Upper = Upper + 1;
assert(Upper != Lower && "Upper part of range has wrapped!");
}
+ } else if (match(LHS, m_NUWShl(m_ConstantInt(CI2), m_Value()))) {
+ // 'shl nuw CI2, x' produces [CI2, CI2 << CLZ(CI2)]
+ Lower = CI2->getValue();
+ Upper = Lower.shl(Lower.countLeadingZeros()) + 1;
+ } else if (match(LHS, m_NSWShl(m_ConstantInt(CI2), m_Value()))) {
+ if (CI2->isNegative()) {
+ // 'shl nsw CI2, x' produces [CI2 << CLO(CI2)-1, CI2]
+ unsigned ShiftAmount = CI2->getValue().countLeadingOnes() - 1;
+ Lower = CI2->getValue().shl(ShiftAmount);
+ Upper = CI2->getValue() + 1;
+ } else {
+ // 'shl nsw CI2, x' produces [CI2, CI2 << CLZ(CI2)-1]
+ unsigned ShiftAmount = CI2->getValue().countLeadingZeros() - 1;
+ Lower = CI2->getValue();
+ Upper = CI2->getValue().shl(ShiftAmount) + 1;
+ }
} else if (match(LHS, m_LShr(m_Value(), m_ConstantInt(CI2)))) {
// 'lshr x, CI2' produces [0, UINT_MAX >> CI2].
APInt NegOne = APInt::getAllOnesValue(Width);
return getTrue(ITy);
}
+ // handle:
+ // CI2 << X == CI
+ // CI2 << X != CI
+ //
+ // where CI2 is a power of 2 and CI isn't
+ if (auto *CI = dyn_cast<ConstantInt>(RHS)) {
+ const APInt *CI2Val, *CIVal = &CI->getValue();
+ if (LBO && match(LBO, m_Shl(m_APInt(CI2Val), m_Value())) &&
+ CI2Val->isPowerOf2()) {
+ if (!CIVal->isPowerOf2()) {
+ // CI2 << X can equal zero in some circumstances,
+ // this simplification is unsafe if CI is zero.
+ //
+ // We know it is safe if:
+ // - The shift is nsw, we can't shift out the one bit.
+ // - The shift is nuw, we can't shift out the one bit.
+ // - CI2 is one
+ // - CI isn't zero
+ if (LBO->hasNoSignedWrap() || LBO->hasNoUnsignedWrap() ||
+ *CI2Val == 1 || !CI->isZero()) {
+ if (Pred == ICmpInst::ICMP_EQ)
+ return ConstantInt::getFalse(RHS->getContext());
+ if (Pred == ICmpInst::ICMP_NE)
+ return ConstantInt::getTrue(RHS->getContext());
+ }
+ }
+ if (CIVal->isSignBit() && *CI2Val == 1) {
+ if (Pred == ICmpInst::ICMP_UGT)
+ return ConstantInt::getFalse(RHS->getContext());
+ if (Pred == ICmpInst::ICMP_ULE)
+ return ConstantInt::getTrue(RHS->getContext());
+ }
+ }
+ }
+
if (MaxRecurse && LBO && RBO && LBO->getOpcode() == RBO->getOpcode() &&
LBO->getOperand(1) == RBO->getOperand(1)) {
switch (LBO->getOpcode()) {
if (Ops.size() == 1)
return Ops[0];
- if (isa<UndefValue>(Ops[0])) {
- // Compute the (pointer) type returned by the GEP instruction.
- Type *LastType = GetElementPtrInst::getIndexedType(PtrTy, Ops.slice(1));
- Type *GEPTy = PointerType::get(LastType, AS);
- if (VectorType *VT = dyn_cast<VectorType>(Ops[0]->getType()))
- GEPTy = VectorType::get(GEPTy, VT->getNumElements());
+ // Compute the (pointer) type returned by the GEP instruction.
+ Type *LastType = GetElementPtrInst::getIndexedType(PtrTy, Ops.slice(1));
+ Type *GEPTy = PointerType::get(LastType, AS);
+ if (VectorType *VT = dyn_cast<VectorType>(Ops[0]->getType()))
+ GEPTy = VectorType::get(GEPTy, VT->getNumElements());
+
+ if (isa<UndefValue>(Ops[0]))
return UndefValue::get(GEPTy);
- }
if (Ops.size() == 2) {
// getelementptr P, 0 -> P.
// doesn't truncate the pointers.
if (Ops[1]->getType()->getScalarSizeInBits() ==
Q.DL->getPointerSizeInBits(AS)) {
- // getelementptr P, (sub Q, P) -> Q if P points to a type of size 1.
+ auto PtrToIntOrZero = [GEPTy](Value *P) -> Value * {
+ if (match(P, m_Zero()))
+ return Constant::getNullValue(GEPTy);
+ Value *Temp;
+ if (match(P, m_PtrToInt(m_Value(Temp))))
+ if (Temp->getType() == GEPTy)
+ return Temp;
+ return nullptr;
+ };
+
+ // getelementptr V, (sub P, V) -> P if P points to a type of size 1.
if (TyAllocSize == 1 &&
- match(Ops[1], m_Sub(m_PtrToInt(m_Value(P)),
- m_PtrToInt(m_Specific(Ops[0])))))
- return P;
+ match(Ops[1], m_Sub(m_Value(P), m_PtrToInt(m_Specific(Ops[0])))))
+ if (Value *R = PtrToIntOrZero(P))
+ return R;
- // getelementptr P, (ashr (sub Q, P), C) -> Q
+ // 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_PtrToInt(m_Value(P)),
- m_PtrToInt(m_Specific(Ops[0]))),
- m_ConstantInt(C))) &&
+ if (match(Ops[1],
+ m_AShr(m_Sub(m_Value(P), m_PtrToInt(m_Specific(Ops[0]))),
+ m_ConstantInt(C))) &&
TyAllocSize == 1ULL << C)
- return P;
+ if (Value *R = PtrToIntOrZero(P))
+ return R;
- // getelementptr P, (sdiv (sub Q, P), C) -> Q
+ // 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_PtrToInt(m_Value(P)),
- m_PtrToInt(m_Specific(Ops[0]))),
- m_SpecificInt(TyAllocSize))))
- return P;
+ if (match(Ops[1],
+ m_SDiv(m_Sub(m_Value(P), m_PtrToInt(m_Specific(Ops[0]))),
+ m_SpecificInt(TyAllocSize))))
+ if (Value *R = PtrToIntOrZero(P))
+ return R;
}
}
}