diff options
Diffstat (limited to 'llvm/lib')
| -rw-r--r-- | llvm/lib/Transforms/InstCombine/InstCombineAddSub.cpp | 15 |
1 files changed, 7 insertions, 8 deletions
diff --git a/llvm/lib/Transforms/InstCombine/InstCombineAddSub.cpp b/llvm/lib/Transforms/InstCombine/InstCombineAddSub.cpp index 22538b4..2962300a 100644 --- a/llvm/lib/Transforms/InstCombine/InstCombineAddSub.cpp +++ b/llvm/lib/Transforms/InstCombine/InstCombineAddSub.cpp @@ -960,10 +960,15 @@ Instruction *InstCombiner::foldAddWithConstant(BinaryOperator &Add) { return NV; Value *X; - if (match(Op0, m_ZExt(m_Value(X))) && X->getType()->getScalarSizeInBits() == 1) - // zext(bool) + C -> bool ? C + 1 : C + // zext(bool) + C -> bool ? C + 1 : C + if (match(Op0, m_ZExt(m_Value(X))) && + X->getType()->getScalarSizeInBits() == 1) return SelectInst::Create(X, AddOne(Op1C), Op1); + // ~X + C --> (C-1) - X + if (match(Op0, m_Not(m_Value(X)))) + return BinaryOperator::CreateSub(SubOne(Op1C), X); + const APInt *C; if (!match(Op1, m_APInt(C))) return nullptr; @@ -1117,12 +1122,6 @@ Instruction *InstCombiner::visitAdd(BinaryOperator &I) { if (haveNoCommonBitsSet(LHS, RHS, DL, &AC, &I, &DT)) return BinaryOperator::CreateOr(LHS, RHS); - if (Constant *CRHS = dyn_cast<Constant>(RHS)) { - Value *X; - if (match(LHS, m_Not(m_Value(X)))) // ~X + C --> (C-1) - X - return BinaryOperator::CreateSub(SubOne(CRHS), X); - } - // FIXME: We already did a check for ConstantInt RHS above this. // FIXME: Is this pattern covered by another fold? No regression tests fail on // removal. |