X-Git-Url: http://git.sourceforge.jp/view?a=blobdiff_plain;f=gcc%2Ftree-ssa-copyrename.c;h=393bfb600c6b196110b8e5ab5f0a5b58559722e8;hb=48be990a98811c6114000276eefdec809e20272a;hp=a05935f574299be4e4a57447fe3aff73b8c61e46;hpb=d471893dcbdfab38ec021b746517d648db7dbb42;p=pf3gnuchains%2Fgcc-fork.git

diff --git a/gcc/tree-ssa-copyrename.c b/gcc/tree-ssa-copyrename.c
index a05935f5742..393bfb600c6 100644
--- a/gcc/tree-ssa-copyrename.c
+++ b/gcc/tree-ssa-copyrename.c
@@ -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)
     {
@@ -253,6 +246,18 @@ 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 alasing sets. No coalesce.\n");
+      return;
+    }
+
+
   /* Merge the two partitions.  */
   p3 = partition_union (map->var_partition, p1, p2);
 
@@ -286,7 +291,7 @@ 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 void
 rename_ssa_copies (void)
 {
   var_map map;
@@ -391,6 +396,7 @@ struct tree_opt_pass pass_rename_ssa_copies =
   0,					/* properties_provided */
   0,					/* properties_destroyed */
   0,					/* todo_flags_start */ 
-  TODO_dump_func | TODO_verify_ssa      /* todo_flags_finish */
+  TODO_dump_func | TODO_verify_ssa,     /* todo_flags_finish */
+  0					/* letter */
 };