diff options
Diffstat (limited to 'llvm/lib/Transforms/InstCombine')
| -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 f06a0e83c9b..c6294d173d9 100644 --- a/llvm/lib/Transforms/InstCombine/InstCombineCompares.cpp +++ b/llvm/lib/Transforms/InstCombine/InstCombineCompares.cpp @@ -2887,6 +2887,7 @@ Instruction *InstCombiner::foldICmpInstWithConstantNotInt(ICmpInst &I) { /// Where Mask is some pattern that produces all-ones in low bits: /// (-1 >> y) /// ~(-1 << y) +/// ((1 << y) + (-1)) <- non-canonical, has extra uses /// The Mask can be a constant, too. /// For some predicates, the operands are commutative. /// For others, x can only be on a specific side. @@ -2894,8 +2895,10 @@ static Value *foldICmpWithLowBitMaskedVal(ICmpInst &I, InstCombiner::BuilderTy &Builder) { ICmpInst::Predicate SrcPred; Value *X, *M; - auto m_VariableMask = m_CombineOr(m_Not(m_Shl(m_AllOnes(), m_Value())), - m_LShr(m_AllOnes(), m_Value())); + auto m_VariableMask = + m_CombineOr(m_CombineOr(m_Not(m_Shl(m_AllOnes(), m_Value())), + m_Add(m_Shl(m_One(), m_Value()), m_AllOnes())), + m_LShr(m_AllOnes(), m_Value())); auto m_Mask = m_CombineOr(m_VariableMask, m_LowBitMask()); if (!match(&I, m_c_ICmp(SrcPred, m_c_And(m_CombineAnd(m_Mask, m_Value(M)), m_Value(X)), |
