2009-10-05  Richard Guenther  <rguenther@suse.de>

	PR tree-optimization/23821
	* tree-vrp.c (vrp_finalize): Do not perform copy propagation.
	* tree-ssa-dom.c (cprop_operand): Do not propagate copies into
	simple IV increments.

	* gcc.dg/torture/pr23821.c: New testcase.

From-SVN: r152449