2 Commits

Author	SHA1	Message	Date
Matthias Braun	3757169d38	InstCombine: Restrict computeKnownBits() on all Values to OptLevel > 2 ... As part of r251146 InstCombine was extended to call computeKnownBits on every value in the function to determine whether it happens to be constant. This increases typical compiletime by 1-3% (5% in irgen+opt time) in my measurements. On the other hand this case did not trigger once in the whole llvm-testsuite. This patch introduces the notion of ExpensiveCombines which are only enabled for OptLevel > 2. I removed the check in InstructionSimplify as that is called from various places where the OptLevel is not known but given the rarity of the situation I think a check in InstCombine is enough. Differential Revision: http://reviews.llvm.org/D16835 llvm-svn: 263047	2016-03-09 18:47:11 +00:00
Sanjoy Das	2819145e6a	[ValueTracking] Use !range metadata more aggressively in KnownBits ... Summary: Teach `computeKnownBitsFromRangeMetadata` to use `!range` metadata more aggressively. Reviewers: majnemer, nlewycky, jingyue Subscribers: llvm-commits Differential Revision: http://reviews.llvm.org/D14100 llvm-svn: 251487	2015-10-28 03:20:15 +00:00