tree-vectorizer.c (vect_analyze_offset_expr): Strip conversions that don't narrow the value.

        * tree-vectorizer.c (vect_analyze_offset_expr): Strip conversions
        that don't narrow the value.  Fail for other conversions.

From-SVN: r92804

gcc/ChangeLog

 2005-01-01  Richard Henderson  <rth@redhat.com>
 
+	* tree-vectorizer.c (vect_analyze_offset_expr): Strip conversions
+	that don't narrow the value.  Fail for other conversions.
+
+2005-01-01  Richard Henderson  <rth@redhat.com>
+
 	PR c/19031
 	* c-decl.c (pop_file_scope): Call maybe_apply_pending_pragma_weaks.
 	* c-lang.c (finish_file): Don't do it here.

gcc/tree-vectorizer.c

@@ -1390,7 +1390,22 @@ vect_analyze_offset_expr (tree expr,
   enum tree_code code;
   tree init, evolution, def_stmt;
 
-  STRIP_NOPS (expr);
+  /* Strip conversions that don't narrow the mode.  */
+  while (TREE_CODE (expr) == NOP_EXPR || TREE_CODE (expr) == CONVERT_EXPR)
+    {
+      tree to, ti;
+
+      to = TREE_TYPE (expr);
+      oprnd0 = TREE_OPERAND (expr, 0);
+      ti = TREE_TYPE (oprnd0);
+
+      if (!INTEGRAL_TYPE_P (to) || !INTEGRAL_TYPE_P (ti))
+	return false;
+      if (GET_MODE_SIZE (TYPE_MODE (to)) < GET_MODE_SIZE (TYPE_MODE (ti)))
+	return false;
+
+      expr = oprnd0;
+    }
   
   *step = NULL_TREE;
   *misalign = NULL_TREE;