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authorPete Cooper <peter_cooper@apple.com>2011-12-15 00:56:45 +0000
committerPete Cooper <peter_cooper@apple.com>2011-12-15 00:56:45 +0000
commit4e5a1ab10b62b7ca842afd0e99ac982153f217fb (patch)
tree6d1ec10d4f0722223378a44a48bf330829337f42 /lib/Transforms
parent4e0adfa7f7fa5617a7a06028cdad0e4a50cac22a (diff)
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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
Diffstat (limited to 'lib/Transforms')
-rw-r--r--lib/Transforms/InstCombine/InstCombineSelect.cpp7
1 files changed, 7 insertions, 0 deletions
diff --git a/lib/Transforms/InstCombine/InstCombineSelect.cpp b/lib/Transforms/InstCombine/InstCombineSelect.cpp
index 84f80f0d74..f1ea8ead1f 100644
--- a/lib/Transforms/InstCombine/InstCombineSelect.cpp
+++ b/lib/Transforms/InstCombine/InstCombineSelect.cpp
@@ -682,6 +682,13 @@ Instruction *InstCombiner::visitSelectInst(SelectInst &SI) {
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?