Really check that the bits that will become zero are actually already zero
authorDan Gohman <gohman@apple.com>
Thu, 9 Dec 2010 02:52:17 +0000 (02:52 +0000)
committerDan Gohman <gohman@apple.com>
Thu, 9 Dec 2010 02:52:17 +0000 (02:52 +0000)
commitd8e0c0438ab1ec86b2bd42da7a439caa7f0a61eb
treee40cb8e64fcdfcf9e8d257ff9cea52b233d2af89
parent1a48c032bd7c240fc4c52aee6dad57f8043a77d9
Really check that the bits that will become zero are actually already zero
before eliminating the operation that zeros them. This fixes rdar://8739316.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@121353 91177308-0d34-0410-b5e6-96231b3b80d8
lib/Transforms/InstCombine/InstCombineShifts.cpp
test/Transforms/InstCombine/2010-11-01-lshr-mask.ll