1/* Loop optimizer initialization routines and RTL loop optimization passes.
2 Copyright (C) 2002, 2003, 2004, 2005 Free Software Foundation, Inc.
3
4This file is part of GCC.
5
6GCC is free software; you can redistribute it and/or modify it under
7the terms of the GNU General Public License as published by the Free
8Software Foundation; either version 2, or (at your option) any later
9version.
10
11GCC is distributed in the hope that it will be useful, but WITHOUT ANY
12WARRANTY; without even the implied warranty of MERCHANTABILITY or
13FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
14for more details.
15
16You should have received a copy of the GNU General Public License
17along with GCC; see the file COPYING. If not, write to the Free
18Software Foundation, 51 Franklin Street, Fifth Floor, Boston, MA
1902110-1301, USA. */
20
21#include "config.h"
22#include "system.h"
23#include "coretypes.h"
24#include "tm.h"
25#include "rtl.h"
26#include "hard-reg-set.h"
27#include "obstack.h"
28#include "basic-block.h"
29#include "cfgloop.h"
30#include "cfglayout.h"
31#include "tree-pass.h"
32#include "timevar.h"
33#include "flags.h"
34
35
36/* Initialize loop optimizer. This is used by the tree and RTL loop
37 optimizers. FLAGS specify what properties to compute and/or ensure for
38 loops. */
39
40struct loops *
41loop_optimizer_init (unsigned flags)
42{
43 struct loops *loops = XCNEW (struct loops);
44 edge e;
45 edge_iterator ei;
46 static bool first_time = true;
47
48 if (first_time)
49 {
50 first_time = false;
51 init_set_costs ();
52 }
53
54 /* Avoid annoying special cases of edges going to exit
55 block. */
56
57 for (ei = ei_start (EXIT_BLOCK_PTR->preds); (e = ei_safe_edge (ei)); )
58 if ((e->flags & EDGE_FALLTHRU) && !single_succ_p (e->src))
59 split_edge (e);
60 else
61 ei_next (&ei);
62
63 /* Find the loops. */
64
65 if (flow_loops_find (loops) <= 1)
66 {
67 /* No loops. */
68 flow_loops_free (loops);
69 free (loops);
70
71 return NULL;
72 }
73
74 /* Not going to update these. */
75 free (loops->cfg.rc_order);
76 loops->cfg.rc_order = NULL;
77 free (loops->cfg.dfs_order);
78 loops->cfg.dfs_order = NULL;
79
80 /* Create pre-headers. */
81 if (flags & LOOPS_HAVE_PREHEADERS)
82 create_preheaders (loops, CP_SIMPLE_PREHEADERS);
83
84 /* Force all latches to have only single successor. */
85 if (flags & LOOPS_HAVE_SIMPLE_LATCHES)
86 force_single_succ_latches (loops);
87
88 /* Mark irreducible loops. */
89 if (flags & LOOPS_HAVE_MARKED_IRREDUCIBLE_REGIONS)
90 mark_irreducible_loops (loops);
91
92 if (flags & LOOPS_HAVE_MARKED_SINGLE_EXITS)
93 mark_single_exit_loops (loops);
94
95 /* Dump loops. */
96 flow_loops_dump (loops, dump_file, NULL, 1);
97
98#ifdef ENABLE_CHECKING
99 verify_dominators (CDI_DOMINATORS);
100 verify_loop_structure (loops);
101#endif
102
103 return loops;
104}
105
106/* Finalize loop optimizer. */
107void
108loop_optimizer_finalize (struct loops *loops)
109{
110 unsigned i;
111
112 if (!loops)
113 return;
114
115 for (i = 1; i < loops->num; i++)
116 if (loops->parray[i])
117 free_simple_loop_desc (loops->parray[i]);
118
119 /* Clean up. */
120 flow_loops_free (loops);
121 free (loops);
122
123 /* Checking. */
124#ifdef ENABLE_CHECKING
125 verify_flow_info ();
126#endif
127}
128
129
130/* Gate for the RTL loop superpass. The actual passes are subpasses.
131 See passes.c for more on that. */
132
133static bool
134gate_handle_loop2 (void)
135{
136 return (optimize > 0
137 && (flag_move_loop_invariants
138 || flag_unswitch_loops
139 || flag_peel_loops
140 || flag_unroll_loops
141#ifdef HAVE_doloop_end
142 || (flag_branch_on_count_reg && HAVE_doloop_end)
143#endif
144 ));
145}
146
147struct tree_opt_pass pass_loop2 =
148{
149 "loop2", /* name */
150 gate_handle_loop2, /* gate */
151 NULL, /* execute */
152 NULL, /* sub */
153 NULL, /* next */
154 0, /* static_pass_number */
155 TV_LOOP, /* tv_id */
156 0, /* properties_required */
157 0, /* properties_provided */
158 0, /* properties_destroyed */
159 0, /* todo_flags_start */
160 TODO_dump_func |
161 TODO_ggc_collect, /* todo_flags_finish */
162 'L' /* letter */
163};
164
165
166/* Initialization of the RTL loop passes. */
167static unsigned int
168rtl_loop_init (void)
169{
170 if (dump_file)
171 dump_flow_info (dump_file, dump_flags);
172
173 /* Initialize structures for layout changes. */
174 cfg_layout_initialize (0);
175
176 current_loops = loop_optimizer_init (LOOPS_NORMAL);
177 return 0;
178}
179
180struct tree_opt_pass pass_rtl_loop_init =
181{
182 "loop2_init", /* name */
183 NULL, /* gate */
184 rtl_loop_init, /* execute */
185 NULL, /* sub */
186 NULL, /* next */
187 0, /* static_pass_number */
188 TV_LOOP, /* tv_id */
189 0, /* properties_required */
190 0, /* properties_provided */
191 0, /* properties_destroyed */
192 0, /* todo_flags_start */
193 TODO_dump_func, /* todo_flags_finish */
194 'L' /* letter */
195};
196
197
198/* Finalization of the RTL loop passes. */
199static unsigned int
200rtl_loop_done (void)
201{
202 basic_block bb;
203
204 if (current_loops)
205 loop_optimizer_finalize (current_loops);
206
207 free_dominance_info (CDI_DOMINATORS);
208
209 /* Finalize layout changes. */
210 FOR_EACH_BB (bb)
211 if (bb->next_bb != EXIT_BLOCK_PTR)
212 bb->aux = bb->next_bb;
213 cfg_layout_finalize ();
214
215 cleanup_cfg (CLEANUP_EXPENSIVE);
216 delete_trivially_dead_insns (get_insns (), max_reg_num ());
217 reg_scan (get_insns (), max_reg_num ());
218 if (dump_file)
219 dump_flow_info (dump_file, dump_flags);
220
221 current_loops = NULL;
222 return 0;
223}
224
225struct tree_opt_pass pass_rtl_loop_done =
226{
227 "loop2_done", /* name */
228 NULL, /* gate */
229 rtl_loop_done, /* execute */
230 NULL, /* sub */
231 NULL, /* next */
232 0, /* static_pass_number */
233 TV_LOOP, /* tv_id */
234 0, /* properties_required */
235 0, /* properties_provided */
236 0, /* properties_destroyed */
237 0, /* todo_flags_start */
238 TODO_dump_func, /* todo_flags_finish */
239 'L' /* letter */
240};
241
242
243/* Loop invariant code motion. */
244static bool
245gate_rtl_move_loop_invariants (void)
246{
247 return flag_move_loop_invariants;
248}
249
250static unsigned int
251rtl_move_loop_invariants (void)
252{
253 if (current_loops)
254 move_loop_invariants (current_loops);
255 return 0;
256}
257
258struct tree_opt_pass pass_rtl_move_loop_invariants =
259{
260 "loop2_invariant", /* name */
261 gate_rtl_move_loop_invariants, /* gate */
262 rtl_move_loop_invariants, /* execute */
263 NULL, /* sub */
264 NULL, /* next */
265 0, /* static_pass_number */
266 TV_LOOP, /* tv_id */
267 0, /* properties_required */
268 0, /* properties_provided */
269 0, /* properties_destroyed */
270 0, /* todo_flags_start */
271 TODO_dump_func, /* todo_flags_finish */
272 'L' /* letter */
273};
274
275
276/* Loop unswitching for RTL. */
277static bool
278gate_rtl_unswitch (void)
279{
280 return flag_unswitch_loops;
281}
282
283static unsigned int
284rtl_unswitch (void)
285{
286 if (current_loops)
287 unswitch_loops (current_loops);
288 return 0;
289}
290
291struct tree_opt_pass pass_rtl_unswitch =
292{
293 "loop2_unswitch", /* name */
294 gate_rtl_unswitch, /* gate */
295 rtl_unswitch, /* execute */
296 NULL, /* sub */
297 NULL, /* next */
298 0, /* static_pass_number */
299 TV_LOOP, /* tv_id */
300 0, /* properties_required */
301 0, /* properties_provided */
302 0, /* properties_destroyed */
303 0, /* todo_flags_start */
304 TODO_dump_func, /* todo_flags_finish */
305 'L' /* letter */
306};
307
308
309/* Loop unswitching for RTL. */
310static bool
311gate_rtl_unroll_and_peel_loops (void)
312{
313 return (flag_peel_loops || flag_unroll_loops || flag_unroll_all_loops);
314}
315
316static unsigned int
317rtl_unroll_and_peel_loops (void)
318{
319 if (current_loops)
320 {
321 int flags = 0;
322
323 if (flag_peel_loops)
324 flags |= UAP_PEEL;
325 if (flag_unroll_loops)
326 flags |= UAP_UNROLL;
327 if (flag_unroll_all_loops)
328 flags |= UAP_UNROLL_ALL;
329
330 unroll_and_peel_loops (current_loops, flags);
331 }
332 return 0;
333}
334
335struct tree_opt_pass pass_rtl_unroll_and_peel_loops =
336{
337 "loop2_unroll", /* name */
338 gate_rtl_unroll_and_peel_loops, /* gate */
339 rtl_unroll_and_peel_loops, /* execute */
340 NULL, /* sub */
341 NULL, /* next */
342 0, /* static_pass_number */
343 TV_LOOP, /* tv_id */
344 0, /* properties_required */
345 0, /* properties_provided */
346 0, /* properties_destroyed */
347 0, /* todo_flags_start */
348 TODO_dump_func, /* todo_flags_finish */
349 'L' /* letter */
350};
351
352
353/* The doloop optimization. */
354static bool
355gate_rtl_doloop (void)
356{
357#ifdef HAVE_doloop_end
358 return (flag_branch_on_count_reg && HAVE_doloop_end);
359#else
360 return 0;
361#endif
362}
363
364static unsigned int
365rtl_doloop (void)
366{
367#ifdef HAVE_doloop_end
368 if (current_loops)
369 doloop_optimize_loops (current_loops);
370#endif
371 return 0;
372}
373
374struct tree_opt_pass pass_rtl_doloop =
375{
376 "loop2_doloop", /* name */
377 gate_rtl_doloop, /* gate */
378 rtl_doloop, /* execute */
379 NULL, /* sub */
380 NULL, /* next */
381 0, /* static_pass_number */
382 TV_LOOP, /* tv_id */
383 0, /* properties_required */
384 0, /* properties_provided */
385 0, /* properties_destroyed */
386 0, /* todo_flags_start */
387 TODO_dump_func, /* todo_flags_finish */
388 'L' /* letter */
389};
390
2 Copyright (C) 2002, 2003, 2004, 2005 Free Software Foundation, Inc.
3
4This file is part of GCC.
5
6GCC is free software; you can redistribute it and/or modify it under
7the terms of the GNU General Public License as published by the Free
8Software Foundation; either version 2, or (at your option) any later
9version.
10
11GCC is distributed in the hope that it will be useful, but WITHOUT ANY
12WARRANTY; without even the implied warranty of MERCHANTABILITY or
13FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
14for more details.
15
16You should have received a copy of the GNU General Public License
17along with GCC; see the file COPYING. If not, write to the Free
18Software Foundation, 51 Franklin Street, Fifth Floor, Boston, MA
1902110-1301, USA. */
20
21#include "config.h"
22#include "system.h"
23#include "coretypes.h"
24#include "tm.h"
25#include "rtl.h"
26#include "hard-reg-set.h"
27#include "obstack.h"
28#include "basic-block.h"
29#include "cfgloop.h"
30#include "cfglayout.h"
31#include "tree-pass.h"
32#include "timevar.h"
33#include "flags.h"
34
35
36/* Initialize loop optimizer. This is used by the tree and RTL loop
37 optimizers. FLAGS specify what properties to compute and/or ensure for
38 loops. */
39
40struct loops *
41loop_optimizer_init (unsigned flags)
42{
43 struct loops *loops = XCNEW (struct loops);
44 edge e;
45 edge_iterator ei;
46 static bool first_time = true;
47
48 if (first_time)
49 {
50 first_time = false;
51 init_set_costs ();
52 }
53
54 /* Avoid annoying special cases of edges going to exit
55 block. */
56
57 for (ei = ei_start (EXIT_BLOCK_PTR->preds); (e = ei_safe_edge (ei)); )
58 if ((e->flags & EDGE_FALLTHRU) && !single_succ_p (e->src))
59 split_edge (e);
60 else
61 ei_next (&ei);
62
63 /* Find the loops. */
64
65 if (flow_loops_find (loops) <= 1)
66 {
67 /* No loops. */
68 flow_loops_free (loops);
69 free (loops);
70
71 return NULL;
72 }
73
74 /* Not going to update these. */
75 free (loops->cfg.rc_order);
76 loops->cfg.rc_order = NULL;
77 free (loops->cfg.dfs_order);
78 loops->cfg.dfs_order = NULL;
79
80 /* Create pre-headers. */
81 if (flags & LOOPS_HAVE_PREHEADERS)
82 create_preheaders (loops, CP_SIMPLE_PREHEADERS);
83
84 /* Force all latches to have only single successor. */
85 if (flags & LOOPS_HAVE_SIMPLE_LATCHES)
86 force_single_succ_latches (loops);
87
88 /* Mark irreducible loops. */
89 if (flags & LOOPS_HAVE_MARKED_IRREDUCIBLE_REGIONS)
90 mark_irreducible_loops (loops);
91
92 if (flags & LOOPS_HAVE_MARKED_SINGLE_EXITS)
93 mark_single_exit_loops (loops);
94
95 /* Dump loops. */
96 flow_loops_dump (loops, dump_file, NULL, 1);
97
98#ifdef ENABLE_CHECKING
99 verify_dominators (CDI_DOMINATORS);
100 verify_loop_structure (loops);
101#endif
102
103 return loops;
104}
105
106/* Finalize loop optimizer. */
107void
108loop_optimizer_finalize (struct loops *loops)
109{
110 unsigned i;
111
112 if (!loops)
113 return;
114
115 for (i = 1; i < loops->num; i++)
116 if (loops->parray[i])
117 free_simple_loop_desc (loops->parray[i]);
118
119 /* Clean up. */
120 flow_loops_free (loops);
121 free (loops);
122
123 /* Checking. */
124#ifdef ENABLE_CHECKING
125 verify_flow_info ();
126#endif
127}
128
129
130/* Gate for the RTL loop superpass. The actual passes are subpasses.
131 See passes.c for more on that. */
132
133static bool
134gate_handle_loop2 (void)
135{
136 return (optimize > 0
137 && (flag_move_loop_invariants
138 || flag_unswitch_loops
139 || flag_peel_loops
140 || flag_unroll_loops
141#ifdef HAVE_doloop_end
142 || (flag_branch_on_count_reg && HAVE_doloop_end)
143#endif
144 ));
145}
146
147struct tree_opt_pass pass_loop2 =
148{
149 "loop2", /* name */
150 gate_handle_loop2, /* gate */
151 NULL, /* execute */
152 NULL, /* sub */
153 NULL, /* next */
154 0, /* static_pass_number */
155 TV_LOOP, /* tv_id */
156 0, /* properties_required */
157 0, /* properties_provided */
158 0, /* properties_destroyed */
159 0, /* todo_flags_start */
160 TODO_dump_func |
161 TODO_ggc_collect, /* todo_flags_finish */
162 'L' /* letter */
163};
164
165
166/* Initialization of the RTL loop passes. */
167static unsigned int
168rtl_loop_init (void)
169{
170 if (dump_file)
171 dump_flow_info (dump_file, dump_flags);
172
173 /* Initialize structures for layout changes. */
174 cfg_layout_initialize (0);
175
176 current_loops = loop_optimizer_init (LOOPS_NORMAL);
177 return 0;
178}
179
180struct tree_opt_pass pass_rtl_loop_init =
181{
182 "loop2_init", /* name */
183 NULL, /* gate */
184 rtl_loop_init, /* execute */
185 NULL, /* sub */
186 NULL, /* next */
187 0, /* static_pass_number */
188 TV_LOOP, /* tv_id */
189 0, /* properties_required */
190 0, /* properties_provided */
191 0, /* properties_destroyed */
192 0, /* todo_flags_start */
193 TODO_dump_func, /* todo_flags_finish */
194 'L' /* letter */
195};
196
197
198/* Finalization of the RTL loop passes. */
199static unsigned int
200rtl_loop_done (void)
201{
202 basic_block bb;
203
204 if (current_loops)
205 loop_optimizer_finalize (current_loops);
206
207 free_dominance_info (CDI_DOMINATORS);
208
209 /* Finalize layout changes. */
210 FOR_EACH_BB (bb)
211 if (bb->next_bb != EXIT_BLOCK_PTR)
212 bb->aux = bb->next_bb;
213 cfg_layout_finalize ();
214
215 cleanup_cfg (CLEANUP_EXPENSIVE);
216 delete_trivially_dead_insns (get_insns (), max_reg_num ());
217 reg_scan (get_insns (), max_reg_num ());
218 if (dump_file)
219 dump_flow_info (dump_file, dump_flags);
220
221 current_loops = NULL;
222 return 0;
223}
224
225struct tree_opt_pass pass_rtl_loop_done =
226{
227 "loop2_done", /* name */
228 NULL, /* gate */
229 rtl_loop_done, /* execute */
230 NULL, /* sub */
231 NULL, /* next */
232 0, /* static_pass_number */
233 TV_LOOP, /* tv_id */
234 0, /* properties_required */
235 0, /* properties_provided */
236 0, /* properties_destroyed */
237 0, /* todo_flags_start */
238 TODO_dump_func, /* todo_flags_finish */
239 'L' /* letter */
240};
241
242
243/* Loop invariant code motion. */
244static bool
245gate_rtl_move_loop_invariants (void)
246{
247 return flag_move_loop_invariants;
248}
249
250static unsigned int
251rtl_move_loop_invariants (void)
252{
253 if (current_loops)
254 move_loop_invariants (current_loops);
255 return 0;
256}
257
258struct tree_opt_pass pass_rtl_move_loop_invariants =
259{
260 "loop2_invariant", /* name */
261 gate_rtl_move_loop_invariants, /* gate */
262 rtl_move_loop_invariants, /* execute */
263 NULL, /* sub */
264 NULL, /* next */
265 0, /* static_pass_number */
266 TV_LOOP, /* tv_id */
267 0, /* properties_required */
268 0, /* properties_provided */
269 0, /* properties_destroyed */
270 0, /* todo_flags_start */
271 TODO_dump_func, /* todo_flags_finish */
272 'L' /* letter */
273};
274
275
276/* Loop unswitching for RTL. */
277static bool
278gate_rtl_unswitch (void)
279{
280 return flag_unswitch_loops;
281}
282
283static unsigned int
284rtl_unswitch (void)
285{
286 if (current_loops)
287 unswitch_loops (current_loops);
288 return 0;
289}
290
291struct tree_opt_pass pass_rtl_unswitch =
292{
293 "loop2_unswitch", /* name */
294 gate_rtl_unswitch, /* gate */
295 rtl_unswitch, /* execute */
296 NULL, /* sub */
297 NULL, /* next */
298 0, /* static_pass_number */
299 TV_LOOP, /* tv_id */
300 0, /* properties_required */
301 0, /* properties_provided */
302 0, /* properties_destroyed */
303 0, /* todo_flags_start */
304 TODO_dump_func, /* todo_flags_finish */
305 'L' /* letter */
306};
307
308
309/* Loop unswitching for RTL. */
310static bool
311gate_rtl_unroll_and_peel_loops (void)
312{
313 return (flag_peel_loops || flag_unroll_loops || flag_unroll_all_loops);
314}
315
316static unsigned int
317rtl_unroll_and_peel_loops (void)
318{
319 if (current_loops)
320 {
321 int flags = 0;
322
323 if (flag_peel_loops)
324 flags |= UAP_PEEL;
325 if (flag_unroll_loops)
326 flags |= UAP_UNROLL;
327 if (flag_unroll_all_loops)
328 flags |= UAP_UNROLL_ALL;
329
330 unroll_and_peel_loops (current_loops, flags);
331 }
332 return 0;
333}
334
335struct tree_opt_pass pass_rtl_unroll_and_peel_loops =
336{
337 "loop2_unroll", /* name */
338 gate_rtl_unroll_and_peel_loops, /* gate */
339 rtl_unroll_and_peel_loops, /* execute */
340 NULL, /* sub */
341 NULL, /* next */
342 0, /* static_pass_number */
343 TV_LOOP, /* tv_id */
344 0, /* properties_required */
345 0, /* properties_provided */
346 0, /* properties_destroyed */
347 0, /* todo_flags_start */
348 TODO_dump_func, /* todo_flags_finish */
349 'L' /* letter */
350};
351
352
353/* The doloop optimization. */
354static bool
355gate_rtl_doloop (void)
356{
357#ifdef HAVE_doloop_end
358 return (flag_branch_on_count_reg && HAVE_doloop_end);
359#else
360 return 0;
361#endif
362}
363
364static unsigned int
365rtl_doloop (void)
366{
367#ifdef HAVE_doloop_end
368 if (current_loops)
369 doloop_optimize_loops (current_loops);
370#endif
371 return 0;
372}
373
374struct tree_opt_pass pass_rtl_doloop =
375{
376 "loop2_doloop", /* name */
377 gate_rtl_doloop, /* gate */
378 rtl_doloop, /* execute */
379 NULL, /* sub */
380 NULL, /* next */
381 0, /* static_pass_number */
382 TV_LOOP, /* tv_id */
383 0, /* properties_required */
384 0, /* properties_provided */
385 0, /* properties_destroyed */
386 0, /* todo_flags_start */
387 TODO_dump_func, /* todo_flags_finish */
388 'L' /* letter */
389};
390