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[InstSimplify] Match PtrToInt more directly in a GEP transform (NFC)

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In preparation for D98611, the upcoming change will need to apply additional checks to `P` and `V`,
and so this refactor paves the way for adding additional checks in a less awkward way.

Reviewed By: lebedev.ri

Differential Revision: https://reviews.llvm.org/D98672
This commit is contained in:
Simonas Kazlauskas 2021-03-14 22:54:18 +02:00
parent 0a3d22f26f
commit 533dfa60d2
1 changed files with 23 additions and 29 deletions
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52
lib/Analysis/InstructionSimplify.cpp
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@ -4349,40 +4349,34 @@ static Value *SimplifyGEPInst(Type *SrcTy, ArrayRef<Value *> Ops,
// doesn't truncate the pointers.
if (Ops[1]->getType()->getScalarSizeInBits() ==
Q.DL.getPointerSizeInBits(AS)) {
auto PtrToInt = [GEPTy](Value *P) -> Value * {
Value *Temp;
if (match(P, m_PtrToInt(m_Value(Temp))))
if (Temp->getType() == GEPTy)
return Temp;
return nullptr;
auto CanSimplify = [GEPTy, &P]() -> bool {
// FIXME: The following transforms are only legal if P and V have the
// same provenance (PR44403). Check whether getUnderlyingObject() is
// the same?
return P->getType() == GEPTy;
};
// FIXME: The following transforms are only legal if P and V have the
// same provenance (PR44403). Check whether getUnderlyingObject() is
// the same?
// getelementptr V, (sub P, V) -> P if P points to a type of size 1.
if (TyAllocSize == 1 &&
match(Ops[1], m_Sub(m_Value(P), m_PtrToInt(m_Specific(Ops[0])))))
if (Value *R = PtrToInt(P))
return R;
match(Ops[1], m_Sub(m_PtrToInt(m_Value(P)),
m_PtrToInt(m_Specific(Ops[0])))) &&
CanSimplify())
return P;
// getelementptr V, (ashr (sub P, V), C) -> Q
// if P points to a type of size 1 << C.
if (match(Ops[1],
m_AShr(m_Sub(m_Value(P), m_PtrToInt(m_Specific(Ops[0]))),
m_ConstantInt(C))) &&
TyAllocSize == 1ULL << C)
if (Value *R = PtrToInt(P))
return R;
// getelementptr V, (ashr (sub P, V), C) -> P if P points to a type of
// size 1 << C.
if (match(Ops[1], m_AShr(m_Sub(m_PtrToInt(m_Value(P)),
m_PtrToInt(m_Specific(Ops[0]))),
m_ConstantInt(C))) &&
TyAllocSize == 1ULL << C && CanSimplify())
return P;
// getelementptr V, (sdiv (sub P, V), C) -> Q
// if P points to a type of size C.
if (match(Ops[1],
m_SDiv(m_Sub(m_Value(P), m_PtrToInt(m_Specific(Ops[0]))),
m_SpecificInt(TyAllocSize))))
if (Value *R = PtrToInt(P))
return R;
// getelementptr V, (sdiv (sub P, V), C) -> P if P points to a type of
// size C.
if (match(Ops[1], m_SDiv(m_Sub(m_PtrToInt(m_Value(P)),
m_PtrToInt(m_Specific(Ops[0]))),
m_SpecificInt(TyAllocSize))) &&
CanSimplify())
return P;
}
}
}