tree-ssa-copy.c (stmt_may_generate_copy): Copies from constants also generate copies.

2011-03-25  Richard Guenther  <rguenther@suse.de>

	* tree-ssa-copy.c (stmt_may_generate_copy): Copies from constants
	also generate copies.
	(fini_copy_prop): Handle constant values properly.

From-SVN: r171465

gcc/ChangeLog

+2011-03-25  Richard Guenther  <rguenther@suse.de>
+
+	* tree-ssa-copy.c (stmt_may_generate_copy): Copies from constants
+	also generate copies.
+	(fini_copy_prop): Handle constant values properly.
+
 2011-03-25  Jakub Jelinek  <jakub@redhat.com>
 
 	* dwarf2out.c (mem_loc_descriptor) <case ZERO_EXTRACT>: Compare

gcc/tree-ssa-copy.c

@@ -315,8 +315,9 @@ stmt_may_generate_copy (gimple stmt)
   /* Otherwise, the only statements that generate useful copies are
      assignments whose RHS is just an SSA name that doesn't flow
      through abnormal edges.  */
-  return (gimple_assign_rhs_code (stmt) == SSA_NAME
-	  && !SSA_NAME_OCCURS_IN_ABNORMAL_PHI (gimple_assign_rhs1 (stmt)));
+  return ((gimple_assign_rhs_code (stmt) == SSA_NAME
+	   && !SSA_NAME_OCCURS_IN_ABNORMAL_PHI (gimple_assign_rhs1 (stmt)))
+	  || is_gimple_min_invariant (gimple_assign_rhs1 (stmt)));
 }
 
 
@@ -771,6 +772,7 @@ fini_copy_prop (void)
 	 of the representative to the first solution we find if
 	 it doesn't have one already.  */
       if (copy_of[i].value != var
+	  && TREE_CODE (copy_of[i].value) == SSA_NAME
 	  && POINTER_TYPE_P (TREE_TYPE (var))
 	  && SSA_NAME_PTR_INFO (var)
 	  && !SSA_NAME_PTR_INFO (copy_of[i].value))