2009-10-23  Richard Guenther  <rguenther@suse.de>

	PR tree-optimization/41778
	* tree-ssa-pre.c (do_regular_insertion): Only insert if a
	redundancy along a path in the CFG we want to optimize for speed
	is going to be removed.
	(execute_pre): Do partial-PRE only if the function is to be
	optimized for speed.
	(gate_pre): Do not turn off all of PRE when not optimizing a
	function for speed.

	* gcc.dg/tree-ssa/ssa-pre-26.c: New testcase.

From-SVN: r153491