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(X + (X << C2)) --> X * ((1 << C2) + 1) ((X << C2) + X) --> X * ((1 << C2) + 1) This means that we now canonicalize "Y+Y+Y" into: %tmp.2 = mul long %Y, 3 ; <long> [#uses=1] instead of: %tmp.10 = shl long %Y, ubyte 1 ; <long> [#uses=1] %tmp.6 = add long %Y, %tmp.10 ; <long> [#uses=1] git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@17701 91177308-0d34-0410-b5e6-96231b3b80d8
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@ -618,6 +618,19 @@ Instruction *InstCombiner::visitAdd(BinaryOperator &I) {
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if (match(RHS, m_And(m_Value(), m_ConstantInt(C2))))
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if (Instruction *R = AssociativeOpt(I, AddMaskingAnd(C2))) return R;
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// (X + (X << C2)) --> X * ((1 << C2) + 1)
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// ((X << C2) + X) --> X * ((1 << C2) + 1)
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Value *Tmp;
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if ((RHS->hasOneUse() && match(RHS, m_Shl(m_Value(Tmp),
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m_ConstantInt(C2))) && LHS == Tmp)||
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(LHS->hasOneUse() && match(LHS, m_Shl(m_Value(Tmp),
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m_ConstantInt(C2))) && RHS == Tmp)){
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ConstantInt *One = ConstantInt::get(LHS->getType(), 1);
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Constant *NewRHS =
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ConstantExpr::getAdd(ConstantExpr::getShl(One, C2), One);
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return BinaryOperator::createMul(Tmp, NewRHS);
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}
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if (ConstantInt *CRHS = dyn_cast<ConstantInt>(RHS)) {
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Value *X;
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if (match(LHS, m_Not(m_Value(X)))) { // ~X + C --> (C-1) - X
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