tree-ssa-copy.c (may_propagate_copy): Test flow sensitive alias information too.

        PR/27087
        * tree-ssa-copy.c (may_propagate_copy): Test flow sensitive
        alias information too.

        * gcc.c-torture/compile/pr27087.c: New test.

From-SVN: r112849

gcc/ChangeLog

+2006-04-03  Jeff Law  <law@redhat.com>
+
+	PR/27087
+	* tree-ssa-copy.c (may_propagate_copy): Test flow sensitive
+	alias information too.
+
 2006-04-10  Mike Frysinger  <vapier@gentoo.org>
 
 	* gcc/Makefile.in (gcc-cross): Add $(exeext) to target name.

gcc/testsuite/ChangeLog

+2006-04-10  Jeff Law  <law@redhat.com>
+
+	PR/27087
+	* gcc.c-torture/compile/pr27087.c: New test.
+
 2006-04-10  Aldy Hernandez  <aldyh@redhat.com>
 
 	PR/21391

gcc/testsuite/gcc.c-torture/compile/pr27087.c

+extern int ptbl[4];
+extern int ctbl[4];
+
+void doViews(void) {
+    int  *c = ctbl, *p = ptbl;
+    while (1)
+  {
+        p++;
+        c++;
+        if (*p)
+        {
+            if (c == p)
+            {
+                if (*c)
+                    return;
+            }
+            else
+              return;
+        }
+    }
+
+    g();
+}

gcc/tree-ssa-copy.c

@@ -117,6 +117,21 @@ may_propagate_copy (tree dest, tree orig)
       else if (get_alias_set (TREE_TYPE (type_d)) != 
 	       get_alias_set (TREE_TYPE (type_o)))
 	return false;
+
+      /* Also verify flow-sensitive information is compatible.  */
+      if (SSA_NAME_PTR_INFO (orig) && SSA_NAME_PTR_INFO (dest))
+	{
+	  struct ptr_info_def *orig_ptr_info = SSA_NAME_PTR_INFO (orig);
+	  struct ptr_info_def *dest_ptr_info = SSA_NAME_PTR_INFO (dest);
+
+	  if (orig_ptr_info->name_mem_tag
+	      && dest_ptr_info->name_mem_tag
+	      && orig_ptr_info->pt_vars
+	      && dest_ptr_info->pt_vars
+	      && !bitmap_intersect_p (dest_ptr_info->pt_vars,
+				      orig_ptr_info->pt_vars))
+	    return false;
+	}
     }
 
   /* If the destination is a SSA_NAME for a virtual operand, then we have