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 optimizer finalization.  */
 115
 116 static void
 117 tree_ssa_loop_done (void)
 118 {
 119   if (!current_loops)
 120     return;
 121
 122   loop_optimizer_finalize (current_loops,
 123                            (dump_flags & TDF_DETAILS ? dump_file : NULL));
 124   current_loops = NULL;
 125   cleanup_tree_cfg ();
 126 }
 127
 128 struct tree_opt_pass pass_loop_done =
 129 {
 130   "loopdone",                           /* name */
 131   NULL,                                 /* gate */
 132   tree_ssa_loop_done,                   /* execute */
 133   NULL,                                 /* sub */
 134   NULL,                                 /* next */
 135   0,                                    /* static_pass_number */
 136   0,                                    /* tv_id */
 137   PROP_cfg,                             /* properties_required */
 138   0,                                    /* properties_provided */
 139   0,                                    /* properties_destroyed */
 140   0,                                    /* todo_flags_start */
 141   0                                     /* todo_flags_finish */
 142 };
 143