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3d436d2a | 1 | /* Natural loop functions |
8d9254fc | 2 | Copyright (C) 1987-2020 Free Software Foundation, Inc. |
3d436d2a ZD |
3 | |
4 | This file is part of GCC. | |
5 | ||
6 | GCC is free software; you can redistribute it and/or modify it under | |
7 | the terms of the GNU General Public License as published by the Free | |
9dcd6f09 | 8 | Software Foundation; either version 3, or (at your option) any later |
3d436d2a ZD |
9 | version. |
10 | ||
11 | GCC is distributed in the hope that it will be useful, but WITHOUT ANY | |
12 | WARRANTY; without even the implied warranty of MERCHANTABILITY or | |
13 | FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License | |
14 | for more details. | |
15 | ||
16 | You should have received a copy of the GNU General Public License | |
9dcd6f09 NC |
17 | along with GCC; see the file COPYING3. If not see |
18 | <http://www.gnu.org/licenses/>. */ | |
3d436d2a | 19 | |
59587b18 JQ |
20 | #ifndef GCC_CFGLOOP_H |
21 | #define GCC_CFGLOOP_H | |
22 | ||
893479de | 23 | #include "cfgloopmanip.h" |
7a8cba34 | 24 | |
3d436d2a ZD |
25 | /* Structure to hold decision about unrolling/peeling. */ |
26 | enum lpt_dec | |
27 | { | |
28 | LPT_NONE, | |
3d436d2a ZD |
29 | LPT_UNROLL_CONSTANT, |
30 | LPT_UNROLL_RUNTIME, | |
31 | LPT_UNROLL_STUPID | |
32 | }; | |
33 | ||
d1b38208 | 34 | struct GTY (()) lpt_decision { |
3d436d2a ZD |
35 | enum lpt_dec decision; |
36 | unsigned times; | |
37 | }; | |
38 | ||
1c1ad7bb SB |
39 | /* The type of extend applied to an IV. */ |
40 | enum iv_extend_code | |
41 | { | |
42 | IV_SIGN_EXTEND, | |
43 | IV_ZERO_EXTEND, | |
44 | IV_UNKNOWN_EXTEND | |
45 | }; | |
46 | ||
86df10e3 SP |
47 | /* The structure describing a bound on number of iterations of a loop. */ |
48 | ||
6c1dae73 MS |
49 | class GTY ((chain_next ("%h.next"))) nb_iter_bound { |
50 | public: | |
946e1bc7 | 51 | /* The statement STMT is executed at most ... */ |
355fe088 | 52 | gimple *stmt; |
946e1bc7 ZD |
53 | |
54 | /* ... BOUND + 1 times (BOUND must be an unsigned constant). | |
55 | The + 1 is added for the following reasons: | |
56 | ||
57 | a) 0 would otherwise be unused, while we would need to care more about | |
58 | overflows (as MAX + 1 is sometimes produced as the estimate on number | |
59 | of executions of STMT). | |
60 | b) it is consistent with the result of number_of_iterations_exit. */ | |
807e902e | 61 | widest_int bound; |
946e1bc7 | 62 | |
b8698a0f | 63 | /* True if the statement will cause the loop to be leaved the (at most) |
946e1bc7 ZD |
64 | BOUND + 1-st time it is executed, that is, all the statements after it |
65 | are executed at most BOUND times. */ | |
66 | bool is_exit; | |
67 | ||
946e1bc7 | 68 | /* The next bound in the list. */ |
99b1c316 | 69 | class nb_iter_bound *next; |
86df10e3 SP |
70 | }; |
71 | ||
6270df4c ZD |
72 | /* Description of the loop exit. */ |
73 | ||
2a22f99c | 74 | struct GTY ((for_user)) loop_exit { |
6270df4c | 75 | /* The exit edge. */ |
b8244d74 | 76 | edge e; |
6270df4c ZD |
77 | |
78 | /* Previous and next exit in the list of the exits of the loop. */ | |
79 | struct loop_exit *prev; | |
80 | struct loop_exit *next; | |
81 | ||
82 | /* Next element in the list of loops from that E exits. */ | |
83 | struct loop_exit *next_e; | |
84 | }; | |
85 | ||
ca752f39 | 86 | struct loop_exit_hasher : ggc_ptr_hash<loop_exit> |
2a22f99c TS |
87 | { |
88 | typedef edge compare_type; | |
89 | ||
90 | static hashval_t hash (loop_exit *); | |
91 | static bool equal (loop_exit *, edge); | |
92 | static void remove (loop_exit *); | |
93 | }; | |
94 | ||
99b1c316 | 95 | typedef class loop *loop_p; |
9ba025a2 | 96 | |
ae50c0cb TN |
97 | /* An integer estimation of the number of iterations. Estimate_state |
98 | describes what is the state of the estimation. */ | |
99 | enum loop_estimation | |
100 | { | |
101 | /* Estimate was not computed yet. */ | |
102 | EST_NOT_COMPUTED, | |
103 | /* Estimate is ready. */ | |
dd366ec3 RB |
104 | EST_AVAILABLE, |
105 | EST_LAST | |
ae50c0cb TN |
106 | }; |
107 | ||
2f07b722 BC |
108 | /* The structure describing non-overflow control induction variable for |
109 | loop's exit edge. */ | |
110 | struct GTY ((chain_next ("%h.next"))) control_iv { | |
111 | tree base; | |
112 | tree step; | |
113 | struct control_iv *next; | |
114 | }; | |
115 | ||
3d436d2a | 116 | /* Structure to hold information for each natural loop. */ |
6c1dae73 MS |
117 | class GTY ((chain_next ("%h.next"))) loop { |
118 | public: | |
542e7230 BC |
119 | /* Index into loops array. Note indices will never be reused after loop |
120 | is destroyed. */ | |
3d436d2a ZD |
121 | int num; |
122 | ||
8f5929e1 JJ |
123 | /* Number of loop insns. */ |
124 | unsigned ninsns; | |
125 | ||
3d436d2a | 126 | /* Basic block of loop header. */ |
b8244d74 | 127 | basic_block header; |
3d436d2a ZD |
128 | |
129 | /* Basic block of loop latch. */ | |
b8244d74 | 130 | basic_block latch; |
3d436d2a | 131 | |
3d436d2a ZD |
132 | /* For loop unrolling/peeling decision. */ |
133 | struct lpt_decision lpt_decision; | |
134 | ||
3d436d2a ZD |
135 | /* Average number of executed insns per iteration. */ |
136 | unsigned av_ninsns; | |
137 | ||
3d436d2a ZD |
138 | /* Number of blocks contained within the loop. */ |
139 | unsigned num_nodes; | |
140 | ||
9ba025a2 | 141 | /* Superloops of the loop, starting with the outermost loop. */ |
9771b263 | 142 | vec<loop_p, va_gc> *superloops; |
3d436d2a ZD |
143 | |
144 | /* The first inner (child) loop or NULL if innermost loop. */ | |
99b1c316 | 145 | class loop *inner; |
3d436d2a ZD |
146 | |
147 | /* Link to the next (sibling) loop. */ | |
99b1c316 | 148 | class loop *next; |
3d436d2a | 149 | |
3d436d2a | 150 | /* Auxiliary info specific to a pass. */ |
9e2f83a5 | 151 | PTR GTY ((skip (""))) aux; |
3d436d2a | 152 | |
0a74c758 SP |
153 | /* The number of times the latch of the loop is executed. This can be an |
154 | INTEGER_CST, or a symbolic expression representing the number of | |
155 | iterations like "N - 1", or a COND_EXPR containing the runtime | |
156 | conditions under which the number of iterations is non zero. | |
157 | ||
158 | Don't access this field directly: number_of_latch_executions | |
159 | computes and caches the computed information in this field. */ | |
9baba81b SP |
160 | tree nb_iterations; |
161 | ||
b4a9343c ZD |
162 | /* An integer guaranteed to be greater or equal to nb_iterations. Only |
163 | valid if any_upper_bound is true. */ | |
807e902e | 164 | widest_int nb_iterations_upper_bound; |
9bdb685e | 165 | |
105e29c5 JH |
166 | widest_int nb_iterations_likely_upper_bound; |
167 | ||
b4a9343c ZD |
168 | /* An integer giving an estimate on nb_iterations. Unlike |
169 | nb_iterations_upper_bound, there is no guarantee that it is at least | |
170 | nb_iterations. */ | |
807e902e | 171 | widest_int nb_iterations_estimate; |
86df10e3 | 172 | |
74bf76ed JJ |
173 | /* If > 0, an integer, where the user asserted that for any |
174 | I in [ 0, nb_iterations ) and for any J in | |
175 | [ I, min ( I + safelen, nb_iterations ) ), the Ith and Jth iterations | |
176 | of the loop can be safely evaluated concurrently. */ | |
177 | int safelen; | |
178 | ||
f63445e5 JJ |
179 | /* Preferred vectorization factor for the loop if non-zero. */ |
180 | int simdlen; | |
181 | ||
18767ebc BC |
182 | /* Constraints are generally set by consumers and affect certain |
183 | semantics of niter analyzer APIs. Currently the APIs affected are | |
184 | number_of_iterations_exit* functions and their callers. One typical | |
185 | use case of constraints is to vectorize possibly infinite loop: | |
186 | ||
187 | 1) Compute niter->assumptions by calling niter analyzer API and | |
188 | record it as possible condition for loop versioning. | |
189 | 2) Clear buffered result of niter/scev analyzer. | |
190 | 3) Set constraint LOOP_C_FINITE assuming the loop is finite. | |
191 | 4) Analyze data references. Since data reference analysis depends | |
192 | on niter/scev analyzer, the point is that niter/scev analysis | |
193 | is done under circumstance of LOOP_C_FINITE constraint. | |
194 | 5) Version the loop with niter->assumptions computed in step 1). | |
195 | 6) Vectorize the versioned loop in which niter->assumptions is | |
196 | checked to be true. | |
197 | 7) Update constraints in versioned loops so that niter analyzer | |
198 | in following passes can use it. | |
199 | ||
200 | Note consumers are usually the loop optimizers and it is consumers' | |
201 | responsibility to set/clear constraints correctly. Failing to do | |
202 | that might result in hard to track down bugs in niter/scev consumers. */ | |
203 | unsigned constraints; | |
204 | ||
34e82342 RB |
205 | /* An integer estimation of the number of iterations. Estimate_state |
206 | describes what is the state of the estimation. */ | |
207 | ENUM_BITFIELD(loop_estimation) estimate_state : 8; | |
208 | ||
209 | unsigned any_upper_bound : 1; | |
210 | unsigned any_estimate : 1; | |
211 | unsigned any_likely_upper_bound : 1; | |
212 | ||
213 | /* True if the loop can be parallel. */ | |
214 | unsigned can_be_parallel : 1; | |
215 | ||
216 | /* True if -Waggressive-loop-optimizations warned about this loop | |
217 | already. */ | |
218 | unsigned warned_aggressive_loop_optimizations : 1; | |
219 | ||
5ce9450f | 220 | /* True if this loop should never be vectorized. */ |
34e82342 | 221 | unsigned dont_vectorize : 1; |
5ce9450f | 222 | |
718c4601 | 223 | /* True if we should try harder to vectorize this loop. */ |
34e82342 | 224 | unsigned force_vectorize : 1; |
718c4601 | 225 | |
886c388d | 226 | /* True if the loop is part of an oacc kernels region. */ |
34e82342 | 227 | unsigned in_oacc_kernels_region : 1; |
886c388d | 228 | |
ff27462e EB |
229 | /* The number of times to unroll the loop. 0 means no information given, |
230 | just do what we always do. A value of 1 means do not unroll the loop. | |
231 | A value of USHRT_MAX means unroll with no specific unrolling factor. | |
232 | Other values means unroll with the given unrolling factor. */ | |
ac9effed EB |
233 | unsigned short unroll; |
234 | ||
94ec37a9 RB |
235 | /* If this loop was inlined the main clique of the callee which does |
236 | not need remapping when copying the loop body. */ | |
237 | unsigned short owned_clique; | |
238 | ||
74bf76ed JJ |
239 | /* For SIMD loops, this is a unique identifier of the loop, referenced |
240 | by IFN_GOMP_SIMD_VF, IFN_GOMP_SIMD_LANE and IFN_GOMP_SIMD_LAST_LANE | |
241 | builtins. */ | |
242 | tree simduid; | |
243 | ||
542e7230 BC |
244 | /* In loop optimization, it's common to generate loops from the original |
245 | loop. This field records the index of the original loop which can be | |
246 | used to track the original loop from newly generated loops. This can | |
247 | be done by calling function get_loop (cfun, orig_loop_num). Note the | |
248 | original loop could be destroyed for various reasons thus no longer | |
249 | exists, as a result, function call to get_loop returns NULL pointer. | |
250 | In this case, this field should not be used and needs to be cleared | |
251 | whenever possible. */ | |
252 | int orig_loop_num; | |
253 | ||
e9eb809d | 254 | /* Upper bound on number of iterations of a loop. */ |
99b1c316 | 255 | class nb_iter_bound *bounds; |
82b85a85 | 256 | |
2f07b722 BC |
257 | /* Non-overflow control ivs of a loop. */ |
258 | struct control_iv *control_ivs; | |
259 | ||
6270df4c | 260 | /* Head of the cyclic list of the exits of the loop. */ |
9e2f83a5 | 261 | struct loop_exit *exits; |
ef23e6a2 RB |
262 | |
263 | /* Number of iteration analysis data for RTL. */ | |
99b1c316 | 264 | class niter_desc *simple_loop_desc; |
e4ca2139 | 265 | |
e4ca2139 RB |
266 | /* For sanity checking during loop fixup we record here the former |
267 | loop header for loops marked for removal. Note that this prevents | |
268 | the basic-block from being collected but its index can still be | |
269 | reused. */ | |
270 | basic_block former_header; | |
3d436d2a ZD |
271 | }; |
272 | ||
18767ebc BC |
273 | /* Set if the loop is known to be infinite. */ |
274 | #define LOOP_C_INFINITE (1 << 0) | |
275 | /* Set if the loop is known to be finite without any assumptions. */ | |
276 | #define LOOP_C_FINITE (1 << 1) | |
277 | ||
278 | /* Set C to the LOOP constraint. */ | |
279 | static inline void | |
99b1c316 | 280 | loop_constraint_set (class loop *loop, unsigned c) |
18767ebc BC |
281 | { |
282 | loop->constraints |= c; | |
283 | } | |
284 | ||
285 | /* Clear C from the LOOP constraint. */ | |
286 | static inline void | |
99b1c316 | 287 | loop_constraint_clear (class loop *loop, unsigned c) |
18767ebc BC |
288 | { |
289 | loop->constraints &= ~c; | |
290 | } | |
291 | ||
292 | /* Check if C is set in the LOOP constraint. */ | |
293 | static inline bool | |
99b1c316 | 294 | loop_constraint_set_p (class loop *loop, unsigned c) |
18767ebc BC |
295 | { |
296 | return (loop->constraints & c) == c; | |
297 | } | |
298 | ||
3d436d2a ZD |
299 | /* Flags for state of loop structure. */ |
300 | enum | |
301 | { | |
302 | LOOPS_HAVE_PREHEADERS = 1, | |
303 | LOOPS_HAVE_SIMPLE_LATCHES = 2, | |
82b85a85 | 304 | LOOPS_HAVE_MARKED_IRREDUCIBLE_REGIONS = 4, |
89f8f30f | 305 | LOOPS_HAVE_RECORDED_EXITS = 8, |
c7b852c8 | 306 | LOOPS_MAY_HAVE_MULTIPLE_LATCHES = 16, |
592c303d | 307 | LOOP_CLOSED_SSA = 32, |
e855c69d AB |
308 | LOOPS_NEED_FIXUP = 64, |
309 | LOOPS_HAVE_FALLTHRU_PREHEADERS = 128 | |
3d436d2a ZD |
310 | }; |
311 | ||
d78f3f78 ZD |
312 | #define LOOPS_NORMAL (LOOPS_HAVE_PREHEADERS | LOOPS_HAVE_SIMPLE_LATCHES \ |
313 | | LOOPS_HAVE_MARKED_IRREDUCIBLE_REGIONS) | |
89f8f30f | 314 | #define AVOID_CFG_MODIFICATIONS (LOOPS_MAY_HAVE_MULTIPLE_LATCHES) |
d78f3f78 | 315 | |
3d436d2a | 316 | /* Structure to hold CFG information about natural loops within a function. */ |
d1b38208 | 317 | struct GTY (()) loops { |
0162f155 RG |
318 | /* State of loops. */ |
319 | int state; | |
3d436d2a | 320 | |
42fd6772 | 321 | /* Array of the loops. */ |
9771b263 | 322 | vec<loop_p, va_gc> *larray; |
3d436d2a | 323 | |
6270df4c ZD |
324 | /* Maps edges to the list of their descriptions as loop exits. Edges |
325 | whose sources or destinations have loop_father == NULL (which may | |
326 | happen during the cfg manipulations) should not appear in EXITS. */ | |
2a22f99c | 327 | hash_table<loop_exit_hasher> *GTY(()) exits; |
6270df4c | 328 | |
3d436d2a | 329 | /* Pointer to root of loop hierarchy tree. */ |
99b1c316 | 330 | class loop *tree_root; |
3d436d2a ZD |
331 | }; |
332 | ||
3d436d2a | 333 | /* Loop recognition. */ |
0375167b | 334 | bool bb_loop_header_p (basic_block); |
dd366ec3 | 335 | void init_loops_structure (struct function *, struct loops *, unsigned); |
0375167b | 336 | extern struct loops *flow_loops_find (struct loops *); |
89f8f30f | 337 | extern void disambiguate_loops_with_multiple_latches (void); |
d329e058 | 338 | extern void flow_loops_free (struct loops *); |
d73be268 | 339 | extern void flow_loops_dump (FILE *, |
99b1c316 MS |
340 | void (*)(const class loop *, FILE *, int), int); |
341 | extern void flow_loop_dump (const class loop *, FILE *, | |
342 | void (*)(const class loop *, FILE *, int), int); | |
343 | class loop *alloc_loop (void); | |
344 | extern void flow_loop_free (class loop *); | |
345 | int flow_loop_nodes_find (basic_block, class loop *); | |
8e89b5b5 | 346 | unsigned fix_loop_structure (bitmap changed_bbs); |
2de58650 | 347 | bool mark_irreducible_loops (void); |
61183076 | 348 | void release_recorded_exits (function *); |
6270df4c ZD |
349 | void record_loop_exits (void); |
350 | void rescan_loop_exit (edge, bool, bool); | |
26993e95 | 351 | void sort_sibling_loops (function *); |
3d436d2a | 352 | |
4d6922ee | 353 | /* Loop data structure manipulation/querying. */ |
99b1c316 MS |
354 | extern void flow_loop_tree_node_add (class loop *, class loop *, |
355 | class loop * = NULL); | |
356 | extern void flow_loop_tree_node_remove (class loop *); | |
357 | extern bool flow_loop_nested_p (const class loop *, const class loop *); | |
358 | extern bool flow_bb_inside_loop_p (const class loop *, const_basic_block); | |
359 | extern class loop * find_common_loop (class loop *, class loop *); | |
360 | class loop *superloop_at_depth (class loop *, unsigned); | |
a79683d5 | 361 | struct eni_weights; |
99b1c316 MS |
362 | extern int num_loop_insns (const class loop *); |
363 | extern int average_num_loop_insns (const class loop *); | |
364 | extern unsigned get_loop_level (const class loop *); | |
365 | extern bool loop_exit_edge_p (const class loop *, const_edge); | |
366 | extern bool loop_exits_to_bb_p (class loop *, basic_block); | |
367 | extern bool loop_exits_from_bb_p (class loop *, basic_block); | |
d73be268 | 368 | extern void mark_loop_exit_edges (void); |
99b1c316 | 369 | extern dump_user_location_t get_loop_location (class loop *loop); |
3d436d2a ZD |
370 | |
371 | /* Loops & cfg manipulation. */ | |
99b1c316 MS |
372 | extern basic_block *get_loop_body (const class loop *); |
373 | extern unsigned get_loop_body_with_size (const class loop *, basic_block *, | |
89f8f30f | 374 | unsigned); |
99b1c316 MS |
375 | extern basic_block *get_loop_body_in_dom_order (const class loop *); |
376 | extern basic_block *get_loop_body_in_bfs_order (const class loop *); | |
377 | extern basic_block *get_loop_body_in_custom_order (const class loop *, | |
e855c69d | 378 | int (*) (const void *, const void *)); |
eef99cd9 GB |
379 | extern basic_block *get_loop_body_in_custom_order (const class loop *, void *, |
380 | int (*) (const void *, const void *, void *)); | |
e855c69d | 381 | |
f10d2d85 | 382 | extern vec<edge> get_loop_exit_edges (const class loop *, basic_block * = NULL); |
99b1c316 | 383 | extern edge single_exit (const class loop *); |
f10d2d85 | 384 | extern edge single_likely_exit (class loop *loop, vec<edge>); |
99b1c316 | 385 | extern unsigned num_loop_branches (const class loop *); |
3d436d2a | 386 | |
99b1c316 MS |
387 | extern edge loop_preheader_edge (const class loop *); |
388 | extern edge loop_latch_edge (const class loop *); | |
3d436d2a | 389 | |
99b1c316 | 390 | extern void add_bb_to_loop (basic_block, class loop *); |
d329e058 | 391 | extern void remove_bb_from_loops (basic_block); |
3d436d2a | 392 | |
99b1c316 MS |
393 | extern void cancel_loop_tree (class loop *); |
394 | extern void delete_loop (class loop *); | |
3d436d2a | 395 | |
3d436d2a | 396 | |
d73be268 | 397 | extern void verify_loop_structure (void); |
3d436d2a ZD |
398 | |
399 | /* Loop analysis. */ | |
99b1c316 MS |
400 | extern bool just_once_each_iteration_p (const class loop *, const_basic_block); |
401 | gcov_type expected_loop_iterations_unbounded (const class loop *, | |
65739a68 | 402 | bool *read_profile_p = NULL, bool by_profile_only = false); |
99b1c316 | 403 | extern unsigned expected_loop_iterations (class loop *); |
30d2ef86 | 404 | extern rtx doloop_condition_get (rtx_insn *); |
617b465c | 405 | |
08c13199 RB |
406 | void mark_loop_for_removal (loop_p); |
407 | ||
50654f6c ZD |
408 | /* Induction variable analysis. */ |
409 | ||
410 | /* The description of induction variable. The things are a bit complicated | |
411 | due to need to handle subregs and extends. The value of the object described | |
412 | by it can be obtained as follows (all computations are done in extend_mode): | |
413 | ||
414 | Value in i-th iteration is | |
415 | delta + mult * extend_{extend_mode} (subreg_{mode} (base + i * step)). | |
416 | ||
417 | If first_special is true, the value in the first iteration is | |
418 | delta + mult * base | |
c22cacf3 | 419 | |
f822d252 | 420 | If extend = UNKNOWN, first_special must be false, delta 0, mult 1 and value is |
50654f6c ZD |
421 | subreg_{mode} (base + i * step) |
422 | ||
423 | The get_iv_value function can be used to obtain these expressions. | |
424 | ||
425 | ??? Add a third mode field that would specify the mode in that inner | |
426 | computation is done, which would enable it to be different from the | |
427 | outer one? */ | |
428 | ||
6c1dae73 | 429 | class rtx_iv |
50654f6c | 430 | { |
6c1dae73 | 431 | public: |
50654f6c ZD |
432 | /* Its base and step (mode of base and step is supposed to be extend_mode, |
433 | see the description above). */ | |
434 | rtx base, step; | |
435 | ||
1c1ad7bb SB |
436 | /* The type of extend applied to it (IV_SIGN_EXTEND, IV_ZERO_EXTEND, |
437 | or IV_UNKNOWN_EXTEND). */ | |
438 | enum iv_extend_code extend; | |
50654f6c ZD |
439 | |
440 | /* Operations applied in the extended mode. */ | |
441 | rtx delta, mult; | |
442 | ||
443 | /* The mode it is extended to. */ | |
3d88d1cd | 444 | scalar_int_mode extend_mode; |
50654f6c ZD |
445 | |
446 | /* The mode the variable iterates in. */ | |
3d88d1cd | 447 | scalar_int_mode mode; |
50654f6c | 448 | |
50654f6c ZD |
449 | /* Whether the first iteration needs to be handled specially. */ |
450 | unsigned first_special : 1; | |
451 | }; | |
452 | ||
f2dca510 ZD |
453 | /* The description of an exit from the loop and of the number of iterations |
454 | till we take the exit. */ | |
50654f6c | 455 | |
6c1dae73 | 456 | class GTY(()) niter_desc |
50654f6c | 457 | { |
6c1dae73 | 458 | public: |
50654f6c ZD |
459 | /* The edge out of the loop. */ |
460 | edge out_edge; | |
461 | ||
462 | /* The other edge leading from the condition. */ | |
463 | edge in_edge; | |
464 | ||
465 | /* True if we are able to say anything about number of iterations of the | |
466 | loop. */ | |
467 | bool simple_p; | |
468 | ||
469 | /* True if the loop iterates the constant number of times. */ | |
470 | bool const_iter; | |
471 | ||
472 | /* Number of iterations if constant. */ | |
a9243bfc | 473 | uint64_t niter; |
50654f6c | 474 | |
50654f6c ZD |
475 | /* Assumptions under that the rest of the information is valid. */ |
476 | rtx assumptions; | |
477 | ||
478 | /* Assumptions under that the loop ends before reaching the latch, | |
479 | even if value of niter_expr says otherwise. */ | |
480 | rtx noloop_assumptions; | |
481 | ||
482 | /* Condition under that the loop is infinite. */ | |
483 | rtx infinite; | |
484 | ||
485 | /* Whether the comparison is signed. */ | |
486 | bool signed_p; | |
487 | ||
488 | /* The mode in that niter_expr should be computed. */ | |
3d88d1cd | 489 | scalar_int_mode mode; |
50654f6c ZD |
490 | |
491 | /* The number of iterations of the loop. */ | |
492 | rtx niter_expr; | |
493 | }; | |
494 | ||
99b1c316 MS |
495 | extern void iv_analysis_loop_init (class loop *); |
496 | extern bool iv_analyze (rtx_insn *, scalar_int_mode, rtx, class rtx_iv *); | |
497 | extern bool iv_analyze_result (rtx_insn *, rtx, class rtx_iv *); | |
3d88d1cd | 498 | extern bool iv_analyze_expr (rtx_insn *, scalar_int_mode, rtx, |
99b1c316 MS |
499 | class rtx_iv *); |
500 | extern rtx get_iv_value (class rtx_iv *, rtx); | |
3d88d1cd | 501 | extern bool biv_p (rtx_insn *, scalar_int_mode, rtx); |
50654f6c ZD |
502 | extern void iv_analysis_done (void); |
503 | ||
99b1c316 MS |
504 | extern class niter_desc *get_simple_loop_desc (class loop *loop); |
505 | extern void free_simple_loop_desc (class loop *loop); | |
50654f6c | 506 | |
99b1c316 MS |
507 | static inline class niter_desc * |
508 | simple_loop_desc (class loop *loop) | |
50654f6c | 509 | { |
ef23e6a2 | 510 | return loop->simple_loop_desc; |
50654f6c ZD |
511 | } |
512 | ||
42fd6772 ZD |
513 | /* Accessors for the loop structures. */ |
514 | ||
0fc822d0 | 515 | /* Returns the loop with index NUM from FNs loop tree. */ |
42fd6772 | 516 | |
99b1c316 | 517 | static inline class loop * |
0fc822d0 | 518 | get_loop (struct function *fn, unsigned num) |
42fd6772 | 519 | { |
0fc822d0 | 520 | return (*loops_for_fn (fn)->larray)[num]; |
42fd6772 ZD |
521 | } |
522 | ||
9ba025a2 ZD |
523 | /* Returns the number of superloops of LOOP. */ |
524 | ||
525 | static inline unsigned | |
99b1c316 | 526 | loop_depth (const class loop *loop) |
9ba025a2 | 527 | { |
9771b263 | 528 | return vec_safe_length (loop->superloops); |
9ba025a2 ZD |
529 | } |
530 | ||
531 | /* Returns the immediate superloop of LOOP, or NULL if LOOP is the outermost | |
532 | loop. */ | |
533 | ||
99b1c316 MS |
534 | static inline class loop * |
535 | loop_outer (const class loop *loop) | |
9ba025a2 | 536 | { |
9771b263 | 537 | unsigned n = vec_safe_length (loop->superloops); |
9ba025a2 ZD |
538 | |
539 | if (n == 0) | |
540 | return NULL; | |
541 | ||
9771b263 | 542 | return (*loop->superloops)[n - 1]; |
9ba025a2 ZD |
543 | } |
544 | ||
07643d76 AM |
545 | /* Returns true if LOOP has at least one exit edge. */ |
546 | ||
547 | static inline bool | |
99b1c316 | 548 | loop_has_exit_edges (const class loop *loop) |
07643d76 AM |
549 | { |
550 | return loop->exits->next->e != NULL; | |
551 | } | |
552 | ||
0fc822d0 | 553 | /* Returns the list of loops in FN. */ |
42fd6772 | 554 | |
0fc822d0 RB |
555 | inline vec<loop_p, va_gc> * |
556 | get_loops (struct function *fn) | |
42fd6772 | 557 | { |
0fc822d0 RB |
558 | struct loops *loops = loops_for_fn (fn); |
559 | if (!loops) | |
42fd6772 ZD |
560 | return NULL; |
561 | ||
0fc822d0 | 562 | return loops->larray; |
42fd6772 ZD |
563 | } |
564 | ||
0fc822d0 | 565 | /* Returns the number of loops in FN (including the removed |
42fd6772 ZD |
566 | ones and the fake loop that forms the root of the loop tree). */ |
567 | ||
568 | static inline unsigned | |
0fc822d0 | 569 | number_of_loops (struct function *fn) |
42fd6772 | 570 | { |
0fc822d0 | 571 | struct loops *loops = loops_for_fn (fn); |
0d0e2af6 | 572 | if (!loops) |
42fd6772 ZD |
573 | return 0; |
574 | ||
0fc822d0 | 575 | return vec_safe_length (loops->larray); |
42fd6772 ZD |
576 | } |
577 | ||
f87000d0 ZD |
578 | /* Returns true if state of the loops satisfies all properties |
579 | described by FLAGS. */ | |
580 | ||
61183076 RB |
581 | static inline bool |
582 | loops_state_satisfies_p (function *fn, unsigned flags) | |
583 | { | |
584 | return (loops_for_fn (fn)->state & flags) == flags; | |
585 | } | |
586 | ||
f87000d0 ZD |
587 | static inline bool |
588 | loops_state_satisfies_p (unsigned flags) | |
589 | { | |
61183076 | 590 | return loops_state_satisfies_p (cfun, flags); |
f87000d0 ZD |
591 | } |
592 | ||
593 | /* Sets FLAGS to the loops state. */ | |
594 | ||
61183076 RB |
595 | static inline void |
596 | loops_state_set (function *fn, unsigned flags) | |
597 | { | |
598 | loops_for_fn (fn)->state |= flags; | |
599 | } | |
600 | ||
f87000d0 ZD |
601 | static inline void |
602 | loops_state_set (unsigned flags) | |
603 | { | |
61183076 | 604 | loops_state_set (cfun, flags); |
f87000d0 ZD |
605 | } |
606 | ||
607 | /* Clears FLAGS from the loops state. */ | |
608 | ||
61183076 RB |
609 | static inline void |
610 | loops_state_clear (function *fn, unsigned flags) | |
611 | { | |
612 | loops_for_fn (fn)->state &= ~flags; | |
613 | } | |
614 | ||
f87000d0 ZD |
615 | static inline void |
616 | loops_state_clear (unsigned flags) | |
617 | { | |
618 | if (!current_loops) | |
619 | return; | |
61183076 | 620 | loops_state_clear (cfun, flags); |
f87000d0 ZD |
621 | } |
622 | ||
a84a49b7 RB |
623 | /* Check loop structure invariants, if internal consistency checks are |
624 | enabled. */ | |
625 | ||
626 | static inline void | |
627 | checking_verify_loop_structure (void) | |
628 | { | |
629 | /* VERIFY_LOOP_STRUCTURE essentially asserts that no loops need fixups. | |
630 | ||
631 | The loop optimizers should never make changes to the CFG which | |
632 | require loop fixups. But the low level CFG manipulation code may | |
633 | set the flag conservatively. | |
634 | ||
635 | Go ahead and clear the flag here. That avoids the assert inside | |
636 | VERIFY_LOOP_STRUCTURE, and if there is an inconsistency in the loop | |
637 | structures VERIFY_LOOP_STRUCTURE will detect it. | |
638 | ||
639 | This also avoid the compile time cost of excessive fixups. */ | |
640 | loops_state_clear (LOOPS_NEED_FIXUP); | |
641 | if (flag_checking) | |
642 | verify_loop_structure (); | |
643 | } | |
644 | ||
42fd6772 ZD |
645 | /* Loop iterators. */ |
646 | ||
647 | /* Flags for loop iteration. */ | |
648 | ||
649 | enum li_flags | |
650 | { | |
677cc14d ZD |
651 | LI_INCLUDE_ROOT = 1, /* Include the fake root of the loop tree. */ |
652 | LI_FROM_INNERMOST = 2, /* Iterate over the loops in the reverse order, | |
653 | starting from innermost ones. */ | |
654 | LI_ONLY_INNERMOST = 4 /* Iterate only over innermost loops. */ | |
42fd6772 ZD |
655 | }; |
656 | ||
657 | /* The iterator for loops. */ | |
658 | ||
6c1dae73 | 659 | class loop_iterator |
42fd6772 | 660 | { |
6c1dae73 | 661 | public: |
61183076 | 662 | loop_iterator (function *fn, loop_p *loop, unsigned flags); |
f0bd40b1 RB |
663 | |
664 | inline loop_p next (); | |
665 | ||
61183076 RB |
666 | /* The function we are visiting. */ |
667 | function *fn; | |
668 | ||
677cc14d | 669 | /* The list of loops to visit. */ |
d78b7095 | 670 | auto_vec<int, 16> to_visit; |
677cc14d ZD |
671 | |
672 | /* The index of the actual loop. */ | |
673 | unsigned idx; | |
f0bd40b1 | 674 | }; |
42fd6772 | 675 | |
f0bd40b1 RB |
676 | inline loop_p |
677 | loop_iterator::next () | |
42fd6772 | 678 | { |
677cc14d ZD |
679 | int anum; |
680 | ||
f0bd40b1 | 681 | while (this->to_visit.iterate (this->idx, &anum)) |
42fd6772 | 682 | { |
f0bd40b1 | 683 | this->idx++; |
61183076 | 684 | loop_p loop = get_loop (fn, anum); |
f0bd40b1 RB |
685 | if (loop) |
686 | return loop; | |
42fd6772 ZD |
687 | } |
688 | ||
f0bd40b1 | 689 | return NULL; |
42fd6772 ZD |
690 | } |
691 | ||
f0bd40b1 | 692 | inline |
61183076 | 693 | loop_iterator::loop_iterator (function *fn, loop_p *loop, unsigned flags) |
42fd6772 | 694 | { |
99b1c316 | 695 | class loop *aloop; |
677cc14d ZD |
696 | unsigned i; |
697 | int mn; | |
698 | ||
f0bd40b1 | 699 | this->idx = 0; |
61183076 RB |
700 | this->fn = fn; |
701 | if (!loops_for_fn (fn)) | |
42fd6772 | 702 | { |
42fd6772 ZD |
703 | *loop = NULL; |
704 | return; | |
705 | } | |
706 | ||
d78b7095 | 707 | this->to_visit.reserve_exact (number_of_loops (fn)); |
677cc14d ZD |
708 | mn = (flags & LI_INCLUDE_ROOT) ? 0 : 1; |
709 | ||
710 | if (flags & LI_ONLY_INNERMOST) | |
711 | { | |
61183076 | 712 | for (i = 0; vec_safe_iterate (loops_for_fn (fn)->larray, i, &aloop); i++) |
677cc14d ZD |
713 | if (aloop != NULL |
714 | && aloop->inner == NULL | |
715 | && aloop->num >= mn) | |
f0bd40b1 | 716 | this->to_visit.quick_push (aloop->num); |
677cc14d ZD |
717 | } |
718 | else if (flags & LI_FROM_INNERMOST) | |
42fd6772 | 719 | { |
677cc14d | 720 | /* Push the loops to LI->TO_VISIT in postorder. */ |
61183076 | 721 | for (aloop = loops_for_fn (fn)->tree_root; |
677cc14d ZD |
722 | aloop->inner != NULL; |
723 | aloop = aloop->inner) | |
724 | continue; | |
725 | ||
726 | while (1) | |
727 | { | |
728 | if (aloop->num >= mn) | |
f0bd40b1 | 729 | this->to_visit.quick_push (aloop->num); |
677cc14d ZD |
730 | |
731 | if (aloop->next) | |
732 | { | |
733 | for (aloop = aloop->next; | |
734 | aloop->inner != NULL; | |
735 | aloop = aloop->inner) | |
736 | continue; | |
737 | } | |
9ba025a2 | 738 | else if (!loop_outer (aloop)) |
677cc14d ZD |
739 | break; |
740 | else | |
9ba025a2 | 741 | aloop = loop_outer (aloop); |
677cc14d | 742 | } |
42fd6772 ZD |
743 | } |
744 | else | |
745 | { | |
677cc14d | 746 | /* Push the loops to LI->TO_VISIT in preorder. */ |
61183076 | 747 | aloop = loops_for_fn (fn)->tree_root; |
677cc14d ZD |
748 | while (1) |
749 | { | |
750 | if (aloop->num >= mn) | |
f0bd40b1 | 751 | this->to_visit.quick_push (aloop->num); |
677cc14d ZD |
752 | |
753 | if (aloop->inner != NULL) | |
754 | aloop = aloop->inner; | |
755 | else | |
756 | { | |
757 | while (aloop != NULL && aloop->next == NULL) | |
9ba025a2 | 758 | aloop = loop_outer (aloop); |
677cc14d ZD |
759 | if (aloop == NULL) |
760 | break; | |
761 | aloop = aloop->next; | |
762 | } | |
763 | } | |
42fd6772 | 764 | } |
677cc14d | 765 | |
f0bd40b1 | 766 | *loop = this->next (); |
42fd6772 ZD |
767 | } |
768 | ||
f0bd40b1 | 769 | #define FOR_EACH_LOOP(LOOP, FLAGS) \ |
61183076 RB |
770 | for (loop_iterator li(cfun, &(LOOP), FLAGS); \ |
771 | (LOOP); \ | |
772 | (LOOP) = li.next ()) | |
773 | ||
774 | #define FOR_EACH_LOOP_FN(FN, LOOP, FLAGS) \ | |
650a8fcf | 775 | for (loop_iterator li(FN, &(LOOP), FLAGS); \ |
f0bd40b1 RB |
776 | (LOOP); \ |
777 | (LOOP) = li.next ()) | |
42fd6772 | 778 | |
8b11a64c | 779 | /* The properties of the target. */ |
4391924a RS |
780 | struct target_cfgloop { |
781 | /* Number of available registers. */ | |
782 | unsigned x_target_avail_regs; | |
8b11a64c | 783 | |
4391924a RS |
784 | /* Number of available registers that are call-clobbered. */ |
785 | unsigned x_target_clobbered_regs; | |
786 | ||
787 | /* Number of registers reserved for temporary expressions. */ | |
788 | unsigned x_target_res_regs; | |
789 | ||
790 | /* The cost for register when there still is some reserve, but we are | |
791 | approaching the number of available registers. */ | |
792 | unsigned x_target_reg_cost[2]; | |
793 | ||
794 | /* The cost for register when we need to spill. */ | |
795 | unsigned x_target_spill_cost[2]; | |
796 | }; | |
797 | ||
798 | extern struct target_cfgloop default_target_cfgloop; | |
799 | #if SWITCHABLE_TARGET | |
800 | extern struct target_cfgloop *this_target_cfgloop; | |
801 | #else | |
802 | #define this_target_cfgloop (&default_target_cfgloop) | |
803 | #endif | |
804 | ||
805 | #define target_avail_regs \ | |
806 | (this_target_cfgloop->x_target_avail_regs) | |
807 | #define target_clobbered_regs \ | |
808 | (this_target_cfgloop->x_target_clobbered_regs) | |
809 | #define target_res_regs \ | |
810 | (this_target_cfgloop->x_target_res_regs) | |
811 | #define target_reg_cost \ | |
812 | (this_target_cfgloop->x_target_reg_cost) | |
813 | #define target_spill_cost \ | |
814 | (this_target_cfgloop->x_target_spill_cost) | |
8b11a64c | 815 | |
5e962776 ZD |
816 | /* Register pressure estimation for induction variable optimizations & loop |
817 | invariant motion. */ | |
bec922f0 | 818 | extern unsigned estimate_reg_pressure_cost (unsigned, unsigned, bool, bool); |
5e962776 ZD |
819 | extern void init_set_costs (void); |
820 | ||
617b465c | 821 | /* Loop optimizer initialization. */ |
598ec7bd | 822 | extern void loop_optimizer_init (unsigned); |
61183076 RB |
823 | extern void loop_optimizer_finalize (function *); |
824 | inline void | |
825 | loop_optimizer_finalize () | |
826 | { | |
827 | loop_optimizer_finalize (cfun); | |
828 | } | |
617b465c ZD |
829 | |
830 | /* Optimization passes. */ | |
b17d5d7c ZD |
831 | enum |
832 | { | |
f8934be7 JH |
833 | UAP_UNROLL = 1, /* Enables unrolling of loops if it seems profitable. */ |
834 | UAP_UNROLL_ALL = 2 /* Enables unrolling of all loops. */ | |
b17d5d7c ZD |
835 | }; |
836 | ||
d73be268 ZD |
837 | extern void doloop_optimize_loops (void); |
838 | extern void move_loop_invariants (void); | |
99b1c316 | 839 | extern vec<basic_block> get_loop_hot_path (const class loop *loop); |
59587b18 | 840 | |
a5497b12 | 841 | /* Returns the outermost loop of the loop nest that contains LOOP.*/ |
99b1c316 MS |
842 | static inline class loop * |
843 | loop_outermost (class loop *loop) | |
a5497b12 | 844 | { |
9771b263 | 845 | unsigned n = vec_safe_length (loop->superloops); |
a5497b12 VK |
846 | |
847 | if (n <= 1) | |
848 | return loop; | |
849 | ||
9771b263 | 850 | return (*loop->superloops)[1]; |
a5497b12 VK |
851 | } |
852 | ||
99b1c316 MS |
853 | extern void record_niter_bound (class loop *, const widest_int &, bool, bool); |
854 | extern HOST_WIDE_INT get_estimated_loop_iterations_int (class loop *); | |
855 | extern HOST_WIDE_INT get_max_loop_iterations_int (const class loop *); | |
856 | extern HOST_WIDE_INT get_likely_max_loop_iterations_int (class loop *); | |
857 | extern bool get_estimated_loop_iterations (class loop *loop, widest_int *nit); | |
858 | extern bool get_max_loop_iterations (const class loop *loop, widest_int *nit); | |
859 | extern bool get_likely_max_loop_iterations (class loop *loop, widest_int *nit); | |
4484a35a | 860 | extern int bb_loop_depth (const_basic_block); |
a5497b12 | 861 | |
807e902e | 862 | /* Converts VAL to widest_int. */ |
71343877 | 863 | |
807e902e KZ |
864 | static inline widest_int |
865 | gcov_type_to_wide_int (gcov_type val) | |
71343877 | 866 | { |
807e902e | 867 | HOST_WIDE_INT a[2]; |
71343877 | 868 | |
807e902e | 869 | a[0] = (unsigned HOST_WIDE_INT) val; |
71343877 AM |
870 | /* If HOST_BITS_PER_WIDE_INT == HOST_BITS_PER_WIDEST_INT, avoid shifting by |
871 | the size of type. */ | |
872 | val >>= HOST_BITS_PER_WIDE_INT - 1; | |
873 | val >>= 1; | |
807e902e | 874 | a[1] = (unsigned HOST_WIDE_INT) val; |
71343877 | 875 | |
807e902e | 876 | return widest_int::from_array (a, 2); |
71343877 | 877 | } |
59587b18 | 878 | #endif /* GCC_CFGLOOP_H */ |