bcm5719-llvm - Project Ortega BCM5719 LLVM

	Commit message (Collapse)	Author	Age	Files	Lines
*	[SCEV] Be less eager about demoting zexts to sexts	Sanjoy Das	2016-03-03	1	-0/+23
	After r262438 we can have provably positive NSW SCEV expressions whose zero extensions cannot be simplified (since r262438 makes SCEV better at computing constant ranges). This means demoting sexts of positive add recurrences eagerly can result in an unsimplified zero extension where we could have had a simplified sign extension. This change fixes the issue by teaching SCEV to demote sext of a positive SCEV expression to a zext only if the sext could not be simplified. llvm-svn: 262638