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[InstSimplify] use m_Specific and commutative matcher to reduce code; NFCI 

llvm-svn: 322955
This commit is contained in:
Sanjay Patel 2018-01-19 16:12:55 +00:00
parent bf4cddaafb
commit 33cb84571f
1 changed files with 8 additions and 9 deletions
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15
llvm/lib/Analysis/InstructionSimplify.cpp
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@ -978,17 +978,16 @@ static Value *simplifyDiv(Instruction::BinaryOps Opcode, Value *Op0, Value *Op1,
bool IsSigned = Opcode == Instruction::SDiv;
// (X * Y) / Y -> X if the multiplication does not overflow.
Value *X = nullptr, *Y = nullptr;
if (match(Op0, m_Mul(m_Value(X), m_Value(Y))) && (X == Op1 || Y == Op1)) {
if (Y != Op1) std::swap(X, Y); // Ensure expression is (X * Y) / Y, Y = Op1
OverflowingBinaryOperator *Mul = cast<OverflowingBinaryOperator>(Op0);
// If the Mul knows it does not overflow, then we are good to go.
Value *X;
if (match(Op0, m_c_Mul(m_Value(X), m_Specific(Op1)))) {
auto *Mul = cast<OverflowingBinaryOperator>(Op0);
// If the Mul does not overflow, then we are good to go.
if ((IsSigned && Mul->hasNoSignedWrap()) ||
(!IsSigned && Mul->hasNoUnsignedWrap()))
return X;
// If X has the form X = A / Y then X * Y cannot overflow.
if (BinaryOperator *Div = dyn_cast<BinaryOperator>(X))
if (Div->getOpcode() == Opcode && Div->getOperand(1) == Y)
// If X has the form X = A / Y, then X * Y cannot overflow.
if ((IsSigned && match(X, m_SDiv(m_Value(), m_Specific(Op1)))) ||
(!IsSigned && match(X, m_UDiv(m_Value(), m_Specific(Op1)))))
return X;
}