diff options
Diffstat (limited to 'llvm/lib/Transforms')
| -rw-r--r-- | llvm/lib/Transforms/InstCombine/InstCombineMulDivRem.cpp | 19 |
1 files changed, 12 insertions, 7 deletions
diff --git a/llvm/lib/Transforms/InstCombine/InstCombineMulDivRem.cpp b/llvm/lib/Transforms/InstCombine/InstCombineMulDivRem.cpp index 899c4dd8fa7..6e7e11a15ae 100644 --- a/llvm/lib/Transforms/InstCombine/InstCombineMulDivRem.cpp +++ b/llvm/lib/Transforms/InstCombine/InstCombineMulDivRem.cpp @@ -891,6 +891,7 @@ bool InstCombiner::simplifyDivRemOfSelectWithZeroOp(BinaryOperator &I) { /// @brief Common integer divide transforms Instruction *InstCombiner::commonIDivTransforms(BinaryOperator &I) { Value *Op0 = I.getOperand(0), *Op1 = I.getOperand(1); + bool IsSigned = I.getOpcode() == Instruction::SDiv; // The RHS is known non-zero. if (Value *V = simplifyValueKnownNonZero(I.getOperand(1), *this, I)) { @@ -908,7 +909,6 @@ Instruction *InstCombiner::commonIDivTransforms(BinaryOperator &I) { if (match(Op1, m_APInt(C2))) { Value *X; const APInt *C1; - bool IsSigned = I.getOpcode() == Instruction::SDiv; // (X / C1) / C2 -> X / (C1*C2) if ((IsSigned && match(LHS, m_SDiv(m_Value(X), m_APInt(C1)))) || @@ -999,13 +999,18 @@ Instruction *InstCombiner::commonIDivTransforms(BinaryOperator &I) { return &I; // (X - (X rem Y)) / Y -> X / Y; usually originates as ((X / Y) * Y) / Y - Value *X = nullptr, *Z = nullptr; - if (match(Op0, m_Sub(m_Value(X), m_Value(Z)))) { // (X - Z) / Y; Y = Op1 - bool isSigned = I.getOpcode() == Instruction::SDiv; - if ((isSigned && match(Z, m_SRem(m_Specific(X), m_Specific(Op1)))) || - (!isSigned && match(Z, m_URem(m_Specific(X), m_Specific(Op1))))) + Value *X, *Z; + if (match(Op0, m_Sub(m_Value(X), m_Value(Z)))) // (X - Z) / Y; Y = Op1 + if ((IsSigned && match(Z, m_SRem(m_Specific(X), m_Specific(Op1)))) || + (!IsSigned && match(Z, m_URem(m_Specific(X), m_Specific(Op1))))) return BinaryOperator::Create(I.getOpcode(), X, Op1); - } + + // (X << Y) / X -> 1 << Y + Value *Y; + if (IsSigned && match(Op0, m_NSWShl(m_Specific(Op1), m_Value(Y)))) + return BinaryOperator::CreateNSWShl(ConstantInt::get(I.getType(), 1), Y); + if (!IsSigned && match(Op0, m_NUWShl(m_Specific(Op1), m_Value(Y)))) + return BinaryOperator::CreateNUWShl(ConstantInt::get(I.getType(), 1), Y); return nullptr; } |
