1 /* Loop optimizer initialization routines.
2 Copyright (C) 2002, 2003 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, 59 Temple Place - Suite 330, Boston, MA
23 #include "coretypes.h"
26 #include "hard-reg-set.h"
27 #include "basic-block.h"
29 #include "cfglayout.h"
31 /* Initialize loop optimizer. */
34 loop_optimizer_init (dumpfile)
37 struct loops *loops = xcalloc (1, sizeof (struct loops));
40 /* Initialize structures for layout changes. */
41 cfg_layout_initialize ();
43 /* Avoid annoying special cases of edges going to exit
45 for (e = EXIT_BLOCK_PTR->pred; e; e = e->pred_next)
46 if ((e->flags & EDGE_FALLTHRU) && e->src->succ->succ_next)
51 if (flow_loops_find (loops, LOOP_TREE) <= 1)
56 flow_loops_free (loops);
60 if (bb->next_bb != EXIT_BLOCK_PTR)
61 bb->rbi->next = bb->next_bb;
62 cfg_layout_finalize ();
66 /* Not going to update these. */
67 free (loops->cfg.rc_order);
68 loops->cfg.rc_order = NULL;
69 free (loops->cfg.dfs_order);
70 loops->cfg.dfs_order = NULL;
72 /* Create pre-headers. */
73 create_preheaders (loops, CP_SIMPLE_PREHEADERS);
75 /* Force all latches to have only single successor. */
76 force_single_succ_latches (loops);
78 /* Mark irreducible loops. */
79 mark_irreducible_loops (loops);
82 flow_loops_dump (loops, dumpfile, NULL, 1);
84 #ifdef ENABLE_CHECKING
85 verify_dominators (loops->cfg.dom);
86 verify_loop_structure (loops);
92 /* Finalize loop optimizer. */
94 loop_optimizer_finalize (loops, dumpfile)
100 /* Finalize layout changes. */
103 if (bb->next_bb != EXIT_BLOCK_PTR)
104 bb->rbi->next = bb->next_bb;
107 flow_loops_dump (loops, dumpfile, NULL, 1);
110 flow_loops_free (loops);
113 /* Finalize changes. */
114 cfg_layout_finalize ();
117 #ifdef ENABLE_CHECKING