//===-- HexagonISelDAGToDAG.cpp - A dag to dag inst selector for Hexagon --===// // // The LLVM Compiler Infrastructure // // This file is distributed under the University of Illinois Open Source // License. See LICENSE.TXT for details. // //===----------------------------------------------------------------------===// // // This file defines an instruction selector for the Hexagon target. // //===----------------------------------------------------------------------===// #include "Hexagon.h" #include "HexagonISelLowering.h" #include "HexagonMachineFunctionInfo.h" #include "HexagonTargetMachine.h" #include "llvm/CodeGen/FunctionLoweringInfo.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" using namespace llvm; #define DEBUG_TYPE "hexagon-isel" static cl::opt EnableAddressRebalancing("isel-rebalance-addr", cl::Hidden, cl::init(true), cl::desc("Rebalance address calculation trees to improve " "instruction selection")); // Rebalance only if this allows e.g. combining a GA with an offset or // factoring out a shift. static cl::opt RebalanceOnlyForOptimizations("rebalance-only-opt", cl::Hidden, cl::init(false), cl::desc("Rebalance address tree only if this allows optimizations")); static cl::opt RebalanceOnlyImbalancedTrees("rebalance-only-imbal", cl::Hidden, cl::init(false), cl::desc("Rebalance address tree only if it is imbalanced")); //===----------------------------------------------------------------------===// // Instruction Selector Implementation //===----------------------------------------------------------------------===// //===--------------------------------------------------------------------===// /// HexagonDAGToDAGISel - Hexagon specific code to select Hexagon machine /// instructions for SelectionDAG operations. /// namespace { class HexagonDAGToDAGISel : public SelectionDAGISel { const HexagonSubtarget *HST; const HexagonInstrInfo *HII; const HexagonRegisterInfo *HRI; public: explicit HexagonDAGToDAGISel(HexagonTargetMachine &tm, CodeGenOpt::Level OptLevel) : SelectionDAGISel(tm, OptLevel), HST(nullptr), HII(nullptr), HRI(nullptr) {} bool runOnMachineFunction(MachineFunction &MF) override { // Reset the subtarget each time through. HST = &MF.getSubtarget(); HII = HST->getInstrInfo(); HRI = HST->getRegisterInfo(); SelectionDAGISel::runOnMachineFunction(MF); return true; } void PreprocessISelDAG() override; void EmitFunctionEntryCode() override; void Select(SDNode *N) override; // Complex Pattern Selectors. inline bool SelectAddrGA(SDValue &N, SDValue &R); inline bool SelectAddrGP(SDValue &N, SDValue &R); bool SelectGlobalAddress(SDValue &N, SDValue &R, bool UseGP); bool SelectAddrFI(SDValue &N, SDValue &R); StringRef getPassName() const override { return "Hexagon DAG->DAG Pattern Instruction Selection"; } // Generate a machine instruction node corresponding to the circ/brev // load intrinsic. MachineSDNode *LoadInstrForLoadIntrinsic(SDNode *IntN); // Given the circ/brev load intrinsic and the already generated machine // instruction, generate the appropriate store (that is a part of the // intrinsic's functionality). SDNode *StoreInstrForLoadIntrinsic(MachineSDNode *LoadN, SDNode *IntN); void SelectFrameIndex(SDNode *N); /// SelectInlineAsmMemoryOperand - Implement addressing mode selection for /// inline asm expressions. bool SelectInlineAsmMemoryOperand(const SDValue &Op, unsigned ConstraintID, std::vector &OutOps) override; bool tryLoadOfLoadIntrinsic(LoadSDNode *N); void SelectLoad(SDNode *N); void SelectIndexedLoad(LoadSDNode *LD, const SDLoc &dl); void SelectIndexedStore(StoreSDNode *ST, const SDLoc &dl); void SelectStore(SDNode *N); void SelectSHL(SDNode *N); void SelectMul(SDNode *N); void SelectZeroExtend(SDNode *N); void SelectIntrinsicWChain(SDNode *N); void SelectIntrinsicWOChain(SDNode *N); void SelectConstant(SDNode *N); void SelectConstantFP(SDNode *N); void SelectBitcast(SDNode *N); // Include the pieces autogenerated from the target description. #include "HexagonGenDAGISel.inc" private: bool isValueExtension(const SDValue &Val, unsigned FromBits, SDValue &Src); bool isOrEquivalentToAdd(const SDNode *N) const; bool isAlignedMemNode(const MemSDNode *N) const; bool isPositiveHalfWord(const SDNode *N) const; SmallDenseMap RootWeights; SmallDenseMap RootHeights; SmallDenseMap GAUsesInFunction; int getWeight(SDNode *N); int getHeight(SDNode *N); SDValue getMultiplierForSHL(SDNode *N); SDValue factorOutPowerOf2(SDValue V, unsigned Power); unsigned getUsesInFunction(const Value *V); SDValue balanceSubTree(SDNode *N, bool Factorize = false); void rebalanceAddressTrees(); }; // end HexagonDAGToDAGISel } // end anonymous namespace /// createHexagonISelDag - This pass converts a legalized DAG into a /// Hexagon-specific DAG, ready for instruction scheduling. /// namespace llvm { FunctionPass *createHexagonISelDag(HexagonTargetMachine &TM, CodeGenOpt::Level OptLevel) { return new HexagonDAGToDAGISel(TM, OptLevel); } } // Intrinsics that return a a predicate. static bool doesIntrinsicReturnPredicate(unsigned ID) { switch (ID) { default: return false; case Intrinsic::hexagon_C2_cmpeq: case Intrinsic::hexagon_C2_cmpgt: case Intrinsic::hexagon_C2_cmpgtu: case Intrinsic::hexagon_C2_cmpgtup: case Intrinsic::hexagon_C2_cmpgtp: case Intrinsic::hexagon_C2_cmpeqp: case Intrinsic::hexagon_C2_bitsset: case Intrinsic::hexagon_C2_bitsclr: case Intrinsic::hexagon_C2_cmpeqi: case Intrinsic::hexagon_C2_cmpgti: case Intrinsic::hexagon_C2_cmpgtui: case Intrinsic::hexagon_C2_cmpgei: case Intrinsic::hexagon_C2_cmpgeui: case Intrinsic::hexagon_C2_cmplt: case Intrinsic::hexagon_C2_cmpltu: case Intrinsic::hexagon_C2_bitsclri: case Intrinsic::hexagon_C2_and: case Intrinsic::hexagon_C2_or: case Intrinsic::hexagon_C2_xor: case Intrinsic::hexagon_C2_andn: case Intrinsic::hexagon_C2_not: case Intrinsic::hexagon_C2_orn: case Intrinsic::hexagon_C2_pxfer_map: case Intrinsic::hexagon_C2_any8: case Intrinsic::hexagon_C2_all8: case Intrinsic::hexagon_A2_vcmpbeq: case Intrinsic::hexagon_A2_vcmpbgtu: case Intrinsic::hexagon_A2_vcmpheq: case Intrinsic::hexagon_A2_vcmphgt: case Intrinsic::hexagon_A2_vcmphgtu: case Intrinsic::hexagon_A2_vcmpweq: case Intrinsic::hexagon_A2_vcmpwgt: case Intrinsic::hexagon_A2_vcmpwgtu: case Intrinsic::hexagon_C2_tfrrp: case Intrinsic::hexagon_S2_tstbit_i: case Intrinsic::hexagon_S2_tstbit_r: return true; } } void HexagonDAGToDAGISel::SelectIndexedLoad(LoadSDNode *LD, const SDLoc &dl) { SDValue Chain = LD->getChain(); SDValue Base = LD->getBasePtr(); SDValue Offset = LD->getOffset(); int32_t Inc = cast(Offset.getNode())->getSExtValue(); EVT LoadedVT = LD->getMemoryVT(); unsigned Opcode = 0; // Check for zero extended loads. Treat any-extend loads as zero extended // loads. ISD::LoadExtType ExtType = LD->getExtensionType(); bool IsZeroExt = (ExtType == ISD::ZEXTLOAD || ExtType == ISD::EXTLOAD); bool IsValidInc = HII->isValidAutoIncImm(LoadedVT, Inc); assert(LoadedVT.isSimple()); switch (LoadedVT.getSimpleVT().SimpleTy) { case MVT::i8: if (IsZeroExt) Opcode = IsValidInc ? Hexagon::L2_loadrub_pi : Hexagon::L2_loadrub_io; else Opcode = IsValidInc ? Hexagon::L2_loadrb_pi : Hexagon::L2_loadrb_io; break; case MVT::i16: if (IsZeroExt) Opcode = IsValidInc ? Hexagon::L2_loadruh_pi : Hexagon::L2_loadruh_io; else Opcode = IsValidInc ? Hexagon::L2_loadrh_pi : Hexagon::L2_loadrh_io; break; case MVT::i32: Opcode = IsValidInc ? Hexagon::L2_loadri_pi : Hexagon::L2_loadri_io; break; case MVT::i64: Opcode = IsValidInc ? Hexagon::L2_loadrd_pi : Hexagon::L2_loadrd_io; break; // 64B case MVT::v64i8: case MVT::v32i16: case MVT::v16i32: case MVT::v8i64: if (isAlignedMemNode(LD)) Opcode = IsValidInc ? Hexagon::V6_vL32b_pi : Hexagon::V6_vL32b_ai; else Opcode = IsValidInc ? Hexagon::V6_vL32Ub_pi : Hexagon::V6_vL32Ub_ai; break; // 128B case MVT::v128i8: case MVT::v64i16: case MVT::v32i32: case MVT::v16i64: if (isAlignedMemNode(LD)) Opcode = IsValidInc ? Hexagon::V6_vL32b_pi_128B : Hexagon::V6_vL32b_ai_128B; else Opcode = IsValidInc ? Hexagon::V6_vL32Ub_pi_128B : Hexagon::V6_vL32Ub_ai_128B; break; default: llvm_unreachable("Unexpected memory type in indexed load"); } SDValue IncV = CurDAG->getTargetConstant(Inc, dl, MVT::i32); MachineSDNode::mmo_iterator MemOp = MF->allocateMemRefsArray(1); MemOp[0] = LD->getMemOperand(); auto getExt64 = [this,ExtType] (MachineSDNode *N, const SDLoc &dl) -> MachineSDNode* { if (ExtType == ISD::ZEXTLOAD || ExtType == ISD::EXTLOAD) { SDValue Zero = CurDAG->getTargetConstant(0, dl, MVT::i32); return CurDAG->getMachineNode(Hexagon::A4_combineir, dl, MVT::i64, Zero, SDValue(N, 0)); } if (ExtType == ISD::SEXTLOAD) return CurDAG->getMachineNode(Hexagon::A2_sxtw, dl, MVT::i64, SDValue(N, 0)); return N; }; // Loaded value Next address Chain SDValue From[3] = { SDValue(LD,0), SDValue(LD,1), SDValue(LD,2) }; SDValue To[3]; EVT ValueVT = LD->getValueType(0); if (ValueVT == MVT::i64 && ExtType != ISD::NON_EXTLOAD) { // A load extending to i64 will actually produce i32, which will then // need to be extended to i64. assert(LoadedVT.getSizeInBits() <= 32); ValueVT = MVT::i32; } if (IsValidInc) { MachineSDNode *L = CurDAG->getMachineNode(Opcode, dl, ValueVT, MVT::i32, MVT::Other, Base, IncV, Chain); L->setMemRefs(MemOp, MemOp+1); To[1] = SDValue(L, 1); // Next address. To[2] = SDValue(L, 2); // Chain. // Handle special case for extension to i64. if (LD->getValueType(0) == MVT::i64) L = getExt64(L, dl); To[0] = SDValue(L, 0); // Loaded (extended) value. } else { SDValue Zero = CurDAG->getTargetConstant(0, dl, MVT::i32); MachineSDNode *L = CurDAG->getMachineNode(Opcode, dl, ValueVT, MVT::Other, Base, Zero, Chain); L->setMemRefs(MemOp, MemOp+1); To[2] = SDValue(L, 1); // Chain. MachineSDNode *A = CurDAG->getMachineNode(Hexagon::A2_addi, dl, MVT::i32, Base, IncV); To[1] = SDValue(A, 0); // Next address. // Handle special case for extension to i64. if (LD->getValueType(0) == MVT::i64) L = getExt64(L, dl); To[0] = SDValue(L, 0); // Loaded (extended) value. } ReplaceUses(From, To, 3); CurDAG->RemoveDeadNode(LD); } MachineSDNode *HexagonDAGToDAGISel::LoadInstrForLoadIntrinsic(SDNode *IntN) { if (IntN->getOpcode() != ISD::INTRINSIC_W_CHAIN) return nullptr; SDLoc dl(IntN); unsigned IntNo = cast(IntN->getOperand(1))->getZExtValue(); static std::map LoadPciMap = { { Intrinsic::hexagon_circ_ldb, Hexagon::L2_loadrb_pci }, { Intrinsic::hexagon_circ_ldub, Hexagon::L2_loadrub_pci }, { Intrinsic::hexagon_circ_ldh, Hexagon::L2_loadrh_pci }, { Intrinsic::hexagon_circ_lduh, Hexagon::L2_loadruh_pci }, { Intrinsic::hexagon_circ_ldw, Hexagon::L2_loadri_pci }, { Intrinsic::hexagon_circ_ldd, Hexagon::L2_loadrd_pci }, }; auto FLC = LoadPciMap.find(IntNo); if (FLC != LoadPciMap.end()) { SDNode *Mod = CurDAG->getMachineNode(Hexagon::A2_tfrrcr, dl, MVT::i32, IntN->getOperand(4)); EVT ValTy = (IntNo == Intrinsic::hexagon_circ_ldd) ? MVT::i64 : MVT::i32; EVT RTys[] = { ValTy, MVT::i32, MVT::Other }; // Operands: { Base, Increment, Modifier, Chain } auto Inc = cast(IntN->getOperand(5)); SDValue I = CurDAG->getTargetConstant(Inc->getSExtValue(), dl, MVT::i32); MachineSDNode *Res = CurDAG->getMachineNode(FLC->second, dl, RTys, { IntN->getOperand(2), I, SDValue(Mod,0), IntN->getOperand(0) }); return Res; } static std::map LoadPbrMap = { { Intrinsic::hexagon_brev_ldb, Hexagon::L2_loadrb_pbr }, { Intrinsic::hexagon_brev_ldub, Hexagon::L2_loadrub_pbr }, { Intrinsic::hexagon_brev_ldh, Hexagon::L2_loadrh_pbr }, { Intrinsic::hexagon_brev_lduh, Hexagon::L2_loadruh_pbr }, { Intrinsic::hexagon_brev_ldw, Hexagon::L2_loadri_pbr }, { Intrinsic::hexagon_brev_ldd, Hexagon::L2_loadrd_pbr }, }; auto FLB = LoadPbrMap.find(IntNo); if (FLB != LoadPbrMap.end()) { SDNode *Mod = CurDAG->getMachineNode(Hexagon::A2_tfrrcr, dl, MVT::i32, IntN->getOperand(4)); EVT ValTy = (IntNo == Intrinsic::hexagon_brev_ldd) ? MVT::i64 : MVT::i32; EVT RTys[] = { ValTy, MVT::i32, MVT::Other }; // Operands: { Base, Modifier, Chain } MachineSDNode *Res = CurDAG->getMachineNode(FLB->second, dl, RTys, { IntN->getOperand(2), SDValue(Mod,0), IntN->getOperand(0) }); return Res; } return nullptr; } SDNode *HexagonDAGToDAGISel::StoreInstrForLoadIntrinsic(MachineSDNode *LoadN, SDNode *IntN) { // The "LoadN" is just a machine load instruction. The intrinsic also // involves storing it. Generate an appropriate store to the location // given in the intrinsic's operand(3). uint64_t F = HII->get(LoadN->getMachineOpcode()).TSFlags; unsigned SizeBits = (F >> HexagonII::MemAccessSizePos) & HexagonII::MemAccesSizeMask; unsigned Size = 1U << (SizeBits-1); SDLoc dl(IntN); MachinePointerInfo PI; SDValue TS; SDValue Loc = IntN->getOperand(3); if (Size >= 4) TS = CurDAG->getStore(SDValue(LoadN, 2), dl, SDValue(LoadN, 0), Loc, PI, Size); else TS = CurDAG->getTruncStore(SDValue(LoadN, 2), dl, SDValue(LoadN, 0), Loc, PI, MVT::getIntegerVT(Size * 8), Size); SDNode *StoreN; { HandleSDNode Handle(TS); SelectStore(TS.getNode()); StoreN = Handle.getValue().getNode(); } // Load's results are { Loaded value, Updated pointer, Chain } ReplaceUses(SDValue(IntN, 0), SDValue(LoadN, 1)); ReplaceUses(SDValue(IntN, 1), SDValue(StoreN, 0)); return StoreN; } bool HexagonDAGToDAGISel::tryLoadOfLoadIntrinsic(LoadSDNode *N) { // The intrinsics for load circ/brev perform two operations: // 1. Load a value V from the specified location, using the addressing // mode corresponding to the intrinsic. // 2. Store V into a specified location. This location is typically a // local, temporary object. // In many cases, the program using these intrinsics will immediately // load V again from the local object. In those cases, when certain // conditions are met, the last load can be removed. // This function identifies and optimizes this pattern. If the pattern // cannot be optimized, it returns nullptr, which will cause the load // to be selected separately from the intrinsic (which will be handled // in SelectIntrinsicWChain). SDValue Ch = N->getOperand(0); SDValue Loc = N->getOperand(1); // Assume that the load and the intrinsic are connected directly with a // chain: // t1: i32,ch = int.load ..., ..., ..., Loc, ... // <-- C // t2: i32,ch = load t1:1, Loc, ... SDNode *C = Ch.getNode(); if (C->getOpcode() != ISD::INTRINSIC_W_CHAIN) return false; // The second load can only be eliminated if its extension type matches // that of the load instruction corresponding to the intrinsic. The user // can provide an address of an unsigned variable to store the result of // a sign-extending intrinsic into (or the other way around). ISD::LoadExtType IntExt; switch (cast(C->getOperand(1))->getZExtValue()) { case Intrinsic::hexagon_brev_ldub: case Intrinsic::hexagon_brev_lduh: case Intrinsic::hexagon_circ_ldub: case Intrinsic::hexagon_circ_lduh: IntExt = ISD::ZEXTLOAD; break; case Intrinsic::hexagon_brev_ldw: case Intrinsic::hexagon_brev_ldd: case Intrinsic::hexagon_circ_ldw: case Intrinsic::hexagon_circ_ldd: IntExt = ISD::NON_EXTLOAD; break; default: IntExt = ISD::SEXTLOAD; break; } if (N->getExtensionType() != IntExt) return false; // Make sure the target location for the loaded value in the load intrinsic // is the location from which LD (or N) is loading. if (C->getNumOperands() < 4 || Loc.getNode() != C->getOperand(3).getNode()) return false; if (MachineSDNode *L = LoadInstrForLoadIntrinsic(C)) { SDNode *S = StoreInstrForLoadIntrinsic(L, C); SDValue F[] = { SDValue(N,0), SDValue(N,1), SDValue(C,0), SDValue(C,1) }; SDValue T[] = { SDValue(L,0), SDValue(S,0), SDValue(L,1), SDValue(S,0) }; ReplaceUses(F, T, array_lengthof(T)); // This transformation will leave the intrinsic dead. If it remains in // the DAG, the selection code will see it again, but without the load, // and it will generate a store that is normally required for it. CurDAG->RemoveDeadNode(C); return true; } return false; } void HexagonDAGToDAGISel::SelectLoad(SDNode *N) { SDLoc dl(N); LoadSDNode *LD = cast(N); ISD::MemIndexedMode AM = LD->getAddressingMode(); // Handle indexed loads. if (AM != ISD::UNINDEXED) { SelectIndexedLoad(LD, dl); return; } // Handle patterns using circ/brev load intrinsics. if (tryLoadOfLoadIntrinsic(LD)) return; SelectCode(LD); } void HexagonDAGToDAGISel::SelectIndexedStore(StoreSDNode *ST, const SDLoc &dl) { SDValue Chain = ST->getChain(); SDValue Base = ST->getBasePtr(); SDValue Offset = ST->getOffset(); SDValue Value = ST->getValue(); // Get the constant value. int32_t Inc = cast(Offset.getNode())->getSExtValue(); EVT StoredVT = ST->getMemoryVT(); EVT ValueVT = Value.getValueType(); bool IsValidInc = HII->isValidAutoIncImm(StoredVT, Inc); unsigned Opcode = 0; assert(StoredVT.isSimple()); switch (StoredVT.getSimpleVT().SimpleTy) { case MVT::i8: Opcode = IsValidInc ? Hexagon::S2_storerb_pi : Hexagon::S2_storerb_io; break; case MVT::i16: Opcode = IsValidInc ? Hexagon::S2_storerh_pi : Hexagon::S2_storerh_io; break; case MVT::i32: Opcode = IsValidInc ? Hexagon::S2_storeri_pi : Hexagon::S2_storeri_io; break; case MVT::i64: Opcode = IsValidInc ? Hexagon::S2_storerd_pi : Hexagon::S2_storerd_io; break; // 64B case MVT::v64i8: case MVT::v32i16: case MVT::v16i32: case MVT::v8i64: if (isAlignedMemNode(ST)) Opcode = IsValidInc ? Hexagon::V6_vS32b_pi : Hexagon::V6_vS32b_ai; else Opcode = IsValidInc ? Hexagon::V6_vS32Ub_pi : Hexagon::V6_vS32Ub_ai; break; // 128B case MVT::v128i8: case MVT::v64i16: case MVT::v32i32: case MVT::v16i64: if (isAlignedMemNode(ST)) Opcode = IsValidInc ? Hexagon::V6_vS32b_pi_128B : Hexagon::V6_vS32b_ai_128B; else Opcode = IsValidInc ? Hexagon::V6_vS32Ub_pi_128B : Hexagon::V6_vS32Ub_ai_128B; break; default: llvm_unreachable("Unexpected memory type in indexed store"); } if (ST->isTruncatingStore() && ValueVT.getSizeInBits() == 64) { assert(StoredVT.getSizeInBits() < 64 && "Not a truncating store"); Value = CurDAG->getTargetExtractSubreg(Hexagon::isub_lo, dl, MVT::i32, Value); } SDValue IncV = CurDAG->getTargetConstant(Inc, dl, MVT::i32); MachineSDNode::mmo_iterator MemOp = MF->allocateMemRefsArray(1); MemOp[0] = ST->getMemOperand(); // Next address Chain SDValue From[2] = { SDValue(ST,0), SDValue(ST,1) }; SDValue To[2]; if (IsValidInc) { // Build post increment store. SDValue Ops[] = { Base, IncV, Value, Chain }; MachineSDNode *S = CurDAG->getMachineNode(Opcode, dl, MVT::i32, MVT::Other, Ops); S->setMemRefs(MemOp, MemOp + 1); To[0] = SDValue(S, 0); To[1] = SDValue(S, 1); } else { SDValue Zero = CurDAG->getTargetConstant(0, dl, MVT::i32); SDValue Ops[] = { Base, Zero, Value, Chain }; MachineSDNode *S = CurDAG->getMachineNode(Opcode, dl, MVT::Other, Ops); S->setMemRefs(MemOp, MemOp + 1); To[1] = SDValue(S, 0); MachineSDNode *A = CurDAG->getMachineNode(Hexagon::A2_addi, dl, MVT::i32, Base, IncV); To[0] = SDValue(A, 0); } ReplaceUses(From, To, 2); CurDAG->RemoveDeadNode(ST); } void HexagonDAGToDAGISel::SelectStore(SDNode *N) { SDLoc dl(N); StoreSDNode *ST = cast(N); ISD::MemIndexedMode AM = ST->getAddressingMode(); // Handle indexed stores. if (AM != ISD::UNINDEXED) { SelectIndexedStore(ST, dl); return; } SelectCode(ST); } void HexagonDAGToDAGISel::SelectMul(SDNode *N) { SDLoc dl(N); // %conv.i = sext i32 %tmp1 to i64 // %conv2.i = sext i32 %add to i64 // %mul.i = mul nsw i64 %conv2.i, %conv.i // // --- match with the following --- // // %mul.i = mpy (%tmp1, %add) // if (N->getValueType(0) == MVT::i64) { // Shifting a i64 signed multiply. SDValue MulOp0 = N->getOperand(0); SDValue MulOp1 = N->getOperand(1); SDValue OP0; SDValue OP1; // Handle sign_extend and sextload. if (MulOp0.getOpcode() == ISD::SIGN_EXTEND) { SDValue Sext0 = MulOp0.getOperand(0); if (Sext0.getNode()->getValueType(0) != MVT::i32) { SelectCode(N); return; } OP0 = Sext0; } else if (MulOp0.getOpcode() == ISD::LOAD) { LoadSDNode *LD = cast(MulOp0.getNode()); if (LD->getMemoryVT() != MVT::i32 || LD->getExtensionType() != ISD::SEXTLOAD || LD->getAddressingMode() != ISD::UNINDEXED) { SelectCode(N); return; } SDValue Chain = LD->getChain(); SDValue TargetConst0 = CurDAG->getTargetConstant(0, dl, MVT::i32); OP0 = SDValue(CurDAG->getMachineNode(Hexagon::L2_loadri_io, dl, MVT::i32, MVT::Other, LD->getBasePtr(), TargetConst0, Chain), 0); } else { SelectCode(N); return; } // Same goes for the second operand. if (MulOp1.getOpcode() == ISD::SIGN_EXTEND) { SDValue Sext1 = MulOp1.getOperand(0); if (Sext1.getNode()->getValueType(0) != MVT::i32) { SelectCode(N); return; } OP1 = Sext1; } else if (MulOp1.getOpcode() == ISD::LOAD) { LoadSDNode *LD = cast(MulOp1.getNode()); if (LD->getMemoryVT() != MVT::i32 || LD->getExtensionType() != ISD::SEXTLOAD || LD->getAddressingMode() != ISD::UNINDEXED) { SelectCode(N); return; } SDValue Chain = LD->getChain(); SDValue TargetConst0 = CurDAG->getTargetConstant(0, dl, MVT::i32); OP1 = SDValue(CurDAG->getMachineNode(Hexagon::L2_loadri_io, dl, MVT::i32, MVT::Other, LD->getBasePtr(), TargetConst0, Chain), 0); } else { SelectCode(N); return; } // Generate a mpy instruction. SDNode *Result = CurDAG->getMachineNode(Hexagon::M2_dpmpyss_s0, dl, MVT::i64, OP0, OP1); ReplaceNode(N, Result); return; } SelectCode(N); } void HexagonDAGToDAGISel::SelectSHL(SDNode *N) { SDLoc dl(N); SDValue Shl_0 = N->getOperand(0); SDValue Shl_1 = N->getOperand(1); auto Default = [this,N] () -> void { SelectCode(N); }; if (N->getValueType(0) != MVT::i32 || Shl_1.getOpcode() != ISD::Constant) return Default(); // RHS is const. int32_t ShlConst = cast(Shl_1)->getSExtValue(); if (Shl_0.getOpcode() == ISD::MUL) { SDValue Mul_0 = Shl_0.getOperand(0); // Val SDValue Mul_1 = Shl_0.getOperand(1); // Const // RHS of mul is const. if (ConstantSDNode *C = dyn_cast(Mul_1)) { int32_t ValConst = C->getSExtValue() << ShlConst; if (isInt<9>(ValConst)) { SDValue Val = CurDAG->getTargetConstant(ValConst, dl, MVT::i32); SDNode *Result = CurDAG->getMachineNode(Hexagon::M2_mpysmi, dl, MVT::i32, Mul_0, Val); ReplaceNode(N, Result); return; } } return Default(); } if (Shl_0.getOpcode() == ISD::SUB) { SDValue Sub_0 = Shl_0.getOperand(0); // Const 0 SDValue Sub_1 = Shl_0.getOperand(1); // Val if (ConstantSDNode *C1 = dyn_cast(Sub_0)) { if (C1->getSExtValue() != 0 || Sub_1.getOpcode() != ISD::SHL) return Default(); SDValue Shl2_0 = Sub_1.getOperand(0); // Val SDValue Shl2_1 = Sub_1.getOperand(1); // Const if (ConstantSDNode *C2 = dyn_cast(Shl2_1)) { int32_t ValConst = 1 << (ShlConst + C2->getSExtValue()); if (isInt<9>(-ValConst)) { SDValue Val = CurDAG->getTargetConstant(-ValConst, dl, MVT::i32); SDNode *Result = CurDAG->getMachineNode(Hexagon::M2_mpysmi, dl, MVT::i32, Shl2_0, Val); ReplaceNode(N, Result); return; } } } } return Default(); } // // If there is an zero_extend followed an intrinsic in DAG (this means - the // result of the intrinsic is predicate); convert the zero_extend to // transfer instruction. // // Zero extend -> transfer is lowered here. Otherwise, zero_extend will be // converted into a MUX as predicate registers defined as 1 bit in the // compiler. Architecture defines them as 8-bit registers. // We want to preserve all the lower 8-bits and, not just 1 LSB bit. // void HexagonDAGToDAGISel::SelectZeroExtend(SDNode *N) { SDLoc dl(N); SDValue Op0 = N->getOperand(0); EVT OpVT = Op0.getValueType(); unsigned OpBW = OpVT.getSizeInBits(); // Special handling for zero-extending a vector of booleans. if (OpVT.isVector() && OpVT.getVectorElementType() == MVT::i1 && OpBW <= 64) { SDNode *Mask = CurDAG->getMachineNode(Hexagon::C2_mask, dl, MVT::i64, Op0); unsigned NE = OpVT.getVectorNumElements(); EVT ExVT = N->getValueType(0); unsigned ES = ExVT.getScalarSizeInBits(); uint64_t MV = 0, Bit = 1; for (unsigned i = 0; i < NE; ++i) { MV |= Bit; Bit <<= ES; } SDValue Ones = CurDAG->getTargetConstant(MV, dl, MVT::i64); SDNode *OnesReg = CurDAG->getMachineNode(Hexagon::CONST64, dl, MVT::i64, Ones); if (ExVT.getSizeInBits() == 32) { SDNode *And = CurDAG->getMachineNode(Hexagon::A2_andp, dl, MVT::i64, SDValue(Mask,0), SDValue(OnesReg,0)); SDValue SubR = CurDAG->getTargetConstant(Hexagon::isub_lo, dl, MVT::i32); ReplaceNode(N, CurDAG->getMachineNode(Hexagon::EXTRACT_SUBREG, dl, ExVT, SDValue(And, 0), SubR)); return; } ReplaceNode(N, CurDAG->getMachineNode(Hexagon::A2_andp, dl, ExVT, SDValue(Mask, 0), SDValue(OnesReg, 0))); return; } SDNode *Int = N->getOperand(0).getNode(); if ((Int->getOpcode() == ISD::INTRINSIC_WO_CHAIN)) { unsigned ID = cast(Int->getOperand(0))->getZExtValue(); if (doesIntrinsicReturnPredicate(ID)) { // Now we need to differentiate target data types. if (N->getValueType(0) == MVT::i64) { // Convert the zero_extend to Rs = Pd followed by A2_combinew(0,Rs). SDValue TargetConst0 = CurDAG->getTargetConstant(0, dl, MVT::i32); SDNode *Result_1 = CurDAG->getMachineNode(Hexagon::C2_tfrpr, dl, MVT::i32, SDValue(Int, 0)); SDNode *Result_2 = CurDAG->getMachineNode(Hexagon::A2_tfrsi, dl, MVT::i32, TargetConst0); SDNode *Result_3 = CurDAG->getMachineNode(Hexagon::A2_combinew, dl, MVT::i64, MVT::Other, SDValue(Result_2, 0), SDValue(Result_1, 0)); ReplaceNode(N, Result_3); return; } if (N->getValueType(0) == MVT::i32) { // Convert the zero_extend to Rs = Pd SDNode* RsPd = CurDAG->getMachineNode(Hexagon::C2_tfrpr, dl, MVT::i32, SDValue(Int, 0)); ReplaceNode(N, RsPd); return; } llvm_unreachable("Unexpected value type"); } } SelectCode(N); } // // Handling intrinsics for circular load and bitreverse load. // void HexagonDAGToDAGISel::SelectIntrinsicWChain(SDNode *N) { if (MachineSDNode *L = LoadInstrForLoadIntrinsic(N)) { StoreInstrForLoadIntrinsic(L, N); CurDAG->RemoveDeadNode(N); return; } SelectCode(N); } void HexagonDAGToDAGISel::SelectIntrinsicWOChain(SDNode *N) { unsigned IID = cast(N->getOperand(0))->getZExtValue(); unsigned Bits; switch (IID) { case Intrinsic::hexagon_S2_vsplatrb: Bits = 8; break; case Intrinsic::hexagon_S2_vsplatrh: Bits = 16; break; default: SelectCode(N); return; } SDValue V = N->getOperand(1); SDValue U; if (isValueExtension(V, Bits, U)) { SDValue R = CurDAG->getNode(N->getOpcode(), SDLoc(N), N->getValueType(0), N->getOperand(0), U); ReplaceNode(N, R.getNode()); SelectCode(R.getNode()); return; } SelectCode(N); } // // Map floating point constant values. // void HexagonDAGToDAGISel::SelectConstantFP(SDNode *N) { SDLoc dl(N); ConstantFPSDNode *CN = dyn_cast(N); APInt A = CN->getValueAPF().bitcastToAPInt(); if (N->getValueType(0) == MVT::f32) { SDValue V = CurDAG->getTargetConstant(A.getZExtValue(), dl, MVT::i32); ReplaceNode(N, CurDAG->getMachineNode(Hexagon::A2_tfrsi, dl, MVT::f32, V)); return; } if (N->getValueType(0) == MVT::f64) { SDValue V = CurDAG->getTargetConstant(A.getZExtValue(), dl, MVT::i64); ReplaceNode(N, CurDAG->getMachineNode(Hexagon::CONST64, dl, MVT::f64, V)); return; } SelectCode(N); } // // Map boolean values. // void HexagonDAGToDAGISel::SelectConstant(SDNode *N) { if (N->getValueType(0) == MVT::i1) { assert(!(cast(N)->getZExtValue() >> 1)); unsigned Opc = (cast(N)->getSExtValue() != 0) ? Hexagon::PS_true : Hexagon::PS_false; ReplaceNode(N, CurDAG->getMachineNode(Opc, SDLoc(N), MVT::i1)); return; } SelectCode(N); } void HexagonDAGToDAGISel::SelectFrameIndex(SDNode *N) { MachineFrameInfo &MFI = MF->getFrameInfo(); const HexagonFrameLowering *HFI = HST->getFrameLowering(); int FX = cast(N)->getIndex(); unsigned StkA = HFI->getStackAlignment(); unsigned MaxA = MFI.getMaxAlignment(); SDValue FI = CurDAG->getTargetFrameIndex(FX, MVT::i32); SDLoc DL(N); SDValue Zero = CurDAG->getTargetConstant(0, DL, MVT::i32); SDNode *R = nullptr; // Use PS_fi when: // - the object is fixed, or // - there are no objects with higher-than-default alignment, or // - there are no dynamically allocated objects. // Otherwise, use PS_fia. if (FX < 0 || MaxA <= StkA || !MFI.hasVarSizedObjects()) { R = CurDAG->getMachineNode(Hexagon::PS_fi, DL, MVT::i32, FI, Zero); } else { auto &HMFI = *MF->getInfo(); unsigned AR = HMFI.getStackAlignBaseVReg(); SDValue CH = CurDAG->getEntryNode(); SDValue Ops[] = { CurDAG->getCopyFromReg(CH, DL, AR, MVT::i32), FI, Zero }; R = CurDAG->getMachineNode(Hexagon::PS_fia, DL, MVT::i32, Ops); } ReplaceNode(N, R); } void HexagonDAGToDAGISel::SelectBitcast(SDNode *N) { EVT SVT = N->getOperand(0).getValueType(); EVT DVT = N->getValueType(0); if (!SVT.isVector() || !DVT.isVector() || SVT.getVectorElementType() == MVT::i1 || DVT.getVectorElementType() == MVT::i1 || SVT.getSizeInBits() != DVT.getSizeInBits()) { SelectCode(N); return; } CurDAG->ReplaceAllUsesOfValueWith(SDValue(N,0), N->getOperand(0)); CurDAG->RemoveDeadNode(N); } void HexagonDAGToDAGISel::Select(SDNode *N) { if (N->isMachineOpcode()) { N->setNodeId(-1); return; // Already selected. } switch (N->getOpcode()) { case ISD::Constant: SelectConstant(N); return; case ISD::ConstantFP: SelectConstantFP(N); return; case ISD::FrameIndex: SelectFrameIndex(N); return; case ISD::BITCAST: SelectBitcast(N); return; case ISD::SHL: SelectSHL(N); return; case ISD::LOAD: SelectLoad(N); return; case ISD::STORE: SelectStore(N); return; case ISD::MUL: SelectMul(N); return; case ISD::ZERO_EXTEND: SelectZeroExtend(N); return; case ISD::INTRINSIC_W_CHAIN: SelectIntrinsicWChain(N); return; case ISD::INTRINSIC_WO_CHAIN: SelectIntrinsicWOChain(N); return; } SelectCode(N); } bool HexagonDAGToDAGISel:: SelectInlineAsmMemoryOperand(const SDValue &Op, unsigned ConstraintID, std::vector &OutOps) { SDValue Inp = Op, Res; switch (ConstraintID) { default: return true; case InlineAsm::Constraint_i: case InlineAsm::Constraint_o: // Offsetable. case InlineAsm::Constraint_v: // Not offsetable. case InlineAsm::Constraint_m: // Memory. if (SelectAddrFI(Inp, Res)) OutOps.push_back(Res); else OutOps.push_back(Inp); break; } OutOps.push_back(CurDAG->getTargetConstant(0, SDLoc(Op), MVT::i32)); return false; } void HexagonDAGToDAGISel::PreprocessISelDAG() { SelectionDAG &DAG = *CurDAG; std::vector Nodes; for (SDNode &Node : DAG.allnodes()) Nodes.push_back(&Node); // Simplify: (or (select c x 0) z) -> (select c (or x z) z) // (or (select c 0 y) z) -> (select c z (or y z)) // This may not be the right thing for all targets, so do it here. for (auto I : Nodes) { if (I->getOpcode() != ISD::OR) continue; auto IsZero = [] (const SDValue &V) -> bool { if (ConstantSDNode *SC = dyn_cast(V.getNode())) return SC->isNullValue(); return false; }; auto IsSelect0 = [IsZero] (const SDValue &Op) -> bool { if (Op.getOpcode() != ISD::SELECT) return false; return IsZero(Op.getOperand(1)) || IsZero(Op.getOperand(2)); }; SDValue N0 = I->getOperand(0), N1 = I->getOperand(1); EVT VT = I->getValueType(0); bool SelN0 = IsSelect0(N0); SDValue SOp = SelN0 ? N0 : N1; SDValue VOp = SelN0 ? N1 : N0; if (SOp.getOpcode() == ISD::SELECT && SOp.getNode()->hasOneUse()) { SDValue SC = SOp.getOperand(0); SDValue SX = SOp.getOperand(1); SDValue SY = SOp.getOperand(2); SDLoc DLS = SOp; if (IsZero(SY)) { SDValue NewOr = DAG.getNode(ISD::OR, DLS, VT, SX, VOp); SDValue NewSel = DAG.getNode(ISD::SELECT, DLS, VT, SC, NewOr, VOp); DAG.ReplaceAllUsesWith(I, NewSel.getNode()); } else if (IsZero(SX)) { SDValue NewOr = DAG.getNode(ISD::OR, DLS, VT, SY, VOp); SDValue NewSel = DAG.getNode(ISD::SELECT, DLS, VT, SC, VOp, NewOr); DAG.ReplaceAllUsesWith(I, NewSel.getNode()); } } } // Transform: (store ch addr (add x (add (shl y c) e))) // to: (store ch addr (add x (shl (add y d) c))), // where e = (shl d c) for some integer d. // The purpose of this is to enable generation of loads/stores with // shifted addressing mode, i.e. mem(x+y<<#c). For that, the shift // value c must be 0, 1 or 2. for (auto I : Nodes) { if (I->getOpcode() != ISD::STORE) continue; // I matched: (store ch addr Off) SDValue Off = I->getOperand(2); // Off needs to match: (add x (add (shl y c) (shl d c)))) if (Off.getOpcode() != ISD::ADD) continue; // Off matched: (add x T0) SDValue T0 = Off.getOperand(1); // T0 needs to match: (add T1 T2): if (T0.getOpcode() != ISD::ADD) continue; // T0 matched: (add T1 T2) SDValue T1 = T0.getOperand(0); SDValue T2 = T0.getOperand(1); // T1 needs to match: (shl y c) if (T1.getOpcode() != ISD::SHL) continue; SDValue C = T1.getOperand(1); ConstantSDNode *CN = dyn_cast(C.getNode()); if (CN == nullptr) continue; unsigned CV = CN->getZExtValue(); if (CV > 2) continue; // T2 needs to match e, where e = (shl d c) for some d. ConstantSDNode *EN = dyn_cast(T2.getNode()); if (EN == nullptr) continue; unsigned EV = EN->getZExtValue(); if (EV % (1 << CV) != 0) continue; unsigned DV = EV / (1 << CV); // Replace T0 with: (shl (add y d) c) SDLoc DL = SDLoc(I); EVT VT = T0.getValueType(); SDValue D = DAG.getConstant(DV, DL, VT); // NewAdd = (add y d) SDValue NewAdd = DAG.getNode(ISD::ADD, DL, VT, T1.getOperand(0), D); // NewShl = (shl NewAdd c) SDValue NewShl = DAG.getNode(ISD::SHL, DL, VT, NewAdd, C); ReplaceNode(T0.getNode(), NewShl.getNode()); } if (EnableAddressRebalancing) { rebalanceAddressTrees(); DEBUG( dbgs() << "************* SelectionDAG after preprocessing: ***********\n"; CurDAG->dump(); dbgs() << "************* End SelectionDAG after preprocessing ********\n"; ); } } void HexagonDAGToDAGISel::EmitFunctionEntryCode() { auto &HST = static_cast(MF->getSubtarget()); auto &HFI = *HST.getFrameLowering(); if (!HFI.needsAligna(*MF)) return; MachineFrameInfo &MFI = MF->getFrameInfo(); MachineBasicBlock *EntryBB = &MF->front(); unsigned AR = FuncInfo->CreateReg(MVT::i32); unsigned MaxA = MFI.getMaxAlignment(); BuildMI(EntryBB, DebugLoc(), HII->get(Hexagon::PS_aligna), AR) .addImm(MaxA); MF->getInfo()->setStackAlignBaseVReg(AR); } // Match a frame index that can be used in an addressing mode. bool HexagonDAGToDAGISel::SelectAddrFI(SDValue& N, SDValue &R) { if (N.getOpcode() != ISD::FrameIndex) return false; auto &HFI = *HST->getFrameLowering(); MachineFrameInfo &MFI = MF->getFrameInfo(); int FX = cast(N)->getIndex(); if (!MFI.isFixedObjectIndex(FX) && HFI.needsAligna(*MF)) return false; R = CurDAG->getTargetFrameIndex(FX, MVT::i32); return true; } inline bool HexagonDAGToDAGISel::SelectAddrGA(SDValue &N, SDValue &R) { return SelectGlobalAddress(N, R, false); } inline bool HexagonDAGToDAGISel::SelectAddrGP(SDValue &N, SDValue &R) { return SelectGlobalAddress(N, R, true); } bool HexagonDAGToDAGISel::SelectGlobalAddress(SDValue &N, SDValue &R, bool UseGP) { switch (N.getOpcode()) { case ISD::ADD: { SDValue N0 = N.getOperand(0); SDValue N1 = N.getOperand(1); unsigned GAOpc = N0.getOpcode(); if (UseGP && GAOpc != HexagonISD::CONST32_GP) return false; if (!UseGP && GAOpc != HexagonISD::CONST32) return false; if (ConstantSDNode *Const = dyn_cast(N1)) { SDValue Addr = N0.getOperand(0); if (GlobalAddressSDNode *GA = dyn_cast(Addr)) { if (GA->getOpcode() == ISD::TargetGlobalAddress) { uint64_t NewOff = GA->getOffset() + (uint64_t)Const->getSExtValue(); R = CurDAG->getTargetGlobalAddress(GA->getGlobal(), SDLoc(Const), N.getValueType(), NewOff); return true; } } } break; } case HexagonISD::CONST32: // The operand(0) of CONST32 is TargetGlobalAddress, which is what we // want in the instruction. if (!UseGP) R = N.getOperand(0); return !UseGP; case HexagonISD::CONST32_GP: if (UseGP) R = N.getOperand(0); return UseGP; default: return false; } return false; } bool HexagonDAGToDAGISel::isValueExtension(const SDValue &Val, unsigned FromBits, SDValue &Src) { unsigned Opc = Val.getOpcode(); switch (Opc) { case ISD::SIGN_EXTEND: case ISD::ZERO_EXTEND: case ISD::ANY_EXTEND: { SDValue const &Op0 = Val.getOperand(0); EVT T = Op0.getValueType(); if (T.isInteger() && T.getSizeInBits() == FromBits) { Src = Op0; return true; } break; } case ISD::SIGN_EXTEND_INREG: case ISD::AssertSext: case ISD::AssertZext: if (Val.getOperand(0).getValueType().isInteger()) { VTSDNode *T = cast(Val.getOperand(1)); if (T->getVT().getSizeInBits() == FromBits) { Src = Val.getOperand(0); return true; } } break; case ISD::AND: { // Check if this is an AND with "FromBits" of lower bits set to 1. uint64_t FromMask = (1 << FromBits) - 1; if (ConstantSDNode *C = dyn_cast(Val.getOperand(0))) { if (C->getZExtValue() == FromMask) { Src = Val.getOperand(1); return true; } } if (ConstantSDNode *C = dyn_cast(Val.getOperand(1))) { if (C->getZExtValue() == FromMask) { Src = Val.getOperand(0); return true; } } break; } case ISD::OR: case ISD::XOR: { // OR/XOR with the lower "FromBits" bits set to 0. uint64_t FromMask = (1 << FromBits) - 1; if (ConstantSDNode *C = dyn_cast(Val.getOperand(0))) { if ((C->getZExtValue() & FromMask) == 0) { Src = Val.getOperand(1); return true; } } if (ConstantSDNode *C = dyn_cast(Val.getOperand(1))) { if ((C->getZExtValue() & FromMask) == 0) { Src = Val.getOperand(0); return true; } } } default: break; } return false; } bool HexagonDAGToDAGISel::isOrEquivalentToAdd(const SDNode *N) const { assert(N->getOpcode() == ISD::OR); auto *C = dyn_cast(N->getOperand(1)); assert(C); // Detect when "or" is used to add an offset to a stack object. if (auto *FN = dyn_cast(N->getOperand(0))) { MachineFrameInfo &MFI = MF->getFrameInfo(); unsigned A = MFI.getObjectAlignment(FN->getIndex()); assert(isPowerOf2_32(A)); int32_t Off = C->getSExtValue(); // If the alleged offset fits in the zero bits guaranteed by // the alignment, then this or is really an add. return (Off >= 0) && (((A-1) & Off) == unsigned(Off)); } return false; } bool HexagonDAGToDAGISel::isAlignedMemNode(const MemSDNode *N) const { return N->getAlignment() >= N->getMemoryVT().getStoreSize(); } // Return true when the given node fits in a positive half word. bool HexagonDAGToDAGISel::isPositiveHalfWord(const SDNode *N) const { if (const ConstantSDNode *CN = dyn_cast(N)) { int64_t V = CN->getSExtValue(); return V > 0 && isInt<16>(V); } if (N->getOpcode() == ISD::SIGN_EXTEND_INREG) { const VTSDNode *VN = dyn_cast(N->getOperand(1)); return VN->getVT().getSizeInBits() <= 16; } return false; } //////////////////////////////////////////////////////////////////////////////// // Rebalancing of address calculation trees static bool isOpcodeHandled(const SDNode *N) { switch (N->getOpcode()) { case ISD::ADD: case ISD::MUL: return true; case ISD::SHL: // We only handle constant shifts because these can be easily flattened // into multiplications by 2^Op1. return isa(N->getOperand(1).getNode()); default: return false; } } /// \brief Return the weight of an SDNode int HexagonDAGToDAGISel::getWeight(SDNode *N) { if (!isOpcodeHandled(N)) return 1; assert(RootWeights.count(N) && "Cannot get weight of unseen root!"); assert(RootWeights[N] != -1 && "Cannot get weight of unvisited root!"); assert(RootWeights[N] != -2 && "Cannot get weight of RAWU'd root!"); return RootWeights[N]; } int HexagonDAGToDAGISel::getHeight(SDNode *N) { if (!isOpcodeHandled(N)) return 0; assert(RootWeights.count(N) && RootWeights[N] >= 0 && "Cannot query height of unvisited/RAUW'd node!"); return RootHeights[N]; } namespace { struct WeightedLeaf { SDValue Value; int Weight; int InsertionOrder; WeightedLeaf() : Value(SDValue()) { } WeightedLeaf(SDValue Value, int Weight, int InsertionOrder) : Value(Value), Weight(Weight), InsertionOrder(InsertionOrder) { assert(Weight >= 0 && "Weight must be >= 0"); } static bool Compare(const WeightedLeaf &A, const WeightedLeaf &B) { assert(A.Value.getNode() && B.Value.getNode()); return A.Weight == B.Weight ? (A.InsertionOrder > B.InsertionOrder) : (A.Weight > B.Weight); } }; /// A specialized priority queue for WeigthedLeaves. It automatically folds /// constants and allows removal of non-top elements while maintaining the /// priority order. class LeafPrioQueue { SmallVector Q; bool HaveConst; WeightedLeaf ConstElt; unsigned Opcode; public: bool empty() { return (!HaveConst && Q.empty()); } size_t size() { return Q.size() + HaveConst; } bool hasConst() { return HaveConst; } const WeightedLeaf &top() { if (HaveConst) return ConstElt; return Q.front(); } WeightedLeaf pop() { if (HaveConst) { HaveConst = false; return ConstElt; } std::pop_heap(Q.begin(), Q.end(), WeightedLeaf::Compare); return Q.pop_back_val(); } void push(WeightedLeaf L, bool SeparateConst=true) { if (!HaveConst && SeparateConst && isa(L.Value)) { if (Opcode == ISD::MUL && cast(L.Value)->getSExtValue() == 1) return; if (Opcode == ISD::ADD && cast(L.Value)->getSExtValue() == 0) return; HaveConst = true; ConstElt = L; } else { Q.push_back(L); std::push_heap(Q.begin(), Q.end(), WeightedLeaf::Compare); } } /// Push L to the bottom of the queue regardless of its weight. If L is /// constant, it will not be folded with other constants in the queue. void pushToBottom(WeightedLeaf L) { L.Weight = 1000; push(L, false); } /// Search for a SHL(x, [<=MaxAmount]) subtree in the queue, return the one of /// lowest weight and remove it from the queue. WeightedLeaf findSHL(uint64_t MaxAmount); WeightedLeaf findMULbyConst(); LeafPrioQueue(unsigned Opcode) : HaveConst(false), Opcode(Opcode) { } }; } // end anonymous namespace WeightedLeaf LeafPrioQueue::findSHL(uint64_t MaxAmount) { int ResultPos; WeightedLeaf Result; for (int Pos = 0, End = Q.size(); Pos != End; ++Pos) { const WeightedLeaf &L = Q[Pos]; const SDValue &Val = L.Value; if (Val.getOpcode() != ISD::SHL || !isa(Val.getOperand(1)) || Val.getConstantOperandVal(1) > MaxAmount) continue; if (!Result.Value.getNode() || Result.Weight > L.Weight || (Result.Weight == L.Weight && Result.InsertionOrder > L.InsertionOrder)) { Result = L; ResultPos = Pos; } } if (Result.Value.getNode()) { Q.erase(&Q[ResultPos]); std::make_heap(Q.begin(), Q.end(), WeightedLeaf::Compare); } return Result; } WeightedLeaf LeafPrioQueue::findMULbyConst() { int ResultPos; WeightedLeaf Result; for (int Pos = 0, End = Q.size(); Pos != End; ++Pos) { const WeightedLeaf &L = Q[Pos]; const SDValue &Val = L.Value; if (Val.getOpcode() != ISD::MUL || !isa(Val.getOperand(1)) || Val.getConstantOperandVal(1) > 127) continue; if (!Result.Value.getNode() || Result.Weight > L.Weight || (Result.Weight == L.Weight && Result.InsertionOrder > L.InsertionOrder)) { Result = L; ResultPos = Pos; } } if (Result.Value.getNode()) { Q.erase(&Q[ResultPos]); std::make_heap(Q.begin(), Q.end(), WeightedLeaf::Compare); } return Result; } SDValue HexagonDAGToDAGISel::getMultiplierForSHL(SDNode *N) { uint64_t MulFactor = 1ull << N->getConstantOperandVal(1); return CurDAG->getConstant(MulFactor, SDLoc(N), N->getOperand(1).getValueType()); } /// @returns the value x for which 2^x is a factor of Val static unsigned getPowerOf2Factor(SDValue Val) { if (Val.getOpcode() == ISD::MUL) { unsigned MaxFactor = 0; for (int i = 0; i < 2; ++i) { ConstantSDNode *C = dyn_cast(Val.getOperand(i)); if (!C) continue; const APInt &CInt = C->getAPIntValue(); if (CInt.getBoolValue()) MaxFactor = CInt.countTrailingZeros(); } return MaxFactor; } if (Val.getOpcode() == ISD::SHL) { if (!isa(Val.getOperand(1).getNode())) return 0; return (unsigned) Val.getConstantOperandVal(1); } return 0; } /// @returns true if V>>Amount will eliminate V's operation on its child static bool willShiftRightEliminate(SDValue V, unsigned Amount) { if (V.getOpcode() == ISD::MUL) { SDValue Ops[] = { V.getOperand(0), V.getOperand(1) }; for (int i = 0; i < 2; ++i) if (isa(Ops[i].getNode()) && V.getConstantOperandVal(i) % (1ULL << Amount) == 0) { uint64_t NewConst = V.getConstantOperandVal(i) >> Amount; return (NewConst == 1); } } else if (V.getOpcode() == ISD::SHL) { return (Amount == V.getConstantOperandVal(1)); } return false; } SDValue HexagonDAGToDAGISel::factorOutPowerOf2(SDValue V, unsigned Power) { SDValue Ops[] = { V.getOperand(0), V.getOperand(1) }; if (V.getOpcode() == ISD::MUL) { for (int i=0; i < 2; ++i) { if (isa(Ops[i].getNode()) && V.getConstantOperandVal(i) % ((uint64_t)1 << Power) == 0) { uint64_t NewConst = V.getConstantOperandVal(i) >> Power; if (NewConst == 1) return Ops[!i]; Ops[i] = CurDAG->getConstant(NewConst, SDLoc(V), V.getValueType()); break; } } } else if (V.getOpcode() == ISD::SHL) { uint64_t ShiftAmount = V.getConstantOperandVal(1); if (ShiftAmount == Power) return Ops[0]; Ops[1] = CurDAG->getConstant(ShiftAmount - Power, SDLoc(V), V.getValueType()); } return CurDAG->getNode(V.getOpcode(), SDLoc(V), V.getValueType(), Ops); } static bool isTargetConstant(const SDValue &V) { return V.getOpcode() == HexagonISD::CONST32 || V.getOpcode() == HexagonISD::CONST32_GP; } unsigned HexagonDAGToDAGISel::getUsesInFunction(const Value *V) { if (GAUsesInFunction.count(V)) return GAUsesInFunction[V]; unsigned Result = 0; const Function *CurF = CurDAG->getMachineFunction().getFunction(); for (const User *U : V->users()) { if (isa(U) && cast(U)->getParent()->getParent() == CurF) ++Result; } GAUsesInFunction[V] = Result; return Result; } /// Note - After calling this, N may be dead. It may have been replaced by a /// new node, so always use the returned value in place of N. /// /// @returns The SDValue taking the place of N (which could be N if it is /// unchanged) SDValue HexagonDAGToDAGISel::balanceSubTree(SDNode *N, bool TopLevel) { assert(RootWeights.count(N) && "Cannot balance non-root node."); assert(RootWeights[N] != -2 && "This node was RAUW'd!"); assert(!TopLevel || N->getOpcode() == ISD::ADD); // Return early if this node was already visited if (RootWeights[N] != -1) return SDValue(N, 0); assert(isOpcodeHandled(N)); SDValue Op0 = N->getOperand(0); SDValue Op1 = N->getOperand(1); // Return early if the operands will remain unchanged or are all roots if ((!isOpcodeHandled(Op0.getNode()) || RootWeights.count(Op0.getNode())) && (!isOpcodeHandled(Op1.getNode()) || RootWeights.count(Op1.getNode()))) { SDNode *Op0N = Op0.getNode(); int Weight; if (isOpcodeHandled(Op0N) && RootWeights[Op0N] == -1) { Weight = getWeight(balanceSubTree(Op0N).getNode()); // Weight = calculateWeight(Op0N); } else Weight = getWeight(Op0N); SDNode *Op1N = N->getOperand(1).getNode(); // Op1 may have been RAUWd if (isOpcodeHandled(Op1N) && RootWeights[Op1N] == -1) { Weight += getWeight(balanceSubTree(Op1N).getNode()); // Weight += calculateWeight(Op1N); } else Weight += getWeight(Op1N); RootWeights[N] = Weight; RootHeights[N] = std::max(getHeight(N->getOperand(0).getNode()), getHeight(N->getOperand(1).getNode())) + 1; DEBUG(dbgs() << "--> No need to balance root (Weight=" << Weight << " Height=" << RootHeights[N] << "): "); DEBUG(N->dump()); return SDValue(N, 0); } DEBUG(dbgs() << "** Balancing root node: "); DEBUG(N->dump()); unsigned NOpcode = N->getOpcode(); LeafPrioQueue Leaves(NOpcode); SmallVector Worklist; Worklist.push_back(SDValue(N, 0)); // SHL nodes will be converted to MUL nodes if (NOpcode == ISD::SHL) NOpcode = ISD::MUL; bool CanFactorize = false; WeightedLeaf Mul1, Mul2; unsigned MaxPowerOf2 = 0; WeightedLeaf GA; // Do not try to factor out a shift if there is already a shift at the tip of // the tree. bool HaveTopLevelShift = false; if (TopLevel && ((isOpcodeHandled(Op0.getNode()) && Op0.getOpcode() == ISD::SHL && Op0.getConstantOperandVal(1) < 4) || (isOpcodeHandled(Op1.getNode()) && Op1.getOpcode() == ISD::SHL && Op1.getConstantOperandVal(1) < 4))) HaveTopLevelShift = true; // Flatten the subtree into an ordered list of leaves; at the same time // determine whether the tree is already balanced. int InsertionOrder = 0; SmallDenseMap NodeHeights; bool Imbalanced = false; int CurrentWeight = 0; while (!Worklist.empty()) { SDValue Child = Worklist.pop_back_val(); if (Child.getNode() != N && RootWeights.count(Child.getNode())) { // CASE 1: Child is a root note int Weight = RootWeights[Child.getNode()]; if (Weight == -1) { Child = balanceSubTree(Child.getNode()); // calculateWeight(Child.getNode()); Weight = getWeight(Child.getNode()); } else if (Weight == -2) { // Whoops, this node was RAUWd by one of the balanceSubTree calls we // made. Our worklist isn't up to date anymore. // Restart the whole process. DEBUG(dbgs() << "--> Subtree was RAUWd. Restarting...\n"); return balanceSubTree(N, TopLevel); } NodeHeights[Child] = 1; CurrentWeight += Weight; unsigned PowerOf2; if (TopLevel && !CanFactorize && !HaveTopLevelShift && (Child.getOpcode() == ISD::MUL || Child.getOpcode() == ISD::SHL) && Child.hasOneUse() && (PowerOf2 = getPowerOf2Factor(Child))) { // Try to identify two factorizable MUL/SHL children greedily. Leave // them out of the priority queue for now so we can deal with them // after. if (!Mul1.Value.getNode()) { Mul1 = WeightedLeaf(Child, Weight, InsertionOrder++); MaxPowerOf2 = PowerOf2; } else { Mul2 = WeightedLeaf(Child, Weight, InsertionOrder++); MaxPowerOf2 = std::min(MaxPowerOf2, PowerOf2); // Our addressing modes can only shift by a maximum of 3 if (MaxPowerOf2 > 3) MaxPowerOf2 = 3; CanFactorize = true; } } else Leaves.push(WeightedLeaf(Child, Weight, InsertionOrder++)); } else if (!isOpcodeHandled(Child.getNode())) { // CASE 2: Child is an unhandled kind of node (e.g. constant) int Weight = getWeight(Child.getNode()); NodeHeights[Child] = getHeight(Child.getNode()); CurrentWeight += Weight; if (isTargetConstant(Child) && !GA.Value.getNode()) GA = WeightedLeaf(Child, Weight, InsertionOrder++); else Leaves.push(WeightedLeaf(Child, Weight, InsertionOrder++)); } else { // CASE 3: Child is a subtree of same opcode // Visit children first, then flatten. unsigned ChildOpcode = Child.getOpcode(); assert(ChildOpcode == NOpcode || (NOpcode == ISD::MUL && ChildOpcode == ISD::SHL)); // Convert SHL to MUL SDValue Op1; if (ChildOpcode == ISD::SHL) Op1 = getMultiplierForSHL(Child.getNode()); else Op1 = Child->getOperand(1); if (!NodeHeights.count(Op1) || !NodeHeights.count(Child->getOperand(0))) { assert(!NodeHeights.count(Child) && "Parent visited before children?"); // Visit children first, then re-visit this node Worklist.push_back(Child); Worklist.push_back(Op1); Worklist.push_back(Child->getOperand(0)); } else { // Back at this node after visiting the children if (std::abs(NodeHeights[Op1] - NodeHeights[Child->getOperand(0)]) > 1) Imbalanced = true; NodeHeights[Child] = std::max(NodeHeights[Op1], NodeHeights[Child->getOperand(0)]) + 1; } } } DEBUG(dbgs() << "--> Current height=" << NodeHeights[SDValue(N, 0)] << " weight=" << CurrentWeight << " imbalanced=" << Imbalanced << "\n"); // Transform MUL(x, C * 2^Y) + SHL(z, Y) -> SHL(ADD(MUL(x, C), z), Y) // This factors out a shift in order to match memw(a< Found common factor for two MUL children!\n"); int Weight = Mul1.Weight + Mul2.Weight; int Height = std::max(NodeHeights[Mul1.Value], NodeHeights[Mul2.Value]) + 1; SDValue Mul1Factored = factorOutPowerOf2(Mul1.Value, MaxPowerOf2); SDValue Mul2Factored = factorOutPowerOf2(Mul2.Value, MaxPowerOf2); SDValue Sum = CurDAG->getNode(ISD::ADD, SDLoc(N), Mul1.Value.getValueType(), Mul1Factored, Mul2Factored); SDValue Const = CurDAG->getConstant(MaxPowerOf2, SDLoc(N), Mul1.Value.getValueType()); SDValue New = CurDAG->getNode(ISD::SHL, SDLoc(N), Mul1.Value.getValueType(), Sum, Const); NodeHeights[New] = Height; Leaves.push(WeightedLeaf(New, Weight, Mul1.InsertionOrder)); } else if (Mul1.Value.getNode()) { // We failed to factorize two MULs, so now the Muls are left outside the // queue... add them back. Leaves.push(Mul1); if (Mul2.Value.getNode()) Leaves.push(Mul2); CanFactorize = false; } // Combine GA + Constant -> GA+Offset, but only if GA is not used elsewhere // and the root node itself is not used more than twice. This reduces the // amount of additional constant extenders introduced by this optimization. bool CombinedGA = false; if (NOpcode == ISD::ADD && GA.Value.getNode() && Leaves.hasConst() && GA.Value.hasOneUse() && N->use_size() < 3) { GlobalAddressSDNode *GANode = cast(GA.Value.getOperand(0)); ConstantSDNode *Offset = cast(Leaves.top().Value); if (getUsesInFunction(GANode->getGlobal()) == 1 && Offset->hasOneUse() && getTargetLowering()->isOffsetFoldingLegal(GANode)) { DEBUG(dbgs() << "--> Combining GA and offset (" << Offset->getSExtValue() << "): "); DEBUG(GANode->dump()); SDValue NewTGA = CurDAG->getTargetGlobalAddress(GANode->getGlobal(), SDLoc(GA.Value), GANode->getValueType(0), GANode->getOffset() + (uint64_t)Offset->getSExtValue()); GA.Value = CurDAG->getNode(GA.Value.getOpcode(), SDLoc(GA.Value), GA.Value.getValueType(), NewTGA); GA.Weight += Leaves.top().Weight; NodeHeights[GA.Value] = getHeight(GA.Value.getNode()); CombinedGA = true; Leaves.pop(); // Remove the offset constant from the queue } } if ((RebalanceOnlyForOptimizations && !CanFactorize && !CombinedGA) || (RebalanceOnlyImbalancedTrees && !Imbalanced)) { RootWeights[N] = CurrentWeight; RootHeights[N] = NodeHeights[SDValue(N, 0)]; return SDValue(N, 0); } // Combine GA + SHL(x, C<=31) so we will match Rx=add(#u8,asl(Rx,#U5)) if (NOpcode == ISD::ADD && GA.Value.getNode()) { WeightedLeaf SHL = Leaves.findSHL(31); if (SHL.Value.getNode()) { int Height = std::max(NodeHeights[GA.Value], NodeHeights[SHL.Value]) + 1; GA.Value = CurDAG->getNode(ISD::ADD, SDLoc(GA.Value), GA.Value.getValueType(), GA.Value, SHL.Value); GA.Weight = SHL.Weight; // Specifically ignore the GA weight here NodeHeights[GA.Value] = Height; } } if (GA.Value.getNode()) Leaves.push(GA); // If this is the top level and we haven't factored out a shift, we should try // to move a constant to the bottom to match addressing modes like memw(rX+C) if (TopLevel && !CanFactorize && Leaves.hasConst()) { DEBUG(dbgs() << "--> Pushing constant to tip of tree."); Leaves.pushToBottom(Leaves.pop()); } const DataLayout &DL = CurDAG->getDataLayout(); const TargetLowering &TLI = *getTargetLowering(); // Rebuild the tree using Huffman's algorithm while (Leaves.size() > 1) { WeightedLeaf L0 = Leaves.pop(); // See whether we can grab a MUL to form an add(Rx,mpyi(Ry,#u6)), // otherwise just get the next leaf WeightedLeaf L1 = Leaves.findMULbyConst(); if (!L1.Value.getNode()) L1 = Leaves.pop(); assert(L0.Weight <= L1.Weight && "Priority queue is broken!"); SDValue V0 = L0.Value; int V0Weight = L0.Weight; SDValue V1 = L1.Value; int V1Weight = L1.Weight; // Make sure that none of these nodes have been RAUW'd if ((RootWeights.count(V0.getNode()) && RootWeights[V0.getNode()] == -2) || (RootWeights.count(V1.getNode()) && RootWeights[V1.getNode()] == -2)) { DEBUG(dbgs() << "--> Subtree was RAUWd. Restarting...\n"); return balanceSubTree(N, TopLevel); } ConstantSDNode *V0C = dyn_cast(V0); ConstantSDNode *V1C = dyn_cast(V1); EVT VT = N->getValueType(0); SDValue NewNode; if (V0C && !V1C) { std::swap(V0, V1); std::swap(V0C, V1C); } // Calculate height of this node assert(NodeHeights.count(V0) && NodeHeights.count(V1) && "Children must have been visited before re-combining them!"); int Height = std::max(NodeHeights[V0], NodeHeights[V1]) + 1; // Rebuild this node (and restore SHL from MUL if needed) if (V1C && NOpcode == ISD::MUL && V1C->getAPIntValue().isPowerOf2()) NewNode = CurDAG->getNode( ISD::SHL, SDLoc(V0), VT, V0, CurDAG->getConstant( V1C->getAPIntValue().logBase2(), SDLoc(N), TLI.getScalarShiftAmountTy(DL, V0.getValueType()))); else NewNode = CurDAG->getNode(NOpcode, SDLoc(N), VT, V0, V1); NodeHeights[NewNode] = Height; int Weight = V0Weight + V1Weight; Leaves.push(WeightedLeaf(NewNode, Weight, L0.InsertionOrder)); DEBUG(dbgs() << "--> Built new node (Weight=" << Weight << ",Height=" << Height << "):\n"); DEBUG(NewNode.dump()); } assert(Leaves.size() == 1); SDValue NewRoot = Leaves.top().Value; assert(NodeHeights.count(NewRoot)); int Height = NodeHeights[NewRoot]; // Restore SHL if we earlier converted it to a MUL if (NewRoot.getOpcode() == ISD::MUL) { ConstantSDNode *V1C = dyn_cast(NewRoot.getOperand(1)); if (V1C && V1C->getAPIntValue().isPowerOf2()) { EVT VT = NewRoot.getValueType(); SDValue V0 = NewRoot.getOperand(0); NewRoot = CurDAG->getNode( ISD::SHL, SDLoc(NewRoot), VT, V0, CurDAG->getConstant( V1C->getAPIntValue().logBase2(), SDLoc(NewRoot), TLI.getScalarShiftAmountTy(DL, V0.getValueType()))); } } if (N != NewRoot.getNode()) { DEBUG(dbgs() << "--> Root is now: "); DEBUG(NewRoot.dump()); // Replace all uses of old root by new root CurDAG->ReplaceAllUsesWith(N, NewRoot.getNode()); // Mark that we have RAUW'd N RootWeights[N] = -2; } else { DEBUG(dbgs() << "--> Root unchanged.\n"); } RootWeights[NewRoot.getNode()] = Leaves.top().Weight; RootHeights[NewRoot.getNode()] = Height; return NewRoot; } void HexagonDAGToDAGISel::rebalanceAddressTrees() { for (auto I = CurDAG->allnodes_begin(), E = CurDAG->allnodes_end(); I != E;) { SDNode *N = &*I++; if (N->getOpcode() != ISD::LOAD && N->getOpcode() != ISD::STORE) continue; SDValue BasePtr = cast(N)->getBasePtr(); if (BasePtr.getOpcode() != ISD::ADD) continue; // We've already processed this node if (RootWeights.count(BasePtr.getNode())) continue; DEBUG(dbgs() << "** Rebalancing address calculation in node: "); DEBUG(N->dump()); // FindRoots SmallVector Worklist; Worklist.push_back(BasePtr.getOperand(0).getNode()); Worklist.push_back(BasePtr.getOperand(1).getNode()); while (!Worklist.empty()) { SDNode *N = Worklist.pop_back_val(); unsigned Opcode = N->getOpcode(); if (!isOpcodeHandled(N)) continue; Worklist.push_back(N->getOperand(0).getNode()); Worklist.push_back(N->getOperand(1).getNode()); // Not a root if it has only one use and same opcode as its parent if (N->hasOneUse() && Opcode == N->use_begin()->getOpcode()) continue; // This root node has already been processed if (RootWeights.count(N)) continue; RootWeights[N] = -1; } // Balance node itself RootWeights[BasePtr.getNode()] = -1; SDValue NewBasePtr = balanceSubTree(BasePtr.getNode(), /*TopLevel=*/ true); if (N->getOpcode() == ISD::LOAD) N = CurDAG->UpdateNodeOperands(N, N->getOperand(0), NewBasePtr, N->getOperand(2)); else N = CurDAG->UpdateNodeOperands(N, N->getOperand(0), N->getOperand(1), NewBasePtr, N->getOperand(3)); DEBUG(dbgs() << "--> Final node: "); DEBUG(N->dump()); } CurDAG->RemoveDeadNodes(); GAUsesInFunction.clear(); RootHeights.clear(); RootWeights.clear(); }