//===-- HexagonISelDAGToDAGHVX.cpp ----------------------------------------===// // // The LLVM Compiler Infrastructure // // This file is distributed under the University of Illinois Open Source // License. See LICENSE.TXT for details. // //===----------------------------------------------------------------------===// #include "Hexagon.h" #include "HexagonISelDAGToDAG.h" #include "HexagonISelLowering.h" #include "HexagonTargetMachine.h" #include "llvm/ADT/SetVector.h" #include "llvm/CodeGen/MachineInstrBuilder.h" #include "llvm/CodeGen/SelectionDAGISel.h" #include "llvm/IR/Intrinsics.h" #include "llvm/Support/CommandLine.h" #include "llvm/Support/Debug.h" #include <deque> #include <map> #include <set> #include <utility> #include <vector> #define DEBUG_TYPE "hexagon-isel" using namespace llvm; namespace { // -------------------------------------------------------------------- // Implementation of permutation networks. // Implementation of the node routing through butterfly networks: // - Forward delta. // - Reverse delta. // - Benes. // // // Forward delta network consists of log(N) steps, where N is the number // of inputs. In each step, an input can stay in place, or it can get // routed to another position[1]. The step after that consists of two // networks, each half in size in terms of the number of nodes. In those // terms, in the given step, an input can go to either the upper or the // lower network in the next step. // // [1] Hexagon's vdelta/vrdelta allow an element to be routed to both // positions as long as there is no conflict. // Here's a delta network for 8 inputs, only the switching routes are // shown: // // Steps: // |- 1 ---------------|- 2 -----|- 3 -| // // Inp[0] *** *** *** *** Out[0] // \ / \ / \ / // \ / \ / X // \ / \ / / \ // Inp[1] *** \ / *** X *** *** Out[1] // \ \ / / \ / \ / // \ \ / / X X // \ \ / / / \ / \ // Inp[2] *** \ \ / / *** X *** *** Out[2] // \ \ X / / / \ \ / // \ \ / \ / / / \ X // \ X X / / \ / \ // Inp[3] *** \ / \ / \ / *** *** *** Out[3] // \ X X X / // \ / \ / \ / \ / // X X X X // / \ / \ / \ / \ // / X X X \ // Inp[4] *** / \ / \ / \ *** *** *** Out[4] // / X X \ \ / \ / // / / \ / \ \ \ / X // / / X \ \ \ / / \ // Inp[5] *** / / \ \ *** X *** *** Out[5] // / / \ \ \ / \ / // / / \ \ X X // / / \ \ / \ / \ // Inp[6] *** / \ *** X *** *** Out[6] // / \ / \ \ / // / \ / \ X // / \ / \ / \ // Inp[7] *** *** *** *** Out[7] // // // Reverse delta network is same as delta network, with the steps in // the opposite order. // // // Benes network is a forward delta network immediately followed by // a reverse delta network. enum class ColorKind { None, Red, Black }; // Graph coloring utility used to partition nodes into two groups: // they will correspond to nodes routed to the upper and lower networks. struct Coloring { using Node = int; using MapType = std::map<Node, ColorKind>; static constexpr Node Ignore = Node(-1); Coloring(ArrayRef<Node> Ord) : Order(Ord) { build(); if (!color()) Colors.clear(); } const MapType &colors() const { return Colors; } ColorKind other(ColorKind Color) { if (Color == ColorKind::None) return ColorKind::Red; return Color == ColorKind::Red ? ColorKind::Black : ColorKind::Red; } void dump() const; private: ArrayRef<Node> Order; MapType Colors; std::set<Node> Needed; using NodeSet = std::set<Node>; std::map<Node,NodeSet> Edges; Node conj(Node Pos) { Node Num = Order.size(); return (Pos < Num/2) ? Pos + Num/2 : Pos - Num/2; } ColorKind getColor(Node N) { auto F = Colors.find(N); return F != Colors.end() ? F->second : ColorKind::None; } std::pair<bool, ColorKind> getUniqueColor(const NodeSet &Nodes); void build(); bool color(); }; } // namespace std::pair<bool, ColorKind> Coloring::getUniqueColor(const NodeSet &Nodes) { auto Color = ColorKind::None; for (Node N : Nodes) { ColorKind ColorN = getColor(N); if (ColorN == ColorKind::None) continue; if (Color == ColorKind::None) Color = ColorN; else if (Color != ColorKind::None && Color != ColorN) return { false, ColorKind::None }; } return { true, Color }; } void Coloring::build() { // Add Order[P] and Order[conj(P)] to Edges. for (unsigned P = 0; P != Order.size(); ++P) { Node I = Order[P]; if (I != Ignore) { Needed.insert(I); Node PC = Order[conj(P)]; if (PC != Ignore && PC != I) Edges[I].insert(PC); } } // Add I and conj(I) to Edges. for (unsigned I = 0; I != Order.size(); ++I) { if (!Needed.count(I)) continue; Node C = conj(I); // This will create an entry in the edge table, even if I is not // connected to any other node. This is necessary, because it still // needs to be colored. NodeSet &Is = Edges[I]; if (Needed.count(C)) Is.insert(C); } } bool Coloring::color() { SetVector<Node> FirstQ; auto Enqueue = [this,&FirstQ] (Node N) { SetVector<Node> Q; Q.insert(N); for (unsigned I = 0; I != Q.size(); ++I) { NodeSet &Ns = Edges[Q[I]]; Q.insert(Ns.begin(), Ns.end()); } FirstQ.insert(Q.begin(), Q.end()); }; for (Node N : Needed) Enqueue(N); for (Node N : FirstQ) { if (Colors.count(N)) continue; NodeSet &Ns = Edges[N]; auto P = getUniqueColor(Ns); if (!P.first) return false; Colors[N] = other(P.second); } // First, color nodes that don't have any dups. for (auto E : Edges) { Node N = E.first; if (!Needed.count(conj(N)) || Colors.count(N)) continue; auto P = getUniqueColor(E.second); if (!P.first) return false; Colors[N] = other(P.second); } // Now, nodes that are still uncolored. Since the graph can be modified // in this step, create a work queue. std::vector<Node> WorkQ; for (auto E : Edges) { Node N = E.first; if (!Colors.count(N)) WorkQ.push_back(N); } for (unsigned I = 0; I < WorkQ.size(); ++I) { Node N = WorkQ[I]; NodeSet &Ns = Edges[N]; auto P = getUniqueColor(Ns); if (P.first) { Colors[N] = other(P.second); continue; } // Coloring failed. Split this node. Node C = conj(N); ColorKind ColorN = other(ColorKind::None); ColorKind ColorC = other(ColorN); NodeSet &Cs = Edges[C]; NodeSet CopyNs = Ns; for (Node M : CopyNs) { ColorKind ColorM = getColor(M); if (ColorM == ColorC) { // Connect M with C, disconnect M from N. Cs.insert(M); Edges[M].insert(C); Ns.erase(M); Edges[M].erase(N); } } Colors[N] = ColorN; Colors[C] = ColorC; } // Explicitly assign "None" to all uncolored nodes. for (unsigned I = 0; I != Order.size(); ++I) if (Colors.count(I) == 0) Colors[I] = ColorKind::None; return true; } LLVM_DUMP_METHOD void Coloring::dump() const { dbgs() << "{ Order: {"; for (unsigned I = 0; I != Order.size(); ++I) { Node P = Order[I]; if (P != Ignore) dbgs() << ' ' << P; else dbgs() << " -"; } dbgs() << " }\n"; dbgs() << " Needed: {"; for (Node N : Needed) dbgs() << ' ' << N; dbgs() << " }\n"; dbgs() << " Edges: {\n"; for (auto E : Edges) { dbgs() << " " << E.first << " -> {"; for (auto N : E.second) dbgs() << ' ' << N; dbgs() << " }\n"; } dbgs() << " }\n"; auto ColorKindToName = [](ColorKind C) { switch (C) { case ColorKind::None: return "None"; case ColorKind::Red: return "Red"; case ColorKind::Black: return "Black"; } llvm_unreachable("all ColorKinds should be handled by the switch above"); }; dbgs() << " Colors: {\n"; for (auto C : Colors) dbgs() << " " << C.first << " -> " << ColorKindToName(C.second) << "\n"; dbgs() << " }\n}\n"; } namespace { // Base class of for reordering networks. They don't strictly need to be // permutations, as outputs with repeated occurrences of an input element // are allowed. struct PermNetwork { using Controls = std::vector<uint8_t>; using ElemType = int; static constexpr ElemType Ignore = ElemType(-1); enum : uint8_t { None, Pass, Switch }; enum : uint8_t { Forward, Reverse }; PermNetwork(ArrayRef<ElemType> Ord, unsigned Mult = 1) { Order.assign(Ord.data(), Ord.data()+Ord.size()); Log = 0; unsigned S = Order.size(); while (S >>= 1) ++Log; Table.resize(Order.size()); for (RowType &Row : Table) Row.resize(Mult*Log, None); } void getControls(Controls &V, unsigned StartAt, uint8_t Dir) const { unsigned Size = Order.size(); V.resize(Size); for (unsigned I = 0; I != Size; ++I) { unsigned W = 0; for (unsigned L = 0; L != Log; ++L) { unsigned C = ctl(I, StartAt+L) == Switch; if (Dir == Forward) W |= C << (Log-1-L); else W |= C << L; } assert(isUInt<8>(W)); V[I] = uint8_t(W); } } uint8_t ctl(ElemType Pos, unsigned Step) const { return Table[Pos][Step]; } unsigned size() const { return Order.size(); } unsigned steps() const { return Log; } protected: unsigned Log; std::vector<ElemType> Order; using RowType = std::vector<uint8_t>; std::vector<RowType> Table; }; struct ForwardDeltaNetwork : public PermNetwork { ForwardDeltaNetwork(ArrayRef<ElemType> Ord) : PermNetwork(Ord) {} bool run(Controls &V) { if (!route(Order.data(), Table.data(), size(), 0)) return false; getControls(V, 0, Forward); return true; } private: bool route(ElemType *P, RowType *T, unsigned Size, unsigned Step); }; struct ReverseDeltaNetwork : public PermNetwork { ReverseDeltaNetwork(ArrayRef<ElemType> Ord) : PermNetwork(Ord) {} bool run(Controls &V) { if (!route(Order.data(), Table.data(), size(), 0)) return false; getControls(V, 0, Reverse); return true; } private: bool route(ElemType *P, RowType *T, unsigned Size, unsigned Step); }; struct BenesNetwork : public PermNetwork { BenesNetwork(ArrayRef<ElemType> Ord) : PermNetwork(Ord, 2) {} bool run(Controls &F, Controls &R) { if (!route(Order.data(), Table.data(), size(), 0)) return false; getControls(F, 0, Forward); getControls(R, Log, Reverse); return true; } private: bool route(ElemType *P, RowType *T, unsigned Size, unsigned Step); }; } // namespace bool ForwardDeltaNetwork::route(ElemType *P, RowType *T, unsigned Size, unsigned Step) { bool UseUp = false, UseDown = false; ElemType Num = Size; // Cannot use coloring here, because coloring is used to determine // the "big" switch, i.e. the one that changes halves, and in a forward // network, a color can be simultaneously routed to both halves in the // step we're working on. for (ElemType J = 0; J != Num; ++J) { ElemType I = P[J]; // I is the position in the input, // J is the position in the output. if (I == Ignore) continue; uint8_t S; if (I < Num/2) S = (J < Num/2) ? Pass : Switch; else S = (J < Num/2) ? Switch : Pass; // U is the element in the table that needs to be updated. ElemType U = (S == Pass) ? I : (I < Num/2 ? I+Num/2 : I-Num/2); if (U < Num/2) UseUp = true; else UseDown = true; if (T[U][Step] != S && T[U][Step] != None) return false; T[U][Step] = S; } for (ElemType J = 0; J != Num; ++J) if (P[J] != Ignore && P[J] >= Num/2) P[J] -= Num/2; if (Step+1 < Log) { if (UseUp && !route(P, T, Size/2, Step+1)) return false; if (UseDown && !route(P+Size/2, T+Size/2, Size/2, Step+1)) return false; } return true; } bool ReverseDeltaNetwork::route(ElemType *P, RowType *T, unsigned Size, unsigned Step) { unsigned Pets = Log-1 - Step; bool UseUp = false, UseDown = false; ElemType Num = Size; // In this step half-switching occurs, so coloring can be used. Coloring G({P,Size}); const Coloring::MapType &M = G.colors(); if (M.empty()) return false; ColorKind ColorUp = ColorKind::None; for (ElemType J = 0; J != Num; ++J) { ElemType I = P[J]; // I is the position in the input, // J is the position in the output. if (I == Ignore) continue; ColorKind C = M.at(I); if (C == ColorKind::None) continue; // During "Step", inputs cannot switch halves, so if the "up" color // is still unknown, make sure that it is selected in such a way that // "I" will stay in the same half. bool InpUp = I < Num/2; if (ColorUp == ColorKind::None) ColorUp = InpUp ? C : G.other(C); if ((C == ColorUp) != InpUp) { // If I should go to a different half than where is it now, give up. return false; } uint8_t S; if (InpUp) { S = (J < Num/2) ? Pass : Switch; UseUp = true; } else { S = (J < Num/2) ? Switch : Pass; UseDown = true; } T[J][Pets] = S; } // Reorder the working permutation according to the computed switch table // for the last step (i.e. Pets). for (ElemType J = 0, E = Size / 2; J != E; ++J) { ElemType PJ = P[J]; // Current values of P[J] ElemType PC = P[J+Size/2]; // and P[conj(J)] ElemType QJ = PJ; // New values of P[J] ElemType QC = PC; // and P[conj(J)] if (T[J][Pets] == Switch) QC = PJ; if (T[J+Size/2][Pets] == Switch) QJ = PC; P[J] = QJ; P[J+Size/2] = QC; } for (ElemType J = 0; J != Num; ++J) if (P[J] != Ignore && P[J] >= Num/2) P[J] -= Num/2; if (Step+1 < Log) { if (UseUp && !route(P, T, Size/2, Step+1)) return false; if (UseDown && !route(P+Size/2, T+Size/2, Size/2, Step+1)) return false; } return true; } bool BenesNetwork::route(ElemType *P, RowType *T, unsigned Size, unsigned Step) { Coloring G({P,Size}); const Coloring::MapType &M = G.colors(); if (M.empty()) return false; ElemType Num = Size; unsigned Pets = 2*Log-1 - Step; bool UseUp = false, UseDown = false; // Both assignments, i.e. Red->Up and Red->Down are valid, but they will // result in different controls. Let's pick the one where the first // control will be "Pass". ColorKind ColorUp = ColorKind::None; for (ElemType J = 0; J != Num; ++J) { ElemType I = P[J]; if (I == Ignore) continue; ColorKind C = M.at(I); if (C == ColorKind::None) continue; if (ColorUp == ColorKind::None) { ColorUp = (I < Num / 2) ? ColorKind::Red : ColorKind::Black; } unsigned CI = (I < Num/2) ? I+Num/2 : I-Num/2; if (C == ColorUp) { if (I < Num/2) T[I][Step] = Pass; else T[CI][Step] = Switch; T[J][Pets] = (J < Num/2) ? Pass : Switch; UseUp = true; } else { // Down if (I < Num/2) T[CI][Step] = Switch; else T[I][Step] = Pass; T[J][Pets] = (J < Num/2) ? Switch : Pass; UseDown = true; } } // Reorder the working permutation according to the computed switch table // for the last step (i.e. Pets). for (ElemType J = 0; J != Num/2; ++J) { ElemType PJ = P[J]; // Current values of P[J] ElemType PC = P[J+Num/2]; // and P[conj(J)] ElemType QJ = PJ; // New values of P[J] ElemType QC = PC; // and P[conj(J)] if (T[J][Pets] == Switch) QC = PJ; if (T[J+Num/2][Pets] == Switch) QJ = PC; P[J] = QJ; P[J+Num/2] = QC; } for (ElemType J = 0; J != Num; ++J) if (P[J] != Ignore && P[J] >= Num/2) P[J] -= Num/2; if (Step+1 < Log) { if (UseUp && !route(P, T, Size/2, Step+1)) return false; if (UseDown && !route(P+Size/2, T+Size/2, Size/2, Step+1)) return false; } return true; } // -------------------------------------------------------------------- // Support for building selection results (output instructions that are // parts of the final selection). namespace { struct OpRef { OpRef(SDValue V) : OpV(V) {} bool isValue() const { return OpV.getNode() != nullptr; } bool isValid() const { return isValue() || !(OpN & Invalid); } static OpRef res(int N) { return OpRef(Whole | (N & Index)); } static OpRef fail() { return OpRef(Invalid); } static OpRef lo(const OpRef &R) { assert(!R.isValue()); return OpRef(R.OpN & (Undef | Index | LoHalf)); } static OpRef hi(const OpRef &R) { assert(!R.isValue()); return OpRef(R.OpN & (Undef | Index | HiHalf)); } static OpRef undef(MVT Ty) { return OpRef(Undef | Ty.SimpleTy); } // Direct value. SDValue OpV = SDValue(); // Reference to the operand of the input node: // If the 31st bit is 1, it's undef, otherwise, bits 28..0 are the // operand index: // If bit 30 is set, it's the high half of the operand. // If bit 29 is set, it's the low half of the operand. unsigned OpN = 0; enum : unsigned { Invalid = 0x10000000, LoHalf = 0x20000000, HiHalf = 0x40000000, Whole = LoHalf | HiHalf, Undef = 0x80000000, Index = 0x0FFFFFFF, // Mask of the index value. IndexBits = 28, }; void print(raw_ostream &OS, const SelectionDAG &G) const; private: OpRef(unsigned N) : OpN(N) {} }; struct NodeTemplate { NodeTemplate() = default; unsigned Opc = 0; MVT Ty = MVT::Other; std::vector<OpRef> Ops; void print(raw_ostream &OS, const SelectionDAG &G) const; }; struct ResultStack { ResultStack(SDNode *Inp) : InpNode(Inp), InpTy(Inp->getValueType(0).getSimpleVT()) {} SDNode *InpNode; MVT InpTy; unsigned push(const NodeTemplate &Res) { List.push_back(Res); return List.size()-1; } unsigned push(unsigned Opc, MVT Ty, std::vector<OpRef> &&Ops) { NodeTemplate Res; Res.Opc = Opc; Res.Ty = Ty; Res.Ops = Ops; return push(Res); } bool empty() const { return List.empty(); } unsigned size() const { return List.size(); } unsigned top() const { return size()-1; } const NodeTemplate &operator[](unsigned I) const { return List[I]; } unsigned reset(unsigned NewTop) { List.resize(NewTop+1); return NewTop; } using BaseType = std::vector<NodeTemplate>; BaseType::iterator begin() { return List.begin(); } BaseType::iterator end() { return List.end(); } BaseType::const_iterator begin() const { return List.begin(); } BaseType::const_iterator end() const { return List.end(); } BaseType List; void print(raw_ostream &OS, const SelectionDAG &G) const; }; } // namespace void OpRef::print(raw_ostream &OS, const SelectionDAG &G) const { if (isValue()) { OpV.getNode()->print(OS, &G); return; } if (OpN & Invalid) { OS << "invalid"; return; } if (OpN & Undef) { OS << "undef"; return; } if ((OpN & Whole) != Whole) { assert((OpN & Whole) == LoHalf || (OpN & Whole) == HiHalf); if (OpN & LoHalf) OS << "lo "; else OS << "hi "; } OS << '#' << SignExtend32(OpN & Index, IndexBits); } void NodeTemplate::print(raw_ostream &OS, const SelectionDAG &G) const { const TargetInstrInfo &TII = *G.getSubtarget().getInstrInfo(); OS << format("%8s", EVT(Ty).getEVTString().c_str()) << " " << TII.getName(Opc); bool Comma = false; for (const auto &R : Ops) { if (Comma) OS << ','; Comma = true; OS << ' '; R.print(OS, G); } } void ResultStack::print(raw_ostream &OS, const SelectionDAG &G) const { OS << "Input node:\n"; #ifndef NDEBUG InpNode->dumpr(&G); #endif OS << "Result templates:\n"; for (unsigned I = 0, E = List.size(); I != E; ++I) { OS << '[' << I << "] "; List[I].print(OS, G); OS << '\n'; } } namespace { struct ShuffleMask { ShuffleMask(ArrayRef<int> M) : Mask(M) { for (unsigned I = 0, E = Mask.size(); I != E; ++I) { int M = Mask[I]; if (M == -1) continue; MinSrc = (MinSrc == -1) ? M : std::min(MinSrc, M); MaxSrc = (MaxSrc == -1) ? M : std::max(MaxSrc, M); } } ArrayRef<int> Mask; int MinSrc = -1, MaxSrc = -1; ShuffleMask lo() const { size_t H = Mask.size()/2; return ShuffleMask(Mask.take_front(H)); } ShuffleMask hi() const { size_t H = Mask.size()/2; return ShuffleMask(Mask.take_back(H)); } void print(raw_ostream &OS) const { OS << "MinSrc:" << MinSrc << ", MaxSrc:" << MaxSrc << " {"; for (int M : Mask) OS << ' ' << M; OS << " }"; } }; } // namespace // -------------------------------------------------------------------- // The HvxSelector class. static const HexagonTargetLowering &getHexagonLowering(SelectionDAG &G) { return static_cast<const HexagonTargetLowering&>(G.getTargetLoweringInfo()); } static const HexagonSubtarget &getHexagonSubtarget(SelectionDAG &G) { return static_cast<const HexagonSubtarget&>(G.getSubtarget()); } namespace llvm { struct HvxSelector { const HexagonTargetLowering &Lower; HexagonDAGToDAGISel &ISel; SelectionDAG &DAG; const HexagonSubtarget &HST; const unsigned HwLen; HvxSelector(HexagonDAGToDAGISel &HS, SelectionDAG &G) : Lower(getHexagonLowering(G)), ISel(HS), DAG(G), HST(getHexagonSubtarget(G)), HwLen(HST.getVectorLength()) {} MVT getSingleVT(MVT ElemTy) const { unsigned NumElems = HwLen / (ElemTy.getSizeInBits()/8); return MVT::getVectorVT(ElemTy, NumElems); } MVT getPairVT(MVT ElemTy) const { unsigned NumElems = (2*HwLen) / (ElemTy.getSizeInBits()/8); return MVT::getVectorVT(ElemTy, NumElems); } void selectShuffle(SDNode *N); void selectRor(SDNode *N); void selectVAlign(SDNode *N); private: void materialize(const ResultStack &Results); SDValue getVectorConstant(ArrayRef<uint8_t> Data, const SDLoc &dl); enum : unsigned { None, PackMux, }; OpRef concat(OpRef Va, OpRef Vb, ResultStack &Results); OpRef packs(ShuffleMask SM, OpRef Va, OpRef Vb, ResultStack &Results, MutableArrayRef<int> NewMask, unsigned Options = None); OpRef packp(ShuffleMask SM, OpRef Va, OpRef Vb, ResultStack &Results, MutableArrayRef<int> NewMask); OpRef vmuxs(ArrayRef<uint8_t> Bytes, OpRef Va, OpRef Vb, ResultStack &Results); OpRef vmuxp(ArrayRef<uint8_t> Bytes, OpRef Va, OpRef Vb, ResultStack &Results); OpRef shuffs1(ShuffleMask SM, OpRef Va, ResultStack &Results); OpRef shuffs2(ShuffleMask SM, OpRef Va, OpRef Vb, ResultStack &Results); OpRef shuffp1(ShuffleMask SM, OpRef Va, ResultStack &Results); OpRef shuffp2(ShuffleMask SM, OpRef Va, OpRef Vb, ResultStack &Results); OpRef butterfly(ShuffleMask SM, OpRef Va, ResultStack &Results); OpRef contracting(ShuffleMask SM, OpRef Va, OpRef Vb, ResultStack &Results); OpRef expanding(ShuffleMask SM, OpRef Va, ResultStack &Results); OpRef perfect(ShuffleMask SM, OpRef Va, ResultStack &Results); bool selectVectorConstants(SDNode *N); bool scalarizeShuffle(ArrayRef<int> Mask, const SDLoc &dl, MVT ResTy, SDValue Va, SDValue Vb, SDNode *N); }; } static void splitMask(ArrayRef<int> Mask, MutableArrayRef<int> MaskL, MutableArrayRef<int> MaskR) { unsigned VecLen = Mask.size(); assert(MaskL.size() == VecLen && MaskR.size() == VecLen); for (unsigned I = 0; I != VecLen; ++I) { int M = Mask[I]; if (M < 0) { MaskL[I] = MaskR[I] = -1; } else if (unsigned(M) < VecLen) { MaskL[I] = M; MaskR[I] = -1; } else { MaskL[I] = -1; MaskR[I] = M-VecLen; } } } static std::pair<int,unsigned> findStrip(ArrayRef<int> A, int Inc, unsigned MaxLen) { assert(A.size() > 0 && A.size() >= MaxLen); int F = A[0]; int E = F; for (unsigned I = 1; I != MaxLen; ++I) { if (A[I] - E != Inc) return { F, I }; E = A[I]; } return { F, MaxLen }; } static bool isUndef(ArrayRef<int> Mask) { for (int Idx : Mask) if (Idx != -1) return false; return true; } static bool isIdentity(ArrayRef<int> Mask) { for (int I = 0, E = Mask.size(); I != E; ++I) { int M = Mask[I]; if (M >= 0 && M != I) return false; } return true; } static bool isPermutation(ArrayRef<int> Mask) { // Check by adding all numbers only works if there is no overflow. assert(Mask.size() < 0x00007FFF && "Sanity failure"); int Sum = 0; for (int Idx : Mask) { if (Idx == -1) return false; Sum += Idx; } int N = Mask.size(); return 2*Sum == N*(N-1); } bool HvxSelector::selectVectorConstants(SDNode *N) { // Constant vectors are generated as loads from constant pools or as // splats of a constant value. Since they are generated during the // selection process, the main selection algorithm is not aware of them. // Select them directly here. SmallVector<SDNode*,4> Nodes; SetVector<SDNode*> WorkQ; // The one-use test for VSPLATW's operand may fail due to dead nodes // left over in the DAG. DAG.RemoveDeadNodes(); // The DAG can change (due to CSE) during selection, so cache all the // unselected nodes first to avoid traversing a mutating DAG. auto IsNodeToSelect = [] (SDNode *N) { if (N->isMachineOpcode()) return false; switch (N->getOpcode()) { case HexagonISD::VZERO: case HexagonISD::VSPLATW: return true; case ISD::LOAD: { SDValue Addr = cast<LoadSDNode>(N)->getBasePtr(); unsigned AddrOpc = Addr.getOpcode(); if (AddrOpc == HexagonISD::AT_PCREL || AddrOpc == HexagonISD::CP) if (Addr.getOperand(0).getOpcode() == ISD::TargetConstantPool) return true; } break; } // Make sure to select the operand of VSPLATW. bool IsSplatOp = N->hasOneUse() && N->use_begin()->getOpcode() == HexagonISD::VSPLATW; return IsSplatOp; }; WorkQ.insert(N); for (unsigned i = 0; i != WorkQ.size(); ++i) { SDNode *W = WorkQ[i]; if (IsNodeToSelect(W)) Nodes.push_back(W); for (unsigned j = 0, f = W->getNumOperands(); j != f; ++j) WorkQ.insert(W->getOperand(j).getNode()); } for (SDNode *L : Nodes) ISel.Select(L); return !Nodes.empty(); } void HvxSelector::materialize(const ResultStack &Results) { DEBUG_WITH_TYPE("isel", { dbgs() << "Materializing\n"; Results.print(dbgs(), DAG); }); if (Results.empty()) return; const SDLoc &dl(Results.InpNode); std::vector<SDValue> Output; for (unsigned I = 0, E = Results.size(); I != E; ++I) { const NodeTemplate &Node = Results[I]; std::vector<SDValue> Ops; for (const OpRef &R : Node.Ops) { assert(R.isValid()); if (R.isValue()) { Ops.push_back(R.OpV); continue; } if (R.OpN & OpRef::Undef) { MVT::SimpleValueType SVT = MVT::SimpleValueType(R.OpN & OpRef::Index); Ops.push_back(ISel.selectUndef(dl, MVT(SVT))); continue; } // R is an index of a result. unsigned Part = R.OpN & OpRef::Whole; int Idx = SignExtend32(R.OpN & OpRef::Index, OpRef::IndexBits); if (Idx < 0) Idx += I; assert(Idx >= 0 && unsigned(Idx) < Output.size()); SDValue Op = Output[Idx]; MVT OpTy = Op.getValueType().getSimpleVT(); if (Part != OpRef::Whole) { assert(Part == OpRef::LoHalf || Part == OpRef::HiHalf); MVT HalfTy = MVT::getVectorVT(OpTy.getVectorElementType(), OpTy.getVectorNumElements()/2); unsigned Sub = (Part == OpRef::LoHalf) ? Hexagon::vsub_lo : Hexagon::vsub_hi; Op = DAG.getTargetExtractSubreg(Sub, dl, HalfTy, Op); } Ops.push_back(Op); } // for (Node : Results) assert(Node.Ty != MVT::Other); SDNode *ResN = (Node.Opc == TargetOpcode::COPY) ? Ops.front().getNode() : DAG.getMachineNode(Node.Opc, dl, Node.Ty, Ops); Output.push_back(SDValue(ResN, 0)); } SDNode *OutN = Output.back().getNode(); SDNode *InpN = Results.InpNode; DEBUG_WITH_TYPE("isel", { dbgs() << "Generated node:\n"; OutN->dumpr(&DAG); }); ISel.ReplaceNode(InpN, OutN); selectVectorConstants(OutN); DAG.RemoveDeadNodes(); } OpRef HvxSelector::concat(OpRef Lo, OpRef Hi, ResultStack &Results) { DEBUG_WITH_TYPE("isel", {dbgs() << __func__ << '\n';}); const SDLoc &dl(Results.InpNode); Results.push(TargetOpcode::REG_SEQUENCE, getPairVT(MVT::i8), { DAG.getTargetConstant(Hexagon::HvxWRRegClassID, dl, MVT::i32), Lo, DAG.getTargetConstant(Hexagon::vsub_lo, dl, MVT::i32), Hi, DAG.getTargetConstant(Hexagon::vsub_hi, dl, MVT::i32), }); return OpRef::res(Results.top()); } // Va, Vb are single vectors, SM can be arbitrarily long. OpRef HvxSelector::packs(ShuffleMask SM, OpRef Va, OpRef Vb, ResultStack &Results, MutableArrayRef<int> NewMask, unsigned Options) { DEBUG_WITH_TYPE("isel", {dbgs() << __func__ << '\n';}); if (!Va.isValid() || !Vb.isValid()) return OpRef::fail(); int VecLen = SM.Mask.size(); MVT Ty = getSingleVT(MVT::i8); auto IsExtSubvector = [] (ShuffleMask M) { assert(M.MinSrc >= 0 && M.MaxSrc >= 0); for (int I = 0, E = M.Mask.size(); I != E; ++I) { if (M.Mask[I] >= 0 && M.Mask[I]-I != M.MinSrc) return false; } return true; }; if (SM.MaxSrc - SM.MinSrc < int(HwLen)) { if (SM.MinSrc == 0 || SM.MinSrc == int(HwLen) || !IsExtSubvector(SM)) { // If the mask picks elements from only one of the operands, return // that operand, and update the mask to use index 0 to refer to the // first element of that operand. // If the mask extracts a subvector, it will be handled below, so // skip it here. if (SM.MaxSrc < int(HwLen)) { memcpy(NewMask.data(), SM.Mask.data(), sizeof(int)*VecLen); return Va; } if (SM.MinSrc >= int(HwLen)) { for (int I = 0; I != VecLen; ++I) { int M = SM.Mask[I]; if (M != -1) M -= HwLen; NewMask[I] = M; } return Vb; } } int MinSrc = SM.MinSrc; if (SM.MaxSrc < int(HwLen)) { Vb = Va; } else if (SM.MinSrc > int(HwLen)) { Va = Vb; MinSrc = SM.MinSrc - HwLen; } const SDLoc &dl(Results.InpNode); if (isUInt<3>(MinSrc) || isUInt<3>(HwLen-MinSrc)) { bool IsRight = isUInt<3>(MinSrc); // Right align. SDValue S = DAG.getTargetConstant(IsRight ? MinSrc : HwLen-MinSrc, dl, MVT::i32); unsigned Opc = IsRight ? Hexagon::V6_valignbi : Hexagon::V6_vlalignbi; Results.push(Opc, Ty, {Vb, Va, S}); } else { SDValue S = DAG.getTargetConstant(MinSrc, dl, MVT::i32); Results.push(Hexagon::A2_tfrsi, MVT::i32, {S}); unsigned Top = Results.top(); Results.push(Hexagon::V6_valignb, Ty, {Vb, Va, OpRef::res(Top)}); } for (int I = 0; I != VecLen; ++I) { int M = SM.Mask[I]; if (M != -1) M -= SM.MinSrc; NewMask[I] = M; } return OpRef::res(Results.top()); } if (Options & PackMux) { // If elements picked from Va and Vb have all different (source) indexes // (relative to the start of the argument), do a mux, and update the mask. BitVector Picked(HwLen); SmallVector<uint8_t,128> MuxBytes(HwLen); bool CanMux = true; for (int I = 0; I != VecLen; ++I) { int M = SM.Mask[I]; if (M == -1) continue; if (M >= int(HwLen)) M -= HwLen; else MuxBytes[M] = 0xFF; if (Picked[M]) { CanMux = false; break; } NewMask[I] = M; } if (CanMux) return vmuxs(MuxBytes, Va, Vb, Results); } return OpRef::fail(); } OpRef HvxSelector::packp(ShuffleMask SM, OpRef Va, OpRef Vb, ResultStack &Results, MutableArrayRef<int> NewMask) { DEBUG_WITH_TYPE("isel", {dbgs() << __func__ << '\n';}); unsigned HalfMask = 0; unsigned LogHw = Log2_32(HwLen); for (int M : SM.Mask) { if (M == -1) continue; HalfMask |= (1u << (M >> LogHw)); } if (HalfMask == 0) return OpRef::undef(getPairVT(MVT::i8)); // If more than two halves are used, bail. // TODO: be more aggressive here? if (countPopulation(HalfMask) > 2) return OpRef::fail(); MVT HalfTy = getSingleVT(MVT::i8); OpRef Inp[2] = { Va, Vb }; OpRef Out[2] = { OpRef::undef(HalfTy), OpRef::undef(HalfTy) }; uint8_t HalfIdx[4] = { 0xFF, 0xFF, 0xFF, 0xFF }; unsigned Idx = 0; for (unsigned I = 0; I != 4; ++I) { if ((HalfMask & (1u << I)) == 0) continue; assert(Idx < 2); OpRef Op = Inp[I/2]; Out[Idx] = (I & 1) ? OpRef::hi(Op) : OpRef::lo(Op); HalfIdx[I] = Idx++; } int VecLen = SM.Mask.size(); for (int I = 0; I != VecLen; ++I) { int M = SM.Mask[I]; if (M >= 0) { uint8_t Idx = HalfIdx[M >> LogHw]; assert(Idx == 0 || Idx == 1); M = (M & (HwLen-1)) + HwLen*Idx; } NewMask[I] = M; } return concat(Out[0], Out[1], Results); } OpRef HvxSelector::vmuxs(ArrayRef<uint8_t> Bytes, OpRef Va, OpRef Vb, ResultStack &Results) { DEBUG_WITH_TYPE("isel", {dbgs() << __func__ << '\n';}); MVT ByteTy = getSingleVT(MVT::i8); MVT BoolTy = MVT::getVectorVT(MVT::i1, 8*HwLen); // XXX const SDLoc &dl(Results.InpNode); SDValue B = getVectorConstant(Bytes, dl); Results.push(Hexagon::V6_vd0, ByteTy, {}); Results.push(Hexagon::V6_veqb, BoolTy, {OpRef(B), OpRef::res(-1)}); Results.push(Hexagon::V6_vmux, ByteTy, {OpRef::res(-1), Vb, Va}); return OpRef::res(Results.top()); } OpRef HvxSelector::vmuxp(ArrayRef<uint8_t> Bytes, OpRef Va, OpRef Vb, ResultStack &Results) { DEBUG_WITH_TYPE("isel", {dbgs() << __func__ << '\n';}); size_t S = Bytes.size() / 2; OpRef L = vmuxs(Bytes.take_front(S), OpRef::lo(Va), OpRef::lo(Vb), Results); OpRef H = vmuxs(Bytes.drop_front(S), OpRef::hi(Va), OpRef::hi(Vb), Results); return concat(L, H, Results); } OpRef HvxSelector::shuffs1(ShuffleMask SM, OpRef Va, ResultStack &Results) { DEBUG_WITH_TYPE("isel", {dbgs() << __func__ << '\n';}); unsigned VecLen = SM.Mask.size(); assert(HwLen == VecLen); (void)VecLen; assert(all_of(SM.Mask, [this](int M) { return M == -1 || M < int(HwLen); })); if (isIdentity(SM.Mask)) return Va; if (isUndef(SM.Mask)) return OpRef::undef(getSingleVT(MVT::i8)); OpRef P = perfect(SM, Va, Results); if (P.isValid()) return P; return butterfly(SM, Va, Results); } OpRef HvxSelector::shuffs2(ShuffleMask SM, OpRef Va, OpRef Vb, ResultStack &Results) { DEBUG_WITH_TYPE("isel", {dbgs() << __func__ << '\n';}); if (isUndef(SM.Mask)) return OpRef::undef(getSingleVT(MVT::i8)); OpRef C = contracting(SM, Va, Vb, Results); if (C.isValid()) return C; int VecLen = SM.Mask.size(); SmallVector<int,128> NewMask(VecLen); OpRef P = packs(SM, Va, Vb, Results, NewMask); if (P.isValid()) return shuffs1(ShuffleMask(NewMask), P, Results); SmallVector<int,128> MaskL(VecLen), MaskR(VecLen); splitMask(SM.Mask, MaskL, MaskR); OpRef L = shuffs1(ShuffleMask(MaskL), Va, Results); OpRef R = shuffs1(ShuffleMask(MaskR), Vb, Results); if (!L.isValid() || !R.isValid()) return OpRef::fail(); SmallVector<uint8_t,128> Bytes(VecLen); for (int I = 0; I != VecLen; ++I) { if (MaskL[I] != -1) Bytes[I] = 0xFF; } return vmuxs(Bytes, L, R, Results); } OpRef HvxSelector::shuffp1(ShuffleMask SM, OpRef Va, ResultStack &Results) { DEBUG_WITH_TYPE("isel", {dbgs() << __func__ << '\n';}); int VecLen = SM.Mask.size(); if (isIdentity(SM.Mask)) return Va; if (isUndef(SM.Mask)) return OpRef::undef(getPairVT(MVT::i8)); SmallVector<int,128> PackedMask(VecLen); OpRef P = packs(SM, OpRef::lo(Va), OpRef::hi(Va), Results, PackedMask); if (P.isValid()) { ShuffleMask PM(PackedMask); OpRef E = expanding(PM, P, Results); if (E.isValid()) return E; OpRef L = shuffs1(PM.lo(), P, Results); OpRef H = shuffs1(PM.hi(), P, Results); if (L.isValid() && H.isValid()) return concat(L, H, Results); } OpRef R = perfect(SM, Va, Results); if (R.isValid()) return R; // TODO commute the mask and try the opposite order of the halves. OpRef L = shuffs2(SM.lo(), OpRef::lo(Va), OpRef::hi(Va), Results); OpRef H = shuffs2(SM.hi(), OpRef::lo(Va), OpRef::hi(Va), Results); if (L.isValid() && H.isValid()) return concat(L, H, Results); return OpRef::fail(); } OpRef HvxSelector::shuffp2(ShuffleMask SM, OpRef Va, OpRef Vb, ResultStack &Results) { DEBUG_WITH_TYPE("isel", {dbgs() << __func__ << '\n';}); if (isUndef(SM.Mask)) return OpRef::undef(getPairVT(MVT::i8)); int VecLen = SM.Mask.size(); SmallVector<int,256> PackedMask(VecLen); OpRef P = packp(SM, Va, Vb, Results, PackedMask); if (P.isValid()) return shuffp1(ShuffleMask(PackedMask), P, Results); SmallVector<int,256> MaskL(VecLen), MaskR(VecLen); splitMask(SM.Mask, MaskL, MaskR); OpRef L = shuffp1(ShuffleMask(MaskL), Va, Results); OpRef R = shuffp1(ShuffleMask(MaskR), Vb, Results); if (!L.isValid() || !R.isValid()) return OpRef::fail(); // Mux the results. SmallVector<uint8_t,256> Bytes(VecLen); for (int I = 0; I != VecLen; ++I) { if (MaskL[I] != -1) Bytes[I] = 0xFF; } return vmuxp(Bytes, L, R, Results); } bool HvxSelector::scalarizeShuffle(ArrayRef<int> Mask, const SDLoc &dl, MVT ResTy, SDValue Va, SDValue Vb, SDNode *N) { DEBUG_WITH_TYPE("isel", {dbgs() << __func__ << '\n';}); MVT ElemTy = ResTy.getVectorElementType(); assert(ElemTy == MVT::i8); unsigned VecLen = Mask.size(); bool HavePairs = (2*HwLen == VecLen); MVT SingleTy = getSingleVT(MVT::i8); SmallVector<SDValue,128> Ops; for (int I : Mask) { if (I < 0) { Ops.push_back(ISel.selectUndef(dl, ElemTy)); continue; } SDValue Vec; unsigned M = I; if (M < VecLen) { Vec = Va; } else { Vec = Vb; M -= VecLen; } if (HavePairs) { if (M < HwLen) { Vec = DAG.getTargetExtractSubreg(Hexagon::vsub_lo, dl, SingleTy, Vec); } else { Vec = DAG.getTargetExtractSubreg(Hexagon::vsub_hi, dl, SingleTy, Vec); M -= HwLen; } } SDValue Idx = DAG.getConstant(M, dl, MVT::i32); SDValue Ex = DAG.getNode(ISD::EXTRACT_VECTOR_ELT, dl, ElemTy, {Vec, Idx}); SDValue L = Lower.LowerOperation(Ex, DAG); assert(L.getNode()); Ops.push_back(L); } SDValue LV; if (2*HwLen == VecLen) { SDValue B0 = DAG.getBuildVector(SingleTy, dl, {Ops.data(), HwLen}); SDValue L0 = Lower.LowerOperation(B0, DAG); SDValue B1 = DAG.getBuildVector(SingleTy, dl, {Ops.data()+HwLen, HwLen}); SDValue L1 = Lower.LowerOperation(B1, DAG); // XXX CONCAT_VECTORS is legal for HVX vectors. Legalizing (lowering) // functions may expect to be called only for illegal operations, so // make sure that they are not called for legal ones. Develop a better // mechanism for dealing with this. LV = DAG.getNode(ISD::CONCAT_VECTORS, dl, ResTy, {L0, L1}); } else { SDValue BV = DAG.getBuildVector(ResTy, dl, Ops); LV = Lower.LowerOperation(BV, DAG); } assert(!N->use_empty()); ISel.ReplaceNode(N, LV.getNode()); DAG.RemoveDeadNodes(); std::deque<SDNode*> SubNodes; SubNodes.push_back(LV.getNode()); for (unsigned I = 0; I != SubNodes.size(); ++I) { for (SDValue Op : SubNodes[I]->ops()) SubNodes.push_back(Op.getNode()); } while (!SubNodes.empty()) { SDNode *S = SubNodes.front(); SubNodes.pop_front(); if (S->use_empty()) continue; // This isn't great, but users need to be selected before any nodes that // they use. (The reason is to match larger patterns, and avoid nodes that // cannot be matched on their own, e.g. ValueType, TokenFactor, etc.). bool PendingUser = llvm::any_of(S->uses(), [&SubNodes](const SDNode *U) { return llvm::any_of(SubNodes, [U](const SDNode *T) { return T == U; }); }); if (PendingUser) SubNodes.push_back(S); else ISel.Select(S); } DAG.RemoveDeadNodes(); return true; } OpRef HvxSelector::contracting(ShuffleMask SM, OpRef Va, OpRef Vb, ResultStack &Results) { DEBUG_WITH_TYPE("isel", {dbgs() << __func__ << '\n';}); if (!Va.isValid() || !Vb.isValid()) return OpRef::fail(); // Contracting shuffles, i.e. instructions that always discard some bytes // from the operand vectors. // // V6_vshuff{e,o}b // V6_vdealb4w // V6_vpack{e,o}{b,h} int VecLen = SM.Mask.size(); std::pair<int,unsigned> Strip = findStrip(SM.Mask, 1, VecLen); MVT ResTy = getSingleVT(MVT::i8); // The following shuffles only work for bytes and halfwords. This requires // the strip length to be 1 or 2. if (Strip.second != 1 && Strip.second != 2) return OpRef::fail(); // The patterns for the shuffles, in terms of the starting offsets of the // consecutive strips (L = length of the strip, N = VecLen): // // vpacke: 0, 2L, 4L ... N+0, N+2L, N+4L ... L = 1 or 2 // vpacko: L, 3L, 5L ... N+L, N+3L, N+5L ... L = 1 or 2 // // vshuffe: 0, N+0, 2L, N+2L, 4L ... L = 1 or 2 // vshuffo: L, N+L, 3L, N+3L, 5L ... L = 1 or 2 // // vdealb4w: 0, 4, 8 ... 2, 6, 10 ... N+0, N+4, N+8 ... N+2, N+6, N+10 ... // The value of the element in the mask following the strip will decide // what kind of a shuffle this can be. int NextInMask = SM.Mask[Strip.second]; // Check if NextInMask could be 2L, 3L or 4, i.e. if it could be a mask // for vpack or vdealb4w. VecLen > 4, so NextInMask for vdealb4w would // satisfy this. if (NextInMask < VecLen) { // vpack{e,o} or vdealb4w if (Strip.first == 0 && Strip.second == 1 && NextInMask == 4) { int N = VecLen; // Check if this is vdealb4w (L=1). for (int I = 0; I != N/4; ++I) if (SM.Mask[I] != 4*I) return OpRef::fail(); for (int I = 0; I != N/4; ++I) if (SM.Mask[I+N/4] != 2 + 4*I) return OpRef::fail(); for (int I = 0; I != N/4; ++I) if (SM.Mask[I+N/2] != N + 4*I) return OpRef::fail(); for (int I = 0; I != N/4; ++I) if (SM.Mask[I+3*N/4] != N+2 + 4*I) return OpRef::fail(); // Matched mask for vdealb4w. Results.push(Hexagon::V6_vdealb4w, ResTy, {Vb, Va}); return OpRef::res(Results.top()); } // Check if this is vpack{e,o}. int N = VecLen; int L = Strip.second; // Check if the first strip starts at 0 or at L. if (Strip.first != 0 && Strip.first != L) return OpRef::fail(); // Examine the rest of the mask. for (int I = L; I < N; I += L) { auto S = findStrip(SM.Mask.drop_front(I), 1, N-I); // Check whether the mask element at the beginning of each strip // increases by 2L each time. if (S.first - Strip.first != 2*I) return OpRef::fail(); // Check whether each strip is of the same length. if (S.second != unsigned(L)) return OpRef::fail(); } // Strip.first == 0 => vpacke // Strip.first == L => vpacko assert(Strip.first == 0 || Strip.first == L); using namespace Hexagon; NodeTemplate Res; Res.Opc = Strip.second == 1 // Number of bytes. ? (Strip.first == 0 ? V6_vpackeb : V6_vpackob) : (Strip.first == 0 ? V6_vpackeh : V6_vpackoh); Res.Ty = ResTy; Res.Ops = { Vb, Va }; Results.push(Res); return OpRef::res(Results.top()); } // Check if this is vshuff{e,o}. int N = VecLen; int L = Strip.second; std::pair<int,unsigned> PrevS = Strip; bool Flip = false; for (int I = L; I < N; I += L) { auto S = findStrip(SM.Mask.drop_front(I), 1, N-I); if (S.second != PrevS.second) return OpRef::fail(); int Diff = Flip ? PrevS.first - S.first + 2*L : S.first - PrevS.first; if (Diff != N) return OpRef::fail(); Flip ^= true; PrevS = S; } // Strip.first == 0 => vshuffe // Strip.first == L => vshuffo assert(Strip.first == 0 || Strip.first == L); using namespace Hexagon; NodeTemplate Res; Res.Opc = Strip.second == 1 // Number of bytes. ? (Strip.first == 0 ? V6_vshuffeb : V6_vshuffob) : (Strip.first == 0 ? V6_vshufeh : V6_vshufoh); Res.Ty = ResTy; Res.Ops = { Vb, Va }; Results.push(Res); return OpRef::res(Results.top()); } OpRef HvxSelector::expanding(ShuffleMask SM, OpRef Va, ResultStack &Results) { DEBUG_WITH_TYPE("isel", {dbgs() << __func__ << '\n';}); // Expanding shuffles (using all elements and inserting into larger vector): // // V6_vunpacku{b,h} [*] // // [*] Only if the upper elements (filled with 0s) are "don't care" in Mask. // // Note: V6_vunpacko{b,h} are or-ing the high byte/half in the result, so // they are not shuffles. // // The argument is a single vector. int VecLen = SM.Mask.size(); assert(2*HwLen == unsigned(VecLen) && "Expecting vector-pair type"); std::pair<int,unsigned> Strip = findStrip(SM.Mask, 1, VecLen); // The patterns for the unpacks, in terms of the starting offsets of the // consecutive strips (L = length of the strip, N = VecLen): // // vunpacku: 0, -1, L, -1, 2L, -1 ... if (Strip.first != 0) return OpRef::fail(); // The vunpackus only handle byte and half-word. if (Strip.second != 1 && Strip.second != 2) return OpRef::fail(); int N = VecLen; int L = Strip.second; // First, check the non-ignored strips. for (int I = 2*L; I < 2*N; I += 2*L) { auto S = findStrip(SM.Mask.drop_front(I), 1, N-I); if (S.second != unsigned(L)) return OpRef::fail(); if (2*S.first != I) return OpRef::fail(); } // Check the -1s. for (int I = L; I < 2*N; I += 2*L) { auto S = findStrip(SM.Mask.drop_front(I), 0, N-I); if (S.first != -1 || S.second != unsigned(L)) return OpRef::fail(); } unsigned Opc = Strip.second == 1 ? Hexagon::V6_vunpackub : Hexagon::V6_vunpackuh; Results.push(Opc, getPairVT(MVT::i8), {Va}); return OpRef::res(Results.top()); } OpRef HvxSelector::perfect(ShuffleMask SM, OpRef Va, ResultStack &Results) { DEBUG_WITH_TYPE("isel", {dbgs() << __func__ << '\n';}); // V6_vdeal{b,h} // V6_vshuff{b,h} // V6_vshufoe{b,h} those are quivalent to vshuffvdd(..,{1,2}) // V6_vshuffvdd (V6_vshuff) // V6_dealvdd (V6_vdeal) int VecLen = SM.Mask.size(); assert(isPowerOf2_32(VecLen) && Log2_32(VecLen) <= 8); unsigned LogLen = Log2_32(VecLen); unsigned HwLog = Log2_32(HwLen); // The result length must be the same as the length of a single vector, // or a vector pair. assert(LogLen == HwLog || LogLen == HwLog+1); bool Extend = (LogLen == HwLog); if (!isPermutation(SM.Mask)) return OpRef::fail(); SmallVector<unsigned,8> Perm(LogLen); // Check if this could be a perfect shuffle, or a combination of perfect // shuffles. // // Consider this permutation (using hex digits to make the ASCII diagrams // easier to read): // { 0, 8, 1, 9, 2, A, 3, B, 4, C, 5, D, 6, E, 7, F }. // This is a "deal" operation: divide the input into two halves, and // create the output by picking elements by alternating between these two // halves: // 0 1 2 3 4 5 6 7 --> 0 8 1 9 2 A 3 B 4 C 5 D 6 E 7 F [*] // 8 9 A B C D E F // // Aside from a few special explicit cases (V6_vdealb, etc.), HVX provides // a somwehat different mechanism that could be used to perform shuffle/ // deal operations: a 2x2 transpose. // Consider the halves of inputs again, they can be interpreted as a 2x8 // matrix. A 2x8 matrix can be looked at four 2x2 matrices concatenated // together. Now, when considering 2 elements at a time, it will be a 2x4 // matrix (with elements 01, 23, 45, etc.), or two 2x2 matrices: // 01 23 45 67 // 89 AB CD EF // With groups of 4, this will become a single 2x2 matrix, and so on. // // The 2x2 transpose instruction works by transposing each of the 2x2 // matrices (or "sub-matrices"), given a specific group size. For example, // if the group size is 1 (i.e. each element is its own group), there // will be four transposes of the four 2x2 matrices that form the 2x8. // For example, with the inputs as above, the result will be: // 0 8 2 A 4 C 6 E // 1 9 3 B 5 D 7 F // Now, this result can be tranposed again, but with the group size of 2: // 08 19 4C 5D // 2A 3B 6E 7F // If we then transpose that result, but with the group size of 4, we get: // 0819 2A3B // 4C5D 6E7F // If we concatenate these two rows, it will be // 0 8 1 9 2 A 3 B 4 C 5 D 6 E 7 F // which is the same as the "deal" [*] above. // // In general, a "deal" of individual elements is a series of 2x2 transposes, // with changing group size. HVX has two instructions: // Vdd = V6_vdealvdd Vu, Vv, Rt // Vdd = V6_shufvdd Vu, Vv, Rt // that perform exactly that. The register Rt controls which transposes are // going to happen: a bit at position n (counting from 0) indicates that a // transpose with a group size of 2^n will take place. If multiple bits are // set, multiple transposes will happen: vdealvdd will perform them starting // with the largest group size, vshuffvdd will do them in the reverse order. // // The main observation is that each 2x2 transpose corresponds to swapping // columns of bits in the binary representation of the values. // // The numbers {3,2,1,0} and the log2 of the number of contiguous 1 bits // in a given column. The * denote the columns that will be swapped. // The transpose with the group size 2^n corresponds to swapping columns // 3 (the highest log) and log2(n): // // 3 2 1 0 0 2 1 3 0 2 3 1 // * * * * * * // 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 // 1 0 0 0 1 8 1 0 0 0 8 1 0 0 0 8 1 0 0 0 // 2 0 0 1 0 2 0 0 1 0 1 0 0 0 1 1 0 0 0 1 // 3 0 0 1 1 A 1 0 1 0 9 1 0 0 1 9 1 0 0 1 // 4 0 1 0 0 4 0 1 0 0 4 0 1 0 0 2 0 0 1 0 // 5 0 1 0 1 C 1 1 0 0 C 1 1 0 0 A 1 0 1 0 // 6 0 1 1 0 6 0 1 1 0 5 0 1 0 1 3 0 0 1 1 // 7 0 1 1 1 E 1 1 1 0 D 1 1 0 1 B 1 0 1 1 // 8 1 0 0 0 1 0 0 0 1 2 0 0 1 0 4 0 1 0 0 // 9 1 0 0 1 9 1 0 0 1 A 1 0 1 0 C 1 1 0 0 // A 1 0 1 0 3 0 0 1 1 3 0 0 1 1 5 0 1 0 1 // B 1 0 1 1 B 1 0 1 1 B 1 0 1 1 D 1 1 0 1 // C 1 1 0 0 5 0 1 0 1 6 0 1 1 0 6 0 1 1 0 // D 1 1 0 1 D 1 1 0 1 E 1 1 1 0 E 1 1 1 0 // E 1 1 1 0 7 0 1 1 1 7 0 1 1 1 7 0 1 1 1 // F 1 1 1 1 F 1 1 1 1 F 1 1 1 1 F 1 1 1 1 auto XorPow2 = [] (ArrayRef<int> Mask, unsigned Num) { unsigned X = Mask[0] ^ Mask[Num/2]; // Check that the first half has the X's bits clear. if ((Mask[0] & X) != 0) return 0u; for (unsigned I = 1; I != Num/2; ++I) { if (unsigned(Mask[I] ^ Mask[I+Num/2]) != X) return 0u; if ((Mask[I] & X) != 0) return 0u; } return X; }; // Create a vector of log2's for each column: Perm[i] corresponds to // the i-th bit (lsb is 0). assert(VecLen > 2); for (unsigned I = VecLen; I >= 2; I >>= 1) { // Examine the initial segment of Mask of size I. unsigned X = XorPow2(SM.Mask, I); if (!isPowerOf2_32(X)) return OpRef::fail(); // Check the other segments of Mask. for (int J = I; J < VecLen; J += I) { if (XorPow2(SM.Mask.slice(J, I), I) != X) return OpRef::fail(); } Perm[Log2_32(X)] = Log2_32(I)-1; } // Once we have Perm, represent it as cycles. Denote the maximum log2 // (equal to log2(VecLen)-1) as M. The cycle containing M can then be // written as (M a1 a2 a3 ... an). That cycle can be broken up into // simple swaps as (M a1)(M a2)(M a3)...(M an), with the composition // order being from left to right. Any (contiguous) segment where the // values ai, ai+1...aj are either all increasing or all decreasing, // can be implemented via a single vshuffvdd/vdealvdd respectively. // // If there is a cycle (a1 a2 ... an) that does not involve M, it can // be written as (M an)(a1 a2 ... an)(M a1). The first two cycles can // then be folded to get (M a1 a2 ... an)(M a1), and the above procedure // can be used to generate a sequence of vshuffvdd/vdealvdd. // // Example: // Assume M = 4 and consider a permutation (0 1)(2 3). It can be written // as (4 0 1)(4 0) composed with (4 2 3)(4 2), or simply // (4 0 1)(4 0)(4 2 3)(4 2). // It can then be expanded into swaps as // (4 0)(4 1)(4 0)(4 2)(4 3)(4 2), // and broken up into "increasing" segments as // [(4 0)(4 1)] [(4 0)(4 2)(4 3)] [(4 2)]. // This is equivalent to // (4 0 1)(4 0 2 3)(4 2), // which can be implemented as 3 vshufvdd instructions. using CycleType = SmallVector<unsigned,8>; std::set<CycleType> Cycles; std::set<unsigned> All; for (unsigned I : Perm) All.insert(I); // If the cycle contains LogLen-1, move it to the front of the cycle. // Otherwise, return the cycle unchanged. auto canonicalize = [LogLen](const CycleType &C) -> CycleType { unsigned LogPos, N = C.size(); for (LogPos = 0; LogPos != N; ++LogPos) if (C[LogPos] == LogLen-1) break; if (LogPos == N) return C; CycleType NewC(C.begin()+LogPos, C.end()); NewC.append(C.begin(), C.begin()+LogPos); return NewC; }; auto pfs = [](const std::set<CycleType> &Cs, unsigned Len) { // Ordering: shuff: 5 0 1 2 3 4, deal: 5 4 3 2 1 0 (for Log=6), // for bytes zero is included, for halfwords is not. if (Cs.size() != 1) return 0u; const CycleType &C = *Cs.begin(); if (C[0] != Len-1) return 0u; int D = Len - C.size(); if (D != 0 && D != 1) return 0u; bool IsDeal = true, IsShuff = true; for (unsigned I = 1; I != Len-D; ++I) { if (C[I] != Len-1-I) IsDeal = false; if (C[I] != I-(1-D)) // I-1, I IsShuff = false; } // At most one, IsDeal or IsShuff, can be non-zero. assert(!(IsDeal || IsShuff) || IsDeal != IsShuff); static unsigned Deals[] = { Hexagon::V6_vdealb, Hexagon::V6_vdealh }; static unsigned Shufs[] = { Hexagon::V6_vshuffb, Hexagon::V6_vshuffh }; return IsDeal ? Deals[D] : (IsShuff ? Shufs[D] : 0); }; while (!All.empty()) { unsigned A = *All.begin(); All.erase(A); CycleType C; C.push_back(A); for (unsigned B = Perm[A]; B != A; B = Perm[B]) { C.push_back(B); All.erase(B); } if (C.size() <= 1) continue; Cycles.insert(canonicalize(C)); } MVT SingleTy = getSingleVT(MVT::i8); MVT PairTy = getPairVT(MVT::i8); // Recognize patterns for V6_vdeal{b,h} and V6_vshuff{b,h}. if (unsigned(VecLen) == HwLen) { if (unsigned SingleOpc = pfs(Cycles, LogLen)) { Results.push(SingleOpc, SingleTy, {Va}); return OpRef::res(Results.top()); } } SmallVector<unsigned,8> SwapElems; if (HwLen == unsigned(VecLen)) SwapElems.push_back(LogLen-1); for (const CycleType &C : Cycles) { unsigned First = (C[0] == LogLen-1) ? 1 : 0; SwapElems.append(C.begin()+First, C.end()); if (First == 0) SwapElems.push_back(C[0]); } const SDLoc &dl(Results.InpNode); OpRef Arg = !Extend ? Va : concat(Va, OpRef::undef(SingleTy), Results); for (unsigned I = 0, E = SwapElems.size(); I != E; ) { bool IsInc = I == E-1 || SwapElems[I] < SwapElems[I+1]; unsigned S = (1u << SwapElems[I]); if (I < E-1) { while (++I < E-1 && IsInc == (SwapElems[I] < SwapElems[I+1])) S |= 1u << SwapElems[I]; // The above loop will not add a bit for the final SwapElems[I+1], // so add it here. S |= 1u << SwapElems[I]; } ++I; NodeTemplate Res; Results.push(Hexagon::A2_tfrsi, MVT::i32, { DAG.getTargetConstant(S, dl, MVT::i32) }); Res.Opc = IsInc ? Hexagon::V6_vshuffvdd : Hexagon::V6_vdealvdd; Res.Ty = PairTy; Res.Ops = { OpRef::hi(Arg), OpRef::lo(Arg), OpRef::res(-1) }; Results.push(Res); Arg = OpRef::res(Results.top()); } return !Extend ? Arg : OpRef::lo(Arg); } OpRef HvxSelector::butterfly(ShuffleMask SM, OpRef Va, ResultStack &Results) { DEBUG_WITH_TYPE("isel", {dbgs() << __func__ << '\n';}); // Butterfly shuffles. // // V6_vdelta // V6_vrdelta // V6_vror // The assumption here is that all elements picked by Mask are in the // first operand to the vector_shuffle. This assumption is enforced // by the caller. MVT ResTy = getSingleVT(MVT::i8); PermNetwork::Controls FC, RC; const SDLoc &dl(Results.InpNode); int VecLen = SM.Mask.size(); for (int M : SM.Mask) { if (M != -1 && M >= VecLen) return OpRef::fail(); } // Try the deltas/benes for both single vectors and vector pairs. ForwardDeltaNetwork FN(SM.Mask); if (FN.run(FC)) { SDValue Ctl = getVectorConstant(FC, dl); Results.push(Hexagon::V6_vdelta, ResTy, {Va, OpRef(Ctl)}); return OpRef::res(Results.top()); } // Try reverse delta. ReverseDeltaNetwork RN(SM.Mask); if (RN.run(RC)) { SDValue Ctl = getVectorConstant(RC, dl); Results.push(Hexagon::V6_vrdelta, ResTy, {Va, OpRef(Ctl)}); return OpRef::res(Results.top()); } // Do Benes. BenesNetwork BN(SM.Mask); if (BN.run(FC, RC)) { SDValue CtlF = getVectorConstant(FC, dl); SDValue CtlR = getVectorConstant(RC, dl); Results.push(Hexagon::V6_vdelta, ResTy, {Va, OpRef(CtlF)}); Results.push(Hexagon::V6_vrdelta, ResTy, {OpRef::res(-1), OpRef(CtlR)}); return OpRef::res(Results.top()); } return OpRef::fail(); } SDValue HvxSelector::getVectorConstant(ArrayRef<uint8_t> Data, const SDLoc &dl) { SmallVector<SDValue, 128> Elems; for (uint8_t C : Data) Elems.push_back(DAG.getConstant(C, dl, MVT::i8)); MVT VecTy = MVT::getVectorVT(MVT::i8, Data.size()); SDValue BV = DAG.getBuildVector(VecTy, dl, Elems); SDValue LV = Lower.LowerOperation(BV, DAG); DAG.RemoveDeadNode(BV.getNode()); return LV; } void HvxSelector::selectShuffle(SDNode *N) { DEBUG_WITH_TYPE("isel", { dbgs() << "Starting " << __func__ << " on node:\n"; N->dump(&DAG); }); MVT ResTy = N->getValueType(0).getSimpleVT(); // Assume that vector shuffles operate on vectors of bytes. assert(ResTy.isVector() && ResTy.getVectorElementType() == MVT::i8); auto *SN = cast<ShuffleVectorSDNode>(N); std::vector<int> Mask(SN->getMask().begin(), SN->getMask().end()); // This shouldn't really be necessary. Is it? for (int &Idx : Mask) if (Idx != -1 && Idx < 0) Idx = -1; unsigned VecLen = Mask.size(); bool HavePairs = (2*HwLen == VecLen); assert(ResTy.getSizeInBits() / 8 == VecLen); // Vd = vector_shuffle Va, Vb, Mask // bool UseLeft = false, UseRight = false; for (unsigned I = 0; I != VecLen; ++I) { if (Mask[I] == -1) continue; unsigned Idx = Mask[I]; assert(Idx < 2*VecLen); if (Idx < VecLen) UseLeft = true; else UseRight = true; } DEBUG_WITH_TYPE("isel", { dbgs() << "VecLen=" << VecLen << " HwLen=" << HwLen << " UseLeft=" << UseLeft << " UseRight=" << UseRight << " HavePairs=" << HavePairs << '\n'; }); // If the mask is all -1's, generate "undef". if (!UseLeft && !UseRight) { ISel.ReplaceNode(N, ISel.selectUndef(SDLoc(SN), ResTy).getNode()); return; } SDValue Vec0 = N->getOperand(0); SDValue Vec1 = N->getOperand(1); ResultStack Results(SN); Results.push(TargetOpcode::COPY, ResTy, {Vec0}); Results.push(TargetOpcode::COPY, ResTy, {Vec1}); OpRef Va = OpRef::res(Results.top()-1); OpRef Vb = OpRef::res(Results.top()); OpRef Res = !HavePairs ? shuffs2(ShuffleMask(Mask), Va, Vb, Results) : shuffp2(ShuffleMask(Mask), Va, Vb, Results); bool Done = Res.isValid(); if (Done) { // Make sure that Res is on the stack before materializing. Results.push(TargetOpcode::COPY, ResTy, {Res}); materialize(Results); } else { Done = scalarizeShuffle(Mask, SDLoc(N), ResTy, Vec0, Vec1, N); } if (!Done) { #ifndef NDEBUG dbgs() << "Unhandled shuffle:\n"; SN->dumpr(&DAG); #endif llvm_unreachable("Failed to select vector shuffle"); } } void HvxSelector::selectRor(SDNode *N) { // If this is a rotation by less than 8, use V6_valignbi. MVT Ty = N->getValueType(0).getSimpleVT(); const SDLoc &dl(N); SDValue VecV = N->getOperand(0); SDValue RotV = N->getOperand(1); SDNode *NewN = nullptr; if (auto *CN = dyn_cast<ConstantSDNode>(RotV.getNode())) { unsigned S = CN->getZExtValue() % HST.getVectorLength(); if (S == 0) { NewN = VecV.getNode(); } else if (isUInt<3>(S)) { SDValue C = DAG.getTargetConstant(S, dl, MVT::i32); NewN = DAG.getMachineNode(Hexagon::V6_valignbi, dl, Ty, {VecV, VecV, C}); } } if (!NewN) NewN = DAG.getMachineNode(Hexagon::V6_vror, dl, Ty, {VecV, RotV}); ISel.ReplaceNode(N, NewN); } void HvxSelector::selectVAlign(SDNode *N) { SDValue Vv = N->getOperand(0); SDValue Vu = N->getOperand(1); SDValue Rt = N->getOperand(2); SDNode *NewN = DAG.getMachineNode(Hexagon::V6_valignb, SDLoc(N), N->getValueType(0), {Vv, Vu, Rt}); ISel.ReplaceNode(N, NewN); DAG.RemoveDeadNode(N); } void HexagonDAGToDAGISel::SelectHvxShuffle(SDNode *N) { HvxSelector(*this, *CurDAG).selectShuffle(N); } void HexagonDAGToDAGISel::SelectHvxRor(SDNode *N) { HvxSelector(*this, *CurDAG).selectRor(N); } void HexagonDAGToDAGISel::SelectHvxVAlign(SDNode *N) { HvxSelector(*this, *CurDAG).selectVAlign(N); } void HexagonDAGToDAGISel::SelectV65GatherPred(SDNode *N) { if (!HST->usePackets()) { report_fatal_error("Support for gather requires packets, " "which are disabled"); } const SDLoc &dl(N); SDValue Chain = N->getOperand(0); SDValue Address = N->getOperand(2); SDValue Predicate = N->getOperand(3); SDValue Base = N->getOperand(4); SDValue Modifier = N->getOperand(5); SDValue Offset = N->getOperand(6); unsigned Opcode; unsigned IntNo = cast<ConstantSDNode>(N->getOperand(1))->getZExtValue(); switch (IntNo) { default: llvm_unreachable("Unexpected HVX gather intrinsic."); case Intrinsic::hexagon_V6_vgathermhq: case Intrinsic::hexagon_V6_vgathermhq_128B: Opcode = Hexagon::V6_vgathermhq_pseudo; break; case Intrinsic::hexagon_V6_vgathermwq: case Intrinsic::hexagon_V6_vgathermwq_128B: Opcode = Hexagon::V6_vgathermwq_pseudo; break; case Intrinsic::hexagon_V6_vgathermhwq: case Intrinsic::hexagon_V6_vgathermhwq_128B: Opcode = Hexagon::V6_vgathermhwq_pseudo; break; } SDVTList VTs = CurDAG->getVTList(MVT::Other); SDValue Ops[] = { Address, Predicate, Base, Modifier, Offset, Chain }; SDNode *Result = CurDAG->getMachineNode(Opcode, dl, VTs, Ops); MachineSDNode::mmo_iterator MemOp = MF->allocateMemRefsArray(1); MemOp[0] = cast<MemIntrinsicSDNode>(N)->getMemOperand(); cast<MachineSDNode>(Result)->setMemRefs(MemOp, MemOp + 1); ReplaceNode(N, Result); } void HexagonDAGToDAGISel::SelectV65Gather(SDNode *N) { if (!HST->usePackets()) { report_fatal_error("Support for gather requires packets, " "which are disabled"); } const SDLoc &dl(N); SDValue Chain = N->getOperand(0); SDValue Address = N->getOperand(2); SDValue Base = N->getOperand(3); SDValue Modifier = N->getOperand(4); SDValue Offset = N->getOperand(5); unsigned Opcode; unsigned IntNo = cast<ConstantSDNode>(N->getOperand(1))->getZExtValue(); switch (IntNo) { default: llvm_unreachable("Unexpected HVX gather intrinsic."); case Intrinsic::hexagon_V6_vgathermh: case Intrinsic::hexagon_V6_vgathermh_128B: Opcode = Hexagon::V6_vgathermh_pseudo; break; case Intrinsic::hexagon_V6_vgathermw: case Intrinsic::hexagon_V6_vgathermw_128B: Opcode = Hexagon::V6_vgathermw_pseudo; break; case Intrinsic::hexagon_V6_vgathermhw: case Intrinsic::hexagon_V6_vgathermhw_128B: Opcode = Hexagon::V6_vgathermhw_pseudo; break; } SDVTList VTs = CurDAG->getVTList(MVT::Other); SDValue Ops[] = { Address, Base, Modifier, Offset, Chain }; SDNode *Result = CurDAG->getMachineNode(Opcode, dl, VTs, Ops); MachineSDNode::mmo_iterator MemOp = MF->allocateMemRefsArray(1); MemOp[0] = cast<MemIntrinsicSDNode>(N)->getMemOperand(); cast<MachineSDNode>(Result)->setMemRefs(MemOp, MemOp + 1); ReplaceNode(N, Result); } void HexagonDAGToDAGISel::SelectHVXDualOutput(SDNode *N) { unsigned IID = cast<ConstantSDNode>(N->getOperand(0))->getZExtValue(); SDNode *Result; switch (IID) { case Intrinsic::hexagon_V6_vaddcarry: { SmallVector<SDValue, 3> Ops = { N->getOperand(1), N->getOperand(2), N->getOperand(3) }; SDVTList VTs = CurDAG->getVTList(MVT::v16i32, MVT::v512i1); Result = CurDAG->getMachineNode(Hexagon::V6_vaddcarry, SDLoc(N), VTs, Ops); break; } case Intrinsic::hexagon_V6_vaddcarry_128B: { SmallVector<SDValue, 3> Ops = { N->getOperand(1), N->getOperand(2), N->getOperand(3) }; SDVTList VTs = CurDAG->getVTList(MVT::v32i32, MVT::v1024i1); Result = CurDAG->getMachineNode(Hexagon::V6_vaddcarry, SDLoc(N), VTs, Ops); break; } case Intrinsic::hexagon_V6_vsubcarry: { SmallVector<SDValue, 3> Ops = { N->getOperand(1), N->getOperand(2), N->getOperand(3) }; SDVTList VTs = CurDAG->getVTList(MVT::v16i32, MVT::v512i1); Result = CurDAG->getMachineNode(Hexagon::V6_vsubcarry, SDLoc(N), VTs, Ops); break; } case Intrinsic::hexagon_V6_vsubcarry_128B: { SmallVector<SDValue, 3> Ops = { N->getOperand(1), N->getOperand(2), N->getOperand(3) }; SDVTList VTs = CurDAG->getVTList(MVT::v32i32, MVT::v1024i1); Result = CurDAG->getMachineNode(Hexagon::V6_vsubcarry, SDLoc(N), VTs, Ops); break; } default: llvm_unreachable("Unexpected HVX dual output intrinsic."); } ReplaceUses(N, Result); ReplaceUses(SDValue(N, 0), SDValue(Result, 0)); ReplaceUses(SDValue(N, 1), SDValue(Result, 1)); CurDAG->RemoveDeadNode(N); }