aefc6a0 EB |
1165 | if (get_gimple_rhs_class (code) == GIMPLE_SINGLE_RHS) |
1166 | res = follow_ssa_edge_expr (loop, stmt, gimple_assign_rhs1 (stmt), | |
1167 | halting_phi, evolution_of_loop, limit); | |
1168 | else | |
1169 | res = t_false; | |
1170 | break; | |
726a989a | 1171 | } |
5aefc6a0 EB |
1172 | |
1173 | return res; | |
726a989a RB |
1174 | } |
1175 | ||
9baba81b SP |
1176 | /* Checks whether the I-th argument of a PHI comes from a backedge. */ |
1177 | ||
1178 | static bool | |
726a989a | 1179 | backedge_phi_arg_p (gimple phi, int i) |
9baba81b | 1180 | { |
726a989a | 1181 | const_edge e = gimple_phi_arg_edge (phi, i); |
9baba81b SP |
1182 | |
1183 | /* We would in fact like to test EDGE_DFS_BACK here, but we do not care | |
1184 | about updating it anywhere, and this should work as well most of the | |
1185 | time. */ | |
1186 | if (e->flags & EDGE_IRREDUCIBLE_LOOP) | |
1187 | return true; | |
1188 | ||
1189 | return false; | |
1190 | } | |
1191 | ||
1192 | /* Helper function for one branch of the condition-phi-node. Return | |
1193 | true if the strongly connected component has been found following | |
1194 | this path. */ | |
1195 | ||
c59dabbe | 1196 | static inline t_bool |
9baba81b | 1197 | follow_ssa_edge_in_condition_phi_branch (int i, |
b8698a0f L |
1198 | struct loop *loop, |
1199 | gimple condition_phi, | |
726a989a | 1200 | gimple halting_phi, |
9baba81b | 1201 | tree *evolution_of_branch, |
c59dabbe | 1202 | tree init_cond, int limit) |
9baba81b SP |
1203 | { |
1204 | tree branch = PHI_ARG_DEF (condition_phi, i); | |
1205 | *evolution_of_branch = chrec_dont_know; | |
1206 | ||
1207 | /* Do not follow back edges (they must belong to an irreducible loop, which | |
1208 | we really do not want to worry about). */ | |
1209 | if (backedge_phi_arg_p (condition_phi, i)) | |
c59dabbe | 1210 | return t_false; |
9baba81b SP |
1211 | |
1212 | if (TREE_CODE (branch) == SSA_NAME) | |
1213 | { | |
1214 | *evolution_of_branch = init_cond; | |
b8698a0f | 1215 | return follow_ssa_edge (loop, SSA_NAME_DEF_STMT (branch), halting_phi, |
c59dabbe | 1216 | evolution_of_branch, limit); |
9baba81b SP |
1217 | } |
1218 | ||
b8698a0f | 1219 | /* This case occurs when one of the condition branches sets |
89dbed81 | 1220 | the variable to a constant: i.e. a phi-node like |
b8698a0f L |
1221 | "a_2 = PHI <a_7(5), 2(6)>;". |
1222 | ||
1223 | FIXME: This case have to be refined correctly: | |
9baba81b SP |
1224 | in some cases it is possible to say something better than |
1225 | chrec_dont_know, for example using a wrap-around notation. */ | |
c59dabbe | 1226 | return t_false; |
9baba81b SP |
1227 | } |
1228 | ||
1229 | /* This function merges the branches of a condition-phi-node in a | |
1230 | loop. */ | |
1231 | ||
c59dabbe | 1232 | static t_bool |
9baba81b | 1233 | follow_ssa_edge_in_condition_phi (struct loop *loop, |
b8698a0f L |
1234 | gimple condition_phi, |
1235 | gimple halting_phi, | |
c59dabbe | 1236 | tree *evolution_of_loop, int limit) |
9baba81b | 1237 | { |
726a989a | 1238 | int i, n; |
9baba81b SP |
1239 | tree init = *evolution_of_loop; |
1240 | tree evolution_of_branch; | |
c59dabbe SP |
1241 | t_bool res = follow_ssa_edge_in_condition_phi_branch (0, loop, condition_phi, |
1242 | halting_phi, | |
1243 | &evolution_of_branch, | |
1244 | init, limit); | |
1245 | if (res == t_false || res == t_dont_know) | |
1246 | return res; | |
9baba81b | 1247 | |
9baba81b SP |
1248 | *evolution_of_loop = evolution_of_branch; |
1249 | ||
726a989a | 1250 | n = gimple_phi_num_args (condition_phi); |
726a989a | 1251 | for (i = 1; i < n; i++) |
9baba81b | 1252 | { |
e0afb98a SP |
1253 | /* Quickly give up when the evolution of one of the branches is |
1254 | not known. */ | |
1255 | if (*evolution_of_loop == chrec_dont_know) | |
c59dabbe | 1256 | return t_true; |
e0afb98a | 1257 | |
788d3075 RG |
1258 | /* Increase the limit by the PHI argument number to avoid exponential |
1259 | time and memory complexity. */ | |
c59dabbe SP |
1260 | res = follow_ssa_edge_in_condition_phi_branch (i, loop, condition_phi, |
1261 | halting_phi, | |
1262 | &evolution_of_branch, | |
788d3075 | 1263 | init, limit + i); |
c59dabbe SP |
1264 | if (res == t_false || res == t_dont_know) |
1265 | return res; | |
9baba81b SP |
1266 | |
1267 | *evolution_of_loop = chrec_merge (*evolution_of_loop, | |
1268 | evolution_of_branch); | |
1269 | } | |
b8698a0f | 1270 | |
c59dabbe | 1271 | return t_true; |
9baba81b SP |
1272 | } |
1273 | ||
1274 | /* Follow an SSA edge in an inner loop. It computes the overall | |
1275 | effect of the loop, and following the symbolic initial conditions, | |
1276 | it follows the edges in the parent loop. The inner loop is | |
1277 | considered as a single statement. */ | |
1278 | ||
c59dabbe | 1279 | static t_bool |
9baba81b | 1280 | follow_ssa_edge_inner_loop_phi (struct loop *outer_loop, |
b8698a0f | 1281 | gimple loop_phi_node, |
726a989a | 1282 | gimple halting_phi, |
c59dabbe | 1283 | tree *evolution_of_loop, int limit) |
9baba81b SP |
1284 | { |
1285 | struct loop *loop = loop_containing_stmt (loop_phi_node); | |
1286 | tree ev = analyze_scalar_evolution (loop, PHI_RESULT (loop_phi_node)); | |
1287 | ||
1288 | /* Sometimes, the inner loop is too difficult to analyze, and the | |
1289 | result of the analysis is a symbolic parameter. */ | |
1290 | if (ev == PHI_RESULT (loop_phi_node)) | |
1291 | { | |
c59dabbe | 1292 | t_bool res = t_false; |
726a989a | 1293 | int i, n = gimple_phi_num_args (loop_phi_node); |
9baba81b | 1294 | |
726a989a | 1295 | for (i = 0; i < n; i++) |
9baba81b SP |
1296 | { |
1297 | tree arg = PHI_ARG_DEF (loop_phi_node, i); | |
1298 | basic_block bb; | |
1299 | ||
1300 | /* Follow the edges that exit the inner loop. */ | |
726a989a | 1301 | bb = gimple_phi_arg_edge (loop_phi_node, i)->src; |
9baba81b | 1302 | if (!flow_bb_inside_loop_p (loop, bb)) |
726a989a RB |
1303 | res = follow_ssa_edge_expr (outer_loop, loop_phi_node, |
1304 | arg, halting_phi, | |
1305 | evolution_of_loop, limit); | |
c59dabbe SP |
1306 | if (res == t_true) |
1307 | break; | |
9baba81b SP |
1308 | } |
1309 | ||
1310 | /* If the path crosses this loop-phi, give up. */ | |
c59dabbe | 1311 | if (res == t_true) |
9baba81b SP |
1312 | *evolution_of_loop = chrec_dont_know; |
1313 | ||
1314 | return res; | |
1315 | } | |
1316 | ||
1317 | /* Otherwise, compute the overall effect of the inner loop. */ | |
1318 | ev = compute_overall_effect_of_inner_loop (loop, ev); | |
726a989a RB |
1319 | return follow_ssa_edge_expr (outer_loop, loop_phi_node, ev, halting_phi, |
1320 | evolution_of_loop, limit); | |
9baba81b SP |
1321 | } |
1322 | ||
1323 | /* Follow an SSA edge from a loop-phi-node to itself, constructing a | |
1324 | path that is analyzed on the return walk. */ | |
1325 | ||
c59dabbe | 1326 | static t_bool |
726a989a | 1327 | follow_ssa_edge (struct loop *loop, gimple def, gimple halting_phi, |
c59dabbe | 1328 | tree *evolution_of_loop, int limit) |
9baba81b SP |
1329 | { |
1330 | struct loop *def_loop; | |
b8698a0f | 1331 | |
726a989a | 1332 | if (gimple_nop_p (def)) |
c59dabbe | 1333 | return t_false; |
b8698a0f | 1334 | |
c59dabbe | 1335 | /* Give up if the path is longer than the MAX that we allow. */ |
14dd9aab | 1336 | if (limit > PARAM_VALUE (PARAM_SCEV_MAX_EXPR_COMPLEXITY)) |
c59dabbe | 1337 | return t_dont_know; |
b8698a0f | 1338 | |
9baba81b | 1339 | def_loop = loop_containing_stmt (def); |
b8698a0f | 1340 | |
726a989a | 1341 | switch (gimple_code (def)) |
9baba81b | 1342 | { |
726a989a | 1343 | case GIMPLE_PHI: |
9baba81b SP |
1344 | if (!loop_phi_node_p (def)) |
1345 | /* DEF is a condition-phi-node. Follow the branches, and | |
1346 | record their evolutions. Finally, merge the collected | |
1347 | information and set the approximation to the main | |
1348 | variable. */ | |
b8698a0f | 1349 | return follow_ssa_edge_in_condition_phi |
c59dabbe | 1350 | (loop, def, halting_phi, evolution_of_loop, limit); |
9baba81b SP |
1351 | |
1352 | /* When the analyzed phi is the halting_phi, the | |
1353 | depth-first search is over: we have found a path from | |
1354 | the halting_phi to itself in the loop. */ | |
1355 | if (def == halting_phi) | |
c59dabbe | 1356 | return t_true; |
b8698a0f | 1357 | |
9baba81b | 1358 | /* Otherwise, the evolution of the HALTING_PHI depends |
89dbed81 | 1359 | on the evolution of another loop-phi-node, i.e. the |
9baba81b SP |
1360 | evolution function is a higher degree polynomial. */ |
1361 | if (def_loop == loop) | |
c59dabbe | 1362 | return t_false; |
b8698a0f | 1363 | |
9baba81b SP |
1364 | /* Inner loop. */ |
1365 | if (flow_loop_nested_p (loop, def_loop)) | |
b8698a0f | 1366 | return follow_ssa_edge_inner_loop_phi |
9e824336 | 1367 | (loop, def, halting_phi, evolution_of_loop, limit + 1); |
9baba81b SP |
1368 | |
1369 | /* Outer loop. */ | |
c59dabbe | 1370 | return t_false; |
9baba81b | 1371 | |
726a989a | 1372 | case GIMPLE_ASSIGN: |
b8698a0f | 1373 | return follow_ssa_edge_in_rhs (loop, def, halting_phi, |
c59dabbe | 1374 | evolution_of_loop, limit); |
b8698a0f | 1375 | |
9baba81b SP |
1376 | default: |
1377 | /* At this level of abstraction, the program is just a set | |
726a989a | 1378 | of GIMPLE_ASSIGNs and PHI_NODEs. In principle there is no |
9baba81b | 1379 | other node to be handled. */ |
c59dabbe | 1380 | return t_false; |
9baba81b SP |
1381 | } |
1382 | } | |
1383 | ||
1384 | \f | |
b83b5507 BC |
1385 | /* Simplify PEELED_CHREC represented by (init_cond, arg) in LOOP. |
1386 | Handle below case and return the corresponding POLYNOMIAL_CHREC: | |
1387 | ||
1388 | # i_17 = PHI <i_13(5), 0(3)> | |
1389 | # _20 = PHI <_5(5), start_4(D)(3)> | |
1390 | ... | |
1391 | i_13 = i_17 + 1; | |
1392 | _5 = start_4(D) + i_13; | |
1393 | ||
1394 | Though variable _20 appears as a PEELED_CHREC in the form of | |
1395 | (start_4, _5)_LOOP, it's a POLYNOMIAL_CHREC like {start_4, 1}_LOOP. | |
1396 | ||
1397 | See PR41488. */ | |
1398 | ||
1399 | static tree | |
1400 | simplify_peeled_chrec (struct loop *loop, tree arg, tree init_cond) | |
1401 | { | |
1402 | aff_tree aff1, aff2; | |
1403 | tree ev, left, right, type, step_val; | |
1404 | pointer_map_t *peeled_chrec_map = NULL; | |
1405 | ||
1406 | ev = instantiate_parameters (loop, analyze_scalar_evolution (loop, arg)); | |
1407 | if (ev == NULL_TREE || TREE_CODE (ev) != POLYNOMIAL_CHREC) | |
1408 | return chrec_dont_know; | |
1409 | ||
1410 | left = CHREC_LEFT (ev); | |
1411 | right = CHREC_RIGHT (ev); | |
1412 | type = TREE_TYPE (left); | |
1413 | step_val = chrec_fold_plus (type, init_cond, right); | |
1414 | ||
1415 | /* Transform (init, {left, right}_LOOP)_LOOP to {init, right}_LOOP | |
1416 | if "left" equals to "init + right". */ | |
1417 | if (operand_equal_p (left, step_val, 0)) | |
1418 | { | |
1419 | if (dump_file && (dump_flags & TDF_SCEV)) | |
1420 | fprintf (dump_file, "Simplify PEELED_CHREC into POLYNOMIAL_CHREC.\n"); | |
1421 | ||
1422 | return build_polynomial_chrec (loop->num, init_cond, right); | |
1423 | } | |
1424 | ||
1425 | /* Try harder to check if they are equal. */ | |
1426 | tree_to_aff_combination_expand (left, type, &aff1, &peeled_chrec_map); | |
1427 | tree_to_aff_combination_expand (step_val, type, &aff2, &peeled_chrec_map); | |
1428 | free_affine_expand_cache (&peeled_chrec_map); | |
1429 | aff_combination_scale (&aff2, double_int_minus_one); | |
1430 | aff_combination_add (&aff1, &aff2); | |
1431 | ||
1432 | /* Transform (init, {left, right}_LOOP)_LOOP to {init, right}_LOOP | |
1433 | if "left" equals to "init + right". */ | |
1434 | if (aff_combination_zero_p (&aff1)) | |
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 | return chrec_dont_know; | |
1442 | } | |
9baba81b SP |
1443 | |
1444 | /* Given a LOOP_PHI_NODE, this function determines the evolution | |
1445 | function from LOOP_PHI_NODE to LOOP_PHI_NODE in the loop. */ | |
1446 | ||
1447 | static tree | |
b8698a0f | 1448 | analyze_evolution_in_loop (gimple loop_phi_node, |
9baba81b SP |
1449 | tree init_cond) |
1450 | { | |
726a989a | 1451 | int i, n = gimple_phi_num_args (loop_phi_node); |
9baba81b SP |
1452 | tree evolution_function = chrec_not_analyzed_yet; |
1453 | struct loop *loop = loop_containing_stmt (loop_phi_node); | |
1454 | basic_block bb; | |
b83b5507 | 1455 | static bool simplify_peeled_chrec_p = true; |
b8698a0f | 1456 | |
dfedbe40 | 1457 | if (dump_file && (dump_flags & TDF_SCEV)) |
9baba81b SP |
1458 | { |
1459 | fprintf (dump_file, "(analyze_evolution_in_loop \n"); | |
1460 | fprintf (dump_file, " (loop_phi_node = "); | |
726a989a | 1461 | print_gimple_stmt (dump_file, loop_phi_node, 0, 0); |
9baba81b SP |
1462 | fprintf (dump_file, ")\n"); |
1463 | } | |
b8698a0f | 1464 | |
726a989a | 1465 | for (i = 0; i < n; i++) |
9baba81b SP |
1466 | { |
1467 | tree arg = PHI_ARG_DEF (loop_phi_node, i); | |
726a989a RB |
1468 | gimple ssa_chain; |
1469 | tree ev_fn; | |
874caa00 | 1470 | t_bool res; |
9baba81b SP |
1471 | |
1472 | /* Select the edges that enter the loop body. */ | |
726a989a | 1473 | bb = gimple_phi_arg_edge (loop_phi_node, i)->src; |
9baba81b SP |
1474 | if (!flow_bb_inside_loop_p (loop, bb)) |
1475 | continue; | |
f29deac9 | 1476 | |
9baba81b SP |
1477 | if (TREE_CODE (arg) == SSA_NAME) |
1478 | { | |
f29deac9 SP |
1479 | bool val = false; |
1480 | ||
9baba81b SP |
1481 | ssa_chain = SSA_NAME_DEF_STMT (arg); |
1482 | ||
1483 | /* Pass in the initial condition to the follow edge function. */ | |
1484 | ev_fn = init_cond; | |
c59dabbe | 1485 | res = follow_ssa_edge (loop, ssa_chain, loop_phi_node, &ev_fn, 0); |
f29deac9 SP |
1486 | |
1487 | /* If ev_fn has no evolution in the inner loop, and the | |
1488 | init_cond is not equal to ev_fn, then we have an | |
1489 | ambiguity between two possible values, as we cannot know | |
1490 | the number of iterations at this point. */ | |
1491 | if (TREE_CODE (ev_fn) != POLYNOMIAL_CHREC | |
1492 | && no_evolution_in_loop_p (ev_fn, loop->num, &val) && val | |
1493 | && !operand_equal_p (init_cond, ev_fn, 0)) | |
1494 | ev_fn = chrec_dont_know; | |
9baba81b SP |
1495 | } |
1496 | else | |
874caa00 | 1497 | res = t_false; |
f29deac9 | 1498 | |
9baba81b SP |
1499 | /* When it is impossible to go back on the same |
1500 | loop_phi_node by following the ssa edges, the | |
89dbed81 | 1501 | evolution is represented by a peeled chrec, i.e. the |
9baba81b | 1502 | first iteration, EV_FN has the value INIT_COND, then |
b8698a0f | 1503 | all the other iterations it has the value of ARG. |
9baba81b | 1504 | For the moment, PEELED_CHREC nodes are not built. */ |
874caa00 | 1505 | if (res != t_true) |
b83b5507 BC |
1506 | { |
1507 | ev_fn = chrec_dont_know; | |
1508 | /* Try to recognize POLYNOMIAL_CHREC which appears in | |
1509 | the form of PEELED_CHREC, but guard the process with | |
1510 | a bool variable to keep the analyzer from infinite | |
1511 | recurrence for real PEELED_RECs. */ | |
1512 | if (simplify_peeled_chrec_p && TREE_CODE (arg) == SSA_NAME) | |
1513 | { | |
1514 | simplify_peeled_chrec_p = false; | |
1515 | ev_fn = simplify_peeled_chrec (loop, arg, init_cond); | |
1516 | simplify_peeled_chrec_p = true; | |
1517 | } | |
1518 | } | |
b8698a0f | 1519 | |
9baba81b | 1520 | /* When there are multiple back edges of the loop (which in fact never |
8c27b7d4 | 1521 | happens currently, but nevertheless), merge their evolutions. */ |
9baba81b SP |
1522 | evolution_function = chrec_merge (evolution_function, ev_fn); |
1523 | } | |
b8698a0f | 1524 | |
dfedbe40 | 1525 | if (dump_file && (dump_flags & TDF_SCEV)) |
9baba81b SP |
1526 | { |
1527 | fprintf (dump_file, " (evolution_function = "); | |
1528 | print_generic_expr (dump_file, evolution_function, 0); | |
1529 | fprintf (dump_file, "))\n"); | |
1530 | } | |
b8698a0f | 1531 | |
9baba81b SP |
1532 | return evolution_function; |
1533 | } | |
1534 | ||
1535 | /* Given a loop-phi-node, return the initial conditions of the | |
1536 | variable on entry of the loop. When the CCP has propagated | |
1537 | constants into the loop-phi-node, the initial condition is | |
1538 | instantiated, otherwise the initial condition is kept symbolic. | |
1539 | This analyzer does not analyze the evolution outside the current | |
1540 | loop, and leaves this task to the on-demand tree reconstructor. */ | |
1541 | ||
b8698a0f | 1542 | static tree |
726a989a | 1543 | analyze_initial_condition (gimple loop_phi_node) |
9baba81b | 1544 | { |
726a989a | 1545 | int i, n; |
9baba81b | 1546 | tree init_cond = chrec_not_analyzed_yet; |
726a989a | 1547 | struct loop *loop = loop_containing_stmt (loop_phi_node); |
b8698a0f | 1548 | |
dfedbe40 | 1549 | if (dump_file && (dump_flags & TDF_SCEV)) |
9baba81b SP |
1550 | { |
1551 | fprintf (dump_file, "(analyze_initial_condition \n"); | |
1552 | fprintf (dump_file, " (loop_phi_node = \n"); | |
726a989a | 1553 | print_gimple_stmt (dump_file, loop_phi_node, 0, 0); |
9baba81b SP |
1554 | fprintf (dump_file, ")\n"); |
1555 | } | |
b8698a0f | 1556 | |
726a989a RB |
1557 | n = gimple_phi_num_args (loop_phi_node); |
1558 | for (i = 0; i < n; i++) | |
9baba81b SP |
1559 | { |
1560 | tree branch = PHI_ARG_DEF (loop_phi_node, i); | |
726a989a | 1561 | basic_block bb = gimple_phi_arg_edge (loop_phi_node, i)->src; |
b8698a0f | 1562 | |
9baba81b SP |
1563 | /* When the branch is oriented to the loop's body, it does |
1564 | not contribute to the initial condition. */ | |
1565 | if (flow_bb_inside_loop_p (loop, bb)) | |
1566 | continue; | |
1567 | ||
1568 | if (init_cond == chrec_not_analyzed_yet) | |
1569 | { | |
1570 | init_cond = branch; | |
1571 | continue; | |
1572 | } | |
1573 | ||
1574 | if (TREE_CODE (branch) == SSA_NAME) | |
1575 | { | |
1576 | init_cond = chrec_dont_know; | |
1577 | break; | |
1578 | } | |
1579 | ||
1580 | init_cond = chrec_merge (init_cond, branch); | |
1581 | } | |
1582 | ||
1583 | /* Ooops -- a loop without an entry??? */ | |
1584 | if (init_cond == chrec_not_analyzed_yet) | |
1585 | init_cond = chrec_dont_know; | |
1586 | ||
bf1cbdc6 RG |
1587 | /* During early loop unrolling we do not have fully constant propagated IL. |
1588 | Handle degenerate PHIs here to not miss important unrollings. */ | |
1589 | if (TREE_CODE (init_cond) == SSA_NAME) | |
1590 | { | |
1591 | gimple def = SSA_NAME_DEF_STMT (init_cond); | |
1592 | tree res; | |
1593 | if (gimple_code (def) == GIMPLE_PHI | |
1594 | && (res = degenerate_phi_result (def)) != NULL_TREE | |
1595 | /* Only allow invariants here, otherwise we may break | |
1596 | loop-closed SSA form. */ | |
1597 | && is_gimple_min_invariant (res)) | |
1598 | init_cond = res; | |
1599 | } | |
1600 | ||
dfedbe40 | 1601 | if (dump_file && (dump_flags & TDF_SCEV)) |
9baba81b SP |
1602 | { |
1603 | fprintf (dump_file, " (init_cond = "); | |
1604 | print_generic_expr (dump_file, init_cond, 0); | |
1605 | fprintf (dump_file, "))\n"); | |
1606 | } | |
b8698a0f | 1607 | |
9baba81b SP |
1608 | return init_cond; |
1609 | } | |
1610 | ||
1611 | /* Analyze the scalar evolution for LOOP_PHI_NODE. */ | |
1612 | ||
b8698a0f | 1613 | static tree |
726a989a | 1614 | interpret_loop_phi (struct loop *loop, gimple loop_phi_node) |
9baba81b SP |
1615 | { |
1616 | tree res; | |
1617 | struct loop *phi_loop = loop_containing_stmt (loop_phi_node); | |
1618 | tree init_cond; | |
b8698a0f | 1619 | |
9baba81b SP |
1620 | if (phi_loop != loop) |
1621 | { | |
1622 | struct loop *subloop; | |
1623 | tree evolution_fn = analyze_scalar_evolution | |
1624 | (phi_loop, PHI_RESULT (loop_phi_node)); | |
1625 | ||
1626 | /* Dive one level deeper. */ | |
9ba025a2 | 1627 | subloop = superloop_at_depth (phi_loop, loop_depth (loop) + 1); |
9baba81b SP |
1628 | |
1629 | /* Interpret the subloop. */ | |
1630 | res = compute_overall_effect_of_inner_loop (subloop, evolution_fn); | |
1631 | return res; | |
1632 | } | |
1633 | ||
1634 | /* Otherwise really interpret the loop phi. */ | |
1635 | init_cond = analyze_initial_condition (loop_phi_node); | |
1636 | res = analyze_evolution_in_loop (loop_phi_node, init_cond); | |
1637 | ||
73c865fa RG |
1638 | /* Verify we maintained the correct initial condition throughout |
1639 | possible conversions in the SSA chain. */ | |
1640 | if (res != chrec_dont_know) | |
1641 | { | |
1642 | tree new_init = res; | |
1643 | if (CONVERT_EXPR_P (res) | |
1644 | && TREE_CODE (TREE_OPERAND (res, 0)) == POLYNOMIAL_CHREC) | |
1645 | new_init = fold_convert (TREE_TYPE (res), | |
1646 | CHREC_LEFT (TREE_OPERAND (res, 0))); | |
1647 | else if (TREE_CODE (res) == POLYNOMIAL_CHREC) | |
1648 | new_init = CHREC_LEFT (res); | |
1649 | STRIP_USELESS_TYPE_CONVERSION (new_init); | |
eb723fa3 RG |
1650 | if (TREE_CODE (new_init) == POLYNOMIAL_CHREC |
1651 | || !operand_equal_p (init_cond, new_init, 0)) | |
73c865fa RG |
1652 | return chrec_dont_know; |
1653 | } | |
1654 | ||
9baba81b SP |
1655 | return res; |
1656 | } | |
1657 | ||
1658 | /* This function merges the branches of a condition-phi-node, | |
1659 | contained in the outermost loop, and whose arguments are already | |
1660 | analyzed. */ | |
1661 | ||
1662 | static tree | |
726a989a | 1663 | interpret_condition_phi (struct loop *loop, gimple condition_phi) |
9baba81b | 1664 | { |
726a989a | 1665 | int i, n = gimple_phi_num_args (condition_phi); |
9baba81b | 1666 | tree res = chrec_not_analyzed_yet; |
b8698a0f | 1667 | |
726a989a | 1668 | for (i = 0; i < n; i++) |
9baba81b SP |
1669 | { |
1670 | tree branch_chrec; | |
b8698a0f | 1671 | |
9baba81b SP |
1672 | if (backedge_phi_arg_p (condition_phi, i)) |
1673 | { | |
1674 | res = chrec_dont_know; | |
1675 | break; | |
1676 | } | |
1677 | ||
1678 | branch_chrec = analyze_scalar_evolution | |
1679 | (loop, PHI_ARG_DEF (condition_phi, i)); | |
b8698a0f | 1680 | |
9baba81b SP |
1681 | res = chrec_merge (res, branch_chrec); |
1682 | } | |
1683 | ||
1684 | return res; | |
1685 | } | |
1686 | ||
726a989a | 1687 | /* Interpret the operation RHS1 OP RHS2. If we didn't |
29836d07 | 1688 | analyze this node before, follow the definitions until ending |
726a989a | 1689 | either on an analyzed GIMPLE_ASSIGN, or on a loop-phi-node. On the |
9baba81b SP |
1690 | return path, this function propagates evolutions (ala constant copy |
1691 | propagation). OPND1 is not a GIMPLE expression because we could | |
1692 | analyze the effect of an inner loop: see interpret_loop_phi. */ | |
1693 | ||
1694 | static tree | |
726a989a RB |
1695 | interpret_rhs_expr (struct loop *loop, gimple at_stmt, |
1696 | tree type, tree rhs1, enum tree_code code, tree rhs2) | |
9baba81b | 1697 | { |
726a989a | 1698 | tree res, chrec1, chrec2; |
195b4c50 | 1699 | gimple def; |
726a989a RB |
1700 | |
1701 | if (get_gimple_rhs_class (code) == GIMPLE_SINGLE_RHS) | |
1702 | { | |
1703 | if (is_gimple_min_invariant (rhs1)) | |
1704 | return chrec_convert (type, rhs1, at_stmt); | |
1705 | ||
1706 | if (code == SSA_NAME) | |
1707 | return chrec_convert (type, analyze_scalar_evolution (loop, rhs1), | |
1708 | at_stmt); | |
1e8552eb | 1709 | |
726a989a RB |
1710 | if (code == ASSERT_EXPR) |
1711 | { | |
1712 | rhs1 = ASSERT_EXPR_VAR (rhs1); | |
1713 | return chrec_convert (type, analyze_scalar_evolution (loop, rhs1), | |
1714 | at_stmt); | |
1715 | } | |
726a989a | 1716 | } |
1e8552eb | 1717 | |
726a989a | 1718 | switch (code) |
9baba81b | 1719 | { |
6a02a719 | 1720 | case ADDR_EXPR: |
bef28ced JL |
1721 | if (TREE_CODE (TREE_OPERAND (rhs1, 0)) == MEM_REF |
1722 | || handled_component_p (TREE_OPERAND (rhs1, 0))) | |
1723 | { | |
1724 | enum machine_mode mode; | |
1725 | HOST_WIDE_INT bitsize, bitpos; | |
1726 | int unsignedp; | |
1727 | int volatilep = 0; | |
1728 | tree base, offset; | |
1729 | tree chrec3; | |
1730 | tree unitpos; | |
1731 | ||
1732 | base = get_inner_reference (TREE_OPERAND (rhs1, 0), | |
1733 | &bitsize, &bitpos, &offset, | |
b3ecff82 | 1734 | &mode, &unsignedp, &volatilep, false); |
bef28ced JL |
1735 | |
1736 | if (TREE_CODE (base) == MEM_REF) | |
1737 | { | |
1738 | rhs2 = TREE_OPERAND (base, 1); | |
1739 | rhs1 = TREE_OPERAND (base, 0); | |
1740 | ||
1741 | chrec1 = analyze_scalar_evolution (loop, rhs1); | |
1742 | chrec2 = analyze_scalar_evolution (loop, rhs2); | |
1743 | chrec1 = chrec_convert (type, chrec1, at_stmt); | |
1744 | chrec2 = chrec_convert (TREE_TYPE (rhs2), chrec2, at_stmt); | |
0547c9b6 RB |
1745 | chrec1 = instantiate_parameters (loop, chrec1); |
1746 | chrec2 = instantiate_parameters (loop, chrec2); | |
bef28ced JL |
1747 | res = chrec_fold_plus (type, chrec1, chrec2); |
1748 | } | |
1749 | else | |
1750 | { | |
1751 | chrec1 = analyze_scalar_evolution_for_address_of (loop, base); | |
1752 | chrec1 = chrec_convert (type, chrec1, at_stmt); | |
1753 | res = chrec1; | |
1754 | } | |
6a02a719 | 1755 | |
bef28ced JL |
1756 | if (offset != NULL_TREE) |
1757 | { | |
1758 | chrec2 = analyze_scalar_evolution (loop, offset); | |
1759 | chrec2 = chrec_convert (TREE_TYPE (offset), chrec2, at_stmt); | |
0547c9b6 | 1760 | chrec2 = instantiate_parameters (loop, chrec2); |
bef28ced JL |
1761 | res = chrec_fold_plus (type, res, chrec2); |
1762 | } | |
1763 | ||
1764 | if (bitpos != 0) | |
1765 | { | |
1766 | gcc_assert ((bitpos % BITS_PER_UNIT) == 0); | |
1767 | ||
18dae016 | 1768 | unitpos = size_int (bitpos / BITS_PER_UNIT); |
bef28ced JL |
1769 | chrec3 = analyze_scalar_evolution (loop, unitpos); |
1770 | chrec3 = chrec_convert (TREE_TYPE (unitpos), chrec3, at_stmt); | |
0547c9b6 | 1771 | chrec3 = instantiate_parameters (loop, chrec3); |
bef28ced JL |
1772 | res = chrec_fold_plus (type, res, chrec3); |
1773 | } | |
1774 | } | |
1775 | else | |
1776 | res = chrec_dont_know; | |
1777 | break; | |
6a02a719 | 1778 | |
5be014d5 | 1779 | case POINTER_PLUS_EXPR: |
726a989a RB |
1780 | chrec1 = analyze_scalar_evolution (loop, rhs1); |
1781 | chrec2 = analyze_scalar_evolution (loop, rhs2); | |
1782 | chrec1 = chrec_convert (type, chrec1, at_stmt); | |
0d82a1c8 | 1783 | chrec2 = chrec_convert (TREE_TYPE (rhs2), chrec2, at_stmt); |
0547c9b6 RB |
1784 | chrec1 = instantiate_parameters (loop, chrec1); |
1785 | chrec2 = instantiate_parameters (loop, chrec2); | |
726a989a | 1786 | res = chrec_fold_plus (type, chrec1, chrec2); |
5be014d5 AP |
1787 | break; |
1788 | ||
9baba81b | 1789 | case PLUS_EXPR: |
726a989a RB |
1790 | chrec1 = analyze_scalar_evolution (loop, rhs1); |
1791 | chrec2 = analyze_scalar_evolution (loop, rhs2); | |
1792 | chrec1 = chrec_convert (type, chrec1, at_stmt); | |
1793 | chrec2 = chrec_convert (type, chrec2, at_stmt); | |
0547c9b6 RB |
1794 | chrec1 = instantiate_parameters (loop, chrec1); |
1795 | chrec2 = instantiate_parameters (loop, chrec2); | |
726a989a | 1796 | res = chrec_fold_plus (type, chrec1, chrec2); |
9baba81b | 1797 | break; |
b8698a0f | 1798 | |
9baba81b | 1799 | case MINUS_EXPR: |
726a989a RB |
1800 | chrec1 = analyze_scalar_evolution (loop, rhs1); |
1801 | chrec2 = analyze_scalar_evolution (loop, rhs2); | |
1802 | chrec1 = chrec_convert (type, chrec1, at_stmt); | |
1803 | chrec2 = chrec_convert (type, chrec2, at_stmt); | |
0547c9b6 RB |
1804 | chrec1 = instantiate_parameters (loop, chrec1); |
1805 | chrec2 = instantiate_parameters (loop, chrec2); | |
726a989a | 1806 | res = chrec_fold_minus (type, chrec1, chrec2); |
9baba81b SP |
1807 | break; |
1808 | ||
1809 | case NEGATE_EXPR: | |
726a989a RB |
1810 | chrec1 = analyze_scalar_evolution (loop, rhs1); |
1811 | chrec1 = chrec_convert (type, chrec1, at_stmt); | |
9a75ede0 | 1812 | /* TYPE may be integer, real or complex, so use fold_convert. */ |
0547c9b6 | 1813 | chrec1 = instantiate_parameters (loop, chrec1); |
726a989a | 1814 | res = chrec_fold_multiply (type, chrec1, |
9a75ede0 | 1815 | fold_convert (type, integer_minus_one_node)); |
9baba81b SP |
1816 | break; |
1817 | ||
418df9d7 JJ |
1818 | case BIT_NOT_EXPR: |
1819 | /* Handle ~X as -1 - X. */ | |
1820 | chrec1 = analyze_scalar_evolution (loop, rhs1); | |
1821 | chrec1 = chrec_convert (type, chrec1, at_stmt); | |
0547c9b6 | 1822 | chrec1 = instantiate_parameters (loop, chrec1); |
418df9d7 JJ |
1823 | res = chrec_fold_minus (type, |
1824 | fold_convert (type, integer_minus_one_node), | |
1825 | chrec1); | |
1826 | break; | |
1827 | ||
9baba81b | 1828 | case MULT_EXPR: |
726a989a RB |
1829 | chrec1 = analyze_scalar_evolution (loop, rhs1); |
1830 | chrec2 = analyze_scalar_evolution (loop, rhs2); | |
1831 | chrec1 = chrec_convert (type, chrec1, at_stmt); | |
1832 | chrec2 = chrec_convert (type, chrec2, at_stmt); | |
0547c9b6 RB |
1833 | chrec1 = instantiate_parameters (loop, chrec1); |
1834 | chrec2 = instantiate_parameters (loop, chrec2); | |
726a989a | 1835 | res = chrec_fold_multiply (type, chrec1, chrec2); |
0bca51f0 | 1836 | break; |
b8698a0f | 1837 | |
1043771b | 1838 | CASE_CONVERT: |
195b4c50 RG |
1839 | /* In case we have a truncation of a widened operation that in |
1840 | the truncated type has undefined overflow behavior analyze | |
1841 | the operation done in an unsigned type of the same precision | |
1842 | as the final truncation. We cannot derive a scalar evolution | |
1843 | for the widened operation but for the truncated result. */ | |
1844 | if (TREE_CODE (type) == INTEGER_TYPE | |
1845 | && TREE_CODE (TREE_TYPE (rhs1)) == INTEGER_TYPE | |
1846 | && TYPE_PRECISION (type) < TYPE_PRECISION (TREE_TYPE (rhs1)) | |
1847 | && TYPE_OVERFLOW_UNDEFINED (type) | |
1848 | && TREE_CODE (rhs1) == SSA_NAME | |
1849 | && (def = SSA_NAME_DEF_STMT (rhs1)) | |
1850 | && is_gimple_assign (def) | |
1851 | && TREE_CODE_CLASS (gimple_assign_rhs_code (def)) == tcc_binary | |
1852 | && TREE_CODE (gimple_assign_rhs2 (def)) == INTEGER_CST) | |
1853 | { | |
1854 | tree utype = unsigned_type_for (type); | |
1855 | chrec1 = interpret_rhs_expr (loop, at_stmt, utype, | |
1856 | gimple_assign_rhs1 (def), | |
1857 | gimple_assign_rhs_code (def), | |
1858 | gimple_assign_rhs2 (def)); | |
1859 | } | |
1860 | else | |
1861 | chrec1 = analyze_scalar_evolution (loop, rhs1); | |
726a989a | 1862 | res = chrec_convert (type, chrec1, at_stmt); |
9baba81b | 1863 | break; |
b8698a0f | 1864 | |
9baba81b SP |
1865 | default: |
1866 | res = chrec_dont_know; | |
1867 | break; | |
1868 | } | |
b8698a0f | 1869 | |
9baba81b SP |
1870 | return res; |
1871 | } | |
1872 | ||
726a989a RB |
1873 | /* Interpret the expression EXPR. */ |
1874 | ||
1875 | static tree | |
1876 | interpret_expr (struct loop *loop, gimple at_stmt, tree expr) | |
1877 | { | |
1878 | enum tree_code code; | |
1879 | tree type = TREE_TYPE (expr), op0, op1; | |
1880 | ||
1881 | if (automatically_generated_chrec_p (expr)) | |
1882 | return expr; | |
1883 | ||
4e71066d RG |
1884 | if (TREE_CODE (expr) == POLYNOMIAL_CHREC |
1885 | || get_gimple_rhs_class (TREE_CODE (expr)) == GIMPLE_TERNARY_RHS) | |
726a989a RB |
1886 | return chrec_dont_know; |
1887 | ||
1888 | extract_ops_from_tree (expr, &code, &op0, &op1); | |
1889 | ||
1890 | return interpret_rhs_expr (loop, at_stmt, type, | |
1891 | op0, code, op1); | |
1892 | } | |
1893 | ||
1894 | /* Interpret the rhs of the assignment STMT. */ | |
1895 | ||
1896 | static tree | |
1897 | interpret_gimple_assign (struct loop *loop, gimple stmt) | |
1898 | { | |
1899 | tree type = TREE_TYPE (gimple_assign_lhs (stmt)); | |
1900 | enum tree_code code = gimple_assign_rhs_code (stmt); | |
1901 | ||
1902 | return interpret_rhs_expr (loop, stmt, type, | |
1903 | gimple_assign_rhs1 (stmt), code, | |
1904 | gimple_assign_rhs2 (stmt)); | |
1905 | } | |
1906 | ||
9baba81b SP |
1907 | \f |
1908 | ||
b8698a0f | 1909 | /* This section contains all the entry points: |
9baba81b SP |
1910 | - number_of_iterations_in_loop, |
1911 | - analyze_scalar_evolution, | |
1912 | - instantiate_parameters. | |
1913 | */ | |
1914 | ||
1915 | /* Compute and return the evolution function in WRTO_LOOP, the nearest | |
1916 | common ancestor of DEF_LOOP and USE_LOOP. */ | |
1917 | ||
b8698a0f L |
1918 | static tree |
1919 | compute_scalar_evolution_in_loop (struct loop *wrto_loop, | |
1920 | struct loop *def_loop, | |
9baba81b SP |
1921 | tree ev) |
1922 | { | |
492e5456 | 1923 | bool val; |
9baba81b | 1924 | tree res; |
492e5456 | 1925 | |
9baba81b SP |
1926 | if (def_loop == wrto_loop) |
1927 | return ev; | |
1928 | ||
9ba025a2 | 1929 | def_loop = superloop_at_depth (def_loop, loop_depth (wrto_loop) + 1); |
9baba81b SP |
1930 | res = compute_overall_effect_of_inner_loop (def_loop, ev); |
1931 | ||
492e5456 SP |
1932 | if (no_evolution_in_loop_p (res, wrto_loop->num, &val) && val) |
1933 | return res; | |
1934 | ||
9baba81b SP |
1935 | return analyze_scalar_evolution_1 (wrto_loop, res, chrec_not_analyzed_yet); |
1936 | } | |
1937 | ||
1938 | /* Helper recursive function. */ | |
1939 | ||
1940 | static tree | |
1941 | analyze_scalar_evolution_1 (struct loop *loop, tree var, tree res) | |
1942 | { | |
726a989a RB |
1943 | tree type = TREE_TYPE (var); |
1944 | gimple def; | |
9baba81b SP |
1945 | basic_block bb; |
1946 | struct loop *def_loop; | |
1947 | ||
42d375ed | 1948 | if (loop == NULL || TREE_CODE (type) == VECTOR_TYPE) |
9baba81b SP |
1949 | return chrec_dont_know; |
1950 | ||
1951 | if (TREE_CODE (var) != SSA_NAME) | |
726a989a | 1952 | return interpret_expr (loop, NULL, var); |
9baba81b SP |
1953 | |
1954 | def = SSA_NAME_DEF_STMT (var); | |
726a989a | 1955 | bb = gimple_bb (def); |
9baba81b SP |
1956 | def_loop = bb ? bb->loop_father : NULL; |
1957 | ||
1958 | if (bb == NULL | |
1959 | || !flow_bb_inside_loop_p (loop, bb)) | |
1960 | { | |
1961 | /* Keep the symbolic form. */ | |
1962 | res = var; | |
1963 | goto set_and_end; | |
1964 | } | |
1965 | ||
1966 | if (res != chrec_not_analyzed_yet) | |
1967 | { | |
1968 | if (loop != bb->loop_father) | |
b8698a0f | 1969 | res = compute_scalar_evolution_in_loop |
9baba81b SP |
1970 | (find_common_loop (loop, bb->loop_father), bb->loop_father, res); |
1971 | ||
1972 | goto set_and_end; | |
1973 | } | |
1974 | ||
1975 | if (loop != def_loop) | |
1976 | { | |
1977 | res = analyze_scalar_evolution_1 (def_loop, var, chrec_not_analyzed_yet); | |
1978 | res = compute_scalar_evolution_in_loop (loop, def_loop, res); | |
1979 | ||
1980 | goto set_and_end; | |
1981 | } | |
1982 | ||
726a989a | 1983 | switch (gimple_code (def)) |
9baba81b | 1984 | { |
726a989a RB |
1985 | case GIMPLE_ASSIGN: |
1986 | res = interpret_gimple_assign (loop, def); | |
9baba81b SP |
1987 | break; |
1988 | ||
726a989a | 1989 | case GIMPLE_PHI: |
9baba81b SP |
1990 | if (loop_phi_node_p (def)) |
1991 | res = interpret_loop_phi (loop, def); | |
1992 | else | |
1993 | res = interpret_condition_phi (loop, def); | |
1994 | break; | |
1995 | ||
1996 | default: | |
1997 | res = chrec_dont_know; | |
1998 | break; | |
1999 | } | |
2000 | ||
2001 | set_and_end: | |
2002 | ||
2003 | /* Keep the symbolic form. */ | |
2004 | if (res == chrec_dont_know) | |
2005 | res = var; | |
2006 | ||
2007 | if (loop == def_loop) | |
a213b219 | 2008 | set_scalar_evolution (block_before_loop (loop), var, res); |
9baba81b SP |
2009 | |
2010 | return res; | |
2011 | } | |
2012 | ||
52bdd655 SP |
2013 | /* Analyzes and returns the scalar evolution of the ssa_name VAR in |
2014 | LOOP. LOOP is the loop in which the variable is used. | |
b8698a0f | 2015 | |
9baba81b SP |
2016 | Example of use: having a pointer VAR to a SSA_NAME node, STMT a |
2017 | pointer to the statement that uses this variable, in order to | |
2018 | determine the evolution function of the variable, use the following | |
2019 | calls: | |
b8698a0f | 2020 | |
52bdd655 SP |
2021 | loop_p loop = loop_containing_stmt (stmt); |
2022 | tree chrec_with_symbols = analyze_scalar_evolution (loop, var); | |
3f227a8c | 2023 | tree chrec_instantiated = instantiate_parameters (loop, chrec_with_symbols); |
9baba81b SP |
2024 | */ |
2025 | ||
b8698a0f | 2026 | tree |
9baba81b SP |
2027 | analyze_scalar_evolution (struct loop *loop, tree var) |
2028 | { | |
2029 | tree res; | |
2030 | ||
dfedbe40 | 2031 | if (dump_file && (dump_flags & TDF_SCEV)) |
9baba81b SP |
2032 | { |
2033 | fprintf (dump_file, "(analyze_scalar_evolution \n"); | |
2034 | fprintf (dump_file, " (loop_nb = %d)\n", loop->num); | |
2035 | fprintf (dump_file, " (scalar = "); | |
2036 | print_generic_expr (dump_file, var, 0); | |
2037 | fprintf (dump_file, ")\n"); | |
2038 | } | |
2039 | ||
a213b219 SP |
2040 | res = get_scalar_evolution (block_before_loop (loop), var); |
2041 | res = analyze_scalar_evolution_1 (loop, var, res); | |
9baba81b | 2042 | |
dfedbe40 | 2043 | if (dump_file && (dump_flags & TDF_SCEV)) |
9baba81b SP |
2044 | fprintf (dump_file, ")\n"); |
2045 | ||
2046 | return res; | |
2047 | } | |
2048 | ||
bef28ced JL |
2049 | /* Analyzes and returns the scalar evolution of VAR address in LOOP. */ |
2050 | ||
2051 | static tree | |
2052 | analyze_scalar_evolution_for_address_of (struct loop *loop, tree var) | |
2053 | { | |
2054 | return analyze_scalar_evolution (loop, build_fold_addr_expr (var)); | |
2055 | } | |
2056 | ||
9baba81b | 2057 | /* Analyze scalar evolution of use of VERSION in USE_LOOP with respect to |
f017bf5e | 2058 | WRTO_LOOP (which should be a superloop of USE_LOOP) |
a6f778b2 ZD |
2059 | |
2060 | FOLDED_CASTS is set to true if resolve_mixers used | |
2061 | chrec_convert_aggressive (TODO -- not really, we are way too conservative | |
b8698a0f L |
2062 | at the moment in order to keep things simple). |
2063 | ||
f017bf5e ZD |
2064 | To illustrate the meaning of USE_LOOP and WRTO_LOOP, consider the following |
2065 | example: | |
2066 | ||
2067 | for (i = 0; i < 100; i++) -- loop 1 | |
2068 | { | |
2069 | for (j = 0; j < 100; j++) -- loop 2 | |
2070 | { | |
2071 | k1 = i; | |
2072 | k2 = j; | |
2073 | ||
2074 | use2 (k1, k2); | |
2075 | ||
2076 | for (t = 0; t < 100; t++) -- loop 3 | |
2077 | use3 (k1, k2); | |
2078 | ||
2079 | } | |
2080 | use1 (k1, k2); | |
2081 | } | |
2082 | ||
2083 | Both k1 and k2 are invariants in loop3, thus | |
2084 | analyze_scalar_evolution_in_loop (loop3, loop3, k1) = k1 | |
2085 | analyze_scalar_evolution_in_loop (loop3, loop3, k2) = k2 | |
2086 | ||
2087 | As they are invariant, it does not matter whether we consider their | |
2088 | usage in loop 3 or loop 2, hence | |
2089 | analyze_scalar_evolution_in_loop (loop2, loop3, k1) = | |
2090 | analyze_scalar_evolution_in_loop (loop2, loop2, k1) = i | |
2091 | analyze_scalar_evolution_in_loop (loop2, loop3, k2) = | |
2092 | analyze_scalar_evolution_in_loop (loop2, loop2, k2) = [0,+,1]_2 | |
2093 | ||
2094 | Similarly for their evolutions with respect to loop 1. The values of K2 | |
2095 | in the use in loop 2 vary independently on loop 1, thus we cannot express | |
2096 | the evolution with respect to loop 1: | |
2097 | analyze_scalar_evolution_in_loop (loop1, loop3, k1) = | |
2098 | analyze_scalar_evolution_in_loop (loop1, loop2, k1) = [0,+,1]_1 | |
2099 | analyze_scalar_evolution_in_loop (loop1, loop3, k2) = | |
2100 | analyze_scalar_evolution_in_loop (loop1, loop2, k2) = dont_know | |
2101 | ||
2102 | The value of k2 in the use in loop 1 is known, though: | |
2103 | analyze_scalar_evolution_in_loop (loop1, loop1, k1) = [0,+,1]_1 | |
2104 | analyze_scalar_evolution_in_loop (loop1, loop1, k2) = 100 | |
2105 | */ | |
9baba81b SP |
2106 | |
2107 | static tree | |
2108 | analyze_scalar_evolution_in_loop (struct loop *wrto_loop, struct loop *use_loop, | |
a6f778b2 | 2109 | tree version, bool *folded_casts) |
9baba81b SP |
2110 | { |
2111 | bool val = false; | |
a6f778b2 | 2112 | tree ev = version, tmp; |
9baba81b | 2113 | |
b8698a0f | 2114 | /* We cannot just do |
f017bf5e ZD |
2115 | |
2116 | tmp = analyze_scalar_evolution (use_loop, version); | |
2117 | ev = resolve_mixers (wrto_loop, tmp); | |
2118 | ||
2119 | as resolve_mixers would query the scalar evolution with respect to | |
2120 | wrto_loop. For example, in the situation described in the function | |
2121 | comment, suppose that wrto_loop = loop1, use_loop = loop3 and | |
2122 | version = k2. Then | |
2123 | ||
2124 | analyze_scalar_evolution (use_loop, version) = k2 | |
2125 | ||
2126 | and resolve_mixers (loop1, k2) finds that the value of k2 in loop 1 | |
2127 | is 100, which is a wrong result, since we are interested in the | |
2128 | value in loop 3. | |
2129 | ||
2130 | Instead, we need to proceed from use_loop to wrto_loop loop by loop, | |
2131 | each time checking that there is no evolution in the inner loop. */ | |
2132 | ||
a6f778b2 ZD |
2133 | if (folded_casts) |
2134 | *folded_casts = false; | |
9baba81b SP |
2135 | while (1) |
2136 | { | |
a6f778b2 ZD |
2137 | tmp = analyze_scalar_evolution (use_loop, ev); |
2138 | ev = resolve_mixers (use_loop, tmp); | |
2139 | ||
2140 | if (folded_casts && tmp != ev) | |
2141 | *folded_casts = true; | |
9baba81b SP |
2142 | |
2143 | if (use_loop == wrto_loop) | |
2144 | return ev; | |
2145 | ||
2146 | /* If the value of the use changes in the inner loop, we cannot express | |
2147 | its value in the outer loop (we might try to return interval chrec, | |
2148 | but we do not have a user for it anyway) */ | |
2149 | if (!no_evolution_in_loop_p (ev, use_loop->num, &val) | |
2150 | || !val) | |
2151 | return chrec_dont_know; | |
2152 | ||
9ba025a2 | 2153 | use_loop = loop_outer (use_loop); |
9baba81b SP |
2154 | } |
2155 | } | |
2156 | ||
eb0bc7af | 2157 | |
fdd43ac4 RB |
2158 | /* Hashtable helpers for a temporary hash-table used when |
2159 | instantiating a CHREC or resolving mixers. For this use | |
2160 | instantiated_below is always the same. */ | |
2161 | ||
fdd43ac4 | 2162 | struct instantiate_cache_type |
eb0bc7af | 2163 | { |
a3cc13cc RB |
2164 | htab_t map; |
2165 | vec<scev_info_str> entries; | |
b8698a0f | 2166 | |
c3284718 | 2167 | instantiate_cache_type () : map (NULL), entries (vNULL) {} |
fdd43ac4 | 2168 | ~instantiate_cache_type (); |
0547c9b6 RB |
2169 | tree get (unsigned slot) { return entries[slot].chrec; } |
2170 | void set (unsigned slot, tree chrec) { entries[slot].chrec = chrec; } | |
fdd43ac4 | 2171 | }; |
eb0bc7af | 2172 | |
fdd43ac4 RB |
2173 | instantiate_cache_type::~instantiate_cache_type () |
2174 | { | |
0547c9b6 | 2175 | if (map != NULL) |
fdd43ac4 | 2176 | { |
a3cc13cc | 2177 | htab_delete (map); |
fdd43ac4 RB |
2178 | entries.release (); |
2179 | } | |
eb0bc7af ZD |
2180 | } |
2181 | ||
a3cc13cc RB |
2182 | /* Cache to avoid infinite recursion when instantiating an SSA name. |
2183 | Live during the outermost instantiate_scev or resolve_mixers call. */ | |
2184 | static instantiate_cache_type *global_cache; | |
2185 | ||
2186 | /* Computes a hash function for database element ELT. */ | |
2187 | ||
2188 | static inline hashval_t | |
2189 | hash_idx_scev_info (const void *elt_) | |
2190 | { | |
2191 | unsigned idx = ((size_t) elt_) - 2; | |
2192 | return hash_scev_info (&global_cache->entries[idx]); | |
2193 | } | |
2194 | ||
2195 | /* Compares database elements E1 and E2. */ | |
2196 | ||
2197 | static inline int | |
2198 | eq_idx_scev_info (const void *e1, const void *e2) | |
2199 | { | |
2200 | unsigned idx1 = ((size_t) e1) - 2; | |
2201 | return eq_scev_info (&global_cache->entries[idx1], e2); | |
2202 | } | |
2203 | ||
0547c9b6 | 2204 | /* Returns from CACHE the slot number of the cached chrec for NAME. */ |
fdd43ac4 | 2205 | |
0547c9b6 | 2206 | static unsigned |
a3cc13cc RB |
2207 | get_instantiated_value_entry (instantiate_cache_type &cache, |
2208 | tree name, basic_block instantiate_below) | |
fdd43ac4 | 2209 | { |
0547c9b6 | 2210 | if (!cache.map) |
fdd43ac4 | 2211 | { |
a3cc13cc | 2212 | cache.map = htab_create (10, hash_idx_scev_info, eq_idx_scev_info, NULL); |
fdd43ac4 RB |
2213 | cache.entries.create (10); |
2214 | } | |
b8698a0f | 2215 | |
a3cc13cc RB |
2216 | scev_info_str e; |
2217 | e.name_version = SSA_NAME_VERSION (name); | |
2218 | e.instantiated_below = instantiate_below->index; | |
2219 | void **slot = htab_find_slot_with_hash (cache.map, &e, | |
2220 | hash_scev_info (&e), INSERT); | |
2221 | if (!*slot) | |
fdd43ac4 RB |
2222 | { |
2223 | e.chrec = chrec_not_analyzed_yet; | |
a3cc13cc | 2224 | *slot = (void *)(size_t)(cache.entries.length () + 2); |
fdd43ac4 | 2225 | cache.entries.safe_push (e); |
fdd43ac4 RB |
2226 | } |
2227 | ||
a3cc13cc | 2228 | return ((size_t)*slot) - 2; |
eb0bc7af ZD |
2229 | } |
2230 | ||
0547c9b6 | 2231 | |
18aed06a SP |
2232 | /* Return the closed_loop_phi node for VAR. If there is none, return |
2233 | NULL_TREE. */ | |
2234 | ||
2235 | static tree | |
2236 | loop_closed_phi_def (tree var) | |
2237 | { | |
2238 | struct loop *loop; | |
2239 | edge exit; | |
726a989a RB |
2240 | gimple phi; |
2241 | gimple_stmt_iterator psi; | |
18aed06a SP |
2242 | |
2243 | if (var == NULL_TREE | |
2244 | || TREE_CODE (var) != SSA_NAME) | |
2245 | return NULL_TREE; | |
2246 | ||
2247 | loop = loop_containing_stmt (SSA_NAME_DEF_STMT (var)); | |
ac8f6c69 | 2248 | exit = single_exit (loop); |
18aed06a SP |
2249 | if (!exit) |
2250 | return NULL_TREE; | |
2251 | ||
726a989a RB |
2252 | for (psi = gsi_start_phis (exit->dest); !gsi_end_p (psi); gsi_next (&psi)) |
2253 | { | |
2254 | phi = gsi_stmt (psi); | |
2255 | if (PHI_ARG_DEF_FROM_EDGE (phi, exit) == var) | |
2256 | return PHI_RESULT (phi); | |
2257 | } | |
18aed06a SP |
2258 | |
2259 | return NULL_TREE; | |
2260 | } | |
2261 | ||
8b679c9b | 2262 | static tree instantiate_scev_r (basic_block, struct loop *, struct loop *, |
0547c9b6 | 2263 | tree, bool, int); |
320f5a78 SP |
2264 | |
2265 | /* Analyze all the parameters of the chrec, between INSTANTIATE_BELOW | |
2266 | and EVOLUTION_LOOP, that were left under a symbolic form. | |
2267 | ||
2495a183 | 2268 | CHREC is an SSA_NAME to be instantiated. |
320f5a78 SP |
2269 | |
2270 | CACHE is the cache of already instantiated values. | |
2271 | ||
2272 | FOLD_CONVERSIONS should be set to true when the conversions that | |
2273 | may wrap in signed/pointer type are folded, as long as the value of | |
2274 | the chrec is preserved. | |
2275 | ||
2276 | SIZE_EXPR is used for computing the size of the expression to be | |
2277 | instantiated, and to stop if it exceeds some limit. */ | |
2278 | ||
2279 | static tree | |
2495a183 | 2280 | instantiate_scev_name (basic_block instantiate_below, |
8b679c9b RB |
2281 | struct loop *evolution_loop, struct loop *inner_loop, |
2282 | tree chrec, | |
0547c9b6 | 2283 | bool fold_conversions, |
4a8fb1a1 | 2284 | int size_expr) |
320f5a78 | 2285 | { |
2495a183 SP |
2286 | tree res; |
2287 | struct loop *def_loop; | |
2288 | basic_block def_bb = gimple_bb (SSA_NAME_DEF_STMT (chrec)); | |
20179b0d | 2289 | |
2495a183 SP |
2290 | /* A parameter (or loop invariant and we do not want to include |
2291 | evolutions in outer loops), nothing to do. */ | |
2292 | if (!def_bb | |
2293 | || loop_depth (def_bb->loop_father) == 0 | |
2294 | || dominated_by_p (CDI_DOMINATORS, instantiate_below, def_bb)) | |
2295 | return chrec; | |
20179b0d | 2296 | |
2495a183 SP |
2297 | /* We cache the value of instantiated variable to avoid exponential |
2298 | time complexity due to reevaluations. We also store the convenient | |
2299 | value in the cache in order to prevent infinite recursion -- we do | |
2300 | not want to instantiate the SSA_NAME if it is in a mixer | |
2301 | structure. This is used for avoiding the instantiation of | |
2302 | recursively defined functions, such as: | |
320f5a78 | 2303 | |
2495a183 | 2304 | | a_2 -> {0, +, 1, +, a_2}_1 */ |
20179b0d | 2305 | |
a3cc13cc RB |
2306 | unsigned si = get_instantiated_value_entry (*global_cache, |
2307 | chrec, instantiate_below); | |
0547c9b6 RB |
2308 | if (global_cache->get (si) != chrec_not_analyzed_yet) |
2309 | return global_cache->get (si); | |
20179b0d | 2310 | |
fdd43ac4 | 2311 | /* On recursion return chrec_dont_know. */ |
0547c9b6 | 2312 | global_cache->set (si, chrec_dont_know); |
320f5a78 | 2313 | |
2495a183 SP |
2314 | def_loop = find_common_loop (evolution_loop, def_bb->loop_father); |
2315 | ||
320f5a78 SP |
2316 | /* If the analysis yields a parametric chrec, instantiate the |
2317 | result again. */ | |
2318 | res = analyze_scalar_evolution (def_loop, chrec); | |
2319 | ||
2847388e | 2320 | /* Don't instantiate default definitions. */ |
320f5a78 | 2321 | if (TREE_CODE (res) == SSA_NAME |
2847388e SP |
2322 | && SSA_NAME_IS_DEFAULT_DEF (res)) |
2323 | ; | |
2324 | ||
2325 | /* Don't instantiate loop-closed-ssa phi nodes. */ | |
2326 | else if (TREE_CODE (res) == SSA_NAME | |
2327 | && loop_depth (loop_containing_stmt (SSA_NAME_DEF_STMT (res))) | |
2328 | > loop_depth (def_loop)) | |
320f5a78 SP |
2329 | { |
2330 | if (res == chrec) | |
2331 | res = loop_closed_phi_def (chrec); | |
2332 | else | |
2333 | res = chrec; | |
2334 | ||
7472eb13 SP |
2335 | /* When there is no loop_closed_phi_def, it means that the |
2336 | variable is not used after the loop: try to still compute the | |
2337 | value of the variable when exiting the loop. */ | |
2338 | if (res == NULL_TREE) | |
2339 | { | |
2340 | loop_p loop = loop_containing_stmt (SSA_NAME_DEF_STMT (chrec)); | |
2341 | res = analyze_scalar_evolution (loop, chrec); | |
2342 | res = compute_overall_effect_of_inner_loop (loop, res); | |
8b679c9b RB |
2343 | res = instantiate_scev_r (instantiate_below, evolution_loop, |
2344 | inner_loop, res, | |
0547c9b6 | 2345 | fold_conversions, size_expr); |
7472eb13 SP |
2346 | } |
2347 | else if (!dominated_by_p (CDI_DOMINATORS, instantiate_below, | |
2348 | gimple_bb (SSA_NAME_DEF_STMT (res)))) | |
320f5a78 SP |
2349 | res = chrec_dont_know; |
2350 | } | |
2351 | ||
2352 | else if (res != chrec_dont_know) | |
8b679c9b RB |
2353 | { |
2354 | if (inner_loop | |
63fdb7be | 2355 | && def_bb->loop_father != inner_loop |
8b679c9b RB |
2356 | && !flow_loop_nested_p (def_bb->loop_father, inner_loop)) |
2357 | /* ??? We could try to compute the overall effect of the loop here. */ | |
2358 | res = chrec_dont_know; | |
2359 | else | |
2360 | res = instantiate_scev_r (instantiate_below, evolution_loop, | |
2361 | inner_loop, res, | |
0547c9b6 | 2362 | fold_conversions, size_expr); |
8b679c9b | 2363 | } |
320f5a78 SP |
2364 | |
2365 | /* Store the correct value to the cache. */ | |
0547c9b6 | 2366 | global_cache->set (si, res); |
320f5a78 | 2367 | return res; |
320f5a78 SP |
2368 | } |
2369 | ||
ec6636eb SP |
2370 | /* Analyze all the parameters of the chrec, between INSTANTIATE_BELOW |
2371 | and EVOLUTION_LOOP, that were left under a symbolic form. | |
2372 | ||
2373 | CHREC is a polynomial chain of recurrence to be instantiated. | |
2374 | ||
2375 | CACHE is the cache of already instantiated values. | |
2376 | ||
2377 | FOLD_CONVERSIONS should be set to true when the conversions that | |
2378 | may wrap in signed/pointer type are folded, as long as the value of | |
2379 | the chrec is preserved. | |
2380 | ||
2381 | SIZE_EXPR is used for computing the size of the expression to be | |
2382 | instantiated, and to stop if it exceeds some limit. */ | |
2383 | ||
2384 | static tree | |
2385 | instantiate_scev_poly (basic_block instantiate_below, | |
8b679c9b | 2386 | struct loop *evolution_loop, struct loop *, |
0547c9b6 | 2387 | tree chrec, bool fold_conversions, int size_expr) |
ec6636eb SP |
2388 | { |
2389 | tree op1; | |
9e5dc77f | 2390 | tree op0 = instantiate_scev_r (instantiate_below, evolution_loop, |
8b679c9b | 2391 | get_chrec_loop (chrec), |
0547c9b6 | 2392 | CHREC_LEFT (chrec), fold_conversions, |
ec6636eb SP |
2393 | size_expr); |
2394 | if (op0 == chrec_dont_know) | |
2395 | return chrec_dont_know; | |
2396 | ||
9e5dc77f | 2397 | op1 = instantiate_scev_r (instantiate_below, evolution_loop, |
8b679c9b | 2398 | get_chrec_loop (chrec), |
0547c9b6 | 2399 | CHREC_RIGHT (chrec), fold_conversions, |
ec6636eb SP |
2400 | size_expr); |
2401 | if (op1 == chrec_dont_know) | |
2402 | return chrec_dont_know; | |
2403 | ||
2404 | if (CHREC_LEFT (chrec) != op0 | |
2405 | || CHREC_RIGHT (chrec) != op1) | |
2406 | { | |
2407 | op1 = chrec_convert_rhs (chrec_type (op0), op1, NULL); | |
8b679c9b | 2408 | chrec = build_polynomial_chrec (CHREC_VARIABLE (chrec), op0, op1); |
ec6636eb | 2409 | } |
4bf4e169 | 2410 | |
ec6636eb SP |
2411 | return chrec; |
2412 | } | |
2413 | ||
15fda317 SP |
2414 | /* Analyze all the parameters of the chrec, between INSTANTIATE_BELOW |
2415 | and EVOLUTION_LOOP, that were left under a symbolic form. | |
2416 | ||
ffa34f4b | 2417 | "C0 CODE C1" is a binary expression of type TYPE to be instantiated. |
15fda317 SP |
2418 | |
2419 | CACHE is the cache of already instantiated values. | |
2420 | ||
2421 | FOLD_CONVERSIONS should be set to true when the conversions that | |
2422 | may wrap in signed/pointer type are folded, as long as the value of | |
2423 | the chrec is preserved. | |
2424 | ||
2425 | SIZE_EXPR is used for computing the size of the expression to be | |
2426 | instantiated, and to stop if it exceeds some limit. */ | |
2427 | ||
2428 | static tree | |
2429 | instantiate_scev_binary (basic_block instantiate_below, | |
8b679c9b RB |
2430 | struct loop *evolution_loop, struct loop *inner_loop, |
2431 | tree chrec, enum tree_code code, | |
ffa34f4b | 2432 | tree type, tree c0, tree c1, |
0547c9b6 | 2433 | bool fold_conversions, int size_expr) |
15fda317 SP |
2434 | { |
2435 | tree op1; | |
8b679c9b | 2436 | tree op0 = instantiate_scev_r (instantiate_below, evolution_loop, inner_loop, |
0547c9b6 | 2437 | c0, fold_conversions, size_expr); |
15fda317 SP |
2438 | if (op0 == chrec_dont_know) |
2439 | return chrec_dont_know; | |
2440 | ||
8b679c9b | 2441 | op1 = instantiate_scev_r (instantiate_below, evolution_loop, inner_loop, |
0547c9b6 | 2442 | c1, fold_conversions, size_expr); |
15fda317 SP |
2443 | if (op1 == chrec_dont_know) |
2444 | return chrec_dont_know; | |
2445 | ||
ffa34f4b SP |
2446 | if (c0 != op0 |
2447 | || c1 != op1) | |
15fda317 | 2448 | { |
15fda317 SP |
2449 | op0 = chrec_convert (type, op0, NULL); |
2450 | op1 = chrec_convert_rhs (type, op1, NULL); | |
2451 | ||
ffa34f4b | 2452 | switch (code) |
15fda317 SP |
2453 | { |
2454 | case POINTER_PLUS_EXPR: | |
2455 | case PLUS_EXPR: | |
2456 | return chrec_fold_plus (type, op0, op1); | |
2457 | ||
2458 | case MINUS_EXPR: | |
2459 | return chrec_fold_minus (type, op0, op1); | |
2460 | ||
2461 | case MULT_EXPR: | |
2462 | return chrec_fold_multiply (type, op0, op1); | |
2463 | ||
2464 | default: | |
2465 | gcc_unreachable (); | |
2466 | } | |
2467 | } | |
2468 | ||
ffa34f4b | 2469 | return chrec ? chrec : fold_build2 (code, type, c0, c1); |
15fda317 SP |
2470 | } |
2471 | ||
dbc08079 SP |
2472 | /* Analyze all the parameters of the chrec, between INSTANTIATE_BELOW |
2473 | and EVOLUTION_LOOP, that were left under a symbolic form. | |
2474 | ||
2475 | "CHREC" is an array reference to be instantiated. | |
2476 | ||
2477 | CACHE is the cache of already instantiated values. | |
2478 | ||
2479 | FOLD_CONVERSIONS should be set to true when the conversions that | |
2480 | may wrap in signed/pointer type are folded, as long as the value of | |
2481 | the chrec is preserved. | |
2482 | ||
2483 | SIZE_EXPR is used for computing the size of the expression to be | |
2484 | instantiated, and to stop if it exceeds some limit. */ | |
2485 | ||
2486 | static tree | |
2487 | instantiate_array_ref (basic_block instantiate_below, | |
8b679c9b | 2488 | struct loop *evolution_loop, struct loop *inner_loop, |
0547c9b6 | 2489 | tree chrec, bool fold_conversions, int size_expr) |
dbc08079 SP |
2490 | { |
2491 | tree res; | |
2492 | tree index = TREE_OPERAND (chrec, 1); | |
8b679c9b RB |
2493 | tree op1 = instantiate_scev_r (instantiate_below, evolution_loop, |
2494 | inner_loop, index, | |
0547c9b6 | 2495 | fold_conversions, size_expr); |
dbc08079 SP |
2496 | |
2497 | if (op1 == chrec_dont_know) | |
2498 | return chrec_dont_know; | |
2499 | ||
2500 | if (chrec && op1 == index) | |
2501 | return chrec; | |
2502 | ||
2503 | res = unshare_expr (chrec); | |
2504 | TREE_OPERAND (res, 1) = op1; | |
2505 | return res; | |
2506 | } | |
2507 | ||
a213b219 | 2508 | /* Analyze all the parameters of the chrec, between INSTANTIATE_BELOW |
9c382ce9 SP |
2509 | and EVOLUTION_LOOP, that were left under a symbolic form. |
2510 | ||
2511 | "CHREC" that stands for a convert expression "(TYPE) OP" is to be | |
2512 | instantiated. | |
2513 | ||
2514 | CACHE is the cache of already instantiated values. | |
2515 | ||
2516 | FOLD_CONVERSIONS should be set to true when the conversions that | |
2517 | may wrap in signed/pointer type are folded, as long as the value of | |
2518 | the chrec is preserved. | |
2519 | ||
2520 | SIZE_EXPR is used for computing the size of the expression to be | |
2521 | instantiated, and to stop if it exceeds some limit. */ | |
2522 | ||
2523 | static tree | |
2524 | instantiate_scev_convert (basic_block instantiate_below, | |
8b679c9b | 2525 | struct loop *evolution_loop, struct loop *inner_loop, |
0547c9b6 RB |
2526 | tree chrec, tree type, tree op, |
2527 | bool fold_conversions, int size_expr) | |
9c382ce9 | 2528 | { |
8b679c9b RB |
2529 | tree op0 = instantiate_scev_r (instantiate_below, evolution_loop, |
2530 | inner_loop, op, | |
0547c9b6 | 2531 | fold_conversions, size_expr); |
9c382ce9 SP |
2532 | |
2533 | if (op0 == chrec_dont_know) | |
2534 | return chrec_dont_know; | |
2535 | ||
2536 | if (fold_conversions) | |
2537 | { | |
2538 | tree tmp = chrec_convert_aggressive (type, op0); | |
2539 | if (tmp) | |
2540 | return tmp; | |
2541 | } | |
2542 | ||
2543 | if (chrec && op0 == op) | |
2544 | return chrec; | |
2545 | ||
2546 | /* If we used chrec_convert_aggressive, we can no longer assume that | |
2547 | signed chrecs do not overflow, as chrec_convert does, so avoid | |
2548 | calling it in that case. */ | |
2549 | if (fold_conversions) | |
2550 | return fold_convert (type, op0); | |
2551 | ||
2552 | return chrec_convert (type, op0, NULL); | |
2553 | } | |
2554 | ||
7ec0665d SP |
2555 | /* Analyze all the parameters of the chrec, between INSTANTIATE_BELOW |
2556 | and EVOLUTION_LOOP, that were left under a symbolic form. | |
2557 | ||
4b9d48a1 | 2558 | CHREC is a BIT_NOT_EXPR or a NEGATE_EXPR expression to be instantiated. |
7ec0665d | 2559 | Handle ~X as -1 - X. |
4b9d48a1 | 2560 | Handle -X as -1 * X. |
7ec0665d SP |
2561 | |
2562 | CACHE is the cache of already instantiated values. | |
2563 | ||
2564 | FOLD_CONVERSIONS should be set to true when the conversions that | |
2565 | may wrap in signed/pointer type are folded, as long as the value of | |
2566 | the chrec is preserved. | |
2567 | ||
2568 | SIZE_EXPR is used for computing the size of the expression to be | |
2569 | instantiated, and to stop if it exceeds some limit. */ | |
2570 | ||
2571 | static tree | |
4b9d48a1 | 2572 | instantiate_scev_not (basic_block instantiate_below, |
8b679c9b RB |
2573 | struct loop *evolution_loop, struct loop *inner_loop, |
2574 | tree chrec, | |
20179b0d | 2575 | enum tree_code code, tree type, tree op, |
0547c9b6 | 2576 | bool fold_conversions, int size_expr) |
7ec0665d | 2577 | { |
8b679c9b RB |
2578 | tree op0 = instantiate_scev_r (instantiate_below, evolution_loop, |
2579 | inner_loop, op, | |
0547c9b6 | 2580 | fold_conversions, size_expr); |
20179b0d | 2581 | |
7ec0665d SP |
2582 | if (op0 == chrec_dont_know) |
2583 | return chrec_dont_know; | |
2584 | ||
20179b0d | 2585 | if (op != op0) |
7ec0665d SP |
2586 | { |
2587 | op0 = chrec_convert (type, op0, NULL); | |
4b9d48a1 | 2588 | |
20179b0d | 2589 | switch (code) |
4b9d48a1 SP |
2590 | { |
2591 | case BIT_NOT_EXPR: | |
2592 | return chrec_fold_minus | |
2593 | (type, fold_convert (type, integer_minus_one_node), op0); | |
2594 | ||
2595 | case NEGATE_EXPR: | |
2596 | return chrec_fold_multiply | |
2597 | (type, fold_convert (type, integer_minus_one_node), op0); | |
2598 | ||
2599 | default: | |
2600 | gcc_unreachable (); | |
2601 | } | |
7ec0665d | 2602 | } |
4b9d48a1 | 2603 | |
20179b0d | 2604 | return chrec ? chrec : fold_build1 (code, type, op0); |
7ec0665d SP |
2605 | } |
2606 | ||
d814176c SP |
2607 | /* Analyze all the parameters of the chrec, between INSTANTIATE_BELOW |
2608 | and EVOLUTION_LOOP, that were left under a symbolic form. | |
2609 | ||
2610 | CHREC is an expression with 3 operands to be instantiated. | |
2611 | ||
2612 | CACHE is the cache of already instantiated values. | |
2613 | ||
2614 | FOLD_CONVERSIONS should be set to true when the conversions that | |
2615 | may wrap in signed/pointer type are folded, as long as the value of | |
2616 | the chrec is preserved. | |
2617 | ||
2618 | SIZE_EXPR is used for computing the size of the expression to be | |
2619 | instantiated, and to stop if it exceeds some limit. */ | |
2620 | ||
2621 | static tree | |
2622 | instantiate_scev_3 (basic_block instantiate_below, | |
8b679c9b RB |
2623 | struct loop *evolution_loop, struct loop *inner_loop, |
2624 | tree chrec, | |
0547c9b6 | 2625 | bool fold_conversions, int size_expr) |
d814176c SP |
2626 | { |
2627 | tree op1, op2; | |
9e5dc77f | 2628 | tree op0 = instantiate_scev_r (instantiate_below, evolution_loop, |
8b679c9b | 2629 | inner_loop, TREE_OPERAND (chrec, 0), |
0547c9b6 | 2630 | fold_conversions, size_expr); |
d814176c SP |
2631 | if (op0 == chrec_dont_know) |
2632 | return chrec_dont_know; | |
2633 | ||
9e5dc77f | 2634 | op1 = instantiate_scev_r (instantiate_below, evolution_loop, |
8b679c9b | 2635 | inner_loop, TREE_OPERAND (chrec, 1), |
0547c9b6 | 2636 | fold_conversions, size_expr); |
d814176c SP |
2637 | if (op1 == chrec_dont_know) |
2638 | return chrec_dont_know; | |
2639 | ||
9e5dc77f | 2640 | op2 = instantiate_scev_r (instantiate_below, evolution_loop, |
8b679c9b | 2641 | inner_loop, TREE_OPERAND (chrec, 2), |
0547c9b6 | 2642 | fold_conversions, size_expr); |
d814176c SP |
2643 | if (op2 == chrec_dont_know) |
2644 | return chrec_dont_know; | |
2645 | ||
2646 | if (op0 == TREE_OPERAND (chrec, 0) | |
2647 | && op1 == TREE_OPERAND (chrec, 1) | |
2648 | && op2 == TREE_OPERAND (chrec, 2)) | |
2649 | return chrec; | |
2650 | ||
2651 | return fold_build3 (TREE_CODE (chrec), | |
2652 | TREE_TYPE (chrec), op0, op1, op2); | |
2653 | } | |
2654 | ||
9c382ce9 SP |
2655 | /* Analyze all the parameters of the chrec, between INSTANTIATE_BELOW |
2656 | and EVOLUTION_LOOP, that were left under a symbolic form. | |
5b78fc3e | 2657 | |
9e5dc77f SP |
2658 | CHREC is an expression with 2 operands to be instantiated. |
2659 | ||
2660 | CACHE is the cache of already instantiated values. | |
2661 | ||
2662 | FOLD_CONVERSIONS should be set to true when the conversions that | |
2663 | may wrap in signed/pointer type are folded, as long as the value of | |
2664 | the chrec is preserved. | |
2665 | ||
2666 | SIZE_EXPR is used for computing the size of the expression to be | |
2667 | instantiated, and to stop if it exceeds some limit. */ | |
2668 | ||
2669 | static tree | |
2670 | instantiate_scev_2 (basic_block instantiate_below, | |
8b679c9b RB |
2671 | struct loop *evolution_loop, struct loop *inner_loop, |
2672 | tree chrec, | |
0547c9b6 | 2673 | bool fold_conversions, int size_expr) |
9e5dc77f SP |
2674 | { |
2675 | tree op1; | |
2676 | tree op0 = instantiate_scev_r (instantiate_below, evolution_loop, | |
8b679c9b | 2677 | inner_loop, TREE_OPERAND (chrec, 0), |
0547c9b6 | 2678 | fold_conversions, size_expr); |
9e5dc77f SP |
2679 | if (op0 == chrec_dont_know) |
2680 | return chrec_dont_know; | |
2681 | ||
2682 | op1 = instantiate_scev_r (instantiate_below, evolution_loop, | |
8b679c9b | 2683 | inner_loop, TREE_OPERAND (chrec, 1), |
0547c9b6 | 2684 | fold_conversions, size_expr); |
9e5dc77f SP |
2685 | if (op1 == chrec_dont_know) |
2686 | return chrec_dont_know; | |
2687 | ||
2688 | if (op0 == TREE_OPERAND (chrec, 0) | |
2689 | && op1 == TREE_OPERAND (chrec, 1)) | |
2690 | return chrec; | |
2691 | ||
2692 | return fold_build2 (TREE_CODE (chrec), TREE_TYPE (chrec), op0, op1); | |
2693 | } | |
2694 | ||
2695 | /* Analyze all the parameters of the chrec, between INSTANTIATE_BELOW | |
2696 | and EVOLUTION_LOOP, that were left under a symbolic form. | |
2697 | ||
2698 | CHREC is an expression with 2 operands to be instantiated. | |
5b78fc3e JS |
2699 | |
2700 | CACHE is the cache of already instantiated values. | |
2701 | ||
2702 | FOLD_CONVERSIONS should be set to true when the conversions that | |
2703 | may wrap in signed/pointer type are folded, as long as the value of | |
2704 | the chrec is preserved. | |
2705 | ||
3f227a8c JS |
2706 | SIZE_EXPR is used for computing the size of the expression to be |
2707 | instantiated, and to stop if it exceeds some limit. */ | |
9c382ce9 | 2708 | |
9baba81b | 2709 | static tree |
a213b219 | 2710 | instantiate_scev_1 (basic_block instantiate_below, |
8b679c9b RB |
2711 | struct loop *evolution_loop, struct loop *inner_loop, |
2712 | tree chrec, | |
0547c9b6 | 2713 | bool fold_conversions, int size_expr) |
9baba81b | 2714 | { |
9e5dc77f | 2715 | tree op0 = instantiate_scev_r (instantiate_below, evolution_loop, |
8b679c9b | 2716 | inner_loop, TREE_OPERAND (chrec, 0), |
0547c9b6 | 2717 | fold_conversions, size_expr); |
9e5dc77f SP |
2718 | |
2719 | if (op0 == chrec_dont_know) | |
2720 | return chrec_dont_know; | |
2721 | ||
2722 | if (op0 == TREE_OPERAND (chrec, 0)) | |
2723 | return chrec; | |
2724 | ||
2725 | return fold_build1 (TREE_CODE (chrec), TREE_TYPE (chrec), op0); | |
2726 | } | |
2727 | ||
2728 | /* Analyze all the parameters of the chrec, between INSTANTIATE_BELOW | |
2729 | and EVOLUTION_LOOP, that were left under a symbolic form. | |
2730 | ||
2731 | CHREC is the scalar evolution to instantiate. | |
2732 | ||
2733 | CACHE is the cache of already instantiated values. | |
2282a0e6 | 2734 | |
9e5dc77f SP |
2735 | FOLD_CONVERSIONS should be set to true when the conversions that |
2736 | may wrap in signed/pointer type are folded, as long as the value of | |
2737 | the chrec is preserved. | |
2738 | ||
2739 | SIZE_EXPR is used for computing the size of the expression to be | |
2740 | instantiated, and to stop if it exceeds some limit. */ | |
2741 | ||
2742 | static tree | |
2743 | instantiate_scev_r (basic_block instantiate_below, | |
8b679c9b RB |
2744 | struct loop *evolution_loop, struct loop *inner_loop, |
2745 | tree chrec, | |
0547c9b6 | 2746 | bool fold_conversions, int size_expr) |
9e5dc77f | 2747 | { |
47ae9e4c SP |
2748 | /* Give up if the expression is larger than the MAX that we allow. */ |
2749 | if (size_expr++ > PARAM_VALUE (PARAM_SCEV_MAX_EXPR_SIZE)) | |
2750 | return chrec_dont_know; | |
2751 | ||
81fada9a JJ |
2752 | if (chrec == NULL_TREE |
2753 | || automatically_generated_chrec_p (chrec) | |
d7770457 | 2754 | || is_gimple_min_invariant (chrec)) |
9baba81b SP |
2755 | return chrec; |
2756 | ||
2757 | switch (TREE_CODE (chrec)) | |
2758 | { | |
2759 | case SSA_NAME: | |
8b679c9b RB |
2760 | return instantiate_scev_name (instantiate_below, evolution_loop, |
2761 | inner_loop, chrec, | |
0547c9b6 | 2762 | fold_conversions, size_expr); |
9baba81b SP |
2763 | |
2764 | case POLYNOMIAL_CHREC: | |
8b679c9b RB |
2765 | return instantiate_scev_poly (instantiate_below, evolution_loop, |
2766 | inner_loop, chrec, | |
0547c9b6 | 2767 | fold_conversions, size_expr); |
9baba81b | 2768 | |
5be014d5 | 2769 | case POINTER_PLUS_EXPR: |
9baba81b | 2770 | case PLUS_EXPR: |
9baba81b | 2771 | case MINUS_EXPR: |
9baba81b | 2772 | case MULT_EXPR: |
8b679c9b RB |
2773 | return instantiate_scev_binary (instantiate_below, evolution_loop, |
2774 | inner_loop, chrec, | |
ffa34f4b SP |
2775 | TREE_CODE (chrec), chrec_type (chrec), |
2776 | TREE_OPERAND (chrec, 0), | |
2777 | TREE_OPERAND (chrec, 1), | |
0547c9b6 | 2778 | fold_conversions, size_expr); |
9baba81b | 2779 | |
1043771b | 2780 | CASE_CONVERT: |
8b679c9b RB |
2781 | return instantiate_scev_convert (instantiate_below, evolution_loop, |
2782 | inner_loop, chrec, | |
9c382ce9 | 2783 | TREE_TYPE (chrec), TREE_OPERAND (chrec, 0), |
0547c9b6 | 2784 | fold_conversions, size_expr); |
9baba81b | 2785 | |
4b9d48a1 | 2786 | case NEGATE_EXPR: |
418df9d7 | 2787 | case BIT_NOT_EXPR: |
8b679c9b RB |
2788 | return instantiate_scev_not (instantiate_below, evolution_loop, |
2789 | inner_loop, chrec, | |
20179b0d SP |
2790 | TREE_CODE (chrec), TREE_TYPE (chrec), |
2791 | TREE_OPERAND (chrec, 0), | |
0547c9b6 | 2792 | fold_conversions, size_expr); |
418df9d7 | 2793 | |
4c7d6755 | 2794 | case ADDR_EXPR: |
9baba81b SP |
2795 | case SCEV_NOT_KNOWN: |
2796 | return chrec_dont_know; | |
2797 | ||
2798 | case SCEV_KNOWN: | |
2799 | return chrec_known; | |
15fda317 | 2800 | |
dbc08079 | 2801 | case ARRAY_REF: |
8b679c9b RB |
2802 | return instantiate_array_ref (instantiate_below, evolution_loop, |
2803 | inner_loop, chrec, | |
0547c9b6 | 2804 | fold_conversions, size_expr); |
dbc08079 | 2805 | |
9baba81b SP |
2806 | default: |
2807 | break; | |
2808 | } | |
2809 | ||
0dfb0dc6 SP |
2810 | if (VL_EXP_CLASS_P (chrec)) |
2811 | return chrec_dont_know; | |
2812 | ||
9baba81b SP |
2813 | switch (TREE_CODE_LENGTH (TREE_CODE (chrec))) |
2814 | { | |
2815 | case 3: | |
8b679c9b RB |
2816 | return instantiate_scev_3 (instantiate_below, evolution_loop, |
2817 | inner_loop, chrec, | |
0547c9b6 | 2818 | fold_conversions, size_expr); |
9baba81b SP |
2819 | |
2820 | case 2: | |
8b679c9b RB |
2821 | return instantiate_scev_2 (instantiate_below, evolution_loop, |
2822 | inner_loop, chrec, | |
0547c9b6 | 2823 | fold_conversions, size_expr); |
7ec0665d | 2824 | |
9baba81b | 2825 | case 1: |
8b679c9b RB |
2826 | return instantiate_scev_1 (instantiate_below, evolution_loop, |
2827 | inner_loop, chrec, | |
0547c9b6 | 2828 | fold_conversions, size_expr); |
9baba81b SP |
2829 | |
2830 | case 0: | |
2831 | return chrec; | |
2832 | ||
2833 | default: | |
2834 | break; | |
2835 | } | |
2836 | ||
2837 | /* Too complicated to handle. */ | |
2838 | return chrec_dont_know; | |
2839 | } | |
e9eb809d ZD |
2840 | |
2841 | /* Analyze all the parameters of the chrec that were left under a | |
a213b219 SP |
2842 | symbolic form. INSTANTIATE_BELOW is the basic block that stops the |
2843 | recursive instantiation of parameters: a parameter is a variable | |
2844 | that is defined in a basic block that dominates INSTANTIATE_BELOW or | |
2845 | a function parameter. */ | |
e9eb809d ZD |
2846 | |
2847 | tree | |
a213b219 | 2848 | instantiate_scev (basic_block instantiate_below, struct loop *evolution_loop, |
3f227a8c | 2849 | tree chrec) |
e9eb809d | 2850 | { |
9baba81b SP |
2851 | tree res; |
2852 | ||
dfedbe40 | 2853 | if (dump_file && (dump_flags & TDF_SCEV)) |
9baba81b | 2854 | { |
3f227a8c | 2855 | fprintf (dump_file, "(instantiate_scev \n"); |
a213b219 | 2856 | fprintf (dump_file, " (instantiate_below = %d)\n", instantiate_below->index); |
3f227a8c | 2857 | fprintf (dump_file, " (evolution_loop = %d)\n", evolution_loop->num); |
9baba81b SP |
2858 | fprintf (dump_file, " (chrec = "); |
2859 | print_generic_expr (dump_file, chrec, 0); | |
2860 | fprintf (dump_file, ")\n"); | |
2861 | } | |
b8698a0f | 2862 | |
0547c9b6 RB |
2863 | bool destr = false; |
2864 | if (!global_cache) | |
2865 | { | |
2866 | global_cache = new instantiate_cache_type; | |
2867 | destr = true; | |
2868 | } | |
2869 | ||
8b679c9b | 2870 | res = instantiate_scev_r (instantiate_below, evolution_loop, |
0547c9b6 RB |
2871 | NULL, chrec, false, 0); |
2872 | ||
2873 | if (destr) | |
2874 | { | |
2875 | delete global_cache; | |
2876 | global_cache = NULL; | |
2877 | } | |
9baba81b | 2878 | |
dfedbe40 | 2879 | if (dump_file && (dump_flags & TDF_SCEV)) |
9baba81b SP |
2880 | { |
2881 | fprintf (dump_file, " (res = "); | |
2882 | print_generic_expr (dump_file, res, 0); | |
2883 | fprintf (dump_file, "))\n"); | |
2884 | } | |
eb0bc7af | 2885 | |
9baba81b SP |
2886 | return res; |
2887 | } | |
2888 | ||
2889 | /* Similar to instantiate_parameters, but does not introduce the | |
2282a0e6 ZD |
2890 | evolutions in outer loops for LOOP invariants in CHREC, and does not |
2891 | care about causing overflows, as long as they do not affect value | |
2892 | of an expression. */ | |
9baba81b | 2893 | |
3cb960c7 | 2894 | tree |
9baba81b SP |
2895 | resolve_mixers (struct loop *loop, tree chrec) |
2896 | { | |
0547c9b6 RB |
2897 | bool destr = false; |
2898 | if (!global_cache) | |
2899 | { | |
2900 | global_cache = new instantiate_cache_type; | |
2901 | destr = true; | |
2902 | } | |
2903 | ||
8b679c9b | 2904 | tree ret = instantiate_scev_r (block_before_loop (loop), loop, NULL, |
0547c9b6 RB |
2905 | chrec, true, 0); |
2906 | ||
2907 | if (destr) | |
2908 | { | |
2909 | delete global_cache; | |
2910 | global_cache = NULL; | |
2911 | } | |
2912 | ||
eb0bc7af | 2913 | return ret; |
9baba81b SP |
2914 | } |
2915 | ||
b8698a0f | 2916 | /* Entry point for the analysis of the number of iterations pass. |
9baba81b SP |
2917 | This function tries to safely approximate the number of iterations |
2918 | the loop will run. When this property is not decidable at compile | |
0a74c758 SP |
2919 | time, the result is chrec_dont_know. Otherwise the result is a |
2920 | scalar or a symbolic parameter. When the number of iterations may | |
2921 | be equal to zero and the property cannot be determined at compile | |
2922 | time, the result is a COND_EXPR that represents in a symbolic form | |
2923 | the conditions under which the number of iterations is not zero. | |
b8698a0f | 2924 | |
9baba81b | 2925 | Example of analysis: suppose that the loop has an exit condition: |
b8698a0f | 2926 | |
9baba81b | 2927 | "if (b > 49) goto end_loop;" |
b8698a0f | 2928 | |
9baba81b SP |
2929 | and that in a previous analysis we have determined that the |
2930 | variable 'b' has an evolution function: | |
b8698a0f L |
2931 | |
2932 | "EF = {23, +, 5}_2". | |
2933 | ||
9baba81b SP |
2934 | When we evaluate the function at the point 5, i.e. the value of the |
2935 | variable 'b' after 5 iterations in the loop, we have EF (5) = 48, | |
2936 | and EF (6) = 53. In this case the value of 'b' on exit is '53' and | |
2937 | the loop body has been executed 6 times. */ | |
2938 | ||
b8698a0f | 2939 | tree |
a14865db | 2940 | number_of_latch_executions (struct loop *loop) |
9baba81b | 2941 | { |
9baba81b SP |
2942 | edge exit; |
2943 | struct tree_niter_desc niter_desc; | |
0a74c758 SP |
2944 | tree may_be_zero; |
2945 | tree res; | |
9baba81b | 2946 | |
0a74c758 | 2947 | /* Determine whether the number of iterations in loop has already |
9baba81b SP |
2948 | been computed. */ |
2949 | res = loop->nb_iterations; | |
2950 | if (res) | |
2951 | return res; | |
0a74c758 SP |
2952 | |
2953 | may_be_zero = NULL_TREE; | |
9baba81b | 2954 | |
dfedbe40 | 2955 | if (dump_file && (dump_flags & TDF_SCEV)) |
0a74c758 | 2956 | fprintf (dump_file, "(number_of_iterations_in_loop = \n"); |
b8698a0f | 2957 | |
0a74c758 | 2958 | res = chrec_dont_know; |
ac8f6c69 | 2959 | exit = single_exit (loop); |
9baba81b | 2960 | |
0a74c758 SP |
2961 | if (exit && number_of_iterations_exit (loop, exit, &niter_desc, false)) |
2962 | { | |
2963 | may_be_zero = niter_desc.may_be_zero; | |
2964 | res = niter_desc.niter; | |
2965 | } | |
2966 | ||
2967 | if (res == chrec_dont_know | |
2968 | || !may_be_zero | |
2969 | || integer_zerop (may_be_zero)) | |
2970 | ; | |
2971 | else if (integer_nonzerop (may_be_zero)) | |
2972 | res = build_int_cst (TREE_TYPE (res), 0); | |
9baba81b | 2973 | |
0a74c758 SP |
2974 | else if (COMPARISON_CLASS_P (may_be_zero)) |
2975 | res = fold_build3 (COND_EXPR, TREE_TYPE (res), may_be_zero, | |
2976 | build_int_cst (TREE_TYPE (res), 0), res); | |
9baba81b SP |
2977 | else |
2978 | res = chrec_dont_know; | |
2979 | ||
dfedbe40 | 2980 | if (dump_file && (dump_flags & TDF_SCEV)) |
0a74c758 SP |
2981 | { |
2982 | fprintf (dump_file, " (set_nb_iterations_in_loop = "); | |
2983 | print_generic_expr (dump_file, res, 0); | |
2984 | fprintf (dump_file, "))\n"); | |
2985 | } | |
2986 | ||
2987 | loop->nb_iterations = res; | |
2988 | return res; | |
9baba81b | 2989 | } |
9baba81b SP |
2990 | \f |
2991 | ||
2992 | /* Counters for the stats. */ | |
2993 | ||
b8698a0f | 2994 | struct chrec_stats |
9baba81b SP |
2995 | { |
2996 | unsigned nb_chrecs; | |
2997 | unsigned nb_affine; | |
2998 | unsigned nb_affine_multivar; | |
2999 | unsigned nb_higher_poly; | |
3000 | unsigned nb_chrec_dont_know; | |
3001 | unsigned nb_undetermined; | |
3002 | }; | |
3003 | ||
3004 | /* Reset the counters. */ | |
3005 | ||
3006 | static inline void | |
3007 | reset_chrecs_counters (struct chrec_stats *stats) | |
3008 | { | |
3009 | stats->nb_chrecs = 0; | |
3010 | stats->nb_affine = 0; | |
3011 | stats->nb_affine_multivar = 0; | |
3012 | stats->nb_higher_poly = 0; | |
3013 | stats->nb_chrec_dont_know = 0; | |
3014 | stats->nb_undetermined = 0; | |
3015 | } | |
3016 | ||
3017 | /* Dump the contents of a CHREC_STATS structure. */ | |
3018 | ||
3019 | static void | |
3020 | dump_chrecs_stats (FILE *file, struct chrec_stats *stats) | |
3021 | { | |
3022 | fprintf (file, "\n(\n"); | |
3023 | fprintf (file, "-----------------------------------------\n"); | |
3024 | fprintf (file, "%d\taffine univariate chrecs\n", stats->nb_affine); | |
3025 | fprintf (file, "%d\taffine multivariate chrecs\n", stats->nb_affine_multivar); | |
b8698a0f | 3026 | fprintf (file, "%d\tdegree greater than 2 polynomials\n", |
9baba81b SP |
3027 | stats->nb_higher_poly); |
3028 | fprintf (file, "%d\tchrec_dont_know chrecs\n", stats->nb_chrec_dont_know); | |
3029 | fprintf (file, "-----------------------------------------\n"); | |
3030 | fprintf (file, "%d\ttotal chrecs\n", stats->nb_chrecs); | |
b8698a0f | 3031 | fprintf (file, "%d\twith undetermined coefficients\n", |
9baba81b SP |
3032 | stats->nb_undetermined); |
3033 | fprintf (file, "-----------------------------------------\n"); | |
b8698a0f | 3034 | fprintf (file, "%d\tchrecs in the scev database\n", |
9baba81b SP |
3035 | (int) htab_elements (scalar_evolution_info)); |
3036 | fprintf (file, "%d\tsets in the scev database\n", nb_set_scev); | |
3037 | fprintf (file, "%d\tgets in the scev database\n", nb_get_scev); | |
3038 | fprintf (file, "-----------------------------------------\n"); | |
3039 | fprintf (file, ")\n\n"); | |
3040 | } | |
3041 | ||
3042 | /* Gather statistics about CHREC. */ | |
3043 | ||
3044 | static void | |
3045 | gather_chrec_stats (tree chrec, struct chrec_stats *stats) | |
3046 | { | |
3047 | if (dump_file && (dump_flags & TDF_STATS)) | |
3048 | { | |
3049 | fprintf (dump_file, "(classify_chrec "); | |
3050 | print_generic_expr (dump_file, chrec, 0); | |
3051 | fprintf (dump_file, "\n"); | |
3052 | } | |
b8698a0f | 3053 | |
9baba81b | 3054 | stats->nb_chrecs++; |
b8698a0f | 3055 | |
9baba81b SP |
3056 | if (chrec == NULL_TREE) |
3057 | { | |
3058 | stats->nb_undetermined++; | |
3059 | return; | |
3060 | } | |
b8698a0f | 3061 | |
9baba81b SP |
3062 | switch (TREE_CODE (chrec)) |
3063 | { | |
3064 | case POLYNOMIAL_CHREC: | |
3065 | if (evolution_function_is_affine_p (chrec)) | |
3066 | { | |
3067 | if (dump_file && (dump_flags & TDF_STATS)) | |
3068 | fprintf (dump_file, " affine_univariate\n"); | |
3069 | stats->nb_affine++; | |
3070 | } | |
a50411de | 3071 | else if (evolution_function_is_affine_multivariate_p (chrec, 0)) |
9baba81b SP |
3072 | { |
3073 | if (dump_file && (dump_flags & TDF_STATS)) | |
3074 | fprintf (dump_file, " affine_multivariate\n"); | |
3075 | stats->nb_affine_multivar++; | |
3076 | } | |
3077 | else | |
3078 | { | |
3079 | if (dump_file && (dump_flags & TDF_STATS)) | |
3080 | fprintf (dump_file, " higher_degree_polynomial\n"); | |
3081 | stats->nb_higher_poly++; | |
3082 | } | |
b8698a0f | 3083 | |
9baba81b SP |
3084 | break; |
3085 | ||
3086 | default: | |
3087 | break; | |
3088 | } | |
b8698a0f | 3089 | |
9baba81b SP |
3090 | if (chrec_contains_undetermined (chrec)) |
3091 | { | |
3092 | if (dump_file && (dump_flags & TDF_STATS)) | |
3093 | fprintf (dump_file, " undetermined\n"); | |
3094 | stats->nb_undetermined++; | |
3095 | } | |
b8698a0f | 3096 | |
9baba81b SP |
3097 | if (dump_file && (dump_flags & TDF_STATS)) |
3098 | fprintf (dump_file, ")\n"); | |
3099 | } | |
3100 | ||
9baba81b SP |
3101 | /* Callback for htab_traverse, gathers information on chrecs in the |
3102 | hashtable. */ | |
3103 | ||
3104 | static int | |
3105 | gather_stats_on_scev_database_1 (void **slot, void *stats) | |
3106 | { | |
cceb1885 | 3107 | struct scev_info_str *entry = (struct scev_info_str *) *slot; |
9baba81b | 3108 | |
cceb1885 | 3109 | gather_chrec_stats (entry->chrec, (struct chrec_stats *) stats); |
9baba81b SP |
3110 | |
3111 | return 1; | |
3112 | } | |
3113 | ||
3114 | /* Classify the chrecs of the whole database. */ | |
3115 | ||
b8698a0f | 3116 | void |
9baba81b SP |
3117 | gather_stats_on_scev_database (void) |
3118 | { | |
3119 | struct chrec_stats stats; | |
b8698a0f | 3120 | |
9baba81b SP |
3121 | if (!dump_file) |
3122 | return; | |
b8698a0f | 3123 | |
9baba81b | 3124 | reset_chrecs_counters (&stats); |
b8698a0f | 3125 | |
9baba81b SP |
3126 | htab_traverse (scalar_evolution_info, gather_stats_on_scev_database_1, |
3127 | &stats); | |
3128 | ||
3129 | dump_chrecs_stats (dump_file, &stats); | |
3130 | } | |
3131 | ||
3132 | \f | |
3133 | ||
3134 | /* Initializer. */ | |
3135 | ||
3136 | static void | |
3137 | initialize_scalar_evolutions_analyzer (void) | |
3138 | { | |
3139 | /* The elements below are unique. */ | |
3140 | if (chrec_dont_know == NULL_TREE) | |
3141 | { | |
3142 | chrec_not_analyzed_yet = NULL_TREE; | |
3143 | chrec_dont_know = make_node (SCEV_NOT_KNOWN); | |
3144 | chrec_known = make_node (SCEV_KNOWN); | |
d5ab5675 ZD |
3145 | TREE_TYPE (chrec_dont_know) = void_type_node; |
3146 | TREE_TYPE (chrec_known) = void_type_node; | |
9baba81b SP |
3147 | } |
3148 | } | |
3149 | ||
3150 | /* Initialize the analysis of scalar evolutions for LOOPS. */ | |
3151 | ||
3152 | void | |
d73be268 | 3153 | scev_initialize (void) |
9baba81b | 3154 | { |
42fd6772 | 3155 | struct loop *loop; |
9baba81b | 3156 | |
a9429e29 LB |
3157 | scalar_evolution_info = htab_create_ggc (100, hash_scev_info, eq_scev_info, |
3158 | del_scev_info); | |
b8698a0f | 3159 | |
9baba81b SP |
3160 | initialize_scalar_evolutions_analyzer (); |
3161 | ||
f0bd40b1 | 3162 | FOR_EACH_LOOP (loop, 0) |
42fd6772 ZD |
3163 | { |
3164 | loop->nb_iterations = NULL_TREE; | |
3165 | } | |
9baba81b SP |
3166 | } |
3167 | ||
e3a8f1fa JH |
3168 | /* Return true if SCEV is initialized. */ |
3169 | ||
3170 | bool | |
3171 | scev_initialized_p (void) | |
3172 | { | |
3173 | return scalar_evolution_info != NULL; | |
3174 | } | |
3175 | ||
a7bf45de SP |
3176 | /* Cleans up the information cached by the scalar evolutions analysis |
3177 | in the hash table. */ | |
3178 | ||
3179 | void | |
3180 | scev_reset_htab (void) | |
3181 | { | |
3182 | if (!scalar_evolution_info) | |
3183 | return; | |
3184 | ||
3185 | htab_empty (scalar_evolution_info); | |
3186 | } | |
3187 | ||
3188 | /* Cleans up the information cached by the scalar evolutions analysis | |
3189 | in the hash table and in the loop->nb_iterations. */ | |
9baba81b SP |
3190 | |
3191 | void | |
3192 | scev_reset (void) | |
3193 | { | |
9baba81b SP |
3194 | struct loop *loop; |
3195 | ||
a7bf45de SP |
3196 | scev_reset_htab (); |
3197 | ||
3198 | if (!current_loops) | |
9baba81b SP |
3199 | return; |
3200 | ||
f0bd40b1 | 3201 | FOR_EACH_LOOP (loop, 0) |
9baba81b | 3202 | { |
42fd6772 | 3203 | loop->nb_iterations = NULL_TREE; |
9baba81b | 3204 | } |
e9eb809d ZD |
3205 | } |
3206 | ||
f017bf5e ZD |
3207 | /* Checks whether use of OP in USE_LOOP behaves as a simple affine iv with |
3208 | respect to WRTO_LOOP and returns its base and step in IV if possible | |
3209 | (see analyze_scalar_evolution_in_loop for more details on USE_LOOP | |
3210 | and WRTO_LOOP). If ALLOW_NONCONSTANT_STEP is true, we want step to be | |
3211 | invariant in LOOP. Otherwise we require it to be an integer constant. | |
b8698a0f | 3212 | |
f017bf5e ZD |
3213 | IV->no_overflow is set to true if we are sure the iv cannot overflow (e.g. |
3214 | because it is computed in signed arithmetics). Consequently, adding an | |
3215 | induction variable | |
b8698a0f | 3216 | |
f017bf5e ZD |
3217 | for (i = IV->base; ; i += IV->step) |
3218 | ||
3219 | is only safe if IV->no_overflow is false, or TYPE_OVERFLOW_UNDEFINED is | |
3220 | false for the type of the induction variable, or you can prove that i does | |
3221 | not wrap by some other argument. Otherwise, this might introduce undefined | |
3222 | behavior, and | |
b8698a0f | 3223 | |
f017bf5e ZD |
3224 | for (i = iv->base; ; i = (type) ((unsigned type) i + (unsigned type) iv->step)) |
3225 | ||
3226 | must be used instead. */ | |
e9eb809d ZD |
3227 | |
3228 | bool | |
f017bf5e ZD |
3229 | simple_iv (struct loop *wrto_loop, struct loop *use_loop, tree op, |
3230 | affine_iv *iv, bool allow_nonconstant_step) | |
e9eb809d | 3231 | { |
9baba81b | 3232 | tree type, ev; |
a6f778b2 | 3233 | bool folded_casts; |
9baba81b | 3234 | |
a6f778b2 ZD |
3235 | iv->base = NULL_TREE; |
3236 | iv->step = NULL_TREE; | |
3237 | iv->no_overflow = false; | |
9baba81b SP |
3238 | |
3239 | type = TREE_TYPE (op); | |
1ee0d660 EB |
3240 | if (!POINTER_TYPE_P (type) |
3241 | && !INTEGRAL_TYPE_P (type)) | |
9baba81b SP |
3242 | return false; |
3243 | ||
f017bf5e | 3244 | ev = analyze_scalar_evolution_in_loop (wrto_loop, use_loop, op, |
a6f778b2 | 3245 | &folded_casts); |
f017bf5e ZD |
3246 | if (chrec_contains_undetermined (ev) |
3247 | || chrec_contains_symbols_defined_in_loop (ev, wrto_loop->num)) | |
9baba81b SP |
3248 | return false; |
3249 | ||
f017bf5e | 3250 | if (tree_does_not_contain_chrecs (ev)) |
9baba81b | 3251 | { |
a6f778b2 | 3252 | iv->base = ev; |
6e42ce54 | 3253 | iv->step = build_int_cst (TREE_TYPE (ev), 0); |
a6f778b2 | 3254 | iv->no_overflow = true; |
9baba81b SP |
3255 | return true; |
3256 | } | |
3257 | ||
3258 | if (TREE_CODE (ev) != POLYNOMIAL_CHREC | |
f017bf5e | 3259 | || CHREC_VARIABLE (ev) != (unsigned) wrto_loop->num) |
9baba81b SP |
3260 | return false; |
3261 | ||
a6f778b2 | 3262 | iv->step = CHREC_RIGHT (ev); |
f017bf5e ZD |
3263 | if ((!allow_nonconstant_step && TREE_CODE (iv->step) != INTEGER_CST) |
3264 | || tree_contains_chrecs (iv->step, NULL)) | |
9baba81b | 3265 | return false; |
9be872b7 | 3266 | |
a6f778b2 | 3267 | iv->base = CHREC_LEFT (ev); |
f017bf5e | 3268 | if (tree_contains_chrecs (iv->base, NULL)) |
9baba81b SP |
3269 | return false; |
3270 | ||
eeef0e45 ILT |
3271 | iv->no_overflow = !folded_casts && TYPE_OVERFLOW_UNDEFINED (type); |
3272 | ||
9baba81b SP |
3273 | return true; |
3274 | } | |
3275 | ||
9baba81b SP |
3276 | /* Finalize the scalar evolution analysis. */ |
3277 | ||
3278 | void | |
3279 | scev_finalize (void) | |
3280 | { | |
d51157de ZD |
3281 | if (!scalar_evolution_info) |
3282 | return; | |
9baba81b | 3283 | htab_delete (scalar_evolution_info); |
c7b852c8 | 3284 | scalar_evolution_info = NULL; |
9baba81b SP |
3285 | } |
3286 | ||
771f882e ZD |
3287 | /* Returns true if the expression EXPR is considered to be too expensive |
3288 | for scev_const_prop. */ | |
3289 | ||
3290 | bool | |
3291 | expression_expensive_p (tree expr) | |
3292 | { | |
3293 | enum tree_code code; | |
3294 | ||
3295 | if (is_gimple_val (expr)) | |
3296 | return false; | |
3297 | ||
3298 | code = TREE_CODE (expr); | |
3299 | if (code == TRUNC_DIV_EXPR | |
3300 | || code == CEIL_DIV_EXPR | |
3301 | || code == FLOOR_DIV_EXPR | |
3302 | || code == ROUND_DIV_EXPR | |
3303 | || code == TRUNC_MOD_EXPR | |
3304 | || code == CEIL_MOD_EXPR | |
3305 | || code == FLOOR_MOD_EXPR | |
3306 | || code == ROUND_MOD_EXPR | |
3307 | || code == EXACT_DIV_EXPR) | |
3308 | { | |
3309 | /* Division by power of two is usually cheap, so we allow it. | |
3310 | Forbid anything else. */ | |
3311 | if (!integer_pow2p (TREE_OPERAND (expr, 1))) | |
3312 | return true; | |
3313 | } | |
3314 | ||
3315 | switch (TREE_CODE_CLASS (code)) | |
3316 | { | |
3317 | case tcc_binary: | |
3318 | case tcc_comparison: | |
3319 | if (expression_expensive_p (TREE_OPERAND (expr, 1))) | |
3320 | return true; | |
3321 | ||
3322 | /* Fallthru. */ | |
3323 | case tcc_unary: | |
3324 | return expression_expensive_p (TREE_OPERAND (expr, 0)); | |
3325 | ||
3326 | default: | |
3327 | return true; | |
3328 | } | |
3329 | } | |
3330 | ||
684aaf29 | 3331 | /* Replace ssa names for that scev can prove they are constant by the |
3ac01fde ZD |
3332 | appropriate constants. Also perform final value replacement in loops, |
3333 | in case the replacement expressions are cheap. | |
b8698a0f | 3334 | |
684aaf29 ZD |
3335 | We only consider SSA names defined by phi nodes; rest is left to the |
3336 | ordinary constant propagation pass. */ | |
3337 | ||
c2924966 | 3338 | unsigned int |
684aaf29 ZD |
3339 | scev_const_prop (void) |
3340 | { | |
3341 | basic_block bb; | |
726a989a RB |
3342 | tree name, type, ev; |
3343 | gimple phi, ass; | |
3ac01fde | 3344 | struct loop *loop, *ex_loop; |
684aaf29 | 3345 | bitmap ssa_names_to_remove = NULL; |
3ac01fde | 3346 | unsigned i; |
726a989a | 3347 | gimple_stmt_iterator psi; |
684aaf29 | 3348 | |
0fc822d0 | 3349 | if (number_of_loops (cfun) <= 1) |
c2924966 | 3350 | return 0; |
684aaf29 | 3351 | |
11cd3bed | 3352 | FOR_EACH_BB_FN (bb, cfun) |
684aaf29 ZD |
3353 | { |
3354 | loop = bb->loop_father; | |
3355 | ||
726a989a | 3356 | for (psi = gsi_start_phis (bb); !gsi_end_p (psi); gsi_next (&psi)) |
684aaf29 | 3357 | { |
726a989a | 3358 | phi = gsi_stmt (psi); |
684aaf29 ZD |
3359 | name = PHI_RESULT (phi); |
3360 | ||
ea057359 | 3361 | if (virtual_operand_p (name)) |
684aaf29 ZD |
3362 | continue; |
3363 | ||
3364 | type = TREE_TYPE (name); | |
3365 | ||
3366 | if (!POINTER_TYPE_P (type) | |
3367 | && !INTEGRAL_TYPE_P (type)) | |
3368 | continue; | |
3369 | ||
3370 | ev = resolve_mixers (loop, analyze_scalar_evolution (loop, name)); | |
3371 | if (!is_gimple_min_invariant (ev) | |
3372 | || !may_propagate_copy (name, ev)) | |
3373 | continue; | |
3374 | ||
3375 | /* Replace the uses of the name. */ | |
18aed06a SP |
3376 | if (name != ev) |
3377 | replace_uses_by (name, ev); | |
684aaf29 ZD |
3378 | |
3379 | if (!ssa_names_to_remove) | |
3380 | ssa_names_to_remove = BITMAP_ALLOC (NULL); | |
3381 | bitmap_set_bit (ssa_names_to_remove, SSA_NAME_VERSION (name)); | |
3382 | } | |
3383 | } | |
3384 | ||
9b3b55a1 DN |
3385 | /* Remove the ssa names that were replaced by constants. We do not |
3386 | remove them directly in the previous cycle, since this | |
3387 | invalidates scev cache. */ | |
684aaf29 ZD |
3388 | if (ssa_names_to_remove) |
3389 | { | |
3390 | bitmap_iterator bi; | |
684aaf29 ZD |
3391 | |
3392 | EXECUTE_IF_SET_IN_BITMAP (ssa_names_to_remove, 0, i, bi) | |
3393 | { | |
726a989a | 3394 | gimple_stmt_iterator psi; |
684aaf29 ZD |
3395 | name = ssa_name (i); |
3396 | phi = SSA_NAME_DEF_STMT (name); | |
3397 | ||
726a989a RB |
3398 | gcc_assert (gimple_code (phi) == GIMPLE_PHI); |
3399 | psi = gsi_for_stmt (phi); | |
3400 | remove_phi_node (&psi, true); | |
684aaf29 ZD |
3401 | } |
3402 | ||
3403 | BITMAP_FREE (ssa_names_to_remove); | |
3404 | scev_reset (); | |
3405 | } | |
3ac01fde ZD |
3406 | |
3407 | /* Now the regular final value replacement. */ | |
f0bd40b1 | 3408 | FOR_EACH_LOOP (loop, LI_FROM_INNERMOST) |
3ac01fde ZD |
3409 | { |
3410 | edge exit; | |
726a989a RB |
3411 | tree def, rslt, niter; |
3412 | gimple_stmt_iterator bsi; | |
3ac01fde | 3413 | |
3ac01fde ZD |
3414 | /* If we do not know exact number of iterations of the loop, we cannot |
3415 | replace the final value. */ | |
ac8f6c69 | 3416 | exit = single_exit (loop); |
a6f778b2 ZD |
3417 | if (!exit) |
3418 | continue; | |
3419 | ||
a14865db | 3420 | niter = number_of_latch_executions (loop); |
b3ce5b6e | 3421 | if (niter == chrec_dont_know) |
3ac01fde | 3422 | continue; |
925196ed ZD |
3423 | |
3424 | /* Ensure that it is possible to insert new statements somewhere. */ | |
3425 | if (!single_pred_p (exit->dest)) | |
3426 | split_loop_exit_edge (exit); | |
726a989a | 3427 | bsi = gsi_after_labels (exit->dest); |
925196ed | 3428 | |
9ba025a2 ZD |
3429 | ex_loop = superloop_at_depth (loop, |
3430 | loop_depth (exit->dest->loop_father) + 1); | |
3ac01fde | 3431 | |
726a989a | 3432 | for (psi = gsi_start_phis (exit->dest); !gsi_end_p (psi); ) |
3ac01fde | 3433 | { |
726a989a | 3434 | phi = gsi_stmt (psi); |
925196ed | 3435 | rslt = PHI_RESULT (phi); |
3ac01fde | 3436 | def = PHI_ARG_DEF_FROM_EDGE (phi, exit); |
ea057359 | 3437 | if (virtual_operand_p (def)) |
726a989a RB |
3438 | { |
3439 | gsi_next (&psi); | |
3440 | continue; | |
3441 | } | |
3ac01fde ZD |
3442 | |
3443 | if (!POINTER_TYPE_P (TREE_TYPE (def)) | |
3444 | && !INTEGRAL_TYPE_P (TREE_TYPE (def))) | |
726a989a RB |
3445 | { |
3446 | gsi_next (&psi); | |
3447 | continue; | |
3448 | } | |
3ac01fde | 3449 | |
a6f778b2 | 3450 | def = analyze_scalar_evolution_in_loop (ex_loop, loop, def, NULL); |
925196ed | 3451 | def = compute_overall_effect_of_inner_loop (ex_loop, def); |
3ac01fde | 3452 | if (!tree_does_not_contain_chrecs (def) |
e5db3515 ZD |
3453 | || chrec_contains_symbols_defined_in_loop (def, ex_loop->num) |
3454 | /* Moving the computation from the loop may prolong life range | |
3455 | of some ssa names, which may cause problems if they appear | |
3456 | on abnormal edges. */ | |
771f882e ZD |
3457 | || contains_abnormal_ssa_name_p (def) |
3458 | /* Do not emit expensive expressions. The rationale is that | |
3459 | when someone writes a code like | |
3460 | ||
3461 | while (n > 45) n -= 45; | |
3462 | ||
3463 | he probably knows that n is not large, and does not want it | |
3464 | to be turned into n %= 45. */ | |
3465 | || expression_expensive_p (def)) | |
726a989a | 3466 | { |
3571dde6 MP |
3467 | if (dump_file && (dump_flags & TDF_DETAILS)) |
3468 | { | |
3469 | fprintf (dump_file, "not replacing:\n "); | |
3470 | print_gimple_stmt (dump_file, phi, 0, 0); | |
3471 | fprintf (dump_file, "\n"); | |
3472 | } | |
726a989a RB |
3473 | gsi_next (&psi); |
3474 | continue; | |
3475 | } | |
3ac01fde | 3476 | |
9b3b55a1 | 3477 | /* Eliminate the PHI node and replace it by a computation outside |
925196ed | 3478 | the loop. */ |
3571dde6 MP |
3479 | if (dump_file) |
3480 | { | |
3481 | fprintf (dump_file, "\nfinal value replacement:\n "); | |
3482 | print_gimple_stmt (dump_file, phi, 0, 0); | |
3483 | fprintf (dump_file, " with\n "); | |
3484 | } | |
925196ed | 3485 | def = unshare_expr (def); |
726a989a RB |
3486 | remove_phi_node (&psi, false); |
3487 | ||
3488 | def = force_gimple_operand_gsi (&bsi, def, false, NULL_TREE, | |
3489 | true, GSI_SAME_STMT); | |
3490 | ass = gimple_build_assign (rslt, def); | |
3491 | gsi_insert_before (&bsi, ass, GSI_SAME_STMT); | |
3571dde6 MP |
3492 | if (dump_file) |
3493 | { | |
3494 | print_gimple_stmt (dump_file, ass, 0, 0); | |
3495 | fprintf (dump_file, "\n"); | |
3496 | } | |
3ac01fde ZD |
3497 | } |
3498 | } | |
c2924966 | 3499 | return 0; |
684aaf29 | 3500 | } |
9e2f83a5 ZD |
3501 | |
3502 | #include "gt-tree-scalar-evolution.h" |