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Simplify the code

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No functionality change intended.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@224673 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
David Majnemer 2014-12-20 03:29:59 +00:00
parent 2bea59bd02
commit f666c0549e
1 changed files with 25 additions and 41 deletions
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66
lib/Analysis/InstructionSimplify.cpp
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@ -3153,73 +3153,57 @@ static Value *SimplifySelectInst(Value *CondVal, Value *TrueVal,
return TrueVal;
if (const auto *ICI = dyn_cast<ICmpInst>(CondVal)) {
ICmpInst::Predicate Pred = ICI->getPredicate();
APInt MinSignedValue =
APInt::getSignBit(TrueVal->getType()->getScalarSizeInBits());
Value *X;
const APInt *Y;
ICmpInst::Predicate Pred = ICI->getPredicate();
bool IsBitTest = false;
bool TrueWhenUnset;
if (ICmpInst::isEquality(Pred) &&
match(ICI->getOperand(0), m_And(m_Value(X), m_APInt(Y))) &&
match(ICI->getOperand(1), m_Zero())) {
IsBitTest = true;
TrueWhenUnset = Pred == ICmpInst::ICMP_EQ;
} else if (Pred == ICmpInst::ICMP_SLT &&
match(ICI->getOperand(1), m_Zero())) {
X = ICI->getOperand(0);
Y = &MinSignedValue;
IsBitTest = true;
TrueWhenUnset = false;
} else if (Pred == ICmpInst::ICMP_SGT &&
match(ICI->getOperand(1), m_AllOnes())) {
X = ICI->getOperand(0);
Y = &MinSignedValue;
IsBitTest = true;
TrueWhenUnset = true;
}
if (IsBitTest) {
const APInt *C;
// (X & Y) == 0 ? X & ~Y : X --> X
// (X & Y) != 0 ? X & ~Y : X --> X & ~Y
if (FalseVal == X && match(TrueVal, m_And(m_Specific(X), m_APInt(C))) &&
*Y == ~*C)
return Pred == ICmpInst::ICMP_EQ ? FalseVal : TrueVal;
return TrueWhenUnset ? FalseVal : TrueVal;
// (X & Y) == 0 ? X : X & ~Y --> X & ~Y
// (X & Y) != 0 ? X : X & ~Y --> X
if (TrueVal == X && match(FalseVal, m_And(m_Specific(X), m_APInt(C))) &&
*Y == ~*C)
return Pred == ICmpInst::ICMP_EQ ? FalseVal : TrueVal;
return TrueWhenUnset ? FalseVal : TrueVal;
if (Y->isPowerOf2()) {
// (X & Y) == 0 ? X | Y : X --> X | Y
// (X & Y) != 0 ? X | Y : X --> X
if (FalseVal == X && match(TrueVal, m_Or(m_Specific(X), m_APInt(C))) &&
*Y == *C)
return Pred == ICmpInst::ICMP_EQ ? TrueVal : FalseVal;
return TrueWhenUnset ? TrueVal : FalseVal;
// (X & Y) == 0 ? X : X | Y --> X
// (X & Y) != 0 ? X : X | Y --> X | Y
if (TrueVal == X && match(FalseVal, m_Or(m_Specific(X), m_APInt(C))) &&
*Y == *C)
return Pred == ICmpInst::ICMP_EQ ? TrueVal : FalseVal;
return TrueWhenUnset ? TrueVal : FalseVal;
}
}
if (Pred == ICmpInst::ICMP_SLT && match(ICI->getOperand(1), m_Zero())) {
// (X < 0) ? X : X | SignBit --> X | SignBit
if (TrueVal == ICI->getOperand(0) &&
match(FalseVal, m_Or(m_Specific(TrueVal), m_SignBit())))
return FalseVal;
// (X < 0) ? X | SignBit : X --> X
if (FalseVal == ICI->getOperand(0) &&
match(TrueVal, m_Or(m_Specific(FalseVal), m_SignBit())))
return FalseVal;
// (X < 0) ? X & INT_MAX : X --> X & INT_MAX
if (FalseVal == ICI->getOperand(0) &&
match(TrueVal, m_And(m_Specific(FalseVal), m_MaxSignedValue())))
return TrueVal;
// (X < 0) ? X : X & INT_MAX --> X
if (TrueVal == ICI->getOperand(0) &&
match(FalseVal, m_And(m_Specific(TrueVal), m_MaxSignedValue())))
return TrueVal;
}
if (Pred == ICmpInst::ICMP_SGT && match(ICI->getOperand(1), m_AllOnes())) {
// (X > -1) ? X : X | SignBit --> X
if (TrueVal == ICI->getOperand(0) &&
match(FalseVal, m_Or(m_Specific(TrueVal), m_SignBit())))
return TrueVal;
// (X > -1) ? X | SignBit : X --> X | SignBit
if (FalseVal == ICI->getOperand(0) &&
match(TrueVal, m_Or(m_Specific(FalseVal), m_SignBit())))
return TrueVal;
// (X > -1) ? X & INT_MAX : X --> X
if (FalseVal == ICI->getOperand(0) &&
match(TrueVal, m_And(m_Specific(FalseVal), m_MaxSignedValue())))
return FalseVal;
// (X > -1) ? X : X & INT_MAX --> X & INT_MAX
if (TrueVal == ICI->getOperand(0) &&
match(FalseVal, m_And(m_Specific(TrueVal), m_MaxSignedValue())))
return FalseVal;
}
}
return nullptr;