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/* Loop optimizer initialization routines.
Copyright (C) 2002, 2003, 2004 Free Software Foundation, Inc.
This file is part of GCC.
GCC is free software; you can redistribute it and/or modify it under
the terms of the GNU General Public License as published by the Free
Software Foundation; either version 2, or (at your option) any later
version.
GCC is distributed in the hope that it will be useful, but WITHOUT ANY
WARRANTY; without even the implied warranty of MERCHANTABILITY or
FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
for more details.
You should have received a copy of the GNU General Public License
along with GCC; see the file COPYING. If not, write to the Free
Software Foundation, 59 Temple Place - Suite 330, Boston, MA
02111-1307, USA. */
#include "config.h"
#include "system.h"
#include "coretypes.h"
#include "tm.h"
#include "rtl.h"
#include "hard-reg-set.h"
#include "basic-block.h"
#include "cfgloop.h"
#include "cfglayout.h"
/* Initialize loop optimizer. */
struct loops *
loop_optimizer_init (FILE *dumpfile)
{
struct loops *loops = xcalloc (1, sizeof (struct loops));
edge e;
edge_iterator ei;
static bool first_time = true;
if (first_time)
{
first_time = false;
init_set_costs ();
}
/* Avoid annoying special cases of edges going to exit
block. */
for (ei = ei_start (EXIT_BLOCK_PTR->preds); (e = ei_safe_edge (ei)); )
if ((e->flags & EDGE_FALLTHRU) && EDGE_COUNT (e->src->succs) > 1)
split_edge (e);
else
ei_next (&ei);
/* Find the loops. */
if (flow_loops_find (loops, LOOP_TREE) <= 1)
{
/* No loops. */
flow_loops_free (loops);
free (loops);
return NULL;
}
/* Not going to update these. */
free (loops->cfg.rc_order);
loops->cfg.rc_order = NULL;
free (loops->cfg.dfs_order);
loops->cfg.dfs_order = NULL;
/* Create pre-headers. */
create_preheaders (loops, CP_SIMPLE_PREHEADERS);
/* Force all latches to have only single successor. */
force_single_succ_latches (loops);
/* Mark irreducible loops. */
mark_irreducible_loops (loops);
/* Dump loops. */
flow_loops_dump (loops, dumpfile, NULL, 1);
#ifdef ENABLE_CHECKING
verify_dominators (CDI_DOMINATORS);
verify_loop_structure (loops);
#endif
return loops;
}
/* Finalize loop optimizer. */
void
loop_optimizer_finalize (struct loops *loops, FILE *dumpfile)
{
unsigned i;
if (!loops)
return;
for (i = 1; i < loops->num; i++)
if (loops->parray[i])
free_simple_loop_desc (loops->parray[i]);
/* Another dump. */
flow_loops_dump (loops, dumpfile, NULL, 1);
/* Clean up. */
flow_loops_free (loops);
free (loops);
/* Checking. */
#ifdef ENABLE_CHECKING
verify_flow_info ();
#endif
}
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