diff options
Diffstat (limited to 'lib/Transforms')
| -rw-r--r-- | lib/Transforms/Scalar/InstructionCombining.cpp | 13 |
1 files changed, 13 insertions, 0 deletions
diff --git a/lib/Transforms/Scalar/InstructionCombining.cpp b/lib/Transforms/Scalar/InstructionCombining.cpp index 6689039fbe..3f746a59ee 100644 --- a/lib/Transforms/Scalar/InstructionCombining.cpp +++ b/lib/Transforms/Scalar/InstructionCombining.cpp @@ -618,6 +618,19 @@ Instruction *InstCombiner::visitAdd(BinaryOperator &I) { if (match(RHS, m_And(m_Value(), m_ConstantInt(C2)))) if (Instruction *R = AssociativeOpt(I, AddMaskingAnd(C2))) return R; + // (X + (X << C2)) --> X * ((1 << C2) + 1) + // ((X << C2) + X) --> X * ((1 << C2) + 1) + Value *Tmp; + if ((RHS->hasOneUse() && match(RHS, m_Shl(m_Value(Tmp), + m_ConstantInt(C2))) && LHS == Tmp)|| + (LHS->hasOneUse() && match(LHS, m_Shl(m_Value(Tmp), + m_ConstantInt(C2))) && RHS == Tmp)){ + ConstantInt *One = ConstantInt::get(LHS->getType(), 1); + Constant *NewRHS = + ConstantExpr::getAdd(ConstantExpr::getShl(One, C2), One); + return BinaryOperator::createMul(Tmp, NewRHS); + } + if (ConstantInt *CRHS = dyn_cast<ConstantInt>(RHS)) { Value *X; if (match(LHS, m_Not(m_Value(X)))) { // ~X + C --> (C-1) - X |