PR rtl-optimization/33648

[pf3gnuchains/gcc-fork.git] / gcc / tree-ssa-coalesce.c

diff --git a/gcc/tree-ssa-coalesce.c b/gcc/tree-ssa-coalesce.c
index 1c82c8d..ef1ebca 100644 (file)
--- a/gcc/tree-ssa-coalesce.c
+++ b/gcc/tree-ssa-coalesce.c
@@ -6,7 +6,7 @@ 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)
+the Free Software Foundation; either version 3, or (at your option)
 any later version.
 
 GCC is distributed in the hope that it will be useful,
@@ -15,9 +15,8 @@ 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.  */
+along with GCC; see the file COPYING3.  If not see
+<http://www.gnu.org/licenses/>.  */
 
 #include "config.h"
 #include "system.h"
@@ -48,6 +47,7 @@ typedef struct coalesce_pair
   int second_element;
   int cost;
 } * coalesce_pair_p;
+typedef const struct coalesce_pair *const_coalesce_pair_p;
 
 typedef struct cost_one_pair_d
 {
@@ -174,8 +174,8 @@ pop_best_coalesce (coalesce_list_p cl, int *p1, int *p2)
 static unsigned int 
 coalesce_pair_map_hash (const void *pair)
 {
-  hashval_t a = (hashval_t)(((coalesce_pair_p)pair)->first_element);
-  hashval_t b = (hashval_t)(((coalesce_pair_p)pair)->second_element);
+  hashval_t a = (hashval_t)(((const_coalesce_pair_p)pair)->first_element);
+  hashval_t b = (hashval_t)(((const_coalesce_pair_p)pair)->second_element);
 
   return COALESCE_HASH_FN (a,b);
 }
@@ -187,8 +187,8 @@ coalesce_pair_map_hash (const void *pair)
 static int 
 coalesce_pair_map_eq (const void *pair1, const void *pair2)
 {
-  coalesce_pair_p p1 = (coalesce_pair_p) pair1;
-  coalesce_pair_p p2 = (coalesce_pair_p) pair2;
+  const_coalesce_pair_p const p1 = (const_coalesce_pair_p) pair1;
+  const_coalesce_pair_p const p2 = (const_coalesce_pair_p) pair2;
 
   return (p1->first_element == p2->first_element
          && p1->second_element == p2->second_element);
@@ -314,7 +314,22 @@ add_coalesce (coalesce_list_p cl, int p1, int p2,
 static int 
 compare_pairs (const void *p1, const void *p2)
 {
-  return (*(coalesce_pair_p *)p1)->cost - (*(coalesce_pair_p *)p2)->cost;
+  const_coalesce_pair_p const * pp1 = p1;
+  const_coalesce_pair_p const * pp2 = p2;
+  int result;
+
+  result = (* pp2)->cost - (* pp1)->cost;
+  /* Since qsort does not guarantee stability we use the elements
+     as a secondary key.  This provides us with independence from
+     the host's implementation of the sorting algorithm.  */
+  if (result == 0)
+    {
+      result = (* pp2)->first_element - (* pp1)->first_element;
+      if (result == 0)
+       result = (* pp2)->second_element - (* pp1)->second_element;
+    }
+
+  return result;
 }
 
 
@@ -588,6 +603,24 @@ ssa_conflicts_merge (ssa_conflicts_p ptr, unsigned x, unsigned y)
 }
 
 
+/* Dump a conflicts graph.  */
+
+static void
+ssa_conflicts_dump (FILE *file, ssa_conflicts_p ptr)
+{
+  unsigned x;
+
+  fprintf (file, "\nConflict graph:\n");
+
+  for (x = 0; x < ptr->size; x++)
+    if (ptr->conflicts[x])
+      {
+       fprintf (dump_file, "%d: ", x);
+       dump_bitmap (file, ptr->conflicts[x]);
+      }
+}
+
+
 /* This structure is used to efficiently record the current status of live 
    SSA_NAMES when building a conflict graph.  
    LIVE_BASE_VAR has a bit set for each base variable which has at least one
@@ -1301,6 +1334,8 @@ coalesce_ssa_name (void)
   /* Build a conflict graph.  */
   graph = build_ssa_conflict_graph (liveinfo);
   delete_tree_live_info (liveinfo);
+  if (dump_file && (dump_flags & TDF_DETAILS))
+    ssa_conflicts_dump (dump_file, graph);
 
   sort_coalesce_list (cl);