2012-05-04  Richard Guenther  <rguenther@suse.de>

	PR tree-optimization/53168
	* tree-ssa-pre.c (phi_translate_1): Only handle type-punned
	memory reads when the result is a constant we can pun.

	* gcc.dg/torture/pr53168.c: New testcase.
	* gcc.dg/tree-ssa/ssa-pre-30.c: Likewise.

From-SVN: r187153