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[InstSimplify] refactor 'or' logic folds; NFC 

Reduce duplication for handling the top-level commuted operands.
There are several other folds that should be moved in here, but
we need to make sure there's good test coverage.
This commit is contained in:
Sanjay Patel 2021-11-30 11:47:57 -05:00
parent 1fdb0f6ffd
commit 8dec0b23da
1 changed files with 23 additions and 20 deletions
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43
llvm/lib/Analysis/InstructionSimplify.cpp
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@ -2180,6 +2180,25 @@ Value *llvm::SimplifyAndInst(Value *Op0, Value *Op1, const SimplifyQuery &Q) {
return ::SimplifyAndInst(Op0, Op1, Q, RecursionLimit);
}
static Value *simplifyOrLogic(Value *X, Value *Y) {
assert(X->getType() == Y->getType() && "Expected same type for 'or' ops");
Type *Ty = X->getType();
// X | ~X --> -1
if (match(Y, m_Not(m_Specific(X))))
return ConstantInt::getAllOnesValue(Ty);
// X | ~(X & ?) = -1
if (match(Y, m_Not(m_c_And(m_Specific(X), m_Value()))))
return ConstantInt::getAllOnesValue(Ty);
// X | (X & ?) --> X
if (match(Y, m_c_And(m_Specific(X), m_Value())))
return X;
return nullptr;
}
/// Given operands for an Or, see if we can fold the result.
/// If not, this returns null.
static Value *SimplifyOrInst(Value *Op0, Value *Op1, const SimplifyQuery &Q,
@ -2202,26 +2221,10 @@ static Value *SimplifyOrInst(Value *Op0, Value *Op1, const SimplifyQuery &Q,
if (Op0 == Op1 || match(Op1, m_Zero()))
return Op0;
// A | ~A = ~A | A = -1
if (match(Op0, m_Not(m_Specific(Op1))) ||
match(Op1, m_Not(m_Specific(Op0))))
return Constant::getAllOnesValue(Op0->getType());
// (A & ?) | A = A
if (match(Op0, m_c_And(m_Specific(Op1), m_Value())))
return Op1;
// A | (A & ?) = A
if (match(Op1, m_c_And(m_Specific(Op0), m_Value())))
return Op0;
// ~(A & ?) | A = -1
if (match(Op0, m_Not(m_c_And(m_Specific(Op1), m_Value()))))
return Constant::getAllOnesValue(Op1->getType());
// A | ~(A & ?) = -1
if (match(Op1, m_Not(m_c_And(m_Specific(Op0), m_Value()))))
return Constant::getAllOnesValue(Op0->getType());
if (Value *R = simplifyOrLogic(Op0, Op1))
return R;
if (Value *R = simplifyOrLogic(Op1, Op0))
return R;
if (Value *V = simplifyLogicOfAddSub(Op0, Op1, Instruction::Or))
return V;