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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 | |
75efe9cb RB |
229 | /* True if the loop is known to be finite. This is a localized |
230 | flag_finite_loops or similar pragmas state. */ | |
231 | unsigned finite_p : 1; | |
232 | ||
ff27462e EB |
233 | /* The number of times to unroll the loop. 0 means no information given, |
234 | just do what we always do. A value of 1 means do not unroll the loop. | |
235 | A value of USHRT_MAX means unroll with no specific unrolling factor. | |
236 | Other values means unroll with the given unrolling factor. */ | |
ac9effed EB |
237 | unsigned short unroll; |
238 | ||
94ec37a9 RB |
239 | /* If this loop was inlined the main clique of the callee which does |
240 | not need remapping when copying the loop body. */ | |
241 | unsigned short owned_clique; | |
242 | ||
74bf76ed JJ |
243 | /* For SIMD loops, this is a unique identifier of the loop, referenced |
244 | by IFN_GOMP_SIMD_VF, IFN_GOMP_SIMD_LANE and IFN_GOMP_SIMD_LAST_LANE | |
245 | builtins. */ | |
246 | tree simduid; | |
247 | ||
542e7230 BC |
248 | /* In loop optimization, it's common to generate loops from the original |
249 | loop. This field records the index of the original loop which can be | |
250 | used to track the original loop from newly generated loops. This can | |
251 | be done by calling function get_loop (cfun, orig_loop_num). Note the | |
252 | original loop could be destroyed for various reasons thus no longer | |
253 | exists, as a result, function call to get_loop returns NULL pointer. | |
254 | In this case, this field should not be used and needs to be cleared | |
255 | whenever possible. */ | |
256 | int orig_loop_num; | |
257 | ||
e9eb809d | 258 | /* Upper bound on number of iterations of a loop. */ |
99b1c316 | 259 | class nb_iter_bound *bounds; |
82b85a85 | 260 | |
2f07b722 BC |
261 | /* Non-overflow control ivs of a loop. */ |
262 | struct control_iv *control_ivs; | |
263 | ||
6270df4c | 264 | /* Head of the cyclic list of the exits of the loop. */ |
9e2f83a5 | 265 | struct loop_exit *exits; |
ef23e6a2 RB |
266 | |
267 | /* Number of iteration analysis data for RTL. */ | |
99b1c316 | 268 | class niter_desc *simple_loop_desc; |
e4ca2139 | 269 | |
e4ca2139 RB |
270 | /* For sanity checking during loop fixup we record here the former |
271 | loop header for loops marked for removal. Note that this prevents | |
272 | the basic-block from being collected but its index can still be | |
273 | reused. */ | |
274 | basic_block former_header; | |
3d436d2a ZD |
275 | }; |
276 | ||
18767ebc BC |
277 | /* Set if the loop is known to be infinite. */ |
278 | #define LOOP_C_INFINITE (1 << 0) | |
279 | /* Set if the loop is known to be finite without any assumptions. */ | |
280 | #define LOOP_C_FINITE (1 << 1) | |
281 | ||
282 | /* Set C to the LOOP constraint. */ | |
283 | static inline void | |
99b1c316 | 284 | loop_constraint_set (class loop *loop, unsigned c) |
18767ebc BC |
285 | { |
286 | loop->constraints |= c; | |
287 | } | |
288 | ||
289 | /* Clear C from the LOOP constraint. */ | |
290 | static inline void | |
99b1c316 | 291 | loop_constraint_clear (class loop *loop, unsigned c) |
18767ebc BC |
292 | { |
293 | loop->constraints &= ~c; | |
294 | } | |
295 | ||
296 | /* Check if C is set in the LOOP constraint. */ | |
297 | static inline bool | |
99b1c316 | 298 | loop_constraint_set_p (class loop *loop, unsigned c) |
18767ebc BC |
299 | { |
300 | return (loop->constraints & c) == c; | |
301 | } | |
302 | ||
3d436d2a ZD |
303 | /* Flags for state of loop structure. */ |
304 | enum | |
305 | { | |
306 | LOOPS_HAVE_PREHEADERS = 1, | |
307 | LOOPS_HAVE_SIMPLE_LATCHES = 2, | |
82b85a85 | 308 | LOOPS_HAVE_MARKED_IRREDUCIBLE_REGIONS = 4, |
89f8f30f | 309 | LOOPS_HAVE_RECORDED_EXITS = 8, |
c7b852c8 | 310 | LOOPS_MAY_HAVE_MULTIPLE_LATCHES = 16, |
592c303d | 311 | LOOP_CLOSED_SSA = 32, |
e855c69d AB |
312 | LOOPS_NEED_FIXUP = 64, |
313 | LOOPS_HAVE_FALLTHRU_PREHEADERS = 128 | |
3d436d2a ZD |
314 | }; |
315 | ||
d78f3f78 ZD |
316 | #define LOOPS_NORMAL (LOOPS_HAVE_PREHEADERS | LOOPS_HAVE_SIMPLE_LATCHES \ |
317 | | LOOPS_HAVE_MARKED_IRREDUCIBLE_REGIONS) | |
89f8f30f | 318 | #define AVOID_CFG_MODIFICATIONS (LOOPS_MAY_HAVE_MULTIPLE_LATCHES) |
d78f3f78 | 319 | |
3d436d2a | 320 | /* Structure to hold CFG information about natural loops within a function. */ |
d1b38208 | 321 | struct GTY (()) loops { |
0162f155 RG |
322 | /* State of loops. */ |
323 | int state; | |
3d436d2a | 324 | |
42fd6772 | 325 | /* Array of the loops. */ |
9771b263 | 326 | vec<loop_p, va_gc> *larray; |
3d436d2a | 327 | |
6270df4c ZD |
328 | /* Maps edges to the list of their descriptions as loop exits. Edges |
329 | whose sources or destinations have loop_father == NULL (which may | |
330 | happen during the cfg manipulations) should not appear in EXITS. */ | |
2a22f99c | 331 | hash_table<loop_exit_hasher> *GTY(()) exits; |
6270df4c | 332 | |
3d436d2a | 333 | /* Pointer to root of loop hierarchy tree. */ |
99b1c316 | 334 | class loop *tree_root; |
3d436d2a ZD |
335 | }; |
336 | ||
3d436d2a | 337 | /* Loop recognition. */ |
0375167b | 338 | bool bb_loop_header_p (basic_block); |
dd366ec3 | 339 | void init_loops_structure (struct function *, struct loops *, unsigned); |
0375167b | 340 | extern struct loops *flow_loops_find (struct loops *); |
89f8f30f | 341 | extern void disambiguate_loops_with_multiple_latches (void); |
d329e058 | 342 | extern void flow_loops_free (struct loops *); |
d73be268 | 343 | extern void flow_loops_dump (FILE *, |
99b1c316 MS |
344 | void (*)(const class loop *, FILE *, int), int); |
345 | extern void flow_loop_dump (const class loop *, FILE *, | |
346 | void (*)(const class loop *, FILE *, int), int); | |
347 | class loop *alloc_loop (void); | |
348 | extern void flow_loop_free (class loop *); | |
349 | int flow_loop_nodes_find (basic_block, class loop *); | |
8e89b5b5 | 350 | unsigned fix_loop_structure (bitmap changed_bbs); |
2de58650 | 351 | bool mark_irreducible_loops (void); |
61183076 | 352 | void release_recorded_exits (function *); |
6270df4c ZD |
353 | void record_loop_exits (void); |
354 | void rescan_loop_exit (edge, bool, bool); | |
26993e95 | 355 | void sort_sibling_loops (function *); |
3d436d2a | 356 | |
4d6922ee | 357 | /* Loop data structure manipulation/querying. */ |
99b1c316 MS |
358 | extern void flow_loop_tree_node_add (class loop *, class loop *, |
359 | class loop * = NULL); | |
360 | extern void flow_loop_tree_node_remove (class loop *); | |
361 | extern bool flow_loop_nested_p (const class loop *, const class loop *); | |
362 | extern bool flow_bb_inside_loop_p (const class loop *, const_basic_block); | |
363 | extern class loop * find_common_loop (class loop *, class loop *); | |
364 | class loop *superloop_at_depth (class loop *, unsigned); | |
a79683d5 | 365 | struct eni_weights; |
99b1c316 MS |
366 | extern int num_loop_insns (const class loop *); |
367 | extern int average_num_loop_insns (const class loop *); | |
368 | extern unsigned get_loop_level (const class loop *); | |
369 | extern bool loop_exit_edge_p (const class loop *, const_edge); | |
370 | extern bool loop_exits_to_bb_p (class loop *, basic_block); | |
371 | extern bool loop_exits_from_bb_p (class loop *, basic_block); | |
d73be268 | 372 | extern void mark_loop_exit_edges (void); |
99b1c316 | 373 | extern dump_user_location_t get_loop_location (class loop *loop); |
3d436d2a ZD |
374 | |
375 | /* Loops & cfg manipulation. */ | |
99b1c316 MS |
376 | extern basic_block *get_loop_body (const class loop *); |
377 | extern unsigned get_loop_body_with_size (const class loop *, basic_block *, | |
89f8f30f | 378 | unsigned); |
99b1c316 MS |
379 | extern basic_block *get_loop_body_in_dom_order (const class loop *); |
380 | extern basic_block *get_loop_body_in_bfs_order (const class loop *); | |
381 | extern basic_block *get_loop_body_in_custom_order (const class loop *, | |
e855c69d | 382 | int (*) (const void *, const void *)); |
eef99cd9 GB |
383 | extern basic_block *get_loop_body_in_custom_order (const class loop *, void *, |
384 | int (*) (const void *, const void *, void *)); | |
e855c69d | 385 | |
f10d2d85 | 386 | extern vec<edge> get_loop_exit_edges (const class loop *, basic_block * = NULL); |
99b1c316 | 387 | extern edge single_exit (const class loop *); |
f10d2d85 | 388 | extern edge single_likely_exit (class loop *loop, vec<edge>); |
99b1c316 | 389 | extern unsigned num_loop_branches (const class loop *); |
3d436d2a | 390 | |
99b1c316 MS |
391 | extern edge loop_preheader_edge (const class loop *); |
392 | extern edge loop_latch_edge (const class loop *); | |
3d436d2a | 393 | |
99b1c316 | 394 | extern void add_bb_to_loop (basic_block, class loop *); |
d329e058 | 395 | extern void remove_bb_from_loops (basic_block); |
3d436d2a | 396 | |
99b1c316 MS |
397 | extern void cancel_loop_tree (class loop *); |
398 | extern void delete_loop (class loop *); | |
3d436d2a | 399 | |
3d436d2a | 400 | |
d73be268 | 401 | extern void verify_loop_structure (void); |
3d436d2a ZD |
402 | |
403 | /* Loop analysis. */ | |
99b1c316 MS |
404 | extern bool just_once_each_iteration_p (const class loop *, const_basic_block); |
405 | gcov_type expected_loop_iterations_unbounded (const class loop *, | |
65739a68 | 406 | bool *read_profile_p = NULL, bool by_profile_only = false); |
99b1c316 | 407 | extern unsigned expected_loop_iterations (class loop *); |
30d2ef86 | 408 | extern rtx doloop_condition_get (rtx_insn *); |
617b465c | 409 | |
08c13199 RB |
410 | void mark_loop_for_removal (loop_p); |
411 | ||
50654f6c ZD |
412 | /* Induction variable analysis. */ |
413 | ||
414 | /* The description of induction variable. The things are a bit complicated | |
415 | due to need to handle subregs and extends. The value of the object described | |
416 | by it can be obtained as follows (all computations are done in extend_mode): | |
417 | ||
418 | Value in i-th iteration is | |
419 | delta + mult * extend_{extend_mode} (subreg_{mode} (base + i * step)). | |
420 | ||
421 | If first_special is true, the value in the first iteration is | |
422 | delta + mult * base | |
c22cacf3 | 423 | |
f822d252 | 424 | If extend = UNKNOWN, first_special must be false, delta 0, mult 1 and value is |
50654f6c ZD |
425 | subreg_{mode} (base + i * step) |
426 | ||
427 | The get_iv_value function can be used to obtain these expressions. | |
428 | ||
429 | ??? Add a third mode field that would specify the mode in that inner | |
430 | computation is done, which would enable it to be different from the | |
431 | outer one? */ | |
432 | ||
6c1dae73 | 433 | class rtx_iv |
50654f6c | 434 | { |
6c1dae73 | 435 | public: |
50654f6c ZD |
436 | /* Its base and step (mode of base and step is supposed to be extend_mode, |
437 | see the description above). */ | |
438 | rtx base, step; | |
439 | ||
1c1ad7bb SB |
440 | /* The type of extend applied to it (IV_SIGN_EXTEND, IV_ZERO_EXTEND, |
441 | or IV_UNKNOWN_EXTEND). */ | |
442 | enum iv_extend_code extend; | |
50654f6c ZD |
443 | |
444 | /* Operations applied in the extended mode. */ | |
445 | rtx delta, mult; | |
446 | ||
447 | /* The mode it is extended to. */ | |
3d88d1cd | 448 | scalar_int_mode extend_mode; |
50654f6c ZD |
449 | |
450 | /* The mode the variable iterates in. */ | |
3d88d1cd | 451 | scalar_int_mode mode; |
50654f6c | 452 | |
50654f6c ZD |
453 | /* Whether the first iteration needs to be handled specially. */ |
454 | unsigned first_special : 1; | |
455 | }; | |
456 | ||
f2dca510 ZD |
457 | /* The description of an exit from the loop and of the number of iterations |
458 | till we take the exit. */ | |
50654f6c | 459 | |
6c1dae73 | 460 | class GTY(()) niter_desc |
50654f6c | 461 | { |
6c1dae73 | 462 | public: |
50654f6c ZD |
463 | /* The edge out of the loop. */ |
464 | edge out_edge; | |
465 | ||
466 | /* The other edge leading from the condition. */ | |
467 | edge in_edge; | |
468 | ||
469 | /* True if we are able to say anything about number of iterations of the | |
470 | loop. */ | |
471 | bool simple_p; | |
472 | ||
473 | /* True if the loop iterates the constant number of times. */ | |
474 | bool const_iter; | |
475 | ||
476 | /* Number of iterations if constant. */ | |
a9243bfc | 477 | uint64_t niter; |
50654f6c | 478 | |
50654f6c ZD |
479 | /* Assumptions under that the rest of the information is valid. */ |
480 | rtx assumptions; | |
481 | ||
482 | /* Assumptions under that the loop ends before reaching the latch, | |
483 | even if value of niter_expr says otherwise. */ | |
484 | rtx noloop_assumptions; | |
485 | ||
486 | /* Condition under that the loop is infinite. */ | |
487 | rtx infinite; | |
488 | ||
489 | /* Whether the comparison is signed. */ | |
490 | bool signed_p; | |
491 | ||
492 | /* The mode in that niter_expr should be computed. */ | |
3d88d1cd | 493 | scalar_int_mode mode; |
50654f6c ZD |
494 | |
495 | /* The number of iterations of the loop. */ | |
496 | rtx niter_expr; | |
497 | }; | |
498 | ||
99b1c316 MS |
499 | extern void iv_analysis_loop_init (class loop *); |
500 | extern bool iv_analyze (rtx_insn *, scalar_int_mode, rtx, class rtx_iv *); | |
501 | extern bool iv_analyze_result (rtx_insn *, rtx, class rtx_iv *); | |
3d88d1cd | 502 | extern bool iv_analyze_expr (rtx_insn *, scalar_int_mode, rtx, |
99b1c316 MS |
503 | class rtx_iv *); |
504 | extern rtx get_iv_value (class rtx_iv *, rtx); | |
3d88d1cd | 505 | extern bool biv_p (rtx_insn *, scalar_int_mode, rtx); |
50654f6c ZD |
506 | extern void iv_analysis_done (void); |
507 | ||
99b1c316 MS |
508 | extern class niter_desc *get_simple_loop_desc (class loop *loop); |
509 | extern void free_simple_loop_desc (class loop *loop); | |
50654f6c | 510 | |
99b1c316 MS |
511 | static inline class niter_desc * |
512 | simple_loop_desc (class loop *loop) | |
50654f6c | 513 | { |
ef23e6a2 | 514 | return loop->simple_loop_desc; |
50654f6c ZD |
515 | } |
516 | ||
42fd6772 ZD |
517 | /* Accessors for the loop structures. */ |
518 | ||
0fc822d0 | 519 | /* Returns the loop with index NUM from FNs loop tree. */ |
42fd6772 | 520 | |
99b1c316 | 521 | static inline class loop * |
0fc822d0 | 522 | get_loop (struct function *fn, unsigned num) |
42fd6772 | 523 | { |
0fc822d0 | 524 | return (*loops_for_fn (fn)->larray)[num]; |
42fd6772 ZD |
525 | } |
526 | ||
9ba025a2 ZD |
527 | /* Returns the number of superloops of LOOP. */ |
528 | ||
529 | static inline unsigned | |
99b1c316 | 530 | loop_depth (const class loop *loop) |
9ba025a2 | 531 | { |
9771b263 | 532 | return vec_safe_length (loop->superloops); |
9ba025a2 ZD |
533 | } |
534 | ||
535 | /* Returns the immediate superloop of LOOP, or NULL if LOOP is the outermost | |
536 | loop. */ | |
537 | ||
99b1c316 MS |
538 | static inline class loop * |
539 | loop_outer (const class loop *loop) | |
9ba025a2 | 540 | { |
9771b263 | 541 | unsigned n = vec_safe_length (loop->superloops); |
9ba025a2 ZD |
542 | |
543 | if (n == 0) | |
544 | return NULL; | |
545 | ||
9771b263 | 546 | return (*loop->superloops)[n - 1]; |
9ba025a2 ZD |
547 | } |
548 | ||
07643d76 AM |
549 | /* Returns true if LOOP has at least one exit edge. */ |
550 | ||
551 | static inline bool | |
99b1c316 | 552 | loop_has_exit_edges (const class loop *loop) |
07643d76 AM |
553 | { |
554 | return loop->exits->next->e != NULL; | |
555 | } | |
556 | ||
0fc822d0 | 557 | /* Returns the list of loops in FN. */ |
42fd6772 | 558 | |
0fc822d0 RB |
559 | inline vec<loop_p, va_gc> * |
560 | get_loops (struct function *fn) | |
42fd6772 | 561 | { |
0fc822d0 RB |
562 | struct loops *loops = loops_for_fn (fn); |
563 | if (!loops) | |
42fd6772 ZD |
564 | return NULL; |
565 | ||
0fc822d0 | 566 | return loops->larray; |
42fd6772 ZD |
567 | } |
568 | ||
0fc822d0 | 569 | /* Returns the number of loops in FN (including the removed |
42fd6772 ZD |
570 | ones and the fake loop that forms the root of the loop tree). */ |
571 | ||
572 | static inline unsigned | |
0fc822d0 | 573 | number_of_loops (struct function *fn) |
42fd6772 | 574 | { |
0fc822d0 | 575 | struct loops *loops = loops_for_fn (fn); |
0d0e2af6 | 576 | if (!loops) |
42fd6772 ZD |
577 | return 0; |
578 | ||
0fc822d0 | 579 | return vec_safe_length (loops->larray); |
42fd6772 ZD |
580 | } |
581 | ||
f87000d0 ZD |
582 | /* Returns true if state of the loops satisfies all properties |
583 | described by FLAGS. */ | |
584 | ||
61183076 RB |
585 | static inline bool |
586 | loops_state_satisfies_p (function *fn, unsigned flags) | |
587 | { | |
588 | return (loops_for_fn (fn)->state & flags) == flags; | |
589 | } | |
590 | ||
f87000d0 ZD |
591 | static inline bool |
592 | loops_state_satisfies_p (unsigned flags) | |
593 | { | |
61183076 | 594 | return loops_state_satisfies_p (cfun, flags); |
f87000d0 ZD |
595 | } |
596 | ||
597 | /* Sets FLAGS to the loops state. */ | |
598 | ||
61183076 RB |
599 | static inline void |
600 | loops_state_set (function *fn, unsigned flags) | |
601 | { | |
602 | loops_for_fn (fn)->state |= flags; | |
603 | } | |
604 | ||
f87000d0 ZD |
605 | static inline void |
606 | loops_state_set (unsigned flags) | |
607 | { | |
61183076 | 608 | loops_state_set (cfun, flags); |
f87000d0 ZD |
609 | } |
610 | ||
611 | /* Clears FLAGS from the loops state. */ | |
612 | ||
61183076 RB |
613 | static inline void |
614 | loops_state_clear (function *fn, unsigned flags) | |
615 | { | |
616 | loops_for_fn (fn)->state &= ~flags; | |
617 | } | |
618 | ||
f87000d0 ZD |
619 | static inline void |
620 | loops_state_clear (unsigned flags) | |
621 | { | |
622 | if (!current_loops) | |
623 | return; | |
61183076 | 624 | loops_state_clear (cfun, flags); |
f87000d0 ZD |
625 | } |
626 | ||
a84a49b7 RB |
627 | /* Check loop structure invariants, if internal consistency checks are |
628 | enabled. */ | |
629 | ||
630 | static inline void | |
631 | checking_verify_loop_structure (void) | |
632 | { | |
633 | /* VERIFY_LOOP_STRUCTURE essentially asserts that no loops need fixups. | |
634 | ||
635 | The loop optimizers should never make changes to the CFG which | |
636 | require loop fixups. But the low level CFG manipulation code may | |
637 | set the flag conservatively. | |
638 | ||
639 | Go ahead and clear the flag here. That avoids the assert inside | |
640 | VERIFY_LOOP_STRUCTURE, and if there is an inconsistency in the loop | |
641 | structures VERIFY_LOOP_STRUCTURE will detect it. | |
642 | ||
643 | This also avoid the compile time cost of excessive fixups. */ | |
644 | loops_state_clear (LOOPS_NEED_FIXUP); | |
645 | if (flag_checking) | |
646 | verify_loop_structure (); | |
647 | } | |
648 | ||
42fd6772 ZD |
649 | /* Loop iterators. */ |
650 | ||
651 | /* Flags for loop iteration. */ | |
652 | ||
653 | enum li_flags | |
654 | { | |
677cc14d ZD |
655 | LI_INCLUDE_ROOT = 1, /* Include the fake root of the loop tree. */ |
656 | LI_FROM_INNERMOST = 2, /* Iterate over the loops in the reverse order, | |
657 | starting from innermost ones. */ | |
658 | LI_ONLY_INNERMOST = 4 /* Iterate only over innermost loops. */ | |
42fd6772 ZD |
659 | }; |
660 | ||
661 | /* The iterator for loops. */ | |
662 | ||
6c1dae73 | 663 | class loop_iterator |
42fd6772 | 664 | { |
6c1dae73 | 665 | public: |
61183076 | 666 | loop_iterator (function *fn, loop_p *loop, unsigned flags); |
f0bd40b1 RB |
667 | |
668 | inline loop_p next (); | |
669 | ||
61183076 RB |
670 | /* The function we are visiting. */ |
671 | function *fn; | |
672 | ||
677cc14d | 673 | /* The list of loops to visit. */ |
d78b7095 | 674 | auto_vec<int, 16> to_visit; |
677cc14d ZD |
675 | |
676 | /* The index of the actual loop. */ | |
677 | unsigned idx; | |
f0bd40b1 | 678 | }; |
42fd6772 | 679 | |
f0bd40b1 RB |
680 | inline loop_p |
681 | loop_iterator::next () | |
42fd6772 | 682 | { |
677cc14d ZD |
683 | int anum; |
684 | ||
f0bd40b1 | 685 | while (this->to_visit.iterate (this->idx, &anum)) |
42fd6772 | 686 | { |
f0bd40b1 | 687 | this->idx++; |
61183076 | 688 | loop_p loop = get_loop (fn, anum); |
f0bd40b1 RB |
689 | if (loop) |
690 | return loop; | |
42fd6772 ZD |
691 | } |
692 | ||
f0bd40b1 | 693 | return NULL; |
42fd6772 ZD |
694 | } |
695 | ||
f0bd40b1 | 696 | inline |
61183076 | 697 | loop_iterator::loop_iterator (function *fn, loop_p *loop, unsigned flags) |
42fd6772 | 698 | { |
99b1c316 | 699 | class loop *aloop; |
677cc14d ZD |
700 | unsigned i; |
701 | int mn; | |
702 | ||
f0bd40b1 | 703 | this->idx = 0; |
61183076 RB |
704 | this->fn = fn; |
705 | if (!loops_for_fn (fn)) | |
42fd6772 | 706 | { |
42fd6772 ZD |
707 | *loop = NULL; |
708 | return; | |
709 | } | |
710 | ||
d78b7095 | 711 | this->to_visit.reserve_exact (number_of_loops (fn)); |
677cc14d ZD |
712 | mn = (flags & LI_INCLUDE_ROOT) ? 0 : 1; |
713 | ||
714 | if (flags & LI_ONLY_INNERMOST) | |
715 | { | |
61183076 | 716 | for (i = 0; vec_safe_iterate (loops_for_fn (fn)->larray, i, &aloop); i++) |
677cc14d ZD |
717 | if (aloop != NULL |
718 | && aloop->inner == NULL | |
719 | && aloop->num >= mn) | |
f0bd40b1 | 720 | this->to_visit.quick_push (aloop->num); |
677cc14d ZD |
721 | } |
722 | else if (flags & LI_FROM_INNERMOST) | |
42fd6772 | 723 | { |
677cc14d | 724 | /* Push the loops to LI->TO_VISIT in postorder. */ |
61183076 | 725 | for (aloop = loops_for_fn (fn)->tree_root; |
677cc14d ZD |
726 | aloop->inner != NULL; |
727 | aloop = aloop->inner) | |
728 | continue; | |
729 | ||
730 | while (1) | |
731 | { | |
732 | if (aloop->num >= mn) | |
f0bd40b1 | 733 | this->to_visit.quick_push (aloop->num); |
677cc14d ZD |
734 | |
735 | if (aloop->next) | |
736 | { | |
737 | for (aloop = aloop->next; | |
738 | aloop->inner != NULL; | |
739 | aloop = aloop->inner) | |
740 | continue; | |
741 | } | |
9ba025a2 | 742 | else if (!loop_outer (aloop)) |
677cc14d ZD |
743 | break; |
744 | else | |
9ba025a2 | 745 | aloop = loop_outer (aloop); |
677cc14d | 746 | } |
42fd6772 ZD |
747 | } |
748 | else | |
749 | { | |
677cc14d | 750 | /* Push the loops to LI->TO_VISIT in preorder. */ |
61183076 | 751 | aloop = loops_for_fn (fn)->tree_root; |
677cc14d ZD |
752 | while (1) |
753 | { | |
754 | if (aloop->num >= mn) | |
f0bd40b1 | 755 | this->to_visit.quick_push (aloop->num); |
677cc14d ZD |
756 | |
757 | if (aloop->inner != NULL) | |
758 | aloop = aloop->inner; | |
759 | else | |
760 | { | |
761 | while (aloop != NULL && aloop->next == NULL) | |
9ba025a2 | 762 | aloop = loop_outer (aloop); |
677cc14d ZD |
763 | if (aloop == NULL) |
764 | break; | |
765 | aloop = aloop->next; | |
766 | } | |
767 | } | |
42fd6772 | 768 | } |
677cc14d | 769 | |
f0bd40b1 | 770 | *loop = this->next (); |
42fd6772 ZD |
771 | } |
772 | ||
f0bd40b1 | 773 | #define FOR_EACH_LOOP(LOOP, FLAGS) \ |
61183076 RB |
774 | for (loop_iterator li(cfun, &(LOOP), FLAGS); \ |
775 | (LOOP); \ | |
776 | (LOOP) = li.next ()) | |
777 | ||
778 | #define FOR_EACH_LOOP_FN(FN, LOOP, FLAGS) \ | |
650a8fcf | 779 | for (loop_iterator li(FN, &(LOOP), FLAGS); \ |
f0bd40b1 RB |
780 | (LOOP); \ |
781 | (LOOP) = li.next ()) | |
42fd6772 | 782 | |
8b11a64c | 783 | /* The properties of the target. */ |
4391924a RS |
784 | struct target_cfgloop { |
785 | /* Number of available registers. */ | |
786 | unsigned x_target_avail_regs; | |
8b11a64c | 787 | |
4391924a RS |
788 | /* Number of available registers that are call-clobbered. */ |
789 | unsigned x_target_clobbered_regs; | |
790 | ||
791 | /* Number of registers reserved for temporary expressions. */ | |
792 | unsigned x_target_res_regs; | |
793 | ||
794 | /* The cost for register when there still is some reserve, but we are | |
795 | approaching the number of available registers. */ | |
796 | unsigned x_target_reg_cost[2]; | |
797 | ||
798 | /* The cost for register when we need to spill. */ | |
799 | unsigned x_target_spill_cost[2]; | |
800 | }; | |
801 | ||
802 | extern struct target_cfgloop default_target_cfgloop; | |
803 | #if SWITCHABLE_TARGET | |
804 | extern struct target_cfgloop *this_target_cfgloop; | |
805 | #else | |
806 | #define this_target_cfgloop (&default_target_cfgloop) | |
807 | #endif | |
808 | ||
809 | #define target_avail_regs \ | |
810 | (this_target_cfgloop->x_target_avail_regs) | |
811 | #define target_clobbered_regs \ | |
812 | (this_target_cfgloop->x_target_clobbered_regs) | |
813 | #define target_res_regs \ | |
814 | (this_target_cfgloop->x_target_res_regs) | |
815 | #define target_reg_cost \ | |
816 | (this_target_cfgloop->x_target_reg_cost) | |
817 | #define target_spill_cost \ | |
818 | (this_target_cfgloop->x_target_spill_cost) | |
8b11a64c | 819 | |
5e962776 ZD |
820 | /* Register pressure estimation for induction variable optimizations & loop |
821 | invariant motion. */ | |
bec922f0 | 822 | extern unsigned estimate_reg_pressure_cost (unsigned, unsigned, bool, bool); |
5e962776 ZD |
823 | extern void init_set_costs (void); |
824 | ||
617b465c | 825 | /* Loop optimizer initialization. */ |
598ec7bd | 826 | extern void loop_optimizer_init (unsigned); |
61183076 RB |
827 | extern void loop_optimizer_finalize (function *); |
828 | inline void | |
829 | loop_optimizer_finalize () | |
830 | { | |
831 | loop_optimizer_finalize (cfun); | |
832 | } | |
617b465c ZD |
833 | |
834 | /* Optimization passes. */ | |
b17d5d7c ZD |
835 | enum |
836 | { | |
f8934be7 JH |
837 | UAP_UNROLL = 1, /* Enables unrolling of loops if it seems profitable. */ |
838 | UAP_UNROLL_ALL = 2 /* Enables unrolling of all loops. */ | |
b17d5d7c ZD |
839 | }; |
840 | ||
d73be268 ZD |
841 | extern void doloop_optimize_loops (void); |
842 | extern void move_loop_invariants (void); | |
99b1c316 | 843 | extern vec<basic_block> get_loop_hot_path (const class loop *loop); |
59587b18 | 844 | |
a5497b12 | 845 | /* Returns the outermost loop of the loop nest that contains LOOP.*/ |
99b1c316 MS |
846 | static inline class loop * |
847 | loop_outermost (class loop *loop) | |
a5497b12 | 848 | { |
9771b263 | 849 | unsigned n = vec_safe_length (loop->superloops); |
a5497b12 VK |
850 | |
851 | if (n <= 1) | |
852 | return loop; | |
853 | ||
9771b263 | 854 | return (*loop->superloops)[1]; |
a5497b12 VK |
855 | } |
856 | ||
99b1c316 MS |
857 | extern void record_niter_bound (class loop *, const widest_int &, bool, bool); |
858 | extern HOST_WIDE_INT get_estimated_loop_iterations_int (class loop *); | |
859 | extern HOST_WIDE_INT get_max_loop_iterations_int (const class loop *); | |
860 | extern HOST_WIDE_INT get_likely_max_loop_iterations_int (class loop *); | |
861 | extern bool get_estimated_loop_iterations (class loop *loop, widest_int *nit); | |
862 | extern bool get_max_loop_iterations (const class loop *loop, widest_int *nit); | |
863 | extern bool get_likely_max_loop_iterations (class loop *loop, widest_int *nit); | |
4484a35a | 864 | extern int bb_loop_depth (const_basic_block); |
a5497b12 | 865 | |
807e902e | 866 | /* Converts VAL to widest_int. */ |
71343877 | 867 | |
807e902e KZ |
868 | static inline widest_int |
869 | gcov_type_to_wide_int (gcov_type val) | |
71343877 | 870 | { |
807e902e | 871 | HOST_WIDE_INT a[2]; |
71343877 | 872 | |
807e902e | 873 | a[0] = (unsigned HOST_WIDE_INT) val; |
71343877 AM |
874 | /* If HOST_BITS_PER_WIDE_INT == HOST_BITS_PER_WIDEST_INT, avoid shifting by |
875 | the size of type. */ | |
876 | val >>= HOST_BITS_PER_WIDE_INT - 1; | |
877 | val >>= 1; | |
807e902e | 878 | a[1] = (unsigned HOST_WIDE_INT) val; |
71343877 | 879 | |
807e902e | 880 | return widest_int::from_array (a, 2); |
71343877 | 881 | } |
59587b18 | 882 | #endif /* GCC_CFGLOOP_H */ |