tree-vrp.c (set_value_range): Do not allocate equiv bitmap if it is not about to...

tree-vrp.c (set_value_range): Do not allocate equiv bitmap if it is not about to be set.

2007-05-01  Richard Guenther  <rguenther@suse.de>

	* tree-vrp.c (set_value_range): Do not allocate equiv bitmap
	if it is not about to be set.
	(get_value_range): Do not pre-allocate equiv bitmap.
	(update_value_range): No need to clear equiv field.
	(add_equivalence): Change prototype to get bitmap pointer.
	Allocate bitmap here if it is not already.
	(extract_range_from_assert): Do not allocate bitmap here.
	Update callers to add_equivalence.
	(extract_range_from_ssa_name): Likewise.
	(get_vr_for_comparison): New static helper.
	(compare_name_with_value): Handle NULL equiv bitmap by
	peeling the first iteration of the comparison loop.
	Use get_vr_for_comparison.
	(compare_names): Handle NULL equiv bitmaps by using fake
	ones.  Use get_vr_for_comparison.

From-SVN: r124321