/// looking for a better chain (aliasing node.)
SDValue FindBetterChain(SDNode *N, SDValue Chain);
+ /// Merge consecutive store operations into a wide store.
+ /// This optimization uses wide integers or vectors when possible.
+ /// \return True if some memory operations were changed.
+ bool MergeConsecutiveStores(StoreSDNode *N);
+
public:
DAGCombiner(SelectionDAG &D, AliasAnalysis &A, CodeGenOpt::Level OL)
: DAG(D), TLI(D.getTargetLoweringInfo()), Level(BeforeLegalizeTypes),
return SDValue();
}
+/// Returns the base pointer and an integer offset from that object.
+static std::pair<SDValue, int64_t> GetPointerBaseAndOffset(SDValue Ptr) {
+ if (Ptr->getOpcode() == ISD::ADD && isa<ConstantSDNode>(Ptr->getOperand(1))) {
+ int64_t Offset = cast<ConstantSDNode>(Ptr->getOperand(1))->getSExtValue();
+ SDValue Base = Ptr->getOperand(0);
+ return std::make_pair(Base, Offset);
+ }
+
+ return std::make_pair(Ptr, 0);
+}
+
+/// Holds a pointer to an LSBaseSDNode as well as information on where it
+/// is located in a sequence of memory operations connected by a chain.
+struct MemOpLink {
+ MemOpLink (LSBaseSDNode *N, int64_t Offset, unsigned Seq):
+ MemNode(N), OffsetFromBase(Offset), SequenceNum(Seq) { }
+ // Ptr to the mem node.
+ LSBaseSDNode *MemNode;
+ // Offset from the base ptr.
+ int64_t OffsetFromBase;
+ // What is the sequence number of this mem node.
+ // Lowest mem operand in the DAG starts at zero.
+ unsigned SequenceNum;
+};
+
+/// Sorts store nodes in a link according to their offset from a shared
+// base ptr.
+struct ConsecutiveMemoryChainSorter {
+ bool operator()(MemOpLink LHS, MemOpLink RHS) {
+ return LHS.OffsetFromBase < RHS.OffsetFromBase;
+ }
+};
+
+bool DAGCombiner::MergeConsecutiveStores(StoreSDNode* St) {
+ EVT MemVT = St->getMemoryVT();
+ int64_t ElementSizeBytes = MemVT.getSizeInBits()/8;
+
+ // Don't merge vectors into wider inputs.
+ if (MemVT.isVector() || !MemVT.isSimple())
+ return false;
+
+ // Perform an early exit check. Do not bother looking at stored values that
+ // are not constants or loads.
+ SDValue StoredVal = St->getValue();
+ bool IsLoadSrc = isa<LoadSDNode>(StoredVal);
+ if (!isa<ConstantSDNode>(StoredVal) && !isa<ConstantFPSDNode>(StoredVal) &&
+ !IsLoadSrc)
+ return false;
+
+ // Only look at ends of store sequences.
+ SDValue Chain = SDValue(St, 1);
+ if (Chain->hasOneUse() && Chain->use_begin()->getOpcode() == ISD::STORE)
+ return false;
+
+ // This holds the base pointer and the offset in bytes from the base pointer.
+ std::pair<SDValue, int64_t> BasePtr =
+ GetPointerBaseAndOffset(St->getBasePtr());
+
+ // We must have a base and an offset.
+ if (!BasePtr.first.getNode())
+ return false;
+
+ // Do not handle stores to undef base pointers.
+ if (BasePtr.first.getOpcode() == ISD::UNDEF)
+ return false;
+
+ SmallVector<MemOpLink, 8> StoreNodes;
+ // Walk up the chain and look for nodes with offsets from the same
+ // base pointer. Stop when reaching an instruction with a different kind
+ // or instruction which has a different base pointer.
+ unsigned Seq = 0;
+ StoreSDNode *Index = St;
+ while (Index) {
+ // If the chain has more than one use, then we can't reorder the mem ops.
+ if (Index != St && !SDValue(Index, 1)->hasOneUse())
+ break;
+
+ // Find the base pointer and offset for this memory node.
+ std::pair<SDValue, int64_t> Ptr =
+ GetPointerBaseAndOffset(Index->getBasePtr());
+
+ // Check that the base pointer is the same as the original one.
+ if (Ptr.first.getNode() != BasePtr.first.getNode())
+ break;
+
+ // Check that the alignment is the same.
+ if (Index->getAlignment() != St->getAlignment())
+ break;
+
+ // The memory operands must not be volatile.
+ if (Index->isVolatile() || Index->isIndexed())
+ break;
+
+ // No truncation.
+ if (StoreSDNode *St = dyn_cast<StoreSDNode>(Index))
+ if (St->isTruncatingStore())
+ break;
+
+ // The stored memory type must be the same.
+ if (Index->getMemoryVT() != MemVT)
+ break;
+
+ // We do not allow unaligned stores because we want to prevent overriding
+ // stores.
+ if (Index->getAlignment()*8 != MemVT.getSizeInBits())
+ break;
+
+ // We found a potential memory operand to merge.
+ StoreNodes.push_back(MemOpLink(Index, Ptr.second, Seq++));
+
+ // Move up the chain to the next memory operation.
+ Index = dyn_cast<StoreSDNode>(Index->getChain().getNode());
+ }
+
+ // Check if there is anything to merge.
+ if (StoreNodes.size() < 2)
+ return false;
+
+ // Sort the memory operands according to their distance from the base pointer.
+ std::sort(StoreNodes.begin(), StoreNodes.end(),
+ ConsecutiveMemoryChainSorter());
+
+ // Scan the memory operations on the chain and find the first non-consecutive
+ // store memory address.
+ unsigned LastConsecutiveStore = 0;
+ int64_t StartAddress = StoreNodes[0].OffsetFromBase;
+ for (unsigned i=1; i<StoreNodes.size(); ++i) {
+ int64_t CurrAddress = StoreNodes[i].OffsetFromBase;
+ if (CurrAddress - StartAddress != (ElementSizeBytes * i))
+ break;
+
+ // Mark this node as useful.
+ LastConsecutiveStore = i;
+ }
+
+ // The node with the lowest store address.
+ LSBaseSDNode *FirstInChain = StoreNodes[0].MemNode;
+
+ // Store the constants into memory as one consecutive store.
+ if (!IsLoadSrc) {
+ unsigned LastConst = 0;
+ unsigned LastLegalType = 0;
+ for (unsigned i=0; i<LastConsecutiveStore+1; ++i) {
+ StoreSDNode *St = cast<StoreSDNode>(StoreNodes[i].MemNode);
+ SDValue StoredVal = St->getValue();
+ bool IsConst = (isa<ConstantSDNode>(StoredVal) ||
+ isa<ConstantFPSDNode>(StoredVal));
+ if (!IsConst)
+ break;
+
+ // Mark this index as the largest legal constant.
+ LastConst = i;
+
+ // Find a legal type for the constant store.
+ unsigned StoreBW = (i+1) * ElementSizeBytes * 8;
+ EVT StoreTy = EVT::getIntegerVT(*DAG.getContext(), StoreBW);
+ if (TLI.isTypeLegal(StoreTy))
+ LastLegalType = i+1;
+ }
+
+ // Check if we found a legal integer type to store.
+ if (LastLegalType == 0)
+ return false;
+
+ // We add a +1 because the LastXXX variables refer to array location
+ // while NumElem holds the size.
+ unsigned NumElem = std::min(LastConsecutiveStore, LastConst) + 1;
+ NumElem = std::min(LastLegalType, NumElem);
+
+ unsigned EarliestNodeUsed = 0;
+ for (unsigned i=0; i < NumElem; ++i) {
+ // Find a chain for the new wide-store operand. Notice that some
+ // of the store nodes that we found may not be selected for inclusion
+ // in the wide store. The chain we use needs to be the chain of the
+ // earliest store node which is *used* and replaced by the wide store.
+ if (StoreNodes[i].SequenceNum > StoreNodes[EarliestNodeUsed].SequenceNum)
+ EarliestNodeUsed = i;
+ }
+
+ // The earliest Node in the DAG.
+ LSBaseSDNode *EarliestOp = StoreNodes[EarliestNodeUsed].MemNode;
+
+ // Make sure we have something to merge.
+ if (NumElem < 2)
+ return false;
+
+ DebugLoc DL = StoreNodes[0].MemNode->getDebugLoc();
+ unsigned StoreBW = NumElem * ElementSizeBytes * 8;
+ APInt StoreInt(StoreBW, 0);
+
+ // Construct a single integer constant which is made of the smaller
+ // constant inputs.
+ bool IsLE = TLI.isLittleEndian();
+ for (unsigned i = 0; i < NumElem ; ++i) {
+ unsigned Idx = IsLE ?(NumElem - 1 - i) : i;
+ StoreSDNode *St = cast<StoreSDNode>(StoreNodes[Idx].MemNode);
+ SDValue Val = St->getValue();
+ StoreInt<<=ElementSizeBytes*8;
+ if (ConstantSDNode *C = dyn_cast<ConstantSDNode>(Val)) {
+ StoreInt|=C->getAPIntValue().zext(StoreBW);
+ } else if (ConstantFPSDNode *C = dyn_cast<ConstantFPSDNode>(Val)) {
+ StoreInt|= C->getValueAPF().bitcastToAPInt().zext(StoreBW);
+ } else {
+ assert(false && "Invalid constant element type");
+ }
+ }
+
+ // Create the new Load and Store operations.
+ EVT StoreTy = EVT::getIntegerVT(*DAG.getContext(), StoreBW);
+ SDValue WideInt = DAG.getConstant(StoreInt, StoreTy);
+ SDValue NewStore = DAG.getStore(EarliestOp->getChain(), DL, WideInt,
+ FirstInChain->getBasePtr(),
+ FirstInChain->getPointerInfo(),
+ false, false,
+ FirstInChain->getAlignment());
+
+ // Replace the first store with the new store
+ CombineTo(EarliestOp, NewStore);
+ // Erase all other stores.
+ for (unsigned i = 0; i < NumElem ; ++i) {
+ if (StoreNodes[i].MemNode == EarliestOp)
+ continue;
+ StoreSDNode *St = cast<StoreSDNode>(StoreNodes[i].MemNode);
+ DAG.ReplaceAllUsesOfValueWith(SDValue(St, 0), St->getChain());
+ removeFromWorkList(St);
+ DAG.DeleteNode(St);
+ }
+
+ return true;
+ }
+
+ // Below we handle the case of multiple consecutive stores that
+ // come from multiple consecutive loads. We merge them into a single
+ // wide load and a single wide store.
+
+ // Look for load nodes which are used by the stored values.
+ SmallVector<MemOpLink, 8> LoadNodes;
+
+ // Find acceptable loads. Loads need to have the same chain (token factor),
+ // must not be zext, volatile, indexed, and they must be consecutive.
+ SDValue LdBasePtr;
+ for (unsigned i=0; i<LastConsecutiveStore+1; ++i) {
+ StoreSDNode *St = cast<StoreSDNode>(StoreNodes[i].MemNode);
+ LoadSDNode *Ld = dyn_cast<LoadSDNode>(St->getValue());
+ if (!Ld) break;
+
+ // Loads must only have one use.
+ if (!Ld->hasNUsesOfValue(1, 0))
+ break;
+
+ // Check that the alignment is the same as the stores.
+ if (Ld->getAlignment() != St->getAlignment())
+ break;
+
+ // The memory operands must not be volatile.
+ if (Ld->isVolatile() || Ld->isIndexed())
+ break;
+
+ // We do not accept ext loads.
+ if (Ld->getExtensionType() != ISD::NON_EXTLOAD)
+ break;
+
+ // The stored memory type must be the same.
+ if (Ld->getMemoryVT() != MemVT)
+ break;
+
+ std::pair<SDValue, int64_t> LdPtr =
+ GetPointerBaseAndOffset(Ld->getBasePtr());
+
+ // If this is not the first ptr that we check.
+ if (LdBasePtr.getNode()) {
+ // The base ptr must be the same.
+ if (LdPtr.first != LdBasePtr)
+ break;
+ } else {
+ // Check that all other base pointers are the same as this one.
+ LdBasePtr = LdPtr.first;
+ }
+
+ // We found a potential memory operand to merge.
+ LoadNodes.push_back(MemOpLink(Ld, LdPtr.second, 0));
+ }
+
+ if (LoadNodes.size() < 2)
+ return false;
+
+ // Scan the memory operations on the chain and find the first non-consecutive
+ // load memory address. These variables hold the index in the store node
+ // array.
+ unsigned LastConsecutiveLoad = 0;
+ // This variable refers to the size and not index in the array.
+ unsigned LastLegalVectorType = 0;
+ unsigned LastLegalIntegerType = 0;
+ StartAddress = LoadNodes[0].OffsetFromBase;
+ for (unsigned i=1; i<LoadNodes.size(); ++i) {
+ int64_t CurrAddress = LoadNodes[i].OffsetFromBase;
+ if (CurrAddress - StartAddress != (ElementSizeBytes * i))
+ break;
+ LastConsecutiveLoad = i;
+
+ // Find a legal type for the vector store.
+ EVT StoreTy = EVT::getVectorVT(*DAG.getContext(), MemVT, i+1);
+ if (TLI.isTypeLegal(StoreTy))
+ LastLegalVectorType = i + 1;
+
+ // Find a legal type for the integer store.
+ unsigned StoreBW = (i+1) * ElementSizeBytes * 8;
+ StoreTy = EVT::getIntegerVT(*DAG.getContext(), StoreBW);
+ if (TLI.isTypeLegal(StoreTy))
+ LastLegalIntegerType = i + 1;
+ }
+
+ // Only use vector types if the vector type is larger than the integer type.
+ // If they are the same, use integers.
+ bool UseVectorTy = LastLegalVectorType > LastLegalIntegerType;
+ unsigned LastLegalType = std::max(LastLegalVectorType, LastLegalIntegerType);
+
+ // We add +1 here because the LastXXX variables refer to location while
+ // the NumElem refers to array/index size.
+ unsigned NumElem = std::min(LastConsecutiveStore, LastConsecutiveLoad) + 1;
+ NumElem = std::min(LastLegalType, NumElem);
+
+ if (NumElem < 2)
+ return false;
+
+ // The earliest Node in the DAG.
+ unsigned EarliestNodeUsed = 0;
+ LSBaseSDNode *EarliestOp = StoreNodes[EarliestNodeUsed].MemNode;
+ for (unsigned i=1; i<NumElem; ++i) {
+ // Find a chain for the new wide-store operand. Notice that some
+ // of the store nodes that we found may not be selected for inclusion
+ // in the wide store. The chain we use needs to be the chain of the
+ // earliest store node which is *used* and replaced by the wide store.
+ if (StoreNodes[i].SequenceNum > StoreNodes[EarliestNodeUsed].SequenceNum)
+ EarliestNodeUsed = i;
+ }
+
+ // Find if it is better to use vectors or integers to load and store
+ // to memory.
+ EVT JointMemOpVT;
+ if (UseVectorTy) {
+ JointMemOpVT = EVT::getVectorVT(*DAG.getContext(), MemVT, NumElem);
+ } else {
+ unsigned StoreBW = NumElem * ElementSizeBytes * 8;
+ JointMemOpVT = EVT::getIntegerVT(*DAG.getContext(), StoreBW);
+ }
+
+ DebugLoc LoadDL = LoadNodes[0].MemNode->getDebugLoc();
+ DebugLoc StoreDL = StoreNodes[0].MemNode->getDebugLoc();
+
+ LoadSDNode *FirstLoad = cast<LoadSDNode>(LoadNodes[0].MemNode);
+ SDValue NewLoad = DAG.getLoad(JointMemOpVT, LoadDL,
+ FirstLoad->getChain(),
+ FirstLoad->getBasePtr(),
+ FirstLoad->getPointerInfo(),
+ false, false, false,
+ FirstLoad->getAlignment());
+
+ SDValue NewStore = DAG.getStore(EarliestOp->getChain(), StoreDL, NewLoad,
+ FirstInChain->getBasePtr(),
+ FirstInChain->getPointerInfo(), false, false,
+ FirstInChain->getAlignment());
+
+ // Replace the first store with the new store
+ CombineTo(EarliestOp, NewStore);
+ // Erase all other stores.
+ for (unsigned i = 0; i < NumElem ; ++i) {
+ // Replace all chain users of the old load nodes with the chain of the new
+ // load node.
+ LoadSDNode *Ld = cast<LoadSDNode>(LoadNodes[i].MemNode);
+ DAG.ReplaceAllUsesOfValueWith(SDValue(Ld, 1),
+ SDValue(NewLoad.getNode(), 1));
+
+ // Remove all Store nodes.
+ if (StoreNodes[i].MemNode == EarliestOp)
+ continue;
+ StoreSDNode *St = cast<StoreSDNode>(StoreNodes[i].MemNode);
+ DAG.ReplaceAllUsesOfValueWith(SDValue(St, 0), St->getChain());
+ removeFromWorkList(St);
+ DAG.DeleteNode(St);
+ }
+
+ return true;
+}
+
SDValue DAGCombiner::visitSTORE(SDNode *N) {
StoreSDNode *ST = cast<StoreSDNode>(N);
SDValue Chain = ST->getChain();
ST->getAlignment());
}
+ // Only perform this optimization before the types are legal, because we
+ // don't want to perform this optimization multiple times.
+ if (!LegalTypes && MergeConsecutiveStores(ST))
+ return SDValue(N, 0);
+
return ReduceLoadOpStoreWidth(N);
}
--- /dev/null
+; RUN: llc -march=x86-64 -mcpu=corei7 < %s | FileCheck %s
+
+target datalayout = "e-p:64:64:64-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:64:64-f32:32:32-f64:64:64-v64:64:64-v128:128:128-a0:0:64-s0:64:64-f80:128:128-n8:16:32:64-S128"
+target triple = "x86_64-apple-macosx10.8.0"
+
+%struct.A = type { i8, i8, i8, i8, i8, i8, i8, i8 }
+%struct.B = type { i32, i32, i32, i32, i32, i32, i32, i32 }
+
+; Move all of the constants using a single vector store.
+; CHECK: merge_const_store
+; save 1,2,3 ... as one big integer.
+; CHECK: movabsq $578437695752307201
+; CHECK: ret
+define void @merge_const_store(i32 %count, %struct.A* nocapture %p) nounwind uwtable noinline ssp {
+ %1 = icmp sgt i32 %count, 0
+ br i1 %1, label %.lr.ph, label %._crit_edge
+.lr.ph:
+ %i.02 = phi i32 [ %10, %.lr.ph ], [ 0, %0 ]
+ %.01 = phi %struct.A* [ %11, %.lr.ph ], [ %p, %0 ]
+ %2 = getelementptr inbounds %struct.A* %.01, i64 0, i32 0
+ store i8 1, i8* %2, align 1
+ %3 = getelementptr inbounds %struct.A* %.01, i64 0, i32 1
+ store i8 2, i8* %3, align 1
+ %4 = getelementptr inbounds %struct.A* %.01, i64 0, i32 2
+ store i8 3, i8* %4, align 1
+ %5 = getelementptr inbounds %struct.A* %.01, i64 0, i32 3
+ store i8 4, i8* %5, align 1
+ %6 = getelementptr inbounds %struct.A* %.01, i64 0, i32 4
+ store i8 5, i8* %6, align 1
+ %7 = getelementptr inbounds %struct.A* %.01, i64 0, i32 5
+ store i8 6, i8* %7, align 1
+ %8 = getelementptr inbounds %struct.A* %.01, i64 0, i32 6
+ store i8 7, i8* %8, align 1
+ %9 = getelementptr inbounds %struct.A* %.01, i64 0, i32 7
+ store i8 8, i8* %9, align 1
+ %10 = add nsw i32 %i.02, 1
+ %11 = getelementptr inbounds %struct.A* %.01, i64 1
+ %exitcond = icmp eq i32 %10, %count
+ br i1 %exitcond, label %._crit_edge, label %.lr.ph
+._crit_edge:
+ ret void
+}
+
+; Move the first 4 constants as a single vector. Move the rest as scalars.
+; CHECK: merge_nonconst_store
+; CHECK: movl $67305985
+; CHECK: movb
+; CHECK: movb
+; CHECK: movb
+; CHECK: movb
+; CHECK: ret
+define void @merge_nonconst_store(i32 %count, i8 %zz, %struct.A* nocapture %p) nounwind uwtable noinline ssp {
+ %1 = icmp sgt i32 %count, 0
+ br i1 %1, label %.lr.ph, label %._crit_edge
+.lr.ph:
+ %i.02 = phi i32 [ %10, %.lr.ph ], [ 0, %0 ]
+ %.01 = phi %struct.A* [ %11, %.lr.ph ], [ %p, %0 ]
+ %2 = getelementptr inbounds %struct.A* %.01, i64 0, i32 0
+ store i8 1, i8* %2, align 1
+ %3 = getelementptr inbounds %struct.A* %.01, i64 0, i32 1
+ store i8 2, i8* %3, align 1
+ %4 = getelementptr inbounds %struct.A* %.01, i64 0, i32 2
+ store i8 3, i8* %4, align 1
+ %5 = getelementptr inbounds %struct.A* %.01, i64 0, i32 3
+ store i8 4, i8* %5, align 1
+ %6 = getelementptr inbounds %struct.A* %.01, i64 0, i32 4
+ store i8 %zz, i8* %6, align 1 ; <----------- Not a const;
+ %7 = getelementptr inbounds %struct.A* %.01, i64 0, i32 5
+ store i8 6, i8* %7, align 1
+ %8 = getelementptr inbounds %struct.A* %.01, i64 0, i32 6
+ store i8 7, i8* %8, align 1
+ %9 = getelementptr inbounds %struct.A* %.01, i64 0, i32 7
+ store i8 8, i8* %9, align 1
+ %10 = add nsw i32 %i.02, 1
+ %11 = getelementptr inbounds %struct.A* %.01, i64 1
+ %exitcond = icmp eq i32 %10, %count
+ br i1 %exitcond, label %._crit_edge, label %.lr.ph
+._crit_edge:
+ ret void
+}
+
+
+;CHECK: merge_loads_i16
+; load:
+;CHECK: movw
+; store:
+;CHECK: movw
+;CHECK: ret
+define void @merge_loads_i16(i32 %count, %struct.A* noalias nocapture %q, %struct.A* noalias nocapture %p) nounwind uwtable noinline ssp {
+ %1 = icmp sgt i32 %count, 0
+ br i1 %1, label %.lr.ph, label %._crit_edge
+
+.lr.ph: ; preds = %0
+ %2 = getelementptr inbounds %struct.A* %q, i64 0, i32 0
+ %3 = getelementptr inbounds %struct.A* %q, i64 0, i32 1
+ br label %4
+
+; <label>:4 ; preds = %4, %.lr.ph
+ %i.02 = phi i32 [ 0, %.lr.ph ], [ %9, %4 ]
+ %.01 = phi %struct.A* [ %p, %.lr.ph ], [ %10, %4 ]
+ %5 = load i8* %2, align 1
+ %6 = load i8* %3, align 1
+ %7 = getelementptr inbounds %struct.A* %.01, i64 0, i32 0
+ store i8 %5, i8* %7, align 1
+ %8 = getelementptr inbounds %struct.A* %.01, i64 0, i32 1
+ store i8 %6, i8* %8, align 1
+ %9 = add nsw i32 %i.02, 1
+ %10 = getelementptr inbounds %struct.A* %.01, i64 1
+ %exitcond = icmp eq i32 %9, %count
+ br i1 %exitcond, label %._crit_edge, label %4
+
+._crit_edge: ; preds = %4, %0
+ ret void
+}
+
+; The loads and the stores are interleved. Can't merge them.
+;CHECK: no_merge_loads
+;CHECK: movb
+;CHECK: movb
+;CHECK: movb
+;CHECK: movb
+;CHECK: ret
+define void @no_merge_loads(i32 %count, %struct.A* noalias nocapture %q, %struct.A* noalias nocapture %p) nounwind uwtable noinline ssp {
+ %1 = icmp sgt i32 %count, 0
+ br i1 %1, label %.lr.ph, label %._crit_edge
+
+.lr.ph: ; preds = %0
+ %2 = getelementptr inbounds %struct.A* %q, i64 0, i32 0
+ %3 = getelementptr inbounds %struct.A* %q, i64 0, i32 1
+ br label %a4
+
+a4: ; preds = %4, %.lr.ph
+ %i.02 = phi i32 [ 0, %.lr.ph ], [ %a9, %a4 ]
+ %.01 = phi %struct.A* [ %p, %.lr.ph ], [ %a10, %a4 ]
+ %a5 = load i8* %2, align 1
+ %a7 = getelementptr inbounds %struct.A* %.01, i64 0, i32 0
+ store i8 %a5, i8* %a7, align 1
+ %a8 = getelementptr inbounds %struct.A* %.01, i64 0, i32 1
+ %a6 = load i8* %3, align 1
+ store i8 %a6, i8* %a8, align 1
+ %a9 = add nsw i32 %i.02, 1
+ %a10 = getelementptr inbounds %struct.A* %.01, i64 1
+ %exitcond = icmp eq i32 %a9, %count
+ br i1 %exitcond, label %._crit_edge, label %a4
+
+._crit_edge: ; preds = %4, %0
+ ret void
+}
+
+
+;CHECK: merge_loads_integer
+; load:
+;CHECK: movq
+; store:
+;CHECK: movq
+;CHECK: ret
+define void @merge_loads_integer(i32 %count, %struct.B* noalias nocapture %q, %struct.B* noalias nocapture %p) nounwind uwtable noinline ssp {
+ %1 = icmp sgt i32 %count, 0
+ br i1 %1, label %.lr.ph, label %._crit_edge
+
+.lr.ph: ; preds = %0
+ %2 = getelementptr inbounds %struct.B* %q, i64 0, i32 0
+ %3 = getelementptr inbounds %struct.B* %q, i64 0, i32 1
+ br label %4
+
+; <label>:4 ; preds = %4, %.lr.ph
+ %i.02 = phi i32 [ 0, %.lr.ph ], [ %9, %4 ]
+ %.01 = phi %struct.B* [ %p, %.lr.ph ], [ %10, %4 ]
+ %5 = load i32* %2
+ %6 = load i32* %3
+ %7 = getelementptr inbounds %struct.B* %.01, i64 0, i32 0
+ store i32 %5, i32* %7
+ %8 = getelementptr inbounds %struct.B* %.01, i64 0, i32 1
+ store i32 %6, i32* %8
+ %9 = add nsw i32 %i.02, 1
+ %10 = getelementptr inbounds %struct.B* %.01, i64 1
+ %exitcond = icmp eq i32 %9, %count
+ br i1 %exitcond, label %._crit_edge, label %4
+
+._crit_edge: ; preds = %4, %0
+ ret void
+}
+
+
+;CHECK: merge_loads_vector
+; load:
+;CHECK: movups
+; store:
+;CHECK: movups
+;CHECK: ret
+define void @merge_loads_vector(i32 %count, %struct.B* noalias nocapture %q, %struct.B* noalias nocapture %p) nounwind uwtable noinline ssp {
+ %a1 = icmp sgt i32 %count, 0
+ br i1 %a1, label %.lr.ph, label %._crit_edge
+
+.lr.ph: ; preds = %0
+ %a2 = getelementptr inbounds %struct.B* %q, i64 0, i32 0
+ %a3 = getelementptr inbounds %struct.B* %q, i64 0, i32 1
+ %a4 = getelementptr inbounds %struct.B* %q, i64 0, i32 2
+ %a5 = getelementptr inbounds %struct.B* %q, i64 0, i32 3
+ br label %block4
+
+block4: ; preds = %4, %.lr.ph
+ %i.02 = phi i32 [ 0, %.lr.ph ], [ %c9, %block4 ]
+ %.01 = phi %struct.B* [ %p, %.lr.ph ], [ %c10, %block4 ]
+ %a7 = getelementptr inbounds %struct.B* %.01, i64 0, i32 0
+ %a8 = getelementptr inbounds %struct.B* %.01, i64 0, i32 1
+ %a9 = getelementptr inbounds %struct.B* %.01, i64 0, i32 2
+ %a10 = getelementptr inbounds %struct.B* %.01, i64 0, i32 3
+ %b1 = load i32* %a2
+ %b2 = load i32* %a3
+ %b3 = load i32* %a4
+ %b4 = load i32* %a5
+ store i32 %b1, i32* %a7
+ store i32 %b2, i32* %a8
+ store i32 %b3, i32* %a9
+ store i32 %b4, i32* %a10
+ %c9 = add nsw i32 %i.02, 1
+ %c10 = getelementptr inbounds %struct.B* %.01, i64 1
+ %exitcond = icmp eq i32 %c9, %count
+ br i1 %exitcond, label %._crit_edge, label %block4
+
+._crit_edge: ; preds = %4, %0
+ ret void
+}
+
+
+;CHECK: merge_loads_no_align
+; load:
+;CHECK: movl
+;CHECK: movl
+;CHECK: movl
+;CHECK: movl
+; store:
+;CHECK: movl
+;CHECK: movl
+;CHECK: movl
+;CHECK: movl
+;CHECK: ret
+define void @merge_loads_no_align(i32 %count, %struct.B* noalias nocapture %q, %struct.B* noalias nocapture %p) nounwind uwtable noinline ssp {
+ %a1 = icmp sgt i32 %count, 0
+ br i1 %a1, label %.lr.ph, label %._crit_edge
+
+.lr.ph: ; preds = %0
+ %a2 = getelementptr inbounds %struct.B* %q, i64 0, i32 0
+ %a3 = getelementptr inbounds %struct.B* %q, i64 0, i32 1
+ %a4 = getelementptr inbounds %struct.B* %q, i64 0, i32 2
+ %a5 = getelementptr inbounds %struct.B* %q, i64 0, i32 3
+ br label %block4
+
+block4: ; preds = %4, %.lr.ph
+ %i.02 = phi i32 [ 0, %.lr.ph ], [ %c9, %block4 ]
+ %.01 = phi %struct.B* [ %p, %.lr.ph ], [ %c10, %block4 ]
+ %a7 = getelementptr inbounds %struct.B* %.01, i64 0, i32 0
+ %a8 = getelementptr inbounds %struct.B* %.01, i64 0, i32 1
+ %a9 = getelementptr inbounds %struct.B* %.01, i64 0, i32 2
+ %a10 = getelementptr inbounds %struct.B* %.01, i64 0, i32 3
+ %b1 = load i32* %a2, align 1
+ %b2 = load i32* %a3, align 1
+ %b3 = load i32* %a4, align 1
+ %b4 = load i32* %a5, align 1
+ store i32 %b1, i32* %a7, align 1
+ store i32 %b2, i32* %a8, align 1
+ store i32 %b3, i32* %a9, align 1
+ store i32 %b4, i32* %a10, align 1
+ %c9 = add nsw i32 %i.02, 1
+ %c10 = getelementptr inbounds %struct.B* %.01, i64 1
+ %exitcond = icmp eq i32 %c9, %count
+ br i1 %exitcond, label %._crit_edge, label %block4
+
+._crit_edge: ; preds = %4, %0
+ ret void
+}
+