2007-04-22  Richard Guenther  <rguenther@suse.de>

	PR tree-optimization/29789
	* tree-ssa-loop-im.c (stmt_cost): Adjust cost of shifts.
	(rewrite_reciprocal): New helper split out from
	determine_invariantness_stmt.
	(rewrite_bittest): Likewise.
	(determine_invariantness_stmt): Rewrite (A >> B) & 1 to
	A & (1 << B) if (1 << B) is loop invariant but (A >> B)
	is not.

	* gcc.dg/tree-ssa/ssa-lim-1.c: New testcase.
	* gcc.dg/tree-ssa/ssa-lim-2.c: Likewise.

From-SVN: r124042