diff options
Diffstat (limited to 'llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp')
-rw-r--r-- | llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp | 254 |
1 files changed, 0 insertions, 254 deletions
diff --git a/llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp b/llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp index db7140d1141..da3293bc8c2 100644 --- a/llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp +++ b/llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp @@ -301,10 +301,6 @@ namespace { /// looking for a better chain (aliasing node.) SDValue FindBetterChain(SDNode *N, SDValue Chain); - /// Merge consecutive store operations into a wide store. - /// \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), @@ -7427,250 +7423,6 @@ SDValue DAGCombiner::TransformFPLoadStorePair(SDNode *N) { 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); -} - -struct ConsecutiveMemoryChainSorter { - typedef std::pair<LSBaseSDNode*, int64_t> MemLink; - bool operator()(MemLink LHS, MemLink RHS) { - return LHS.second < RHS.second; - } -}; - -bool DAGCombiner::MergeConsecutiveStores(StoreSDNode* St) { - EVT MemVT = St->getMemoryVT(); - int64_t ElementSizeBytes = MemVT.getSizeInBits()/8; - - // Don't handle vectors. - 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(); - if (!isa<ConstantSDNode>(StoredVal) && !isa<ConstantFPSDNode>(StoredVal) && - !isa<LoadSDNode>(StoredVal)) - return false; - - // Is this a load-to-store or a const-store. - bool IsLoadSrc = isa<LoadSDNode>(StoredVal); - - // Only look at ends of store chains. - 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<std::pair<StoreSDNode*, int64_t>, 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. - 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 found a potential memory operand to merge. - StoreNodes.push_back(std::make_pair(Index,Ptr.second)); - - // 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; - - // Remember which node is the earliest node in the chain. - LSBaseSDNode *EarliestOp = StoreNodes.back().first; - - // Sort the memory operands according to their distance from the base pointer. - std::sort(StoreNodes.begin(), StoreNodes.end(), - ConsecutiveMemoryChainSorter()); - - LSBaseSDNode *FirstInChain = StoreNodes[0].first; - - // Scan the memory operations on the chain and find the first non-consecutive - // store memory address. - unsigned LastConsecutiveStore = 0; - int64_t StartAddress = StoreNodes[0].second; - for (unsigned i=1; i<StoreNodes.size(); ++i) { - int64_t CurrAddress = StoreNodes[i].second; - if (CurrAddress - StartAddress != (ElementSizeBytes * i)) - break; - LastConsecutiveStore = i; - } - - // Store the constants into memory as one consecutive store. - if (!IsLoadSrc) { - unsigned LastConst = 0; - for (unsigned i=0; i<LastConsecutiveStore+1; ++i) { - SDValue StoredVal = StoreNodes[i].first->getValue(); - bool IsConst = (isa<ConstantSDNode>(StoredVal) || isa<ConstantFPSDNode>(StoredVal)); - if (!IsConst) - break; - LastConst = i; - } - unsigned NumElem = std::min(LastConsecutiveStore + 1, LastConst + 1); - if (NumElem < 2) - return false; - - EVT JointMemOpVT = EVT::getVectorVT(*DAG.getContext(), MemVT, NumElem); - DebugLoc DL = StoreNodes[0].first->getDebugLoc(); - SmallVector<SDValue, 8> Ops; - - for (unsigned i = 0; i < NumElem ; ++i) { - StoreSDNode *St = cast<StoreSDNode>(StoreNodes[i].first); - Ops.push_back(St->getValue()); - } - - SDValue BV = DAG.getNode(ISD::BUILD_VECTOR, DL, - JointMemOpVT, &Ops[0], Ops.size()); - - SDValue NewStore = DAG.getStore(EarliestOp->getChain(), DL, BV, - FirstInChain->getBasePtr(), - FirstInChain->getPointerInfo(), false, false, - FirstInChain->getAlignment()); - - for (unsigned i = 0; i < NumElem ; ++i) { - StoreSDNode *St = cast<StoreSDNode>(StoreNodes[i].first); - CombineTo(St, NewStore); - } - return true; - } - - // Look for load nodes wich are used by the stored values. - SmallVector<std::pair<LoadSDNode*, int64_t>, 8> LoadNodes; - - // Find acceptible 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) { - LoadSDNode *Ld = dyn_cast<LoadSDNode>(StoreNodes[i].first->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; - - 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 { - LdBasePtr = LdPtr.first; - } - - // We found a potential memory operand to merge. - LoadNodes.push_back(std::make_pair(Ld, LdPtr.second)); - } - - if (LoadNodes.size() < 2) - return false; - - // Scan the memory operations on the chain and find the first non-consecutive - // load memory address. - unsigned LastConsecutiveLoad = 0; - StartAddress = LoadNodes[0].second; - for (unsigned i=1; i<LoadNodes.size(); ++i) { - int64_t CurrAddress = LoadNodes[i].second; - if (CurrAddress - StartAddress != (ElementSizeBytes * i)) - break; - LastConsecutiveLoad = i; - } - - unsigned NumElem = - std::min(LastConsecutiveStore + 1, LastConsecutiveLoad + 1); - - EVT JointMemOpVT = EVT::getVectorVT(*DAG.getContext(), MemVT, NumElem); - DebugLoc LoadDL = LoadNodes[0].first->getDebugLoc(); - DebugLoc StoreDL = StoreNodes[0].first->getDebugLoc(); - - LoadSDNode *FirstLoad = LoadNodes[0].first; - 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()); - - for (unsigned i = 0; i < NumElem ; ++i) { - StoreSDNode *St = cast<StoreSDNode>(StoreNodes[i].first); - CombineTo(St, NewStore); - } - - return true; -} - SDValue DAGCombiner::visitSTORE(SDNode *N) { StoreSDNode *ST = cast<StoreSDNode>(N); SDValue Chain = ST->getChain(); @@ -7872,12 +7624,6 @@ SDValue DAGCombiner::visitSTORE(SDNode *N) { ST->getAlignment()); } - - // Only perform this optimization before the types are legal, because we - // don't want to generate illegal types in this optimization. - if (!LegalTypes && MergeConsecutiveStores(ST)) - return SDValue(N, 0); - return ReduceLoadOpStoreWidth(N); } |