2008-07-02  Richard Guenther  <rguenther@suse.de>

	* bitmap.h (bitmap_set_bit): Return bool.
	(bitmap_clear_bit): Likewise.
	* bitmap.c (bitmap_set_bit): Return if the bit changed.  Only
	write to the bitmap if it would.
	(bitmap_clear_bit): Likewise.
	* tree-ssa-structalias.c (add_implicit_graph_edge): Use
	bitmap_set_bit return value.
	(add_pred_graph_edge): Likewise.
	(add_graph_edge): Likewise.
	(do_sd_constraint): Likewise.
	(do_ds_constraint): Likewise.

From-SVN: r137345