403 lines
11 KiB
C
403 lines
11 KiB
C
/* Loop optimizer initialization routines and RTL loop optimization passes.
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Copyright (C) 2002, 2003, 2004, 2005, 2006, 2007, 2008
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Free Software Foundation, Inc.
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This file is part of GCC.
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GCC is free software; you can redistribute it and/or modify it under
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the terms of the GNU General Public License as published by the Free
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Software Foundation; either version 3, or (at your option) any later
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version.
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GCC is distributed in the hope that it will be useful, but WITHOUT ANY
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WARRANTY; without even the implied warranty of MERCHANTABILITY or
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FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
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for more details.
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You should have received a copy of the GNU General Public License
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along with GCC; see the file COPYING3. If not see
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<http://www.gnu.org/licenses/>. */
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#include "config.h"
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#include "system.h"
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#include "coretypes.h"
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#include "tm.h"
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#include "rtl.h"
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#include "hard-reg-set.h"
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#include "obstack.h"
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#include "basic-block.h"
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#include "cfgloop.h"
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#include "cfglayout.h"
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#include "tree-pass.h"
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#include "timevar.h"
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#include "flags.h"
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#include "df.h"
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#include "ggc.h"
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/* Initialize loop structures. This is used by the tree and RTL loop
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optimizers. FLAGS specify what properties to compute and/or ensure for
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loops. */
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void
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loop_optimizer_init (unsigned flags)
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{
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struct loops *loops;
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gcc_assert (!current_loops);
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loops = GGC_CNEW (struct loops);
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/* Find the loops. */
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flow_loops_find (loops);
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current_loops = loops;
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if (flags & LOOPS_MAY_HAVE_MULTIPLE_LATCHES)
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{
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/* If the loops may have multiple latches, we cannot canonicalize
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them further (and most of the loop manipulation functions will
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not work). However, we avoid modifying cfg, which some
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passes may want. */
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gcc_assert ((flags & ~(LOOPS_MAY_HAVE_MULTIPLE_LATCHES
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| LOOPS_HAVE_RECORDED_EXITS)) == 0);
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loops_state_set (LOOPS_MAY_HAVE_MULTIPLE_LATCHES);
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}
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else
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disambiguate_loops_with_multiple_latches ();
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/* Create pre-headers. */
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if (flags & LOOPS_HAVE_PREHEADERS)
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{
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int cp_flags = CP_SIMPLE_PREHEADERS;
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if (flags & LOOPS_HAVE_FALLTHRU_PREHEADERS)
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cp_flags |= CP_FALLTHRU_PREHEADERS;
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create_preheaders (cp_flags);
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}
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/* Force all latches to have only single successor. */
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if (flags & LOOPS_HAVE_SIMPLE_LATCHES)
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force_single_succ_latches ();
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/* Mark irreducible loops. */
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if (flags & LOOPS_HAVE_MARKED_IRREDUCIBLE_REGIONS)
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mark_irreducible_loops ();
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if (flags & LOOPS_HAVE_RECORDED_EXITS)
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record_loop_exits ();
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/* Dump loops. */
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flow_loops_dump (dump_file, NULL, 1);
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#ifdef ENABLE_CHECKING
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verify_dominators (CDI_DOMINATORS);
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verify_loop_structure ();
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#endif
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}
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/* Finalize loop structures. */
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void
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loop_optimizer_finalize (void)
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{
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loop_iterator li;
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struct loop *loop;
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basic_block bb;
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gcc_assert (current_loops != NULL);
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FOR_EACH_LOOP (li, loop, 0)
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{
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free_simple_loop_desc (loop);
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}
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/* Clean up. */
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if (loops_state_satisfies_p (LOOPS_HAVE_RECORDED_EXITS))
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release_recorded_exits ();
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flow_loops_free (current_loops);
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ggc_free (current_loops);
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current_loops = NULL;
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FOR_ALL_BB (bb)
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{
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bb->loop_father = NULL;
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}
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/* Checking. */
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#ifdef ENABLE_CHECKING
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/* FIXME: no point to verify flow info after bundling on ia64. Use this
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hack for achieving this. */
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if (!reload_completed)
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verify_flow_info ();
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#endif
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}
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/* Gate for the RTL loop superpass. The actual passes are subpasses.
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See passes.c for more on that. */
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static bool
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gate_handle_loop2 (void)
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{
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return (optimize > 0
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&& (flag_move_loop_invariants
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|| flag_unswitch_loops
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|| flag_peel_loops
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|| flag_unroll_loops
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#ifdef HAVE_doloop_end
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|| (flag_branch_on_count_reg && HAVE_doloop_end)
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#endif
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));
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}
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struct rtl_opt_pass pass_loop2 =
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{
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{
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RTL_PASS,
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"loop2", /* name */
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gate_handle_loop2, /* gate */
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NULL, /* execute */
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NULL, /* sub */
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NULL, /* next */
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0, /* static_pass_number */
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TV_LOOP, /* tv_id */
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0, /* properties_required */
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0, /* properties_provided */
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0, /* properties_destroyed */
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0, /* todo_flags_start */
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TODO_dump_func |
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TODO_ggc_collect /* todo_flags_finish */
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}
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};
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/* Initialization of the RTL loop passes. */
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static unsigned int
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rtl_loop_init (void)
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{
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gcc_assert (current_ir_type () == IR_RTL_CFGLAYOUT);
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if (dump_file)
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dump_flow_info (dump_file, dump_flags);
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loop_optimizer_init (LOOPS_NORMAL);
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return 0;
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}
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struct rtl_opt_pass pass_rtl_loop_init =
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{
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{
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RTL_PASS,
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"loop2_init", /* name */
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NULL, /* gate */
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rtl_loop_init, /* execute */
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NULL, /* sub */
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NULL, /* next */
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0, /* static_pass_number */
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TV_LOOP, /* tv_id */
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0, /* properties_required */
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0, /* properties_provided */
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0, /* properties_destroyed */
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0, /* todo_flags_start */
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TODO_dump_func | TODO_verify_rtl_sharing /* todo_flags_finish */
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}
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};
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/* Finalization of the RTL loop passes. */
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static unsigned int
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rtl_loop_done (void)
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{
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loop_optimizer_finalize ();
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free_dominance_info (CDI_DOMINATORS);
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cleanup_cfg (0);
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if (dump_file)
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dump_flow_info (dump_file, dump_flags);
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return 0;
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}
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struct rtl_opt_pass pass_rtl_loop_done =
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{
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{
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RTL_PASS,
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"loop2_done", /* name */
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NULL, /* gate */
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rtl_loop_done, /* execute */
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NULL, /* sub */
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NULL, /* next */
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0, /* static_pass_number */
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TV_LOOP, /* tv_id */
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0, /* properties_required */
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0, /* properties_provided */
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0, /* properties_destroyed */
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0, /* todo_flags_start */
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TODO_dump_func | TODO_verify_rtl_sharing /* todo_flags_finish */
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}
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};
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/* Loop invariant code motion. */
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static bool
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gate_rtl_move_loop_invariants (void)
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{
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return flag_move_loop_invariants;
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}
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static unsigned int
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rtl_move_loop_invariants (void)
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{
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if (number_of_loops () > 1)
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move_loop_invariants ();
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return 0;
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}
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struct rtl_opt_pass pass_rtl_move_loop_invariants =
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{
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{
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RTL_PASS,
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"loop2_invariant", /* name */
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gate_rtl_move_loop_invariants, /* gate */
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rtl_move_loop_invariants, /* execute */
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NULL, /* sub */
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NULL, /* next */
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0, /* static_pass_number */
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TV_LOOP, /* tv_id */
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0, /* properties_required */
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0, /* properties_provided */
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0, /* properties_destroyed */
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0, /* todo_flags_start */
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TODO_df_verify |
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TODO_df_finish | TODO_verify_rtl_sharing |
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TODO_dump_func /* todo_flags_finish */
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}
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};
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/* Loop unswitching for RTL. */
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static bool
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gate_rtl_unswitch (void)
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{
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return flag_unswitch_loops;
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}
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static unsigned int
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rtl_unswitch (void)
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{
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if (number_of_loops () > 1)
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unswitch_loops ();
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return 0;
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}
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struct rtl_opt_pass pass_rtl_unswitch =
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{
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{
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RTL_PASS,
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"loop2_unswitch", /* name */
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gate_rtl_unswitch, /* gate */
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rtl_unswitch, /* execute */
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NULL, /* sub */
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NULL, /* next */
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0, /* static_pass_number */
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TV_LOOP, /* tv_id */
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0, /* properties_required */
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0, /* properties_provided */
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0, /* properties_destroyed */
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0, /* todo_flags_start */
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TODO_dump_func | TODO_verify_rtl_sharing, /* todo_flags_finish */
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}
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};
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/* Loop unswitching for RTL. */
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static bool
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gate_rtl_unroll_and_peel_loops (void)
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{
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return (flag_peel_loops || flag_unroll_loops || flag_unroll_all_loops);
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}
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static unsigned int
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rtl_unroll_and_peel_loops (void)
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{
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if (number_of_loops () > 1)
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{
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int flags = 0;
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if (dump_file)
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df_dump (dump_file);
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if (flag_peel_loops)
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flags |= UAP_PEEL;
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if (flag_unroll_loops)
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flags |= UAP_UNROLL;
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if (flag_unroll_all_loops)
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flags |= UAP_UNROLL_ALL;
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unroll_and_peel_loops (flags);
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}
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return 0;
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}
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struct rtl_opt_pass pass_rtl_unroll_and_peel_loops =
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{
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{
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RTL_PASS,
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"loop2_unroll", /* name */
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gate_rtl_unroll_and_peel_loops, /* gate */
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rtl_unroll_and_peel_loops, /* execute */
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NULL, /* sub */
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NULL, /* next */
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0, /* static_pass_number */
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TV_LOOP, /* tv_id */
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0, /* properties_required */
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0, /* properties_provided */
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0, /* properties_destroyed */
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0, /* todo_flags_start */
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TODO_dump_func | TODO_verify_rtl_sharing, /* todo_flags_finish */
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}
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};
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/* The doloop optimization. */
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static bool
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gate_rtl_doloop (void)
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{
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#ifdef HAVE_doloop_end
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return (flag_branch_on_count_reg && HAVE_doloop_end);
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#else
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return 0;
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#endif
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}
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static unsigned int
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rtl_doloop (void)
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{
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#ifdef HAVE_doloop_end
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if (number_of_loops () > 1)
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doloop_optimize_loops ();
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#endif
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return 0;
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}
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struct rtl_opt_pass pass_rtl_doloop =
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{
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{
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RTL_PASS,
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"loop2_doloop", /* name */
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gate_rtl_doloop, /* gate */
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rtl_doloop, /* execute */
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NULL, /* sub */
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NULL, /* next */
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0, /* static_pass_number */
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TV_LOOP, /* tv_id */
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0, /* properties_required */
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0, /* properties_provided */
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0, /* properties_destroyed */
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0, /* todo_flags_start */
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TODO_dump_func | TODO_verify_rtl_sharing /* todo_flags_finish */
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}
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};
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