2011-12-07  Martin Jambor  <mjambor@suse.cz>

	PR tree-optimization/50744
	* ipa-cp.c (good_cloning_opportunity_p): Assert size_cost is positive,
	compute evaluation in HOST_WIDEST_INT.
	(safe_add): New function
	(propagate_effects): Use safe_add to accumulate effects.

	* testsuite/gcc.dg/ipa/pr50744.c: New test.

From-SVN: r182076