re PR middle-end/19807 (fold does not fold &a[4]-1)

re PR middle-end/19807 (fold does not fold &a[4]-1)

2005-05-11  Richard Guenther  <rguenth@gcc.gnu.org>

	PR middle-end/19807
	PR tree-optimization/19639
	* fold-const.c (try_move_mult_to_index): Handle INTEGER_CST
	and generic summands for char* as s * delta, too, folding &a[i]
	CODE x to &a[i CODE x/s].  Use tree_int_cst_equal
	for comparison of steps.  Convert types for index addition.
	(fold_binary): Adjust the callers to always dispatch to
	try_move_mult_to_index.
	* tree-ssa-propagate.c (set_rhs): Avoid setting rhs to
	expr with non-gimple ARRAY_REF offset.

	* g++.dg/tree-ssa/pr19807.C: New testcase.

From-SVN: r99568