diff options
Diffstat (limited to 'contrib/gcc/loop-init.c')
| -rw-r--r-- | contrib/gcc/loop-init.c | 390 |
1 files changed, 390 insertions, 0 deletions
diff --git a/contrib/gcc/loop-init.c b/contrib/gcc/loop-init.c new file mode 100644 index 0000000..d2c63404 --- /dev/null +++ b/contrib/gcc/loop-init.c @@ -0,0 +1,390 @@ +/* Loop optimizer initialization routines and RTL loop optimization passes. + Copyright (C) 2002, 2003, 2004, 2005 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, 51 Franklin Street, Fifth Floor, Boston, MA +02110-1301, USA. */ + +#include "config.h" +#include "system.h" +#include "coretypes.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" + + +/* Initialize loop optimizer. 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 (unsigned flags) +{ + struct loops *loops = XCNEW (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) && !single_succ_p (e->src)) + split_edge (e); + else + ei_next (&ei); + + /* Find the loops. */ + + if (flow_loops_find (loops) <= 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. */ + if (flags & LOOPS_HAVE_PREHEADERS) + create_preheaders (loops, CP_SIMPLE_PREHEADERS); + + /* Force all latches to have only single successor. */ + if (flags & LOOPS_HAVE_SIMPLE_LATCHES) + force_single_succ_latches (loops); + + /* Mark irreducible loops. */ + if (flags & LOOPS_HAVE_MARKED_IRREDUCIBLE_REGIONS) + mark_irreducible_loops (loops); + + if (flags & LOOPS_HAVE_MARKED_SINGLE_EXITS) + mark_single_exit_loops (loops); + + /* Dump loops. */ + flow_loops_dump (loops, dump_file, 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) +{ + unsigned i; + + if (!loops) + return; + + for (i = 1; i < loops->num; i++) + if (loops->parray[i]) + free_simple_loop_desc (loops->parray[i]); + + /* Clean up. */ + flow_loops_free (loops); + free (loops); + + /* Checking. */ +#ifdef ENABLE_CHECKING + verify_flow_info (); +#endif +} + + +/* 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 tree_opt_pass pass_loop2 = +{ + "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_dump_func | + TODO_ggc_collect, /* todo_flags_finish */ + 'L' /* letter */ +}; + + +/* Initialization of the RTL loop passes. */ +static unsigned int +rtl_loop_init (void) +{ + if (dump_file) + dump_flow_info (dump_file, dump_flags); + + /* Initialize structures for layout changes. */ + cfg_layout_initialize (0); + + current_loops = loop_optimizer_init (LOOPS_NORMAL); + return 0; +} + +struct tree_opt_pass pass_rtl_loop_init = +{ + "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_dump_func, /* todo_flags_finish */ + 'L' /* letter */ +}; + + +/* Finalization of the RTL loop passes. */ +static unsigned int +rtl_loop_done (void) +{ + basic_block bb; + + if (current_loops) + loop_optimizer_finalize (current_loops); + + free_dominance_info (CDI_DOMINATORS); + + /* Finalize layout changes. */ + FOR_EACH_BB (bb) + if (bb->next_bb != EXIT_BLOCK_PTR) + bb->aux = bb->next_bb; + cfg_layout_finalize (); + + cleanup_cfg (CLEANUP_EXPENSIVE); + delete_trivially_dead_insns (get_insns (), max_reg_num ()); + reg_scan (get_insns (), max_reg_num ()); + if (dump_file) + dump_flow_info (dump_file, dump_flags); + + current_loops = NULL; + return 0; +} + +struct tree_opt_pass pass_rtl_loop_done = +{ + "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_dump_func, /* todo_flags_finish */ + 'L' /* letter */ +}; + + +/* 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 (current_loops) + move_loop_invariants (current_loops); + return 0; +} + +struct tree_opt_pass pass_rtl_move_loop_invariants = +{ + "loop2_invariant", /* name */ + gate_rtl_move_loop_invariants, /* gate */ + rtl_move_loop_invariants, /* 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_dump_func, /* todo_flags_finish */ + 'L' /* letter */ +}; + + +/* Loop unswitching for RTL. */ +static bool +gate_rtl_unswitch (void) +{ + return flag_unswitch_loops; +} + +static unsigned int +rtl_unswitch (void) +{ + if (current_loops) + unswitch_loops (current_loops); + return 0; +} + +struct tree_opt_pass pass_rtl_unswitch = +{ + "loop2_unswitch", /* name */ + gate_rtl_unswitch, /* gate */ + rtl_unswitch, /* 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_dump_func, /* todo_flags_finish */ + 'L' /* letter */ +}; + + +/* 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 (current_loops) + { + int flags = 0; + + 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 (current_loops, flags); + } + return 0; +} + +struct tree_opt_pass pass_rtl_unroll_and_peel_loops = +{ + "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, /* tv_id */ + 0, /* properties_required */ + 0, /* properties_provided */ + 0, /* properties_destroyed */ + 0, /* todo_flags_start */ + TODO_dump_func, /* todo_flags_finish */ + 'L' /* letter */ +}; + + +/* 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 (current_loops) + doloop_optimize_loops (current_loops); +#endif + return 0; +} + +struct tree_opt_pass pass_rtl_doloop = +{ + "loop2_doloop", /* name */ + gate_rtl_doloop, /* gate */ + rtl_doloop, /* 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_dump_func, /* todo_flags_finish */ + 'L' /* letter */ +}; + |
