* cfgloop.h (fix_loop_placement, can_duplicate_loop_p,

	duplicate_loop_to_header_edge, loopify, remove_path, split_loop_bb):
	Declare.
	(DLTHE_FLAG_UPDATE_FREQ): New.
	* cfgloopmanip.c (duplicate_loop, duplicate_subloops, copy_loops_to,
	loop_redirect_edge, loop_delete_branch_edge, copy_bbs, remove_bbs,
	rpe_enum_p, find_branch, alp_enum_p, add_loop, fix_loop_placements,
	fix_bb_placement, fix_bb_placements, place_new_loop,
	scale_loop_frequencies, scale_bbs_frequencies, record_exit_edges):
	New static functions.
	(fix_loop_placement, can_duplicate_loop_p,
	duplicate_loop_to_header_edge, loopify, remove_path, split_loop_bb):
	New functions.

	* cfgloop.h (loop_optimizer_init, loop_optimizer_finalize,
	unswitch_loops): Declare.
	* loop-init.c: New file.
	* loop-unswitch.c: New file.
	* Makefile.in (loop-init.o, loop-unswitch.o): New.
	* params.def (PARAM_MAX_UNSWITCH_INSNS, PARAM_MAX_UNSWITCH_LEVEL): New.
	* toplev.c (DFI_loop2): New dump.
	(flag_unswitch_loops): New.
	(lang_independent_options): Add it.
	(rest_of_compilation): Call new loop optimizer.
	(parse_options_and_default_flags): Turn flag_unswitch_loops on with -O3.


git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@62578 138bc75d-0d04-0410-961f-82ee72b054a4

1 files changed, 116 insertions, 0 deletions

diff --git a/gcc/loop-init.c b/gcc/loop-init.c
new file mode 100644
index 00000000000..44b9d61d5b8
--- /dev/null
+++ b/gcc/loop-init.c
@@ -0,0 +1,116 @@
+/* Loop optimizer initialization routines.
+   Copyright (C) 2002, 2003 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"
+#include "gcov-io.h"
+#include "profile.h"
+
+/* Initialize loop optimizer.  */
+
+struct loops *
+loop_optimizer_init (dumpfile)
+     FILE *dumpfile;
+{
+  struct loops *loops = xcalloc (1, sizeof (struct loops));
+  edge e;
+
+  /* Avoid annoying special cases of edges going to exit
+     block.  */
+  for (e = EXIT_BLOCK_PTR->pred; e; e = e->pred_next)
+    if ((e->flags & EDGE_FALLTHRU) && e->src->succ->succ_next)
+      split_edge (e);
+
+  /* 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;
+
+  /* Initialize structures for layout changes.  */
+  cfg_layout_initialize (loops);
+
+  /* Create pre-headers.  */
+  create_preheaders (loops, CP_SIMPLE_PREHEADERS | CP_INSIDE_CFGLAYOUT);
+
+  /* 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 (loops->cfg.dom);
+  verify_loop_structure (loops);
+#endif
+
+  return loops;
+}
+
+/* Finalize loop optimizer.  */
+void
+loop_optimizer_finalize (loops, dumpfile)
+     struct loops *loops;
+     FILE *dumpfile;
+{
+  basic_block bb;
+
+  /* Finalize layout changes.  */
+  /* Make chain.  */
+  FOR_EACH_BB (bb)
+    if (bb->next_bb != EXIT_BLOCK_PTR)
+      RBI (bb)->next = bb->next_bb;
+
+  /* Another dump.  */
+  flow_loops_dump (loops, dumpfile, NULL, 1);
+
+  /* Clean up.  */
+  flow_loops_free (loops);
+  free (loops);
+ 
+  /* Finalize changes.  */
+  cfg_layout_finalize ();
+
+  /* Checking.  */
+#ifdef ENABLE_CHECKING
+  verify_flow_info ();
+#endif
+}
+