-/* Loop optimizer initialization routines.
- Copyright (C) 2002, 2003, 2004 Free Software Foundation, Inc.
+/* Loop optimizer initialization routines and RTL loop optimization passes.
+ Copyright (C) 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2010
+ 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
+Software Foundation; either version 3, or (at your option) any later
version.
GCC is distributed in the hope that it will be useful, but WITHOUT ANY
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. */
+along with GCC; see the file COPYING3. If not see
+<http://www.gnu.org/licenses/>. */
#include "config.h"
#include "system.h"
#include "tm.h"
#include "rtl.h"
#include "hard-reg-set.h"
+#include "obstack.h"
#include "basic-block.h"
#include "cfgloop.h"
#include "cfglayout.h"
+#include "tree-pass.h"
+#include "timevar.h"
+#include "flags.h"
+#include "df.h"
+#include "ggc.h"
-/* Initialize loop optimizer. */
+\f
+/* Initialize loop structures. This is used by the tree and RTL loop
+ optimizers. FLAGS specify what properties to compute and/or ensure for
+ loops. */
-struct loops *
-loop_optimizer_init (FILE *dumpfile)
+void
+loop_optimizer_init (unsigned flags)
{
- 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. */
+ struct loops *loops;
- 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);
+ gcc_assert (!current_loops);
+ loops = ggc_alloc_cleared_loops ();
/* Find the loops. */
- if (flow_loops_find (loops, LOOP_TREE) <= 1)
- {
- /* No loops. */
- flow_loops_free (loops);
- free (loops);
+ flow_loops_find (loops);
+ current_loops = loops;
- return NULL;
+ if (flags & LOOPS_MAY_HAVE_MULTIPLE_LATCHES)
+ {
+ /* If the loops may have multiple latches, we cannot canonicalize
+ them further (and most of the loop manipulation functions will
+ not work). However, we avoid modifying cfg, which some
+ passes may want. */
+ gcc_assert ((flags & ~(LOOPS_MAY_HAVE_MULTIPLE_LATCHES
+ | LOOPS_HAVE_RECORDED_EXITS)) == 0);
+ loops_state_set (LOOPS_MAY_HAVE_MULTIPLE_LATCHES);
}
-
- /* 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;
+ else
+ disambiguate_loops_with_multiple_latches ();
/* Create pre-headers. */
- create_preheaders (loops, CP_SIMPLE_PREHEADERS);
+ if (flags & LOOPS_HAVE_PREHEADERS)
+ {
+ int cp_flags = CP_SIMPLE_PREHEADERS;
+
+ if (flags & LOOPS_HAVE_FALLTHRU_PREHEADERS)
+ cp_flags |= CP_FALLTHRU_PREHEADERS;
+
+ create_preheaders (cp_flags);
+ }
/* Force all latches to have only single successor. */
- force_single_succ_latches (loops);
+ if (flags & LOOPS_HAVE_SIMPLE_LATCHES)
+ force_single_succ_latches ();
/* Mark irreducible loops. */
- mark_irreducible_loops (loops);
+ if (flags & LOOPS_HAVE_MARKED_IRREDUCIBLE_REGIONS)
+ mark_irreducible_loops ();
+
+ if (flags & LOOPS_HAVE_RECORDED_EXITS)
+ record_loop_exits ();
/* Dump loops. */
- flow_loops_dump (loops, dumpfile, NULL, 1);
+ flow_loops_dump (dump_file, NULL, 1);
#ifdef ENABLE_CHECKING
verify_dominators (CDI_DOMINATORS);
- verify_loop_structure (loops);
+ verify_loop_structure ();
#endif
-
- return loops;
}
-/* Finalize loop optimizer. */
+/* Finalize loop structures. */
+
void
-loop_optimizer_finalize (struct loops *loops, FILE *dumpfile)
+loop_optimizer_finalize (void)
{
- unsigned i;
+ loop_iterator li;
+ struct loop *loop;
+ basic_block bb;
- if (!loops)
- return;
+ gcc_assert (current_loops != NULL);
- 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);
+ FOR_EACH_LOOP (li, loop, 0)
+ {
+ free_simple_loop_desc (loop);
+ }
/* Clean up. */
- flow_loops_free (loops);
- free (loops);
+ if (loops_state_satisfies_p (LOOPS_HAVE_RECORDED_EXITS))
+ release_recorded_exits ();
+ flow_loops_free (current_loops);
+ ggc_free (current_loops);
+ current_loops = NULL;
- /* Checking. */
-#ifdef ENABLE_CHECKING
- verify_flow_info ();
+ FOR_ALL_BB (bb)
+ {
+ bb->loop_father = NULL;
+ }
+}
+
+\f
+/* Gate for the RTL loop superpass. The actual passes are subpasses.
+ See passes.c for more on that. */
+
+static bool
+gate_handle_loop2 (void)
+{
+ return (optimize > 0
+ && (flag_move_loop_invariants
+ || flag_unswitch_loops
+ || flag_peel_loops
+ || flag_unroll_loops
+#ifdef HAVE_doloop_end
+ || (flag_branch_on_count_reg && HAVE_doloop_end)
+#endif
+ ));
+}
+
+struct rtl_opt_pass pass_loop2 =
+{
+ {
+ RTL_PASS,
+ "loop2", /* name */
+ gate_handle_loop2, /* gate */
+ NULL, /* execute */
+ NULL, /* sub */
+ NULL, /* next */
+ 0, /* static_pass_number */
+ TV_LOOP, /* tv_id */
+ 0, /* properties_required */
+ 0, /* properties_provided */
+ 0, /* properties_destroyed */
+ 0, /* todo_flags_start */
+ TODO_ggc_collect /* todo_flags_finish */
+ }
+};
+
+\f
+/* Initialization of the RTL loop passes. */
+static unsigned int
+rtl_loop_init (void)
+{
+ gcc_assert (current_ir_type () == IR_RTL_CFGLAYOUT);
+
+ if (dump_file)
+ dump_flow_info (dump_file, dump_flags);
+
+ loop_optimizer_init (LOOPS_NORMAL);
+ return 0;
+}
+
+struct rtl_opt_pass pass_rtl_loop_init =
+{
+ {
+ RTL_PASS,
+ "loop2_init", /* name */
+ NULL, /* gate */
+ rtl_loop_init, /* execute */
+ NULL, /* sub */
+ NULL, /* next */
+ 0, /* static_pass_number */
+ TV_LOOP, /* tv_id */
+ 0, /* properties_required */
+ 0, /* properties_provided */
+ 0, /* properties_destroyed */
+ 0, /* todo_flags_start */
+ TODO_verify_rtl_sharing /* todo_flags_finish */
+ }
+};
+
+\f
+/* Finalization of the RTL loop passes. */
+
+static unsigned int
+rtl_loop_done (void)
+{
+ loop_optimizer_finalize ();
+ free_dominance_info (CDI_DOMINATORS);
+
+ cleanup_cfg (0);
+ if (dump_file)
+ dump_flow_info (dump_file, dump_flags);
+
+ return 0;
+}
+
+struct rtl_opt_pass pass_rtl_loop_done =
+{
+ {
+ RTL_PASS,
+ "loop2_done", /* name */
+ NULL, /* gate */
+ rtl_loop_done, /* execute */
+ NULL, /* sub */
+ NULL, /* next */
+ 0, /* static_pass_number */
+ TV_LOOP, /* tv_id */
+ 0, /* properties_required */
+ 0, /* properties_provided */
+ 0, /* properties_destroyed */
+ 0, /* todo_flags_start */
+ TODO_verify_flow
+ | TODO_verify_rtl_sharing /* todo_flags_finish */
+ }
+};
+
+\f
+/* Loop invariant code motion. */
+static bool
+gate_rtl_move_loop_invariants (void)
+{
+ return flag_move_loop_invariants;
+}
+
+static unsigned int
+rtl_move_loop_invariants (void)
+{
+ if (number_of_loops () > 1)
+ move_loop_invariants ();
+ return 0;
+}
+
+struct rtl_opt_pass pass_rtl_move_loop_invariants =
+{
+ {
+ RTL_PASS,
+ "loop2_invariant", /* name */
+ gate_rtl_move_loop_invariants, /* gate */
+ rtl_move_loop_invariants, /* execute */
+ NULL, /* sub */
+ NULL, /* next */
+ 0, /* static_pass_number */
+ TV_LOOP_MOVE_INVARIANTS, /* tv_id */
+ 0, /* properties_required */
+ 0, /* properties_provided */
+ 0, /* properties_destroyed */
+ 0, /* todo_flags_start */
+ TODO_df_verify |
+ TODO_df_finish | TODO_verify_rtl_sharing /* todo_flags_finish */
+ }
+};
+
+\f
+/* Loop unswitching for RTL. */
+static bool
+gate_rtl_unswitch (void)
+{
+ return flag_unswitch_loops;
+}
+
+static unsigned int
+rtl_unswitch (void)
+{
+ if (number_of_loops () > 1)
+ unswitch_loops ();
+ return 0;
+}
+
+struct rtl_opt_pass pass_rtl_unswitch =
+{
+ {
+ RTL_PASS,
+ "loop2_unswitch", /* name */
+ gate_rtl_unswitch, /* gate */
+ rtl_unswitch, /* execute */
+ NULL, /* sub */
+ NULL, /* next */
+ 0, /* static_pass_number */
+ TV_LOOP_UNSWITCH, /* tv_id */
+ 0, /* properties_required */
+ 0, /* properties_provided */
+ 0, /* properties_destroyed */
+ 0, /* todo_flags_start */
+ TODO_verify_rtl_sharing, /* todo_flags_finish */
+ }
+};
+
+\f
+/* Loop unswitching for RTL. */
+static bool
+gate_rtl_unroll_and_peel_loops (void)
+{
+ return (flag_peel_loops || flag_unroll_loops || flag_unroll_all_loops);
+}
+
+static unsigned int
+rtl_unroll_and_peel_loops (void)
+{
+ if (number_of_loops () > 1)
+ {
+ int flags = 0;
+ if (dump_file)
+ df_dump (dump_file);
+
+ if (flag_peel_loops)
+ flags |= UAP_PEEL;
+ if (flag_unroll_loops)
+ flags |= UAP_UNROLL;
+ if (flag_unroll_all_loops)
+ flags |= UAP_UNROLL_ALL;
+
+ unroll_and_peel_loops (flags);
+ }
+ return 0;
+}
+
+struct rtl_opt_pass pass_rtl_unroll_and_peel_loops =
+{
+ {
+ RTL_PASS,
+ "loop2_unroll", /* name */
+ gate_rtl_unroll_and_peel_loops, /* gate */
+ rtl_unroll_and_peel_loops, /* execute */
+ NULL, /* sub */
+ NULL, /* next */
+ 0, /* static_pass_number */
+ TV_LOOP_UNROLL, /* tv_id */
+ 0, /* properties_required */
+ 0, /* properties_provided */
+ 0, /* properties_destroyed */
+ 0, /* todo_flags_start */
+ TODO_verify_rtl_sharing, /* todo_flags_finish */
+ }
+};
+
+\f
+/* The doloop optimization. */
+static bool
+gate_rtl_doloop (void)
+{
+#ifdef HAVE_doloop_end
+ return (flag_branch_on_count_reg && HAVE_doloop_end);
+#else
+ return 0;
+#endif
+}
+
+static unsigned int
+rtl_doloop (void)
+{
+#ifdef HAVE_doloop_end
+ if (number_of_loops () > 1)
+ doloop_optimize_loops ();
#endif
+ return 0;
}
+
+struct rtl_opt_pass pass_rtl_doloop =
+{
+ {
+ RTL_PASS,
+ "loop2_doloop", /* name */
+ gate_rtl_doloop, /* gate */
+ rtl_doloop, /* execute */
+ NULL, /* sub */
+ NULL, /* next */
+ 0, /* static_pass_number */
+ TV_LOOP_DOLOOP, /* tv_id */
+ 0, /* properties_required */
+ 0, /* properties_provided */
+ 0, /* properties_destroyed */
+ 0, /* todo_flags_start */
+ TODO_verify_rtl_sharing /* todo_flags_finish */
+ }
+};