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 optimizer. This is used by the tree and RTL loop
40 loop_optimizer_init (FILE *dumpfile
)
42 struct loops
*loops
= xcalloc (1, sizeof (struct loops
));
45 static bool first_time
= true;
53 /* Avoid annoying special cases of edges going to exit
56 for (ei
= ei_start (EXIT_BLOCK_PTR
->preds
); (e
= ei_safe_edge (ei
)); )
57 if ((e
->flags
& EDGE_FALLTHRU
) && !single_succ_p (e
->src
))
64 if (flow_loops_find (loops
) <= 1)
67 flow_loops_free (loops
);
73 /* Not going to update these. */
74 free (loops
->cfg
.rc_order
);
75 loops
->cfg
.rc_order
= NULL
;
76 free (loops
->cfg
.dfs_order
);
77 loops
->cfg
.dfs_order
= NULL
;
79 /* Create pre-headers. */
80 create_preheaders (loops
, CP_SIMPLE_PREHEADERS
);
82 /* Force all latches to have only single successor. */
83 force_single_succ_latches (loops
);
85 /* Mark irreducible loops. */
86 mark_irreducible_loops (loops
);
89 flow_loops_dump (loops
, dumpfile
, NULL
, 1);
91 #ifdef ENABLE_CHECKING
92 verify_dominators (CDI_DOMINATORS
);
93 verify_loop_structure (loops
);
99 /* Finalize loop optimizer. */
101 loop_optimizer_finalize (struct loops
*loops
, FILE *dumpfile
)
108 for (i
= 1; i
< loops
->num
; i
++)
109 if (loops
->parray
[i
])
110 free_simple_loop_desc (loops
->parray
[i
]);
113 flow_loops_dump (loops
, dumpfile
, NULL
, 1);
116 flow_loops_free (loops
);
120 #ifdef ENABLE_CHECKING
126 /* Gate for the RTL loop superpass. The actual passes are subpasses.
127 See passes.c for more on that. */
130 gate_handle_loop2 (void)
132 return (optimize
> 0 && flag_loop_optimize2
133 && (flag_move_loop_invariants
134 || flag_unswitch_loops
137 || flag_branch_on_count_reg
));
140 struct tree_opt_pass pass_loop2
=
143 gate_handle_loop2
, /* gate */
147 0, /* static_pass_number */
149 0, /* properties_required */
150 0, /* properties_provided */
151 0, /* properties_destroyed */
152 0, /* todo_flags_start */
154 TODO_ggc_collect
, /* todo_flags_finish */
159 /* Initialization of the RTL loop passes. */
164 dump_flow_info (dump_file
);
166 /* Initialize structures for layout changes. */
167 cfg_layout_initialize (0);
169 current_loops
= loop_optimizer_init (dump_file
);
172 struct tree_opt_pass pass_rtl_loop_init
=
174 "loopinit", /* name */
176 rtl_loop_init
, /* execute */
179 0, /* static_pass_number */
181 0, /* properties_required */
182 0, /* properties_provided */
183 0, /* properties_destroyed */
184 0, /* todo_flags_start */
185 TODO_dump_func
, /* todo_flags_finish */
190 /* Finalization of the RTL loop passes. */
197 loop_optimizer_finalize (current_loops
, dump_file
);
199 free_dominance_info (CDI_DOMINATORS
);
201 /* Finalize layout changes. */
203 if (bb
->next_bb
!= EXIT_BLOCK_PTR
)
204 bb
->aux
= bb
->next_bb
;
205 cfg_layout_finalize ();
207 cleanup_cfg (CLEANUP_EXPENSIVE
);
208 delete_trivially_dead_insns (get_insns (), max_reg_num ());
209 reg_scan (get_insns (), max_reg_num ());
211 dump_flow_info (dump_file
);
213 current_loops
= NULL
;
216 struct tree_opt_pass pass_rtl_loop_done
=
218 "loopdone", /* name */
220 rtl_loop_done
, /* execute */
223 0, /* static_pass_number */
225 0, /* properties_required */
226 0, /* properties_provided */
227 0, /* properties_destroyed */
228 0, /* todo_flags_start */
229 TODO_dump_func
, /* todo_flags_finish */
234 /* Loop invariant code motion. */
236 rtl_move_loop_invariants (void)
238 if (current_loops
&& flag_move_loop_invariants
)
239 move_loop_invariants (current_loops
);
242 struct tree_opt_pass pass_rtl_move_loop_invariants
=
244 "loop_invariant", /* name */
246 rtl_move_loop_invariants
, /* execute */
249 0, /* static_pass_number */
251 0, /* properties_required */
252 0, /* properties_provided */
253 0, /* properties_destroyed */
254 0, /* todo_flags_start */
255 TODO_dump_func
, /* todo_flags_finish */
260 /* Loop unswitching for RTL. */
264 if (current_loops
&& flag_unswitch_loops
)
265 unswitch_loops (current_loops
);
268 struct tree_opt_pass pass_rtl_unswitch
=
270 "loop_unswitch", /* name */
272 rtl_unswitch
, /* execute */
275 0, /* static_pass_number */
277 0, /* properties_required */
278 0, /* properties_provided */
279 0, /* properties_destroyed */
280 0, /* todo_flags_start */
281 TODO_dump_func
, /* todo_flags_finish */
286 /* Loop unswitching for RTL. */
288 rtl_unroll_and_peel_loops (void)
291 && (flag_peel_loops
|| flag_unroll_loops
|| flag_unroll_all_loops
))
297 if (flag_unroll_loops
)
299 if (flag_unroll_all_loops
)
300 flags
|= UAP_UNROLL_ALL
;
302 unroll_and_peel_loops (current_loops
, flags
);
306 struct tree_opt_pass pass_rtl_unroll_and_peel_loops
=
308 "loop_unroll", /* name */
310 rtl_unroll_and_peel_loops
, /* execute */
313 0, /* static_pass_number */
315 0, /* properties_required */
316 0, /* properties_provided */
317 0, /* properties_destroyed */
318 0, /* todo_flags_start */
319 TODO_dump_func
, /* todo_flags_finish */
324 /* The doloop optimization. */
328 #ifdef HAVE_doloop_end
330 && (flag_branch_on_count_reg
&& HAVE_doloop_end
))
331 doloop_optimize_loops (current_loops
);
335 struct tree_opt_pass pass_rtl_doloop
=
337 "loop_doloop", /* name */
339 rtl_doloop
, /* execute */
342 0, /* static_pass_number */
344 0, /* properties_required */
345 0, /* properties_provided */
346 0, /* properties_destroyed */
347 0, /* todo_flags_start */
348 TODO_dump_func
, /* todo_flags_finish */