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"
33 /* Initialize loop optimizer. */
36 loop_optimizer_init (dumpfile
)
39 struct loops
*loops
= xcalloc (1, sizeof (struct loops
));
42 /* Avoid annoying special cases of edges going to exit
44 for (e
= EXIT_BLOCK_PTR
->pred
; e
; e
= e
->pred_next
)
45 if ((e
->flags
& EDGE_FALLTHRU
) && e
->src
->succ
->succ_next
)
50 if (flow_loops_find (loops
, LOOP_TREE
) <= 1)
53 flow_loops_free (loops
);
58 /* Not going to update these. */
59 free (loops
->cfg
.rc_order
);
60 loops
->cfg
.rc_order
= NULL
;
61 free (loops
->cfg
.dfs_order
);
62 loops
->cfg
.dfs_order
= NULL
;
64 /* Initialize structures for layout changes. */
65 cfg_layout_initialize (loops
);
67 /* Create pre-headers. */
68 create_preheaders (loops
, CP_SIMPLE_PREHEADERS
| CP_INSIDE_CFGLAYOUT
);
70 /* Force all latches to have only single successor. */
71 force_single_succ_latches (loops
);
73 /* Mark irreducible loops. */
74 mark_irreducible_loops (loops
);
77 flow_loops_dump (loops
, dumpfile
, NULL
, 1);
79 #ifdef ENABLE_CHECKING
80 verify_dominators (loops
->cfg
.dom
);
81 verify_loop_structure (loops
);
87 /* Finalize loop optimizer. */
89 loop_optimizer_finalize (loops
, dumpfile
)
95 /* Finalize layout changes. */
98 if (bb
->next_bb
!= EXIT_BLOCK_PTR
)
99 RBI (bb
)->next
= bb
->next_bb
;
102 flow_loops_dump (loops
, dumpfile
, NULL
, 1);
105 flow_loops_free (loops
);
108 /* Finalize changes. */
109 cfg_layout_finalize ();
112 #ifdef ENABLE_CHECKING