diff options
| -rw-r--r-- | lib/Transforms/Scalar/InstructionCombining.cpp | 24 |
1 files changed, 24 insertions, 0 deletions
diff --git a/lib/Transforms/Scalar/InstructionCombining.cpp b/lib/Transforms/Scalar/InstructionCombining.cpp index 1968f9b36e..761b57d2ec 100644 --- a/lib/Transforms/Scalar/InstructionCombining.cpp +++ b/lib/Transforms/Scalar/InstructionCombining.cpp @@ -2123,6 +2123,30 @@ Instruction *InstCombiner::visitAdd(BinaryOperator &I) { if (Instruction *R = AssociativeOpt(I, AddMaskingAnd(C2))) return R; + // W*X + Y*Z --> W * (X+Z) iff W == Y + if (I.getType()->isInteger()) { + Value *W, *X, *Y, *Z; + if (match(LHS, m_Mul(m_Value(W), m_Value(X))) && + match(RHS, m_Mul(m_Value(Y), m_Value(Z)))) { + if (W != Y) { + if (W == Z) { + std::swap(Y, Z); + } else if (Y == X) { + std::swap(W, X); + } else if (X == Z) { + std::swap(Y, Z); + std::swap(W, X); + } + } + + if (W == Y) { + Value *NewAdd = InsertNewInstBefore(BinaryOperator::createAdd(X, Z, + LHS->getName()), I); + return BinaryOperator::createMul(W, NewAdd); + } + } + } + if (ConstantInt *CRHS = dyn_cast<ConstantInt>(RHS)) { Value *X = 0; if (match(LHS, m_Not(m_Value(X)))) // ~X + C --> (C-1) - X |