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"
32 /* Initialize loop optimizer. */
35 loop_optimizer_init (dumpfile)
38 struct loops *loops = xcalloc (1, sizeof (struct loops));
41 /* Avoid annoying special cases of edges going to exit
43 for (e = EXIT_BLOCK_PTR->pred; e; e = e->pred_next)
44 if ((e->flags & EDGE_FALLTHRU) && e->src->succ->succ_next)
49 if (flow_loops_find (loops, LOOP_TREE) <= 1)
52 flow_loops_free (loops);
57 /* Not going to update these. */
58 free (loops->cfg.rc_order);
59 loops->cfg.rc_order = NULL;
60 free (loops->cfg.dfs_order);
61 loops->cfg.dfs_order = NULL;
63 /* Initialize structures for layout changes. */
64 cfg_layout_initialize (loops);
66 /* Create pre-headers. */
67 create_preheaders (loops, CP_SIMPLE_PREHEADERS | CP_INSIDE_CFGLAYOUT);
69 /* Force all latches to have only single successor. */
70 force_single_succ_latches (loops);
72 /* Mark irreducible loops. */
73 mark_irreducible_loops (loops);
76 flow_loops_dump (loops, dumpfile, NULL, 1);
78 #ifdef ENABLE_CHECKING
79 verify_dominators (loops->cfg.dom);
80 verify_loop_structure (loops);
86 /* Finalize loop optimizer. */
88 loop_optimizer_finalize (loops, dumpfile)
94 /* Finalize layout changes. */
97 if (bb->next_bb != EXIT_BLOCK_PTR)
98 RBI (bb)->next = bb->next_bb;
101 flow_loops_dump (loops, dumpfile, NULL, 1);
104 flow_loops_free (loops);
107 /* Finalize changes. */
108 cfg_layout_finalize ();
111 #ifdef ENABLE_CHECKING