1 /* Loop optimizer initialization routines and RTL loop optimization passes.
2 Copyright (C) 2002, 2003, 2004, 2005 Free Software Foundation, Inc.
4 This file is part of GCC.
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
8 Software Foundation; either version 2, or (at your option) any later
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
16 You should have received a copy of the GNU General Public License
17 along with GCC; see the file COPYING. If not, write to the Free
18 Software Foundation, 51 Franklin Street, Fifth Floor, Boston, MA
23 #include "coretypes.h"
26 #include "hard-reg-set.h"
28 #include "basic-block.h"
30 #include "cfglayout.h"
31 #include "tree-pass.h"
36 /* Initialize loop structures. This is used by the tree and RTL loop
37 optimizers. FLAGS specify what properties to compute and/or ensure for
41 loop_optimizer_init (unsigned flags)
45 static bool first_time = true;
54 gcc_assert (!current_loops);
55 loops = XCNEW (struct loops);
57 /* Avoid annoying special cases of edges going to exit
60 for (ei = ei_start (EXIT_BLOCK_PTR->preds); (e = ei_safe_edge (ei)); )
61 if ((e->flags & EDGE_FALLTHRU) && !single_succ_p (e->src))
68 flow_loops_find (loops);
69 current_loops = loops;
71 if (current_loops->num <= 1)
74 loop_optimizer_finalize ();
78 /* Create pre-headers. */
79 if (flags & LOOPS_HAVE_PREHEADERS)
80 create_preheaders (current_loops, CP_SIMPLE_PREHEADERS);
82 /* Force all latches to have only single successor. */
83 if (flags & LOOPS_HAVE_SIMPLE_LATCHES)
84 force_single_succ_latches (current_loops);
86 /* Mark irreducible loops. */
87 if (flags & LOOPS_HAVE_MARKED_IRREDUCIBLE_REGIONS)
88 mark_irreducible_loops (current_loops);
90 if (flags & LOOPS_HAVE_MARKED_SINGLE_EXITS)
91 mark_single_exit_loops (current_loops);
94 flow_loops_dump (current_loops, dump_file, NULL, 1);
96 #ifdef ENABLE_CHECKING
97 verify_dominators (CDI_DOMINATORS);
98 verify_loop_structure (current_loops);
102 /* Finalize loop structures. */
105 loop_optimizer_finalize (void)
113 for (i = 1; i < current_loops->num; i++)
114 if (current_loops->parray[i])
115 free_simple_loop_desc (current_loops->parray[i]);
118 flow_loops_free (current_loops);
119 free (current_loops);
120 current_loops = NULL;
124 bb->loop_father = NULL;
128 #ifdef ENABLE_CHECKING
134 /* Gate for the RTL loop superpass. The actual passes are subpasses.
135 See passes.c for more on that. */
138 gate_handle_loop2 (void)
141 && (flag_move_loop_invariants
142 || flag_unswitch_loops
145 #ifdef HAVE_doloop_end
146 || (flag_branch_on_count_reg && HAVE_doloop_end)
151 struct tree_opt_pass pass_loop2 =
154 gate_handle_loop2, /* gate */
158 0, /* static_pass_number */
160 0, /* properties_required */
161 0, /* properties_provided */
162 0, /* properties_destroyed */
163 0, /* todo_flags_start */
165 TODO_ggc_collect, /* todo_flags_finish */
170 /* Initialization of the RTL loop passes. */
175 dump_flow_info (dump_file, dump_flags);
177 /* Initialize structures for layout changes. */
178 cfg_layout_initialize (0);
180 loop_optimizer_init (LOOPS_NORMAL);
184 struct tree_opt_pass pass_rtl_loop_init =
186 "loop2_init", /* name */
188 rtl_loop_init, /* execute */
191 0, /* static_pass_number */
193 0, /* properties_required */
194 0, /* properties_provided */
195 0, /* properties_destroyed */
196 0, /* todo_flags_start */
197 TODO_dump_func, /* todo_flags_finish */
202 /* Finalization of the RTL loop passes. */
209 loop_optimizer_finalize ();
210 free_dominance_info (CDI_DOMINATORS);
212 /* Finalize layout changes. */
214 if (bb->next_bb != EXIT_BLOCK_PTR)
215 bb->aux = bb->next_bb;
216 cfg_layout_finalize ();
218 cleanup_cfg (CLEANUP_EXPENSIVE);
219 delete_trivially_dead_insns (get_insns (), max_reg_num ());
220 reg_scan (get_insns (), max_reg_num ());
222 dump_flow_info (dump_file, dump_flags);
227 struct tree_opt_pass pass_rtl_loop_done =
229 "loop2_done", /* name */
231 rtl_loop_done, /* execute */
234 0, /* static_pass_number */
236 0, /* properties_required */
237 0, /* properties_provided */
238 0, /* properties_destroyed */
239 0, /* todo_flags_start */
240 TODO_dump_func, /* todo_flags_finish */
245 /* Loop invariant code motion. */
247 gate_rtl_move_loop_invariants (void)
249 return flag_move_loop_invariants;
253 rtl_move_loop_invariants (void)
256 move_loop_invariants (current_loops);
260 struct tree_opt_pass pass_rtl_move_loop_invariants =
262 "loop2_invariant", /* name */
263 gate_rtl_move_loop_invariants, /* gate */
264 rtl_move_loop_invariants, /* execute */
267 0, /* static_pass_number */
269 0, /* properties_required */
270 0, /* properties_provided */
271 0, /* properties_destroyed */
272 0, /* todo_flags_start */
273 TODO_dump_func, /* todo_flags_finish */
278 /* Loop unswitching for RTL. */
280 gate_rtl_unswitch (void)
282 return flag_unswitch_loops;
289 unswitch_loops (current_loops);
293 struct tree_opt_pass pass_rtl_unswitch =
295 "loop2_unswitch", /* name */
296 gate_rtl_unswitch, /* gate */
297 rtl_unswitch, /* execute */
300 0, /* static_pass_number */
302 0, /* properties_required */
303 0, /* properties_provided */
304 0, /* properties_destroyed */
305 0, /* todo_flags_start */
306 TODO_dump_func, /* todo_flags_finish */
311 /* Loop unswitching for RTL. */
313 gate_rtl_unroll_and_peel_loops (void)
315 return (flag_peel_loops || flag_unroll_loops || flag_unroll_all_loops);
319 rtl_unroll_and_peel_loops (void)
327 if (flag_unroll_loops)
329 if (flag_unroll_all_loops)
330 flags |= UAP_UNROLL_ALL;
332 unroll_and_peel_loops (current_loops, flags);
337 struct tree_opt_pass pass_rtl_unroll_and_peel_loops =
339 "loop2_unroll", /* name */
340 gate_rtl_unroll_and_peel_loops, /* gate */
341 rtl_unroll_and_peel_loops, /* execute */
344 0, /* static_pass_number */
346 0, /* properties_required */
347 0, /* properties_provided */
348 0, /* properties_destroyed */
349 0, /* todo_flags_start */
350 TODO_dump_func, /* todo_flags_finish */
355 /* The doloop optimization. */
357 gate_rtl_doloop (void)
359 #ifdef HAVE_doloop_end
360 return (flag_branch_on_count_reg && HAVE_doloop_end);
369 #ifdef HAVE_doloop_end
371 doloop_optimize_loops (current_loops);
376 struct tree_opt_pass pass_rtl_doloop =
378 "loop2_doloop", /* name */
379 gate_rtl_doloop, /* gate */
380 rtl_doloop, /* execute */
383 0, /* static_pass_number */
385 0, /* properties_required */
386 0, /* properties_provided */
387 0, /* properties_destroyed */
388 0, /* todo_flags_start */
389 TODO_dump_func, /* todo_flags_finish */