diff options
Diffstat (limited to 'llvm/lib/Transforms/InstCombine/InstCombineCompares.cpp')
| -rw-r--r-- | llvm/lib/Transforms/InstCombine/InstCombineCompares.cpp | 7 |
1 files changed, 5 insertions, 2 deletions
diff --git a/llvm/lib/Transforms/InstCombine/InstCombineCompares.cpp b/llvm/lib/Transforms/InstCombine/InstCombineCompares.cpp index e71f3e113b96..0dce0077bf15 100644 --- a/llvm/lib/Transforms/InstCombine/InstCombineCompares.cpp +++ b/llvm/lib/Transforms/InstCombine/InstCombineCompares.cpp @@ -4113,9 +4113,12 @@ static bool isMaskOrZero(const Value *V, bool Not, const SimplifyQuery &Q, if (match(V, m_Not(m_Value(X)))) return isMaskOrZero(X, !Not, Q, Depth); + // (X ^ -X) is a ~Mask + if (Not) + return match(V, m_c_Xor(m_Value(X), m_Neg(m_Deferred(X)))); // (X ^ (X - 1)) is a Mask - return !Not && - match(V, m_c_Xor(m_Value(X), m_Add(m_Deferred(X), m_AllOnes()))); + else + return match(V, m_c_Xor(m_Value(X), m_Add(m_Deferred(X), m_AllOnes()))); case Instruction::Select: // c ? Mask0 : Mask1 is a Mask. return isMaskOrZero(I->getOperand(1), Not, Q, Depth) && |