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Generalize the code that handles (A&B)|(A&C) to work where B/C are not constants.

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Add a new xform to simplify (A&B)|(~A&C).  THis implements InstCombine/or2.ll:test1


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@35760 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Chris Lattner 2007-04-08 07:47:01 +00:00
parent 251396a6f2
commit c5e7ea49eb
1 changed files with 81 additions and 28 deletions
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109
lib/Transforms/Scalar/InstructionCombining.cpp
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@ -3709,36 +3709,89 @@ Instruction *InstCombiner::visitOr(BinaryOperator &I) {
return BinaryOperator::createXor(NOr, C1);
}
// (A & C1)|(B & C2)
if (match(Op0, m_And(m_Value(A), m_ConstantInt(C1))) &&
match(Op1, m_And(m_Value(B), m_ConstantInt(C2)))) {
// (A & C)|(B & D)
Value *C, *D;
if (match(Op0, m_And(m_Value(A), m_Value(C))) &&
match(Op1, m_And(m_Value(B), m_Value(D)))) {
if (A == B) // (A & C1)|(A & C2) == A & (C1|C2)
return BinaryOperator::createAnd(A,
ConstantInt::get(C1->getValue() | C2->getValue()));
// If we have: ((V + N) & C1) | (V & C2)
// .. and C2 = ~C1 and C2 is 0+1+ and (N & C2) == 0
// replace with V+N.
if (C1->getValue() == ~C2->getValue()) {
Value *V1 = 0, *V2 = 0;
if ((C2->getValue() & (C2->getValue()+1)) == 0 && // C2 == 0+1+
match(A, m_Add(m_Value(V1), m_Value(V2)))) {
// Add commutes, try both ways.
if (V1 == B && MaskedValueIsZero(V2, C2->getValue()))
return ReplaceInstUsesWith(I, A);
if (V2 == B && MaskedValueIsZero(V1, C2->getValue()))
return ReplaceInstUsesWith(I, A);
// Check to see if we have any common things being and'ed. If so, find the
// terms for V1 & (V2|V3).
Value *V1 = 0, *V2 = 0, *V3 = 0;
if (isOnlyUse(Op0) || isOnlyUse(Op1)) {
if (A == B) // (A & C)|(A & D) == A & (C|D)
V1 = A, V2 = C, V3 = D;
else if (A == D) // (A & C)|(B & A) == A & (B|C)
V1 = A, V2 = B, V3 = C;
else if (C == B) // (A & C)|(C & D) == C & (A|D)
V1 = C, V2 = A, V3 = D;
else if (C == D) // (A & C)|(B & C) == C & (A|B)
V1 = C, V2 = A, V3 = B;
if (V1) {
Value *Or =
InsertNewInstBefore(BinaryOperator::createOr(V2, V3, "tmp"), I);
return BinaryOperator::createAnd(V1, Or);
}
// Or commutes, try both ways.
if ((C1->getValue() & (C1->getValue()+1)) == 0 &&
match(B, m_Add(m_Value(V1), m_Value(V2)))) {
// Add commutes, try both ways.
if (V1 == A && MaskedValueIsZero(V2, C1->getValue()))
return ReplaceInstUsesWith(I, B);
if (V2 == A && MaskedValueIsZero(V1, C1->getValue()))
return ReplaceInstUsesWith(I, B);
// (V1 & V3)|(V2 & ~V3) -> ((V1 ^ V2) & V3) ^ V2
if (isOnlyUse(Op0) && isOnlyUse(Op1)) {
// Try all combination of terms to find V3 and ~V3.
if (A->hasOneUse() && match(A, m_Not(m_Value(V3)))) {
if (V3 == B)
V1 = D, V2 = C;
else if (V3 == D)
V1 = B, V2 = C;
}
if (B->hasOneUse() && match(B, m_Not(m_Value(V3)))) {
if (V3 == A)
V1 = C, V2 = D;
else if (V3 == C)
V1 = A, V2 = D;
}
if (C->hasOneUse() && match(C, m_Not(m_Value(V3)))) {
if (V3 == B)
V1 = D, V2 = A;
else if (V3 == D)
V1 = B, V2 = A;
}
if (D->hasOneUse() && match(D, m_Not(m_Value(V3)))) {
if (V3 == A)
V1 = C, V2 = B;
else if (V3 == C)
V1 = A, V2 = B;
}
if (V1) {
A = InsertNewInstBefore(BinaryOperator::createXor(V1, V2, "tmp"), I);
A = InsertNewInstBefore(BinaryOperator::createAnd(A, V3, "tmp"), I);
return BinaryOperator::createXor(A, V2);
}
}
}
C1 = dyn_cast<ConstantInt>(C);
C2 = dyn_cast<ConstantInt>(D);
if (C1 && C2) { // (A & C1)|(B & C2)
// If we have: ((V + N) & C1) | (V & C2)
// .. and C2 = ~C1 and C2 is 0+1+ and (N & C2) == 0
// replace with V+N.
if (C1->getValue() == ~C2->getValue()) {
if ((C2->getValue() & (C2->getValue()+1)) == 0 && // C2 == 0+1+
match(A, m_Add(m_Value(V1), m_Value(V2)))) {
// Add commutes, try both ways.
if (V1 == B && MaskedValueIsZero(V2, C2->getValue()))
return ReplaceInstUsesWith(I, A);
if (V2 == B && MaskedValueIsZero(V1, C2->getValue()))
return ReplaceInstUsesWith(I, A);
}
// Or commutes, try both ways.
if ((C1->getValue() & (C1->getValue()+1)) == 0 &&
match(B, m_Add(m_Value(V1), m_Value(V2)))) {
// Add commutes, try both ways.
if (V1 == A && MaskedValueIsZero(V2, C1->getValue()))
return ReplaceInstUsesWith(I, B);
if (V2 == A && MaskedValueIsZero(V1, C1->getValue()))
return ReplaceInstUsesWith(I, B);
}
}
}
}