diff options
Diffstat (limited to 'llvm/lib/Transforms/InstCombine/InstCombineAndOrXor.cpp')
| -rw-r--r-- | llvm/lib/Transforms/InstCombine/InstCombineAndOrXor.cpp | 17 |
1 files changed, 9 insertions, 8 deletions
diff --git a/llvm/lib/Transforms/InstCombine/InstCombineAndOrXor.cpp b/llvm/lib/Transforms/InstCombine/InstCombineAndOrXor.cpp index 68c4156af2c4..85a7abe211b3 100644 --- a/llvm/lib/Transforms/InstCombine/InstCombineAndOrXor.cpp +++ b/llvm/lib/Transforms/InstCombine/InstCombineAndOrXor.cpp @@ -3221,11 +3221,6 @@ Instruction *InstCombinerImpl::visitXor(BinaryOperator &I) { } } - // ~(X - Y) --> ~X + Y - if (match(NotVal, m_Sub(m_Value(X), m_Value(Y)))) - if (isa<Constant>(X) || NotVal->hasOneUse()) - return BinaryOperator::CreateAdd(Builder.CreateNot(X), Y); - // ~(~X >>s Y) --> (X >>s Y) if (match(NotVal, m_AShr(m_Not(m_Value(X)), m_Value(Y)))) return BinaryOperator::CreateAShr(X, Y); @@ -3256,9 +3251,15 @@ Instruction *InstCombinerImpl::visitXor(BinaryOperator &I) { return BinaryOperator::CreateAShr(ConstantExpr::getNot(C), Y); } - // ~(X + C) --> -(C + 1) - X - if (match(Op0, m_Add(m_Value(X), m_Constant(C)))) - return BinaryOperator::CreateSub(ConstantExpr::getNeg(AddOne(C)), X); + // ~(X + C) --> ~C - X + if (match(NotVal, m_c_Add(m_Value(X), m_ImmConstant(C)))) + return BinaryOperator::CreateSub(ConstantExpr::getNot(C), X); + + // ~(X - Y) --> ~X + Y + // FIXME: is it really beneficial to sink the `not` here? + if (match(NotVal, m_Sub(m_Value(X), m_Value(Y)))) + if (isa<Constant>(X) || NotVal->hasOneUse()) + return BinaryOperator::CreateAdd(Builder.CreateNot(X), Y); // ~(~X + Y) --> X - Y if (match(NotVal, m_c_Add(m_Not(m_Value(X)), m_Value(Y)))) |