gcc/tree-ssa-loop.c

   1 /* Loop optimizations over tree-ssa.
   2    Copyright (C) 2003 Free Software Foundation, Inc.
   3
   4 This file is part of GCC.
   5
   6 GCC is free software; you can redistribute it and/or modify it
   7 under the terms of the GNU General Public License as published by the
   8 Free Software Foundation; either version 2, or (at your option) any
   9 later version.
  10
  11 GCC is distributed in the hope that it will be useful, but WITHOUT
  12 ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  13 FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  14 for more details.
  15
  16 You should have received a copy of the GNU General Public License
  17 along with GCC; see the file COPYING.  If not, write to the Free
  18 Software Foundation, 59 Temple Place - Suite 330, Boston, MA
  19 02111-1307, USA.  */
  20
  21 #include "config.h"
  22 #include "system.h"
  23 #include "coretypes.h"
  24 #include "tm.h"
  25 #include "tree.h"
  26 #include "rtl.h"
  27 #include "tm_p.h"
  28 #include "hard-reg-set.h"
  29 #include "basic-block.h"
  30 #include "output.h"
  31 #include "diagnostic.h"
  32 #include "basic-block.h"
  33 #include "tree-flow.h"
  34 #include "tree-dump.h"
  35 #include "tree-pass.h"
  36 #include "timevar.h"
  37 #include "cfgloop.h"
  38 #include "flags.h"
  39 #include "tree-inline.h"
  40
  41 /* The loop tree currently optimized.  */
  42
  43 struct loops *current_loops;
  44
  45 /* Initializes the loop structures.  DUMP is the file to that the details
  46    about the analysis should be dumped.  */
  47
  48 static struct loops *
  49 tree_loop_optimizer_init (FILE *dump)
  50 {
  51   struct loops *loops = loop_optimizer_init (dump);
  52
  53   if (!loops)
  54     return NULL;
  55
  56   /* Creation of preheaders may create redundant phi nodes if the loop is
  57      entered by more than one edge, but the initial value of the induction
  58      variable is the same on all of them.  */
  59   kill_redundant_phi_nodes ();
  60   rewrite_into_ssa (false);
  61   bitmap_clear (vars_to_rename);
  62
  63   return loops;
  64 }
  65
  66 /* The loop superpass.  */
  67
  68 static bool
  69 gate_loop (void)
  70 {
  71   return flag_tree_loop_optimize != 0;
  72 }
  73
  74 struct tree_opt_pass pass_loop =
  75 {
  76   "loop",                               /* name */
  77   gate_loop,                            /* gate */
  78   NULL,                                 /* execute */
  79   NULL,                                 /* sub */
  80   NULL,                                 /* next */
  81   0,                                    /* static_pass_number */
  82   TV_TREE_LOOP,                         /* tv_id */
  83   PROP_cfg,                             /* properties_required */
  84   0,                                    /* properties_provided */
  85   0,                                    /* properties_destroyed */
  86   TODO_ggc_collect,                     /* todo_flags_start */
  87   TODO_dump_func | TODO_verify_ssa | TODO_ggc_collect   /* todo_flags_finish */
  88 };
  89
  90 /* Loop optimizer initialization.  */
  91
  92 static void
  93 tree_ssa_loop_init (void)
  94 {
  95   current_loops = tree_loop_optimizer_init (dump_file);
  96 }
  97
  98 struct tree_opt_pass pass_loop_init =
  99 {
 100   "loopinit",                           /* name */
 101   NULL,                                 /* gate */
 102   tree_ssa_loop_init,                   /* execute */
 103   NULL,                                 /* sub */
 104   NULL,                                 /* next */
 105   0,                                    /* static_pass_number */
 106   0,                                    /* tv_id */
 107   PROP_cfg,                             /* properties_required */
 108   0,                                    /* properties_provided */
 109   0,                                    /* properties_destroyed */
 110   0,                                    /* todo_flags_start */
 111   0                                     /* todo_flags_finish */
 112 };
 113
 114 /* Loop invariant motion pass.  */
 115
 116 static void
 117 tree_ssa_loop_im (void)
 118 {
 119   if (!current_loops)
 120     return;
 121
 122   tree_ssa_lim (current_loops);
 123 }
 124
 125 static bool
 126 gate_tree_ssa_loop_im (void)
 127 {
 128   return flag_tree_lim != 0;
 129 }
 130
 131 struct tree_opt_pass pass_lim =
 132 {
 133   "lim",                                /* name */
 134   gate_tree_ssa_loop_im,                /* gate */
 135   tree_ssa_loop_im,                     /* execute */
 136   NULL,                                 /* sub */
 137   NULL,                                 /* next */
 138   0,                                    /* static_pass_number */
 139   TV_LIM,                               /* tv_id */
 140   PROP_cfg,                             /* properties_required */
 141   0,                                    /* properties_provided */
 142   0,                                    /* properties_destroyed */
 143   0,                                    /* todo_flags_start */
 144   TODO_dump_func                        /* todo_flags_finish */
 145 };
 146
 147 /* Loop optimizer finalization.  */
 148
 149 static void
 150 tree_ssa_loop_done (void)
 151 {
 152   if (!current_loops)
 153     return;
 154
 155   loop_optimizer_finalize (current_loops,
 156                            (dump_flags & TDF_DETAILS ? dump_file : NULL));
 157   current_loops = NULL;
 158   cleanup_tree_cfg ();
 159 }
 160
 161 struct tree_opt_pass pass_loop_done =
 162 {
 163   "loopdone",                           /* name */
 164   NULL,                                 /* gate */
 165   tree_ssa_loop_done,                   /* execute */
 166   NULL,                                 /* sub */
 167   NULL,                                 /* next */
 168   0,                                    /* static_pass_number */
 169   0,                                    /* tv_id */
 170   PROP_cfg,                             /* properties_required */
 171   0,                                    /* properties_provided */
 172   0,                                    /* properties_destroyed */
 173   0,                                    /* todo_flags_start */
 174   0                                     /* todo_flags_finish */
 175 };
 176