ArrayIdx, ElementSize, GEP);
Value *LHS = nullptr;
ConstantInt *RHS = nullptr;
- // TODO: handle shl. e.g., we could treat (S << 2) as (S * 4).
- //
// One alternative is matching the SCEV of ArrayIdx instead of ArrayIdx
// itself. This would allow us to handle the shl case for free. However,
// matching SCEVs has two issues:
// SLSR is currently unsafe if i * S may overflow.
// GEP = Base + sext(LHS *nsw RHS) * ElementSize
allocateCandidateAndFindBasisForGEP(Base, RHS, LHS, ElementSize, GEP);
+ } else if (match(ArrayIdx, m_NSWShl(m_Value(LHS), m_ConstantInt(RHS)))) {
+ // GEP = Base + sext(LHS <<nsw RHS) * ElementSize
+ // = Base + sext(LHS *nsw (1 << RHS)) * ElementSize
+ APInt One(RHS->getBitWidth(), 1);
+ ConstantInt *PowerOf2 =
+ ConstantInt::get(RHS->getContext(), One << RHS->getValue());
+ allocateCandidateAndFindBasisForGEP(Base, PowerOf2, LHS, ElementSize, GEP);
}
}
Type *CharTy = Type::getInt8PtrTy(Basis.Ins->getContext(), AS);
Reduced = Builder.CreateBitCast(Basis.Ins, CharTy);
if (InBounds)
- Reduced = Builder.CreateInBoundsGEP(Reduced, Bump);
+ Reduced =
+ Builder.CreateInBoundsGEP(Builder.getInt8Ty(), Reduced, Bump);
else
Reduced = Builder.CreateGEP(Builder.getInt8Ty(), Reduced, Bump);
Reduced = Builder.CreateBitCast(Reduced, C.Ins->getType());
// Canonicalize bump to pointer size.
Bump = Builder.CreateSExtOrTrunc(Bump, IntPtrTy);
if (InBounds)
- Reduced = Builder.CreateInBoundsGEP(Basis.Ins, Bump);
+ Reduced = Builder.CreateInBoundsGEP(nullptr, Basis.Ins, Bump);
else
Reduced = Builder.CreateGEP(nullptr, Basis.Ins, Bump);
}