Added InstCombine for "select cond, ~cond, x" type patterns
These can be reduced to "~cond & x" or "~cond | x"
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@146624 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Transforms/InstCombine/InstCombineSelect.cpp b/lib/Transforms/InstCombine/InstCombineSelect.cpp
index 84f80f0..f1ea8ea 100644
--- a/lib/Transforms/InstCombine/InstCombineSelect.cpp
+++ b/lib/Transforms/InstCombine/InstCombineSelect.cpp
@@ -682,6 +682,13 @@
return BinaryOperator::CreateOr(CondVal, FalseVal);
else if (CondVal == FalseVal)
return BinaryOperator::CreateAnd(CondVal, TrueVal);
+
+ // select a, ~a, b -> (~a)&b
+ // select a, b, ~a -> (~a)|b
+ if (match(TrueVal, m_Not(m_Specific(CondVal))))
+ return BinaryOperator::CreateAnd(TrueVal, FalseVal);
+ else if (match(FalseVal, m_Not(m_Specific(CondVal))))
+ return BinaryOperator::CreateOr(TrueVal, FalseVal);
}
// Selecting between two integer constants?