===================================================================
@@ -5257,20 +5257,26 @@ unchecked_convert (tree type, tree expr,
? TYPE_RM_SIZE (etype)
: TYPE_SIZE (etype)) == 0)))
{
- tree base_type
- = gnat_type_for_size (TREE_INT_CST_LOW (TYPE_SIZE (type)),
- type_unsigned_for_rm (type));
- tree shift_expr
- = convert (base_type,
- size_binop (MINUS_EXPR,
- TYPE_SIZE (type), TYPE_RM_SIZE (type)));
- expr
- = convert (type,
- build_binary_op (RSHIFT_EXPR, base_type,
- build_binary_op (LSHIFT_EXPR, base_type,
- convert (base_type, expr),
- shift_expr),
- shift_expr));
+ if (integer_zerop (TYPE_RM_SIZE (type)))
+ expr = build_int_cst (type, 0);
+ else
+ {
+ tree base_type
+ = gnat_type_for_size (TREE_INT_CST_LOW (TYPE_SIZE (type)),
+ type_unsigned_for_rm (type));
+ tree shift_expr
+ = convert (base_type,
+ size_binop (MINUS_EXPR,
+ TYPE_SIZE (type), TYPE_RM_SIZE (type)));
+ expr
+ = convert (type,
+ build_binary_op (RSHIFT_EXPR, base_type,
+ build_binary_op (LSHIFT_EXPR, base_type,
+ convert (base_type,
+ expr),
+ shift_expr),
+ shift_expr));
+ }
}
/* An unchecked conversion should never raise Constraint_Error. The code