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Commit | Line | Data |
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3d436d2a | 1 | /* Natural loop functions |
6fb5fa3c | 2 | Copyright (C) 1987, 1997, 1998, 1999, 2000, 2001, 2002, 2003, 2004, |
d652f226 | 3 | 2005, 2006, 2007, 2008, 2009, 2010 Free Software Foundation, Inc. |
3d436d2a ZD |
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 |
3d436d2a 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/>. */ | |
3d436d2a | 20 | |
59587b18 JQ |
21 | #ifndef GCC_CFGLOOP_H |
22 | #define GCC_CFGLOOP_H | |
23 | ||
24 | #include "basic-block.h" | |
677cc14d | 25 | #include "vecprim.h" |
df582833 | 26 | #include "double-int.h" |
59587b18 | 27 | |
7a8cba34 SB |
28 | #include "bitmap.h" |
29 | #include "sbitmap.h" | |
30 | ||
3d436d2a ZD |
31 | /* Structure to hold decision about unrolling/peeling. */ |
32 | enum lpt_dec | |
33 | { | |
34 | LPT_NONE, | |
35 | LPT_PEEL_COMPLETELY, | |
36 | LPT_PEEL_SIMPLE, | |
37 | LPT_UNROLL_CONSTANT, | |
38 | LPT_UNROLL_RUNTIME, | |
39 | LPT_UNROLL_STUPID | |
40 | }; | |
41 | ||
d1b38208 | 42 | struct GTY (()) lpt_decision { |
3d436d2a ZD |
43 | enum lpt_dec decision; |
44 | unsigned times; | |
45 | }; | |
46 | ||
1c1ad7bb SB |
47 | /* The type of extend applied to an IV. */ |
48 | enum iv_extend_code | |
49 | { | |
50 | IV_SIGN_EXTEND, | |
51 | IV_ZERO_EXTEND, | |
52 | IV_UNKNOWN_EXTEND | |
53 | }; | |
54 | ||
86df10e3 SP |
55 | /* The structure describing a bound on number of iterations of a loop. */ |
56 | ||
d1b38208 | 57 | struct GTY ((chain_next ("%h.next"))) nb_iter_bound { |
946e1bc7 | 58 | /* The statement STMT is executed at most ... */ |
726a989a | 59 | gimple stmt; |
946e1bc7 ZD |
60 | |
61 | /* ... BOUND + 1 times (BOUND must be an unsigned constant). | |
62 | The + 1 is added for the following reasons: | |
63 | ||
64 | a) 0 would otherwise be unused, while we would need to care more about | |
65 | overflows (as MAX + 1 is sometimes produced as the estimate on number | |
66 | of executions of STMT). | |
67 | b) it is consistent with the result of number_of_iterations_exit. */ | |
68 | double_int bound; | |
69 | ||
b8698a0f | 70 | /* True if the statement will cause the loop to be leaved the (at most) |
946e1bc7 ZD |
71 | BOUND + 1-st time it is executed, that is, all the statements after it |
72 | are executed at most BOUND times. */ | |
73 | bool is_exit; | |
74 | ||
946e1bc7 | 75 | /* The next bound in the list. */ |
86df10e3 | 76 | struct nb_iter_bound *next; |
86df10e3 SP |
77 | }; |
78 | ||
6270df4c ZD |
79 | /* Description of the loop exit. */ |
80 | ||
d1b38208 | 81 | struct GTY (()) loop_exit { |
6270df4c | 82 | /* The exit edge. */ |
b8244d74 | 83 | edge e; |
6270df4c ZD |
84 | |
85 | /* Previous and next exit in the list of the exits of the loop. */ | |
86 | struct loop_exit *prev; | |
87 | struct loop_exit *next; | |
88 | ||
89 | /* Next element in the list of loops from that E exits. */ | |
90 | struct loop_exit *next_e; | |
91 | }; | |
92 | ||
9ba025a2 ZD |
93 | typedef struct loop *loop_p; |
94 | DEF_VEC_P (loop_p); | |
95 | DEF_VEC_ALLOC_P (loop_p, heap); | |
9e2f83a5 | 96 | DEF_VEC_ALLOC_P (loop_p, gc); |
9ba025a2 | 97 | |
ae50c0cb TN |
98 | /* An integer estimation of the number of iterations. Estimate_state |
99 | describes what is the state of the estimation. */ | |
100 | enum loop_estimation | |
101 | { | |
102 | /* Estimate was not computed yet. */ | |
103 | EST_NOT_COMPUTED, | |
104 | /* Estimate is ready. */ | |
105 | EST_AVAILABLE | |
106 | }; | |
107 | ||
3d436d2a | 108 | /* Structure to hold information for each natural loop. */ |
d1b38208 | 109 | struct GTY ((chain_next ("%h.next"))) loop { |
3d436d2a ZD |
110 | /* Index into loops array. */ |
111 | int num; | |
112 | ||
8f5929e1 JJ |
113 | /* Number of loop insns. */ |
114 | unsigned ninsns; | |
115 | ||
3d436d2a | 116 | /* Basic block of loop header. */ |
b8244d74 | 117 | basic_block header; |
3d436d2a ZD |
118 | |
119 | /* Basic block of loop latch. */ | |
b8244d74 | 120 | basic_block latch; |
3d436d2a | 121 | |
3d436d2a ZD |
122 | /* For loop unrolling/peeling decision. */ |
123 | struct lpt_decision lpt_decision; | |
124 | ||
3d436d2a ZD |
125 | /* Average number of executed insns per iteration. */ |
126 | unsigned av_ninsns; | |
127 | ||
3d436d2a ZD |
128 | /* Number of blocks contained within the loop. */ |
129 | unsigned num_nodes; | |
130 | ||
9ba025a2 | 131 | /* Superloops of the loop, starting with the outermost loop. */ |
9e2f83a5 | 132 | VEC (loop_p, gc) *superloops; |
3d436d2a ZD |
133 | |
134 | /* The first inner (child) loop or NULL if innermost loop. */ | |
135 | struct loop *inner; | |
136 | ||
137 | /* Link to the next (sibling) loop. */ | |
138 | struct loop *next; | |
139 | ||
3d436d2a | 140 | /* Auxiliary info specific to a pass. */ |
9e2f83a5 | 141 | PTR GTY ((skip (""))) aux; |
3d436d2a | 142 | |
0a74c758 SP |
143 | /* The number of times the latch of the loop is executed. This can be an |
144 | INTEGER_CST, or a symbolic expression representing the number of | |
145 | iterations like "N - 1", or a COND_EXPR containing the runtime | |
146 | conditions under which the number of iterations is non zero. | |
147 | ||
148 | Don't access this field directly: number_of_latch_executions | |
149 | computes and caches the computed information in this field. */ | |
9baba81b SP |
150 | tree nb_iterations; |
151 | ||
b4a9343c ZD |
152 | /* An integer guaranteed to be greater or equal to nb_iterations. Only |
153 | valid if any_upper_bound is true. */ | |
9bdb685e ZD |
154 | double_int nb_iterations_upper_bound; |
155 | ||
b4a9343c ZD |
156 | /* An integer giving an estimate on nb_iterations. Unlike |
157 | nb_iterations_upper_bound, there is no guarantee that it is at least | |
158 | nb_iterations. */ | |
9bdb685e | 159 | double_int nb_iterations_estimate; |
86df10e3 | 160 | |
8f5929e1 JJ |
161 | bool any_upper_bound; |
162 | bool any_estimate; | |
163 | ||
448f65db NF |
164 | /* True if the loop can be parallel. */ |
165 | bool can_be_parallel; | |
166 | ||
8f5929e1 JJ |
167 | /* An integer estimation of the number of iterations. Estimate_state |
168 | describes what is the state of the estimation. */ | |
169 | enum loop_estimation estimate_state; | |
170 | ||
e9eb809d ZD |
171 | /* Upper bound on number of iterations of a loop. */ |
172 | struct nb_iter_bound *bounds; | |
82b85a85 | 173 | |
6270df4c | 174 | /* Head of the cyclic list of the exits of the loop. */ |
9e2f83a5 | 175 | struct loop_exit *exits; |
3d436d2a ZD |
176 | }; |
177 | ||
178 | /* Flags for state of loop structure. */ | |
179 | enum | |
180 | { | |
181 | LOOPS_HAVE_PREHEADERS = 1, | |
182 | LOOPS_HAVE_SIMPLE_LATCHES = 2, | |
82b85a85 | 183 | LOOPS_HAVE_MARKED_IRREDUCIBLE_REGIONS = 4, |
89f8f30f | 184 | LOOPS_HAVE_RECORDED_EXITS = 8, |
c7b852c8 | 185 | LOOPS_MAY_HAVE_MULTIPLE_LATCHES = 16, |
592c303d | 186 | LOOP_CLOSED_SSA = 32, |
e855c69d AB |
187 | LOOPS_NEED_FIXUP = 64, |
188 | LOOPS_HAVE_FALLTHRU_PREHEADERS = 128 | |
3d436d2a ZD |
189 | }; |
190 | ||
d78f3f78 ZD |
191 | #define LOOPS_NORMAL (LOOPS_HAVE_PREHEADERS | LOOPS_HAVE_SIMPLE_LATCHES \ |
192 | | LOOPS_HAVE_MARKED_IRREDUCIBLE_REGIONS) | |
89f8f30f | 193 | #define AVOID_CFG_MODIFICATIONS (LOOPS_MAY_HAVE_MULTIPLE_LATCHES) |
d78f3f78 | 194 | |
3d436d2a | 195 | /* Structure to hold CFG information about natural loops within a function. */ |
d1b38208 | 196 | struct GTY (()) loops { |
0162f155 RG |
197 | /* State of loops. */ |
198 | int state; | |
3d436d2a | 199 | |
42fd6772 | 200 | /* Array of the loops. */ |
9e2f83a5 | 201 | VEC (loop_p, gc) *larray; |
3d436d2a | 202 | |
6270df4c ZD |
203 | /* Maps edges to the list of their descriptions as loop exits. Edges |
204 | whose sources or destinations have loop_father == NULL (which may | |
205 | happen during the cfg manipulations) should not appear in EXITS. */ | |
9e2f83a5 | 206 | htab_t GTY((param_is (struct loop_exit))) exits; |
6270df4c | 207 | |
3d436d2a ZD |
208 | /* Pointer to root of loop hierarchy tree. */ |
209 | struct loop *tree_root; | |
3d436d2a ZD |
210 | }; |
211 | ||
3d436d2a | 212 | /* Loop recognition. */ |
70388d94 | 213 | extern int flow_loops_find (struct loops *); |
89f8f30f | 214 | extern void disambiguate_loops_with_multiple_latches (void); |
d329e058 | 215 | extern void flow_loops_free (struct loops *); |
d73be268 | 216 | extern void flow_loops_dump (FILE *, |
d329e058 AJ |
217 | void (*)(const struct loop *, FILE *, int), int); |
218 | extern void flow_loop_dump (const struct loop *, FILE *, | |
219 | void (*)(const struct loop *, FILE *, int), int); | |
6270df4c | 220 | struct loop *alloc_loop (void); |
d329e058 | 221 | extern void flow_loop_free (struct loop *); |
2b271002 | 222 | int flow_loop_nodes_find (basic_block, struct loop *); |
d73be268 | 223 | void fix_loop_structure (bitmap changed_bbs); |
2de58650 | 224 | bool mark_irreducible_loops (void); |
6270df4c ZD |
225 | void release_recorded_exits (void); |
226 | void record_loop_exits (void); | |
227 | void rescan_loop_exit (edge, bool, bool); | |
3d436d2a | 228 | |
4d6922ee | 229 | /* Loop data structure manipulation/querying. */ |
d329e058 AJ |
230 | extern void flow_loop_tree_node_add (struct loop *, struct loop *); |
231 | extern void flow_loop_tree_node_remove (struct loop *); | |
89f8f30f | 232 | extern void add_loop (struct loop *, struct loop *); |
d329e058 | 233 | extern bool flow_loop_nested_p (const struct loop *, const struct loop *); |
ed7a4b4b | 234 | extern bool flow_bb_inside_loop_p (const struct loop *, const_basic_block); |
d329e058 | 235 | extern struct loop * find_common_loop (struct loop *, struct loop *); |
a7e5372d | 236 | struct loop *superloop_at_depth (struct loop *, unsigned); |
7f9bc51b ZD |
237 | struct eni_weights_d; |
238 | extern unsigned tree_num_loop_insns (struct loop *, struct eni_weights_d *); | |
ed7a4b4b KG |
239 | extern int num_loop_insns (const struct loop *); |
240 | extern int average_num_loop_insns (const struct loop *); | |
689ba89d | 241 | extern unsigned get_loop_level (const struct loop *); |
ed7a4b4b | 242 | extern bool loop_exit_edge_p (const struct loop *, const_edge); |
f4ce375d VK |
243 | extern bool loop_exits_to_bb_p (struct loop *, basic_block); |
244 | extern bool loop_exits_from_bb_p (struct loop *, basic_block); | |
d73be268 | 245 | extern void mark_loop_exit_edges (void); |
3d436d2a ZD |
246 | |
247 | /* Loops & cfg manipulation. */ | |
d329e058 | 248 | extern basic_block *get_loop_body (const struct loop *); |
89f8f30f ZD |
249 | extern unsigned get_loop_body_with_size (const struct loop *, basic_block *, |
250 | unsigned); | |
50654f6c | 251 | extern basic_block *get_loop_body_in_dom_order (const struct loop *); |
40923b20 | 252 | extern basic_block *get_loop_body_in_bfs_order (const struct loop *); |
b8698a0f | 253 | extern basic_block *get_loop_body_in_custom_order (const struct loop *, |
e855c69d AB |
254 | int (*) (const void *, const void *)); |
255 | ||
ca83d385 | 256 | extern VEC (edge, heap) *get_loop_exit_edges (const struct loop *); |
ac8f6c69 | 257 | edge single_exit (const struct loop *); |
50654f6c | 258 | extern unsigned num_loop_branches (const struct loop *); |
3d436d2a | 259 | |
d329e058 AJ |
260 | extern edge loop_preheader_edge (const struct loop *); |
261 | extern edge loop_latch_edge (const struct loop *); | |
3d436d2a | 262 | |
d329e058 AJ |
263 | extern void add_bb_to_loop (basic_block, struct loop *); |
264 | extern void remove_bb_from_loops (basic_block); | |
3d436d2a | 265 | |
d73be268 | 266 | extern void cancel_loop_tree (struct loop *); |
42fd6772 | 267 | extern void delete_loop (struct loop *); |
3d436d2a | 268 | |
3d436d2a ZD |
269 | enum |
270 | { | |
e855c69d AB |
271 | CP_SIMPLE_PREHEADERS = 1, |
272 | CP_FALLTHRU_PREHEADERS = 2 | |
3d436d2a ZD |
273 | }; |
274 | ||
b02b9b53 | 275 | basic_block create_preheader (struct loop *, int); |
d73be268 ZD |
276 | extern void create_preheaders (int); |
277 | extern void force_single_succ_latches (void); | |
3d436d2a | 278 | |
d73be268 | 279 | extern void verify_loop_structure (void); |
3d436d2a ZD |
280 | |
281 | /* Loop analysis. */ | |
ed7a4b4b | 282 | extern bool just_once_each_iteration_p (const struct loop *, const_basic_block); |
ac84e05e | 283 | gcov_type expected_loop_iterations_unbounded (const struct loop *); |
d329e058 | 284 | extern unsigned expected_loop_iterations (const struct loop *); |
75c70254 | 285 | extern rtx doloop_condition_get (rtx); |
617b465c | 286 | |
421e6082 | 287 | void estimate_numbers_of_iterations_loop (struct loop *); |
03fd03d5 | 288 | void record_niter_bound (struct loop *, double_int, bool, bool); |
652c4c71 RG |
289 | bool estimated_loop_iterations (struct loop *, double_int *); |
290 | bool max_loop_iterations (struct loop *, double_int *); | |
291 | HOST_WIDE_INT estimated_loop_iterations_int (struct loop *); | |
292 | HOST_WIDE_INT max_loop_iterations_int (struct loop *); | |
293 | bool max_stmt_executions (struct loop *, double_int *); | |
294 | bool estimated_stmt_executions (struct loop *, double_int *); | |
295 | HOST_WIDE_INT max_stmt_executions_int (struct loop *); | |
296 | HOST_WIDE_INT estimated_stmt_executions_int (struct loop *); | |
4839cb59 | 297 | |
617b465c | 298 | /* Loop manipulation. */ |
ed7a4b4b | 299 | extern bool can_duplicate_loop_p (const struct loop *loop); |
617b465c ZD |
300 | |
301 | #define DLTHE_FLAG_UPDATE_FREQ 1 /* Update frequencies in | |
302 | duplicate_loop_to_header_edge. */ | |
7f7b1718 JH |
303 | #define DLTHE_RECORD_COPY_NUMBER 2 /* Record copy number in the aux |
304 | field of newly create BB. */ | |
178df94f | 305 | #define DLTHE_FLAG_COMPLETTE_PEEL 4 /* Update frequencies expecting |
a4d05547 | 306 | a complete peeling. */ |
617b465c | 307 | |
f8bf9252 SP |
308 | extern edge create_empty_if_region_on_edge (edge, tree); |
309 | extern struct loop *create_empty_loop_on_edge (edge, tree, tree, tree, tree, | |
8e74b397 | 310 | tree *, tree *, struct loop *); |
d73be268 | 311 | extern struct loop * duplicate_loop (struct loop *, struct loop *); |
48710229 | 312 | extern void duplicate_subloops (struct loop *, struct loop *); |
b8698a0f | 313 | extern bool duplicate_loop_to_header_edge (struct loop *, edge, |
ee8c1b05 ZD |
314 | unsigned, sbitmap, edge, |
315 | VEC (edge, heap) **, int); | |
d73be268 | 316 | extern struct loop *loopify (edge, edge, |
03cb2019 ZD |
317 | basic_block, edge, edge, bool, |
318 | unsigned, unsigned); | |
d73be268 | 319 | struct loop * loop_version (struct loop *, void *, |
03cb2019 | 320 | basic_block *, unsigned, unsigned, unsigned, bool); |
d73be268 | 321 | extern bool remove_path (edge); |
03cb2019 | 322 | void scale_loop_frequencies (struct loop *, int, int); |
617b465c | 323 | |
50654f6c ZD |
324 | /* Induction variable analysis. */ |
325 | ||
326 | /* The description of induction variable. The things are a bit complicated | |
327 | due to need to handle subregs and extends. The value of the object described | |
328 | by it can be obtained as follows (all computations are done in extend_mode): | |
329 | ||
330 | Value in i-th iteration is | |
331 | delta + mult * extend_{extend_mode} (subreg_{mode} (base + i * step)). | |
332 | ||
333 | If first_special is true, the value in the first iteration is | |
334 | delta + mult * base | |
c22cacf3 | 335 | |
f822d252 | 336 | If extend = UNKNOWN, first_special must be false, delta 0, mult 1 and value is |
50654f6c ZD |
337 | subreg_{mode} (base + i * step) |
338 | ||
339 | The get_iv_value function can be used to obtain these expressions. | |
340 | ||
341 | ??? Add a third mode field that would specify the mode in that inner | |
342 | computation is done, which would enable it to be different from the | |
343 | outer one? */ | |
344 | ||
345 | struct rtx_iv | |
346 | { | |
347 | /* Its base and step (mode of base and step is supposed to be extend_mode, | |
348 | see the description above). */ | |
349 | rtx base, step; | |
350 | ||
1c1ad7bb SB |
351 | /* The type of extend applied to it (IV_SIGN_EXTEND, IV_ZERO_EXTEND, |
352 | or IV_UNKNOWN_EXTEND). */ | |
353 | enum iv_extend_code extend; | |
50654f6c ZD |
354 | |
355 | /* Operations applied in the extended mode. */ | |
356 | rtx delta, mult; | |
357 | ||
358 | /* The mode it is extended to. */ | |
359 | enum machine_mode extend_mode; | |
360 | ||
361 | /* The mode the variable iterates in. */ | |
362 | enum machine_mode mode; | |
363 | ||
50654f6c ZD |
364 | /* Whether the first iteration needs to be handled specially. */ |
365 | unsigned first_special : 1; | |
366 | }; | |
367 | ||
f2dca510 ZD |
368 | /* The description of an exit from the loop and of the number of iterations |
369 | till we take the exit. */ | |
50654f6c ZD |
370 | |
371 | struct niter_desc | |
372 | { | |
373 | /* The edge out of the loop. */ | |
374 | edge out_edge; | |
375 | ||
376 | /* The other edge leading from the condition. */ | |
377 | edge in_edge; | |
378 | ||
379 | /* True if we are able to say anything about number of iterations of the | |
380 | loop. */ | |
381 | bool simple_p; | |
382 | ||
383 | /* True if the loop iterates the constant number of times. */ | |
384 | bool const_iter; | |
385 | ||
386 | /* Number of iterations if constant. */ | |
387 | unsigned HOST_WIDEST_INT niter; | |
388 | ||
50654f6c ZD |
389 | /* Assumptions under that the rest of the information is valid. */ |
390 | rtx assumptions; | |
391 | ||
392 | /* Assumptions under that the loop ends before reaching the latch, | |
393 | even if value of niter_expr says otherwise. */ | |
394 | rtx noloop_assumptions; | |
395 | ||
396 | /* Condition under that the loop is infinite. */ | |
397 | rtx infinite; | |
398 | ||
399 | /* Whether the comparison is signed. */ | |
400 | bool signed_p; | |
401 | ||
402 | /* The mode in that niter_expr should be computed. */ | |
403 | enum machine_mode mode; | |
404 | ||
405 | /* The number of iterations of the loop. */ | |
406 | rtx niter_expr; | |
407 | }; | |
408 | ||
409 | extern void iv_analysis_loop_init (struct loop *); | |
6d4e0ecc | 410 | extern bool iv_analyze (rtx, rtx, struct rtx_iv *); |
03fd2215 ZD |
411 | extern bool iv_analyze_result (rtx, rtx, struct rtx_iv *); |
412 | extern bool iv_analyze_expr (rtx, rtx, enum machine_mode, struct rtx_iv *); | |
50654f6c | 413 | extern rtx get_iv_value (struct rtx_iv *, rtx); |
113d659a | 414 | extern bool biv_p (rtx, rtx); |
50654f6c | 415 | extern void find_simple_exit (struct loop *, struct niter_desc *); |
50654f6c ZD |
416 | extern void iv_analysis_done (void); |
417 | ||
418 | extern struct niter_desc *get_simple_loop_desc (struct loop *loop); | |
419 | extern void free_simple_loop_desc (struct loop *loop); | |
420 | ||
421 | static inline struct niter_desc * | |
422 | simple_loop_desc (struct loop *loop) | |
423 | { | |
cceb1885 | 424 | return (struct niter_desc *) loop->aux; |
50654f6c ZD |
425 | } |
426 | ||
42fd6772 ZD |
427 | /* Accessors for the loop structures. */ |
428 | ||
429 | /* Returns the loop with index NUM from current_loops. */ | |
430 | ||
431 | static inline struct loop * | |
432 | get_loop (unsigned num) | |
433 | { | |
434 | return VEC_index (loop_p, current_loops->larray, num); | |
435 | } | |
436 | ||
9ba025a2 ZD |
437 | /* Returns the number of superloops of LOOP. */ |
438 | ||
439 | static inline unsigned | |
440 | loop_depth (const struct loop *loop) | |
441 | { | |
442 | return VEC_length (loop_p, loop->superloops); | |
443 | } | |
444 | ||
391886c8 RG |
445 | /* Returns the loop depth of the loop BB belongs to. */ |
446 | ||
447 | static inline int | |
448 | bb_loop_depth (const_basic_block bb) | |
449 | { | |
450 | return bb->loop_father ? loop_depth (bb->loop_father) : 0; | |
451 | } | |
452 | ||
9ba025a2 ZD |
453 | /* Returns the immediate superloop of LOOP, or NULL if LOOP is the outermost |
454 | loop. */ | |
455 | ||
456 | static inline struct loop * | |
457 | loop_outer (const struct loop *loop) | |
458 | { | |
459 | unsigned n = VEC_length (loop_p, loop->superloops); | |
460 | ||
461 | if (n == 0) | |
462 | return NULL; | |
463 | ||
464 | return VEC_index (loop_p, loop->superloops, n - 1); | |
465 | } | |
466 | ||
07643d76 AM |
467 | /* Returns true if LOOP has at least one exit edge. */ |
468 | ||
469 | static inline bool | |
470 | loop_has_exit_edges (const struct loop *loop) | |
471 | { | |
472 | return loop->exits->next->e != NULL; | |
473 | } | |
474 | ||
42fd6772 ZD |
475 | /* Returns the list of loops in current_loops. */ |
476 | ||
9e2f83a5 | 477 | static inline VEC (loop_p, gc) * |
42fd6772 ZD |
478 | get_loops (void) |
479 | { | |
480 | if (!current_loops) | |
481 | return NULL; | |
482 | ||
483 | return current_loops->larray; | |
484 | } | |
485 | ||
486 | /* Returns the number of loops in current_loops (including the removed | |
487 | ones and the fake loop that forms the root of the loop tree). */ | |
488 | ||
489 | static inline unsigned | |
490 | number_of_loops (void) | |
491 | { | |
492 | if (!current_loops) | |
493 | return 0; | |
494 | ||
495 | return VEC_length (loop_p, current_loops->larray); | |
496 | } | |
497 | ||
f87000d0 ZD |
498 | /* Returns true if state of the loops satisfies all properties |
499 | described by FLAGS. */ | |
500 | ||
501 | static inline bool | |
502 | loops_state_satisfies_p (unsigned flags) | |
503 | { | |
504 | return (current_loops->state & flags) == flags; | |
505 | } | |
506 | ||
507 | /* Sets FLAGS to the loops state. */ | |
508 | ||
509 | static inline void | |
510 | loops_state_set (unsigned flags) | |
511 | { | |
512 | current_loops->state |= flags; | |
513 | } | |
514 | ||
515 | /* Clears FLAGS from the loops state. */ | |
516 | ||
517 | static inline void | |
518 | loops_state_clear (unsigned flags) | |
519 | { | |
520 | if (!current_loops) | |
521 | return; | |
522 | current_loops->state &= ~flags; | |
523 | } | |
524 | ||
42fd6772 ZD |
525 | /* Loop iterators. */ |
526 | ||
527 | /* Flags for loop iteration. */ | |
528 | ||
529 | enum li_flags | |
530 | { | |
677cc14d ZD |
531 | LI_INCLUDE_ROOT = 1, /* Include the fake root of the loop tree. */ |
532 | LI_FROM_INNERMOST = 2, /* Iterate over the loops in the reverse order, | |
533 | starting from innermost ones. */ | |
534 | LI_ONLY_INNERMOST = 4 /* Iterate only over innermost loops. */ | |
42fd6772 ZD |
535 | }; |
536 | ||
537 | /* The iterator for loops. */ | |
538 | ||
539 | typedef struct | |
540 | { | |
677cc14d ZD |
541 | /* The list of loops to visit. */ |
542 | VEC(int,heap) *to_visit; | |
543 | ||
544 | /* The index of the actual loop. */ | |
545 | unsigned idx; | |
42fd6772 ZD |
546 | } loop_iterator; |
547 | ||
548 | static inline void | |
677cc14d | 549 | fel_next (loop_iterator *li, loop_p *loop) |
42fd6772 | 550 | { |
677cc14d ZD |
551 | int anum; |
552 | ||
553 | while (VEC_iterate (int, li->to_visit, li->idx, anum)) | |
42fd6772 | 554 | { |
42fd6772 | 555 | li->idx++; |
677cc14d ZD |
556 | *loop = get_loop (anum); |
557 | if (*loop) | |
558 | return; | |
42fd6772 ZD |
559 | } |
560 | ||
677cc14d | 561 | VEC_free (int, heap, li->to_visit); |
42fd6772 ZD |
562 | *loop = NULL; |
563 | } | |
564 | ||
565 | static inline void | |
566 | fel_init (loop_iterator *li, loop_p *loop, unsigned flags) | |
567 | { | |
677cc14d ZD |
568 | struct loop *aloop; |
569 | unsigned i; | |
570 | int mn; | |
571 | ||
572 | li->idx = 0; | |
42fd6772 ZD |
573 | if (!current_loops) |
574 | { | |
677cc14d | 575 | li->to_visit = NULL; |
42fd6772 ZD |
576 | *loop = NULL; |
577 | return; | |
578 | } | |
579 | ||
677cc14d ZD |
580 | li->to_visit = VEC_alloc (int, heap, number_of_loops ()); |
581 | mn = (flags & LI_INCLUDE_ROOT) ? 0 : 1; | |
582 | ||
583 | if (flags & LI_ONLY_INNERMOST) | |
584 | { | |
585 | for (i = 0; VEC_iterate (loop_p, current_loops->larray, i, aloop); i++) | |
586 | if (aloop != NULL | |
587 | && aloop->inner == NULL | |
588 | && aloop->num >= mn) | |
589 | VEC_quick_push (int, li->to_visit, aloop->num); | |
590 | } | |
591 | else if (flags & LI_FROM_INNERMOST) | |
42fd6772 | 592 | { |
677cc14d ZD |
593 | /* Push the loops to LI->TO_VISIT in postorder. */ |
594 | for (aloop = current_loops->tree_root; | |
595 | aloop->inner != NULL; | |
596 | aloop = aloop->inner) | |
597 | continue; | |
598 | ||
599 | while (1) | |
600 | { | |
601 | if (aloop->num >= mn) | |
602 | VEC_quick_push (int, li->to_visit, aloop->num); | |
603 | ||
604 | if (aloop->next) | |
605 | { | |
606 | for (aloop = aloop->next; | |
607 | aloop->inner != NULL; | |
608 | aloop = aloop->inner) | |
609 | continue; | |
610 | } | |
9ba025a2 | 611 | else if (!loop_outer (aloop)) |
677cc14d ZD |
612 | break; |
613 | else | |
9ba025a2 | 614 | aloop = loop_outer (aloop); |
677cc14d | 615 | } |
42fd6772 ZD |
616 | } |
617 | else | |
618 | { | |
677cc14d ZD |
619 | /* Push the loops to LI->TO_VISIT in preorder. */ |
620 | aloop = current_loops->tree_root; | |
621 | while (1) | |
622 | { | |
623 | if (aloop->num >= mn) | |
624 | VEC_quick_push (int, li->to_visit, aloop->num); | |
625 | ||
626 | if (aloop->inner != NULL) | |
627 | aloop = aloop->inner; | |
628 | else | |
629 | { | |
630 | while (aloop != NULL && aloop->next == NULL) | |
9ba025a2 | 631 | aloop = loop_outer (aloop); |
677cc14d ZD |
632 | if (aloop == NULL) |
633 | break; | |
634 | aloop = aloop->next; | |
635 | } | |
636 | } | |
42fd6772 | 637 | } |
677cc14d ZD |
638 | |
639 | fel_next (li, loop); | |
42fd6772 ZD |
640 | } |
641 | ||
642 | #define FOR_EACH_LOOP(LI, LOOP, FLAGS) \ | |
643 | for (fel_init (&(LI), &(LOOP), FLAGS); \ | |
644 | (LOOP); \ | |
677cc14d ZD |
645 | fel_next (&(LI), &(LOOP))) |
646 | ||
647 | #define FOR_EACH_LOOP_BREAK(LI) \ | |
648 | { \ | |
f5843d08 | 649 | VEC_free (int, heap, (LI).to_visit); \ |
677cc14d ZD |
650 | break; \ |
651 | } | |
42fd6772 | 652 | |
8b11a64c | 653 | /* The properties of the target. */ |
4391924a RS |
654 | struct target_cfgloop { |
655 | /* Number of available registers. */ | |
656 | unsigned x_target_avail_regs; | |
8b11a64c | 657 | |
4391924a RS |
658 | /* Number of available registers that are call-clobbered. */ |
659 | unsigned x_target_clobbered_regs; | |
660 | ||
661 | /* Number of registers reserved for temporary expressions. */ | |
662 | unsigned x_target_res_regs; | |
663 | ||
664 | /* The cost for register when there still is some reserve, but we are | |
665 | approaching the number of available registers. */ | |
666 | unsigned x_target_reg_cost[2]; | |
667 | ||
668 | /* The cost for register when we need to spill. */ | |
669 | unsigned x_target_spill_cost[2]; | |
670 | }; | |
671 | ||
672 | extern struct target_cfgloop default_target_cfgloop; | |
673 | #if SWITCHABLE_TARGET | |
674 | extern struct target_cfgloop *this_target_cfgloop; | |
675 | #else | |
676 | #define this_target_cfgloop (&default_target_cfgloop) | |
677 | #endif | |
678 | ||
679 | #define target_avail_regs \ | |
680 | (this_target_cfgloop->x_target_avail_regs) | |
681 | #define target_clobbered_regs \ | |
682 | (this_target_cfgloop->x_target_clobbered_regs) | |
683 | #define target_res_regs \ | |
684 | (this_target_cfgloop->x_target_res_regs) | |
685 | #define target_reg_cost \ | |
686 | (this_target_cfgloop->x_target_reg_cost) | |
687 | #define target_spill_cost \ | |
688 | (this_target_cfgloop->x_target_spill_cost) | |
8b11a64c | 689 | |
5e962776 ZD |
690 | /* Register pressure estimation for induction variable optimizations & loop |
691 | invariant motion. */ | |
bec922f0 | 692 | extern unsigned estimate_reg_pressure_cost (unsigned, unsigned, bool, bool); |
5e962776 ZD |
693 | extern void init_set_costs (void); |
694 | ||
617b465c | 695 | /* Loop optimizer initialization. */ |
598ec7bd ZD |
696 | extern void loop_optimizer_init (unsigned); |
697 | extern void loop_optimizer_finalize (void); | |
617b465c ZD |
698 | |
699 | /* Optimization passes. */ | |
d73be268 | 700 | extern void unswitch_loops (void); |
617b465c | 701 | |
b17d5d7c ZD |
702 | enum |
703 | { | |
704 | UAP_PEEL = 1, /* Enables loop peeling. */ | |
598ec7bd ZD |
705 | UAP_UNROLL = 2, /* Enables unrolling of loops if it seems profitable. */ |
706 | UAP_UNROLL_ALL = 4 /* Enables unrolling of all loops. */ | |
b17d5d7c ZD |
707 | }; |
708 | ||
d73be268 ZD |
709 | extern void unroll_and_peel_loops (int); |
710 | extern void doloop_optimize_loops (void); | |
711 | extern void move_loop_invariants (void); | |
f87c9042 | 712 | extern bool finite_loop_p (struct loop *); |
e78410bf | 713 | extern void scale_loop_profile (struct loop *loop, int scale, int iteration_bound); |
59587b18 JQ |
714 | |
715 | #endif /* GCC_CFGLOOP_H */ |