Revert "mp"

Commit was pushed by accident.

This reverts commit 0e15f24.

Author: fhahn

llvm/lib/Analysis/LoopAccessAnalysis.cpp

@@ -1881,90 +1881,70 @@ MemoryDepChecker::Dependence::DepType MemoryDepChecker::isDependent(
     unsigned BIdx, const DenseMap<Value *, const SCEV *> &Strides,
     const DenseMap<Value *, SmallVector<const Value *, 16>>
         &UnderlyingObjects) {
-  ScalarEvolution &SE = *PSE.getSE();
-  auto &DL = InnermostLoop->getHeader()->getModule()->getDataLayout();
+  assert (AIdx < BIdx && "Must pass arguments in program order");
 
-  // Get the dependence distance, stride, type size in whether i is a write for
-  // the dependence between A and B. Returns a DepType, if we can prove there's
-  // no dependence or the analysis fails. Outlined to lambda to limit he scope
-  // of various temporary variables, like A/BPtr, StrideA/BPtr and others.
-  auto Res =
-      [&]() -> std::variant<
-                MemoryDepChecker::Dependence::DepType,
-                std::tuple<const SCEV *, uint64_t, uint64_t, bool, bool>> {
-    auto [APtr, AIsWrite] = A;
-    auto [BPtr, BIsWrite] = B;
-
-    // Two reads are independent.
-    if (!AIsWrite && !BIsWrite)
-      return Dependence::NoDep;
-
-    assert(AIdx < BIdx && "Must pass arguments in program order");
-    Type *ATy = getLoadStoreType(InstMap[AIdx]);
-    Type *BTy = getLoadStoreType(InstMap[BIdx]);
-
-    // We cannot check pointers in different address spaces.
-    if (APtr->getType()->getPointerAddressSpace() !=
-        BPtr->getType()->getPointerAddressSpace())
-      return Dependence::Unknown;
-
-    int64_t StrideAPtr =
-        getPtrStride(PSE, ATy, APtr, InnermostLoop, Strides, true).value_or(0);
-    int64_t StrideBPtr =
-        getPtrStride(PSE, BTy, BPtr, InnermostLoop, Strides, true).value_or(0);
-
-    const SCEV *Src = PSE.getSCEV(APtr);
-    const SCEV *Sink = PSE.getSCEV(BPtr);
-
-    // If the induction step is negative we have to invert source and sink of
-    // the dependence.
-    if (StrideAPtr < 0) {
-      std::swap(APtr, BPtr);
-      std::swap(ATy, BTy);
-      std::swap(Src, Sink);
-      std::swap(AIsWrite, BIsWrite);
-      std::swap(AIdx, BIdx);
-      std::swap(StrideAPtr, StrideBPtr);
-    }
+  auto [APtr, AIsWrite] = A;
+  auto [BPtr, BIsWrite] = B;
+  Type *ATy = getLoadStoreType(InstMap[AIdx]);
+  Type *BTy = getLoadStoreType(InstMap[BIdx]);
 
-    const SCEV *Dist = SE.getMinusSCEV(Sink, Src);
-
-    LLVM_DEBUG(dbgs() << "LAA: Src Scev: " << *Src << "Sink Scev: " << *Sink
-                      << "(Induction step: " << StrideAPtr << ")\n");
-    LLVM_DEBUG(dbgs() << "LAA: Distance for " << *InstMap[AIdx] << " to "
-                      << *InstMap[BIdx] << ": " << *Dist << "\n");
-
-    // Needs accesses where the addresses of the accessed underlying objects do
-    // not change within the loop.
-    if (isLoopVariantIndirectAddress(UnderlyingObjects.find(APtr)->second, SE,
-                                     InnermostLoop) ||
-        isLoopVariantIndirectAddress(UnderlyingObjects.find(BPtr)->second, SE,
-                                     InnermostLoop))
-      return Dependence::IndirectUnsafe;
-
-    // Need accesses with constant stride. We don't want to vectorize
-    // "A[B[i]] += ..." and similar code or pointer arithmetic that could wrap
-    // in the address space.
-    if (!StrideAPtr || !StrideBPtr || StrideAPtr != StrideBPtr) {
-      LLVM_DEBUG(dbgs() << "Pointer access with non-constant stride\n");
-      return Dependence::Unknown;
-    }
+  // Two reads are independent.
+  if (!AIsWrite && !BIsWrite)
+    return Dependence::NoDep;
+
+  // We cannot check pointers in different address spaces.
+  if (APtr->getType()->getPointerAddressSpace() !=
+      BPtr->getType()->getPointerAddressSpace())
+    return Dependence::Unknown;
+
+  int64_t StrideAPtr =
+    getPtrStride(PSE, ATy, APtr, InnermostLoop, Strides, true).value_or(0);
+  int64_t StrideBPtr =
+    getPtrStride(PSE, BTy, BPtr, InnermostLoop, Strides, true).value_or(0);
+
+  const SCEV *Src = PSE.getSCEV(APtr);
+  const SCEV *Sink = PSE.getSCEV(BPtr);
 
-    uint64_t TypeByteSize = DL.getTypeAllocSize(ATy);
-    bool HasSameSize =
-        DL.getTypeStoreSizeInBits(ATy) == DL.getTypeStoreSizeInBits(BTy);
-    if (!HasSameSize)
-      TypeByteSize = 0;
-    uint64_t Stride = std::abs(StrideAPtr);
-    return std::make_tuple(Dist, Stride, TypeByteSize, AIsWrite, BIsWrite);
-  }();
-
-  if (std::holds_alternative<Dependence::DepType>(Res))
-    return std::get<Dependence::DepType>(Res);
-
-  const auto &[Dist, Stride, TypeByteSize, AIsWrite, BIsWrite] =
-      std::get<std::tuple<const SCEV *, uint64_t, uint64_t, bool, bool>>(Res);
-  bool HasSameSize = TypeByteSize > 0;
+  // If the induction step is negative we have to invert source and sink of the
+  // dependence.
+  if (StrideAPtr < 0) {
+    std::swap(APtr, BPtr);
+    std::swap(ATy, BTy);
+    std::swap(Src, Sink);
+    std::swap(AIsWrite, BIsWrite);
+    std::swap(AIdx, BIdx);
+    std::swap(StrideAPtr, StrideBPtr);
+  }
+
+  ScalarEvolution &SE = *PSE.getSE();
+  const SCEV *Dist = SE.getMinusSCEV(Sink, Src);
+
+  LLVM_DEBUG(dbgs() << "LAA: Src Scev: " << *Src << "Sink Scev: " << *Sink
+                    << "(Induction step: " << StrideAPtr << ")\n");
+  LLVM_DEBUG(dbgs() << "LAA: Distance for " << *InstMap[AIdx] << " to "
+                    << *InstMap[BIdx] << ": " << *Dist << "\n");
+
+  // Needs accesses where the addresses of the accessed underlying objects do
+  // not change within the loop.
+  if (isLoopVariantIndirectAddress(UnderlyingObjects.find(APtr)->second, SE,
+                                   InnermostLoop) ||
+      isLoopVariantIndirectAddress(UnderlyingObjects.find(BPtr)->second, SE,
+                                   InnermostLoop))
+    return Dependence::IndirectUnsafe;
+
+  // Need accesses with constant stride. We don't want to vectorize
+  // "A[B[i]] += ..." and similar code or pointer arithmetic that could wrap in
+  // the address space.
+  if (!StrideAPtr || !StrideBPtr || StrideAPtr != StrideBPtr){
+    LLVM_DEBUG(dbgs() << "Pointer access with non-constant stride\n");
+    return Dependence::Unknown;
+  }
+
+  auto &DL = InnermostLoop->getHeader()->getModule()->getDataLayout();
+  uint64_t TypeByteSize = DL.getTypeAllocSize(ATy);
+  bool HasSameSize =
+      DL.getTypeStoreSizeInBits(ATy) == DL.getTypeStoreSizeInBits(BTy);
+  uint64_t Stride = std::abs(StrideAPtr);
 
   if (!isa<SCEVCouldNotCompute>(Dist) && HasSameSize &&
       isSafeDependenceDistance(DL, SE, *(PSE.getBackedgeTakenCount()), *Dist,