Revert r216439 (and r216441, else the former doesn't revert cleanly).
It caused PR 20771. I'll land a test on the clang side.
llvm-svn: 216582
diff --git a/llvm/lib/Analysis/InstructionSimplify.cpp b/llvm/lib/Analysis/InstructionSimplify.cpp
index 118579d..da5c83c 100644
--- a/llvm/lib/Analysis/InstructionSimplify.cpp
+++ b/llvm/lib/Analysis/InstructionSimplify.cpp
@@ -2799,71 +2799,29 @@
static Value *SimplifyGEPInst(ArrayRef<Value *> Ops, const Query &Q, unsigned) {
// The type of the GEP pointer operand.
PointerType *PtrTy = cast<PointerType>(Ops[0]->getType()->getScalarType());
- unsigned AS = PtrTy->getAddressSpace();
// getelementptr P -> P.
if (Ops.size() == 1)
return 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());
-
- if (isa<UndefValue>(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, PtrTy->getAddressSpace());
+ if (VectorType *VT = dyn_cast<VectorType>(Ops[0]->getType()))
+ GEPTy = VectorType::get(GEPTy, VT->getNumElements());
return UndefValue::get(GEPTy);
+ }
if (Ops.size() == 2) {
// getelementptr P, 0 -> P.
if (match(Ops[1], m_Zero()))
return Ops[0];
-
- Type *Ty = PtrTy->getElementType();
- if (Q.DL && Ty->isSized()) {
- Value *P;
- uint64_t C;
- uint64_t TyAllocSize = Q.DL->getTypeAllocSize(Ty);
- // getelementptr P, N -> P if P points to a type of zero size.
- if (TyAllocSize == 0)
+ // getelementptr P, N -> P if P points to a type of zero size.
+ if (Q.DL) {
+ Type *Ty = PtrTy->getElementType();
+ if (Ty->isSized() && Q.DL->getTypeAllocSize(Ty) == 0)
return Ops[0];
-
- // The following transforms are only safe if the ptrtoint cast
- // doesn't truncate the pointers.
- if (Ops[1]->getType()->getScalarSizeInBits() ==
- Q.DL->getPointerSizeInBits(AS)) {
- 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))))
- 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_Value(P), m_PtrToInt(m_Specific(Ops[0])))))
- if (Value *R = PtrToIntOrZero(P))
- return R;
-
- // 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 = PtrToIntOrZero(P))
- return R;
-
- // 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 = PtrToIntOrZero(P))
- return R;
- }
}
}