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[X86] Add test case to show missed opportunity to remove an explicit AND on the bit...
authorCraig Topper <craig.topper@intel.com>
Wed, 20 Feb 2019 18:45:38 +0000 (18:45 +0000)
committerCraig Topper <craig.topper@intel.com>
Wed, 20 Feb 2019 18:45:38 +0000 (18:45 +0000)
commit350bc2910b07dec014bf5550053d21c26846052f
tree9f0e524926a2df18c92f46720e3a72ef0fb49d0e
parent55fee71f49fa383bcced354cff073c9dc3b75432
[X86] Add test case to show missed opportunity to remove an explicit AND on the bit position from BT when it has known zeros.

If the bit position has known zeros in it, then the AND immediate will likely be optimized to remove bits.

This can prevent GetDemandedBits from recognizing that the AND is unnecessary.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@354498 91177308-0d34-0410-b5e6-96231b3b80d8
lib/CodeGen/SelectionDAG/SelectionDAG.cpp
test/CodeGen/X86/bt.ll