| /* 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 "obstack.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 |
| } |