diff options
Diffstat (limited to 'contrib/llvm-project/llvm/lib/Transforms/InstCombine/InstCombineMulDivRem.cpp')
| -rw-r--r-- | contrib/llvm-project/llvm/lib/Transforms/InstCombine/InstCombineMulDivRem.cpp | 7 |
1 files changed, 7 insertions, 0 deletions
diff --git a/contrib/llvm-project/llvm/lib/Transforms/InstCombine/InstCombineMulDivRem.cpp b/contrib/llvm-project/llvm/lib/Transforms/InstCombine/InstCombineMulDivRem.cpp index e5566578869d..f0ea3d9fcad5 100644 --- a/contrib/llvm-project/llvm/lib/Transforms/InstCombine/InstCombineMulDivRem.cpp +++ b/contrib/llvm-project/llvm/lib/Transforms/InstCombine/InstCombineMulDivRem.cpp @@ -350,6 +350,13 @@ Instruction *InstCombinerImpl::visitMul(BinaryOperator &I) { if (match(&I, m_c_Mul(m_OneUse(m_Neg(m_Value(X))), m_Value(Y)))) return BinaryOperator::CreateNeg(Builder.CreateMul(X, Y)); + // (-X * Y) * -X --> (X * Y) * X + // (-X << Y) * -X --> (X << Y) * X + if (match(Op1, m_Neg(m_Value(X)))) { + if (Value *NegOp0 = Negator::Negate(false, /*IsNSW*/ false, Op0, *this)) + return BinaryOperator::CreateMul(NegOp0, X); + } + // (X / Y) * Y = X - (X % Y) // (X / Y) * -Y = (X % Y) - X { |