[InstSimplify] move logic-of-icmps helper functions; NFC

Putting these next to each other should make it easier to see
what's missing from each side. Patch to plug one of those holes
should be posted soon.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@302178 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Sanjay Patel 2017-05-04 18:19:17 +00:00
parent e611018a3f
commit b6a618217b

View File

@ -1493,6 +1493,32 @@ static Value *simplifyAndOfICmpsWithSameOperands(ICmpInst *Op0, ICmpInst *Op1) {
return nullptr;
}
/// Commuted variants are assumed to be handled by calling this function again
/// with the parameters swapped.
static Value *simplifyOrOfICmpsWithSameOperands(ICmpInst *Op0, ICmpInst *Op1) {
ICmpInst::Predicate Pred0, Pred1;
Value *A ,*B;
if (!match(Op0, m_ICmp(Pred0, m_Value(A), m_Value(B))) ||
!match(Op1, m_ICmp(Pred1, m_Specific(A), m_Specific(B))))
return nullptr;
// We have (icmp Pred0, A, B) | (icmp Pred1, A, B).
// If Op1 is always implied true by Op0, then Op0 is a subset of Op1, and we
// can eliminate Op0 from this 'or'.
if (ICmpInst::isImpliedTrueByMatchingCmp(Pred0, Pred1))
return Op1;
// Check for any combination of predicates that cover the entire range of
// possibilities.
if ((Pred0 == ICmpInst::getInversePredicate(Pred1)) ||
(Pred0 == ICmpInst::ICMP_NE && ICmpInst::isTrueWhenEqual(Pred1)) ||
(Pred0 == ICmpInst::ICMP_SLE && Pred1 == ICmpInst::ICMP_SGE) ||
(Pred0 == ICmpInst::ICMP_ULE && Pred1 == ICmpInst::ICMP_UGE))
return getTrue(Op0->getType());
return nullptr;
}
/// Commuted variants are assumed to be handled by calling this function again
/// with the parameters swapped.
static Value *SimplifyAndOfICmps(ICmpInst *Op0, ICmpInst *Op1) {
@ -1565,6 +1591,60 @@ static Value *SimplifyAndOfICmps(ICmpInst *Op0, ICmpInst *Op1) {
return nullptr;
}
/// Commuted variants are assumed to be handled by calling this function again
/// with the parameters swapped.
static Value *SimplifyOrOfICmps(ICmpInst *Op0, ICmpInst *Op1) {
if (Value *X = simplifyUnsignedRangeCheck(Op0, Op1, /*IsAnd=*/false))
return X;
if (Value *X = simplifyOrOfICmpsWithSameOperands(Op0, Op1))
return X;
// (icmp (add V, C0), C1) | (icmp V, C0)
ICmpInst::Predicate Pred0, Pred1;
const APInt *C0, *C1;
Value *V;
if (!match(Op0, m_ICmp(Pred0, m_Add(m_Value(V), m_APInt(C0)), m_APInt(C1))))
return nullptr;
if (!match(Op1, m_ICmp(Pred1, m_Specific(V), m_Value())))
return nullptr;
auto *AddInst = cast<BinaryOperator>(Op0->getOperand(0));
if (AddInst->getOperand(1) != Op1->getOperand(1))
return nullptr;
Type *ITy = Op0->getType();
bool isNSW = AddInst->hasNoSignedWrap();
bool isNUW = AddInst->hasNoUnsignedWrap();
const APInt Delta = *C1 - *C0;
if (C0->isStrictlyPositive()) {
if (Delta == 2) {
if (Pred0 == ICmpInst::ICMP_UGE && Pred1 == ICmpInst::ICMP_SLE)
return getTrue(ITy);
if (Pred0 == ICmpInst::ICMP_SGE && Pred1 == ICmpInst::ICMP_SLE && isNSW)
return getTrue(ITy);
}
if (Delta == 1) {
if (Pred0 == ICmpInst::ICMP_UGT && Pred1 == ICmpInst::ICMP_SLE)
return getTrue(ITy);
if (Pred0 == ICmpInst::ICMP_SGT && Pred1 == ICmpInst::ICMP_SLE && isNSW)
return getTrue(ITy);
}
}
if (C0->getBoolValue() && isNUW) {
if (Delta == 2)
if (Pred0 == ICmpInst::ICMP_UGE && Pred1 == ICmpInst::ICMP_ULE)
return getTrue(ITy);
if (Delta == 1)
if (Pred0 == ICmpInst::ICMP_UGT && Pred1 == ICmpInst::ICMP_ULE)
return getTrue(ITy);
}
return nullptr;
}
/// Given operands for an And, see if we can fold the result.
/// If not, this returns null.
static Value *SimplifyAndInst(Value *Op0, Value *Op1, const SimplifyQuery &Q,
@ -1678,86 +1758,6 @@ Value *llvm::SimplifyAndInst(Value *Op0, Value *Op1, const SimplifyQuery &Q) {
return ::SimplifyAndInst(Op0, Op1, Q, RecursionLimit);
}
/// Commuted variants are assumed to be handled by calling this function again
/// with the parameters swapped.
static Value *simplifyOrOfICmpsWithSameOperands(ICmpInst *Op0, ICmpInst *Op1) {
ICmpInst::Predicate Pred0, Pred1;
Value *A ,*B;
if (!match(Op0, m_ICmp(Pred0, m_Value(A), m_Value(B))) ||
!match(Op1, m_ICmp(Pred1, m_Specific(A), m_Specific(B))))
return nullptr;
// We have (icmp Pred0, A, B) | (icmp Pred1, A, B).
// If Op1 is always implied true by Op0, then Op0 is a subset of Op1, and we
// can eliminate Op0 from this 'or'.
if (ICmpInst::isImpliedTrueByMatchingCmp(Pred0, Pred1))
return Op1;
// Check for any combination of predicates that cover the entire range of
// possibilities.
if ((Pred0 == ICmpInst::getInversePredicate(Pred1)) ||
(Pred0 == ICmpInst::ICMP_NE && ICmpInst::isTrueWhenEqual(Pred1)) ||
(Pred0 == ICmpInst::ICMP_SLE && Pred1 == ICmpInst::ICMP_SGE) ||
(Pred0 == ICmpInst::ICMP_ULE && Pred1 == ICmpInst::ICMP_UGE))
return getTrue(Op0->getType());
return nullptr;
}
/// Commuted variants are assumed to be handled by calling this function again
/// with the parameters swapped.
static Value *SimplifyOrOfICmps(ICmpInst *Op0, ICmpInst *Op1) {
if (Value *X = simplifyUnsignedRangeCheck(Op0, Op1, /*IsAnd=*/false))
return X;
if (Value *X = simplifyOrOfICmpsWithSameOperands(Op0, Op1))
return X;
// (icmp (add V, C0), C1) | (icmp V, C0)
ICmpInst::Predicate Pred0, Pred1;
const APInt *C0, *C1;
Value *V;
if (!match(Op0, m_ICmp(Pred0, m_Add(m_Value(V), m_APInt(C0)), m_APInt(C1))))
return nullptr;
if (!match(Op1, m_ICmp(Pred1, m_Specific(V), m_Value())))
return nullptr;
auto *AddInst = cast<BinaryOperator>(Op0->getOperand(0));
if (AddInst->getOperand(1) != Op1->getOperand(1))
return nullptr;
Type *ITy = Op0->getType();
bool isNSW = AddInst->hasNoSignedWrap();
bool isNUW = AddInst->hasNoUnsignedWrap();
const APInt Delta = *C1 - *C0;
if (C0->isStrictlyPositive()) {
if (Delta == 2) {
if (Pred0 == ICmpInst::ICMP_UGE && Pred1 == ICmpInst::ICMP_SLE)
return getTrue(ITy);
if (Pred0 == ICmpInst::ICMP_SGE && Pred1 == ICmpInst::ICMP_SLE && isNSW)
return getTrue(ITy);
}
if (Delta == 1) {
if (Pred0 == ICmpInst::ICMP_UGT && Pred1 == ICmpInst::ICMP_SLE)
return getTrue(ITy);
if (Pred0 == ICmpInst::ICMP_SGT && Pred1 == ICmpInst::ICMP_SLE && isNSW)
return getTrue(ITy);
}
}
if (C0->getBoolValue() && isNUW) {
if (Delta == 2)
if (Pred0 == ICmpInst::ICMP_UGE && Pred1 == ICmpInst::ICMP_ULE)
return getTrue(ITy);
if (Delta == 1)
if (Pred0 == ICmpInst::ICMP_UGT && Pred1 == ICmpInst::ICMP_ULE)
return getTrue(ITy);
}
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,