* check.c (same_type_check): Typo fix in comment.

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

diff --git a/gcc/tree-ssa-copyrename.c b/gcc/tree-ssa-copyrename.c
index db85d9c..45f6567 100644 (file)
--- a/gcc/tree-ssa-copyrename.c
+++ b/gcc/tree-ssa-copyrename.c
@@ -16,8 +16,8 @@ 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.  */
+the Free Software Foundation, 51 Franklin Street, Fifth Floor,
+Boston, MA 02110-1301, USA.  */
 
 #include "config.h"
 #include "system.h"
@@ -33,15 +33,12 @@ Boston, MA 02111-1307, USA.  */
 #include "tree-gimple.h"
 #include "tree-inline.h"
 #include "timevar.h"
-#include "tree-alias-common.h"
 #include "hashtab.h"
 #include "tree-dump.h"
 #include "tree-ssa-live.h"
 #include "tree-pass.h"
 #include "langhooks.h"
 
-extern void rename_ssa_copies (void);
-
 /* The following routines implement the SSA copy renaming phase.
 
    This optimization looks for copies between 2 SSA_NAMES, either through a
@@ -49,7 +46,7 @@ extern void rename_ssa_copies (void);
 
    Each copy is examined to determine if it is possible to rename the base
    variable of one of the operands to the same variable as the other operand.
-   ie.
+   i.e.
    T.3_5 = <blah>
    a_1 = T.3_5
 
@@ -117,13 +114,12 @@ copy_rename_partition_coalesce (var_map map, tree var1, tree var2, FILE *debug)
 {
   int p1, p2, p3;
   tree root1, root2;
+  tree rep1, rep2;
   var_ann_t ann1, ann2, ann3;
-  bool ign1, ign2;
+  bool ign1, ign2, abnorm;
 
-#ifdef ENABLE_CHECKING
-  if (TREE_CODE (var1) != SSA_NAME || TREE_CODE (var2) != SSA_NAME)
-    abort ();
-#endif
+  gcc_assert (TREE_CODE (var1) == SSA_NAME);
+  gcc_assert (TREE_CODE (var2) == SSA_NAME);
 
   register_ssa_partition (map, var1, false);
   register_ssa_partition (map, var2, true);
@@ -140,26 +136,13 @@ copy_rename_partition_coalesce (var_map map, tree var1, tree var2, FILE *debug)
       fprintf (debug, "(P%d)", p2);
     }
 
-#ifdef ENABLE_CHECKING
-  if (p1 == NO_PARTITION || p2 == NO_PARTITION)
-    abort ();
-#endif
-
-  root1 = SSA_NAME_VAR (partition_to_var (map, p1));
-  root2 = SSA_NAME_VAR (partition_to_var (map, p2));
+  gcc_assert (p1 != NO_PARTITION);
+  gcc_assert (p2 != NO_PARTITION);
 
-  if (DECL_HARD_REGISTER (root1) || DECL_HARD_REGISTER (root2))
-    {
-      if (debug)
-        {
-         if (DECL_HARD_REGISTER (root1))
-           print_generic_expr (debug, var1, TDF_SLIM);
-         else
-           print_generic_expr (debug, var2, TDF_SLIM);
-         fprintf (debug, " is a hardware register.  No Coalescing.\n");
-       }
-      return;
-    }
+  rep1 = partition_to_var (map, p1);
+  rep2 = partition_to_var (map, p2);
+  root1 = SSA_NAME_VAR (rep1);
+  root2 = SSA_NAME_VAR (rep2);
 
   ann1 = var_ann (root1);
   ann2 = var_ann (root2);
@@ -171,6 +154,16 @@ copy_rename_partition_coalesce (var_map map, tree var1, tree var2, FILE *debug)
       return;
     }
 
+  /* Don't coalesce if one of the variables occurs in an abnormal PHI.  */
+  abnorm = (SSA_NAME_OCCURS_IN_ABNORMAL_PHI (rep1)
+           || SSA_NAME_OCCURS_IN_ABNORMAL_PHI (rep2));
+  if (abnorm)
+    {
+      if (debug)
+       fprintf (debug, " : Abnormal PHI barrier.  No coalesce.\n");
+      return;
+    }
+
   /* Partitions already have the same root, simply merge them.  */
   if (root1 == root2)
     {
@@ -215,8 +208,9 @@ copy_rename_partition_coalesce (var_map map, tree var1, tree var2, FILE *debug)
     }
 
   /* Don't coalesce if there are two different memory tags.  */
-  if (ann1->type_mem_tag && ann2->type_mem_tag
-      && ann1->type_mem_tag != ann2->type_mem_tag)
+  if (ann1->symbol_mem_tag
+      && ann2->symbol_mem_tag
+      && ann1->symbol_mem_tag != ann2->symbol_mem_tag)
     {
       if (debug)
        fprintf (debug, " : 2 memory tags. No coalesce.\n");
@@ -253,6 +247,18 @@ copy_rename_partition_coalesce (var_map map, tree var1, tree var2, FILE *debug)
       return;
     }
 
+  /* Don't coalesce if the aliasing sets of the types are different.  */
+  if (POINTER_TYPE_P (TREE_TYPE (root1))
+      && POINTER_TYPE_P (TREE_TYPE (root2))
+      && get_alias_set (TREE_TYPE (TREE_TYPE (root1)))
+          != get_alias_set (TREE_TYPE (TREE_TYPE (root2))))
+    {
+      if (debug)
+       fprintf (debug, " : 2 different aliasing sets. No coalesce.\n");
+      return;
+    }
+
+
   /* Merge the two partitions.  */
   p3 = partition_union (map->var_partition, p1, p2);
 
@@ -265,10 +271,10 @@ copy_rename_partition_coalesce (var_map map, tree var1, tree var2, FILE *debug)
 
   /* Update the various flag widgitry of the current base representative.  */
   ann3 = var_ann (SSA_NAME_VAR (partition_to_var (map, p3)));
-  if (ann1->type_mem_tag)
-    ann3->type_mem_tag = ann1->type_mem_tag;
+  if (ann1->symbol_mem_tag)
+    ann3->symbol_mem_tag = ann1->symbol_mem_tag;
   else
-    ann3->type_mem_tag = ann2->type_mem_tag;
+    ann3->symbol_mem_tag = ann2->symbol_mem_tag;
 
   if (debug)
     {
@@ -286,7 +292,7 @@ copy_rename_partition_coalesce (var_map map, tree var1, tree var2, FILE *debug)
    then cause the SSA->normal pass to attempt to coalesce them all to the same 
    variable.  */
 
-void
+static unsigned int
 rename_ssa_copies (void)
 {
   var_map map;
@@ -368,6 +374,7 @@ rename_ssa_copies (void)
     }
 
   delete_var_map (map);
+  return 0;
 }
 
 /* Return true if copy rename is to be performed.  */