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Diffstat (limited to 'contrib/llvm-project/llvm/lib/Target/Hexagon/HexagonOptAddrMode.cpp')
| -rw-r--r-- | contrib/llvm-project/llvm/lib/Target/Hexagon/HexagonOptAddrMode.cpp | 827 |
1 files changed, 827 insertions, 0 deletions
diff --git a/contrib/llvm-project/llvm/lib/Target/Hexagon/HexagonOptAddrMode.cpp b/contrib/llvm-project/llvm/lib/Target/Hexagon/HexagonOptAddrMode.cpp new file mode 100644 index 000000000000..547da9fd598f --- /dev/null +++ b/contrib/llvm-project/llvm/lib/Target/Hexagon/HexagonOptAddrMode.cpp @@ -0,0 +1,827 @@ +//===- HexagonOptAddrMode.cpp ---------------------------------------------===// +// +// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. +// See https://llvm.org/LICENSE.txt for license information. +// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception +// +//===----------------------------------------------------------------------===// +// This implements a Hexagon-specific pass to optimize addressing mode for +// load/store instructions. +//===----------------------------------------------------------------------===// + +#include "HexagonInstrInfo.h" +#include "HexagonSubtarget.h" +#include "MCTargetDesc/HexagonBaseInfo.h" +#include "RDFGraph.h" +#include "RDFLiveness.h" +#include "RDFRegisters.h" +#include "llvm/ADT/DenseMap.h" +#include "llvm/ADT/DenseSet.h" +#include "llvm/ADT/StringRef.h" +#include "llvm/CodeGen/MachineBasicBlock.h" +#include "llvm/CodeGen/MachineDominanceFrontier.h" +#include "llvm/CodeGen/MachineDominators.h" +#include "llvm/CodeGen/MachineFunction.h" +#include "llvm/CodeGen/MachineFunctionPass.h" +#include "llvm/CodeGen/MachineInstr.h" +#include "llvm/CodeGen/MachineInstrBuilder.h" +#include "llvm/CodeGen/MachineOperand.h" +#include "llvm/CodeGen/MachineRegisterInfo.h" +#include "llvm/CodeGen/TargetSubtargetInfo.h" +#include "llvm/MC/MCInstrDesc.h" +#include "llvm/Pass.h" +#include "llvm/Support/CommandLine.h" +#include "llvm/Support/Debug.h" +#include "llvm/Support/ErrorHandling.h" +#include "llvm/Support/raw_ostream.h" +#include <cassert> +#include <cstdint> + +#define DEBUG_TYPE "opt-addr-mode" + +using namespace llvm; +using namespace rdf; + +static cl::opt<int> CodeGrowthLimit("hexagon-amode-growth-limit", + cl::Hidden, cl::init(0), cl::desc("Code growth limit for address mode " + "optimization")); + +namespace llvm { + + FunctionPass *createHexagonOptAddrMode(); + void initializeHexagonOptAddrModePass(PassRegistry&); + +} // end namespace llvm + +namespace { + +class HexagonOptAddrMode : public MachineFunctionPass { +public: + static char ID; + + HexagonOptAddrMode() : MachineFunctionPass(ID) {} + + StringRef getPassName() const override { + return "Optimize addressing mode of load/store"; + } + + void getAnalysisUsage(AnalysisUsage &AU) const override { + MachineFunctionPass::getAnalysisUsage(AU); + AU.addRequired<MachineDominatorTree>(); + AU.addRequired<MachineDominanceFrontier>(); + AU.setPreservesAll(); + } + + bool runOnMachineFunction(MachineFunction &MF) override; + +private: + using MISetType = DenseSet<MachineInstr *>; + using InstrEvalMap = DenseMap<MachineInstr *, bool>; + + MachineRegisterInfo *MRI = nullptr; + const HexagonInstrInfo *HII = nullptr; + const HexagonRegisterInfo *HRI = nullptr; + MachineDominatorTree *MDT = nullptr; + DataFlowGraph *DFG = nullptr; + DataFlowGraph::DefStackMap DefM; + Liveness *LV = nullptr; + MISetType Deleted; + + bool processBlock(NodeAddr<BlockNode *> BA); + bool xformUseMI(MachineInstr *TfrMI, MachineInstr *UseMI, + NodeAddr<UseNode *> UseN, unsigned UseMOnum); + bool processAddUses(NodeAddr<StmtNode *> AddSN, MachineInstr *AddMI, + const NodeList &UNodeList); + bool updateAddUses(MachineInstr *AddMI, MachineInstr *UseMI); + bool analyzeUses(unsigned DefR, const NodeList &UNodeList, + InstrEvalMap &InstrEvalResult, short &SizeInc); + bool hasRepForm(MachineInstr &MI, unsigned TfrDefR); + bool canRemoveAddasl(NodeAddr<StmtNode *> AddAslSN, MachineInstr &MI, + const NodeList &UNodeList); + bool isSafeToExtLR(NodeAddr<StmtNode *> SN, MachineInstr *MI, + unsigned LRExtReg, const NodeList &UNodeList); + void getAllRealUses(NodeAddr<StmtNode *> SN, NodeList &UNodeList); + bool allValidCandidates(NodeAddr<StmtNode *> SA, NodeList &UNodeList); + short getBaseWithLongOffset(const MachineInstr &MI) const; + bool changeStore(MachineInstr *OldMI, MachineOperand ImmOp, + unsigned ImmOpNum); + bool changeLoad(MachineInstr *OldMI, MachineOperand ImmOp, unsigned ImmOpNum); + bool changeAddAsl(NodeAddr<UseNode *> AddAslUN, MachineInstr *AddAslMI, + const MachineOperand &ImmOp, unsigned ImmOpNum); + bool isValidOffset(MachineInstr *MI, int Offset); +}; + +} // end anonymous namespace + +char HexagonOptAddrMode::ID = 0; + +INITIALIZE_PASS_BEGIN(HexagonOptAddrMode, "amode-opt", + "Optimize addressing mode", false, false) +INITIALIZE_PASS_DEPENDENCY(MachineDominatorTree) +INITIALIZE_PASS_DEPENDENCY(MachineDominanceFrontier) +INITIALIZE_PASS_END(HexagonOptAddrMode, "amode-opt", "Optimize addressing mode", + false, false) + +bool HexagonOptAddrMode::hasRepForm(MachineInstr &MI, unsigned TfrDefR) { + const MCInstrDesc &MID = MI.getDesc(); + + if ((!MID.mayStore() && !MID.mayLoad()) || HII->isPredicated(MI)) + return false; + + if (MID.mayStore()) { + MachineOperand StOp = MI.getOperand(MI.getNumOperands() - 1); + if (StOp.isReg() && StOp.getReg() == TfrDefR) + return false; + } + + if (HII->getAddrMode(MI) == HexagonII::BaseRegOffset) + // Tranform to Absolute plus register offset. + return (HII->changeAddrMode_rr_ur(MI) >= 0); + else if (HII->getAddrMode(MI) == HexagonII::BaseImmOffset) + // Tranform to absolute addressing mode. + return (HII->changeAddrMode_io_abs(MI) >= 0); + + return false; +} + +// Check if addasl instruction can be removed. This is possible only +// if it's feeding to only load/store instructions with base + register +// offset as these instruction can be tranformed to use 'absolute plus +// shifted register offset'. +// ex: +// Rs = ##foo +// Rx = addasl(Rs, Rt, #2) +// Rd = memw(Rx + #28) +// Above three instructions can be replaced with Rd = memw(Rt<<#2 + ##foo+28) + +bool HexagonOptAddrMode::canRemoveAddasl(NodeAddr<StmtNode *> AddAslSN, + MachineInstr &MI, + const NodeList &UNodeList) { + // check offset size in addasl. if 'offset > 3' return false + const MachineOperand &OffsetOp = MI.getOperand(3); + if (!OffsetOp.isImm() || OffsetOp.getImm() > 3) + return false; + + unsigned OffsetReg = MI.getOperand(2).getReg(); + RegisterRef OffsetRR; + NodeId OffsetRegRD = 0; + for (NodeAddr<UseNode *> UA : AddAslSN.Addr->members_if(DFG->IsUse, *DFG)) { + RegisterRef RR = UA.Addr->getRegRef(*DFG); + if (OffsetReg == RR.Reg) { + OffsetRR = RR; + OffsetRegRD = UA.Addr->getReachingDef(); + } + } + + for (auto I = UNodeList.rbegin(), E = UNodeList.rend(); I != E; ++I) { + NodeAddr<UseNode *> UA = *I; + NodeAddr<InstrNode *> IA = UA.Addr->getOwner(*DFG); + if (UA.Addr->getFlags() & NodeAttrs::PhiRef) + return false; + NodeAddr<RefNode*> AA = LV->getNearestAliasedRef(OffsetRR, IA); + if ((DFG->IsDef(AA) && AA.Id != OffsetRegRD) || + AA.Addr->getReachingDef() != OffsetRegRD) + return false; + + MachineInstr &UseMI = *NodeAddr<StmtNode *>(IA).Addr->getCode(); + NodeAddr<DefNode *> OffsetRegDN = DFG->addr<DefNode *>(OffsetRegRD); + // Reaching Def to an offset register can't be a phi. + if ((OffsetRegDN.Addr->getFlags() & NodeAttrs::PhiRef) && + MI.getParent() != UseMI.getParent()) + return false; + + const MCInstrDesc &UseMID = UseMI.getDesc(); + if ((!UseMID.mayLoad() && !UseMID.mayStore()) || + HII->getAddrMode(UseMI) != HexagonII::BaseImmOffset || + getBaseWithLongOffset(UseMI) < 0) + return false; + + // Addasl output can't be a store value. + if (UseMID.mayStore() && UseMI.getOperand(2).isReg() && + UseMI.getOperand(2).getReg() == MI.getOperand(0).getReg()) + return false; + + for (auto &Mo : UseMI.operands()) + if (Mo.isFI()) + return false; + } + return true; +} + +bool HexagonOptAddrMode::allValidCandidates(NodeAddr<StmtNode *> SA, + NodeList &UNodeList) { + for (auto I = UNodeList.rbegin(), E = UNodeList.rend(); I != E; ++I) { + NodeAddr<UseNode *> UN = *I; + RegisterRef UR = UN.Addr->getRegRef(*DFG); + NodeSet Visited, Defs; + const auto &P = LV->getAllReachingDefsRec(UR, UN, Visited, Defs); + if (!P.second) { + LLVM_DEBUG({ + dbgs() << "*** Unable to collect all reaching defs for use ***\n" + << PrintNode<UseNode*>(UN, *DFG) << '\n' + << "The program's complexity may exceed the limits.\n"; + }); + return false; + } + const auto &ReachingDefs = P.first; + if (ReachingDefs.size() > 1) { + LLVM_DEBUG({ + dbgs() << "*** Multiple Reaching Defs found!!! ***\n"; + for (auto DI : ReachingDefs) { + NodeAddr<UseNode *> DA = DFG->addr<UseNode *>(DI); + NodeAddr<StmtNode *> TempIA = DA.Addr->getOwner(*DFG); + dbgs() << "\t\t[Reaching Def]: " + << Print<NodeAddr<InstrNode *>>(TempIA, *DFG) << "\n"; + } + }); + return false; + } + } + return true; +} + +void HexagonOptAddrMode::getAllRealUses(NodeAddr<StmtNode *> SA, + NodeList &UNodeList) { + for (NodeAddr<DefNode *> DA : SA.Addr->members_if(DFG->IsDef, *DFG)) { + LLVM_DEBUG(dbgs() << "\t\t[DefNode]: " + << Print<NodeAddr<DefNode *>>(DA, *DFG) << "\n"); + RegisterRef DR = DFG->getPRI().normalize(DA.Addr->getRegRef(*DFG)); + + auto UseSet = LV->getAllReachedUses(DR, DA); + + for (auto UI : UseSet) { + NodeAddr<UseNode *> UA = DFG->addr<UseNode *>(UI); + LLVM_DEBUG({ + NodeAddr<StmtNode *> TempIA = UA.Addr->getOwner(*DFG); + dbgs() << "\t\t\t[Reached Use]: " + << Print<NodeAddr<InstrNode *>>(TempIA, *DFG) << "\n"; + }); + + if (UA.Addr->getFlags() & NodeAttrs::PhiRef) { + NodeAddr<PhiNode *> PA = UA.Addr->getOwner(*DFG); + NodeId id = PA.Id; + const Liveness::RefMap &phiUse = LV->getRealUses(id); + LLVM_DEBUG(dbgs() << "\t\t\t\tphi real Uses" + << Print<Liveness::RefMap>(phiUse, *DFG) << "\n"); + if (!phiUse.empty()) { + for (auto I : phiUse) { + if (!DFG->getPRI().alias(RegisterRef(I.first), DR)) + continue; + auto phiUseSet = I.second; + for (auto phiUI : phiUseSet) { + NodeAddr<UseNode *> phiUA = DFG->addr<UseNode *>(phiUI.first); + UNodeList.push_back(phiUA); + } + } + } + } else + UNodeList.push_back(UA); + } + } +} + +bool HexagonOptAddrMode::isSafeToExtLR(NodeAddr<StmtNode *> SN, + MachineInstr *MI, unsigned LRExtReg, + const NodeList &UNodeList) { + RegisterRef LRExtRR; + NodeId LRExtRegRD = 0; + // Iterate through all the UseNodes in SN and find the reaching def + // for the LRExtReg. + for (NodeAddr<UseNode *> UA : SN.Addr->members_if(DFG->IsUse, *DFG)) { + RegisterRef RR = UA.Addr->getRegRef(*DFG); + if (LRExtReg == RR.Reg) { + LRExtRR = RR; + LRExtRegRD = UA.Addr->getReachingDef(); + } + } + + for (auto I = UNodeList.rbegin(), E = UNodeList.rend(); I != E; ++I) { + NodeAddr<UseNode *> UA = *I; + NodeAddr<InstrNode *> IA = UA.Addr->getOwner(*DFG); + // The reaching def of LRExtRR at load/store node should be same as the + // one reaching at the SN. + if (UA.Addr->getFlags() & NodeAttrs::PhiRef) + return false; + NodeAddr<RefNode*> AA = LV->getNearestAliasedRef(LRExtRR, IA); + if ((DFG->IsDef(AA) && AA.Id != LRExtRegRD) || + AA.Addr->getReachingDef() != LRExtRegRD) { + LLVM_DEBUG( + dbgs() << "isSafeToExtLR: Returning false; another reaching def\n"); + return false; + } + + MachineInstr *UseMI = NodeAddr<StmtNode *>(IA).Addr->getCode(); + NodeAddr<DefNode *> LRExtRegDN = DFG->addr<DefNode *>(LRExtRegRD); + // Reaching Def to LRExtReg can't be a phi. + if ((LRExtRegDN.Addr->getFlags() & NodeAttrs::PhiRef) && + MI->getParent() != UseMI->getParent()) + return false; + } + return true; +} + +bool HexagonOptAddrMode::isValidOffset(MachineInstr *MI, int Offset) { + unsigned AlignMask = 0; + switch (HII->getMemAccessSize(*MI)) { + case HexagonII::MemAccessSize::DoubleWordAccess: + AlignMask = 0x7; + break; + case HexagonII::MemAccessSize::WordAccess: + AlignMask = 0x3; + break; + case HexagonII::MemAccessSize::HalfWordAccess: + AlignMask = 0x1; + break; + case HexagonII::MemAccessSize::ByteAccess: + AlignMask = 0x0; + break; + default: + return false; + } + + if ((AlignMask & Offset) != 0) + return false; + return HII->isValidOffset(MI->getOpcode(), Offset, HRI, false); +} + +bool HexagonOptAddrMode::processAddUses(NodeAddr<StmtNode *> AddSN, + MachineInstr *AddMI, + const NodeList &UNodeList) { + + unsigned AddDefR = AddMI->getOperand(0).getReg(); + for (auto I = UNodeList.rbegin(), E = UNodeList.rend(); I != E; ++I) { + NodeAddr<UseNode *> UN = *I; + NodeAddr<StmtNode *> SN = UN.Addr->getOwner(*DFG); + MachineInstr *MI = SN.Addr->getCode(); + const MCInstrDesc &MID = MI->getDesc(); + if ((!MID.mayLoad() && !MID.mayStore()) || + HII->getAddrMode(*MI) != HexagonII::BaseImmOffset || + HII->isHVXVec(*MI)) + return false; + + MachineOperand BaseOp = MID.mayLoad() ? MI->getOperand(1) + : MI->getOperand(0); + + if (!BaseOp.isReg() || BaseOp.getReg() != AddDefR) + return false; + + MachineOperand OffsetOp = MID.mayLoad() ? MI->getOperand(2) + : MI->getOperand(1); + if (!OffsetOp.isImm()) + return false; + + int64_t newOffset = OffsetOp.getImm() + AddMI->getOperand(2).getImm(); + if (!isValidOffset(MI, newOffset)) + return false; + + // Since we'll be extending the live range of Rt in the following example, + // make sure that is safe. another definition of Rt doesn't exist between 'add' + // and load/store instruction. + // + // Ex: Rx= add(Rt,#10) + // memw(Rx+#0) = Rs + // will be replaced with => memw(Rt+#10) = Rs + unsigned BaseReg = AddMI->getOperand(1).getReg(); + if (!isSafeToExtLR(AddSN, AddMI, BaseReg, UNodeList)) + return false; + } + + // Update all the uses of 'add' with the appropriate base and offset + // values. + bool Changed = false; + for (auto I = UNodeList.rbegin(), E = UNodeList.rend(); I != E; ++I) { + NodeAddr<UseNode *> UseN = *I; + assert(!(UseN.Addr->getFlags() & NodeAttrs::PhiRef) && + "Found a PhiRef node as a real reached use!!"); + + NodeAddr<StmtNode *> OwnerN = UseN.Addr->getOwner(*DFG); + MachineInstr *UseMI = OwnerN.Addr->getCode(); + LLVM_DEBUG(dbgs() << "\t\t[MI <BB#" << UseMI->getParent()->getNumber() + << ">]: " << *UseMI << "\n"); + Changed |= updateAddUses(AddMI, UseMI); + } + + if (Changed) + Deleted.insert(AddMI); + + return Changed; +} + +bool HexagonOptAddrMode::updateAddUses(MachineInstr *AddMI, + MachineInstr *UseMI) { + const MachineOperand ImmOp = AddMI->getOperand(2); + const MachineOperand AddRegOp = AddMI->getOperand(1); + unsigned newReg = AddRegOp.getReg(); + const MCInstrDesc &MID = UseMI->getDesc(); + + MachineOperand &BaseOp = MID.mayLoad() ? UseMI->getOperand(1) + : UseMI->getOperand(0); + MachineOperand &OffsetOp = MID.mayLoad() ? UseMI->getOperand(2) + : UseMI->getOperand(1); + BaseOp.setReg(newReg); + BaseOp.setIsUndef(AddRegOp.isUndef()); + BaseOp.setImplicit(AddRegOp.isImplicit()); + OffsetOp.setImm(ImmOp.getImm() + OffsetOp.getImm()); + MRI->clearKillFlags(newReg); + + return true; +} + +bool HexagonOptAddrMode::analyzeUses(unsigned tfrDefR, + const NodeList &UNodeList, + InstrEvalMap &InstrEvalResult, + short &SizeInc) { + bool KeepTfr = false; + bool HasRepInstr = false; + InstrEvalResult.clear(); + + for (auto I = UNodeList.rbegin(), E = UNodeList.rend(); I != E; ++I) { + bool CanBeReplaced = false; + NodeAddr<UseNode *> UN = *I; + NodeAddr<StmtNode *> SN = UN.Addr->getOwner(*DFG); + MachineInstr &MI = *SN.Addr->getCode(); + const MCInstrDesc &MID = MI.getDesc(); + if ((MID.mayLoad() || MID.mayStore())) { + if (!hasRepForm(MI, tfrDefR)) { + KeepTfr = true; + continue; + } + SizeInc++; + CanBeReplaced = true; + } else if (MI.getOpcode() == Hexagon::S2_addasl_rrri) { + NodeList AddaslUseList; + + LLVM_DEBUG(dbgs() << "\nGetting ReachedUses for === " << MI << "\n"); + getAllRealUses(SN, AddaslUseList); + // Process phi nodes. + if (allValidCandidates(SN, AddaslUseList) && + canRemoveAddasl(SN, MI, AddaslUseList)) { + SizeInc += AddaslUseList.size(); + SizeInc -= 1; // Reduce size by 1 as addasl itself can be removed. + CanBeReplaced = true; + } else + SizeInc++; + } else + // Currently, only load/store and addasl are handled. + // Some other instructions to consider - + // A2_add -> A2_addi + // M4_mpyrr_addr -> M4_mpyrr_addi + KeepTfr = true; + + InstrEvalResult[&MI] = CanBeReplaced; + HasRepInstr |= CanBeReplaced; + } + + // Reduce total size by 2 if original tfr can be deleted. + if (!KeepTfr) + SizeInc -= 2; + + return HasRepInstr; +} + +bool HexagonOptAddrMode::changeLoad(MachineInstr *OldMI, MachineOperand ImmOp, + unsigned ImmOpNum) { + bool Changed = false; + MachineBasicBlock *BB = OldMI->getParent(); + auto UsePos = MachineBasicBlock::iterator(OldMI); + MachineBasicBlock::instr_iterator InsertPt = UsePos.getInstrIterator(); + ++InsertPt; + unsigned OpStart; + unsigned OpEnd = OldMI->getNumOperands(); + MachineInstrBuilder MIB; + + if (ImmOpNum == 1) { + if (HII->getAddrMode(*OldMI) == HexagonII::BaseRegOffset) { + short NewOpCode = HII->changeAddrMode_rr_ur(*OldMI); + assert(NewOpCode >= 0 && "Invalid New opcode\n"); + MIB = BuildMI(*BB, InsertPt, OldMI->getDebugLoc(), HII->get(NewOpCode)); + MIB.add(OldMI->getOperand(0)); + MIB.add(OldMI->getOperand(2)); + MIB.add(OldMI->getOperand(3)); + MIB.add(ImmOp); + OpStart = 4; + Changed = true; + } else if (HII->getAddrMode(*OldMI) == HexagonII::BaseImmOffset && + OldMI->getOperand(2).isImm()) { + short NewOpCode = HII->changeAddrMode_io_abs(*OldMI); + assert(NewOpCode >= 0 && "Invalid New opcode\n"); + MIB = BuildMI(*BB, InsertPt, OldMI->getDebugLoc(), HII->get(NewOpCode)) + .add(OldMI->getOperand(0)); + const GlobalValue *GV = ImmOp.getGlobal(); + int64_t Offset = ImmOp.getOffset() + OldMI->getOperand(2).getImm(); + + MIB.addGlobalAddress(GV, Offset, ImmOp.getTargetFlags()); + OpStart = 3; + Changed = true; + } else + Changed = false; + + LLVM_DEBUG(dbgs() << "[Changing]: " << *OldMI << "\n"); + LLVM_DEBUG(dbgs() << "[TO]: " << *MIB << "\n"); + } else if (ImmOpNum == 2) { + if (OldMI->getOperand(3).isImm() && OldMI->getOperand(3).getImm() == 0) { + short NewOpCode = HII->changeAddrMode_rr_io(*OldMI); + assert(NewOpCode >= 0 && "Invalid New opcode\n"); + MIB = BuildMI(*BB, InsertPt, OldMI->getDebugLoc(), HII->get(NewOpCode)); + MIB.add(OldMI->getOperand(0)); + MIB.add(OldMI->getOperand(1)); + MIB.add(ImmOp); + OpStart = 4; + Changed = true; + LLVM_DEBUG(dbgs() << "[Changing]: " << *OldMI << "\n"); + LLVM_DEBUG(dbgs() << "[TO]: " << *MIB << "\n"); + } + } + + if (Changed) + for (unsigned i = OpStart; i < OpEnd; ++i) + MIB.add(OldMI->getOperand(i)); + + return Changed; +} + +bool HexagonOptAddrMode::changeStore(MachineInstr *OldMI, MachineOperand ImmOp, + unsigned ImmOpNum) { + bool Changed = false; + unsigned OpStart; + unsigned OpEnd = OldMI->getNumOperands(); + MachineBasicBlock *BB = OldMI->getParent(); + auto UsePos = MachineBasicBlock::iterator(OldMI); + MachineBasicBlock::instr_iterator InsertPt = UsePos.getInstrIterator(); + ++InsertPt; + MachineInstrBuilder MIB; + if (ImmOpNum == 0) { + if (HII->getAddrMode(*OldMI) == HexagonII::BaseRegOffset) { + short NewOpCode = HII->changeAddrMode_rr_ur(*OldMI); + assert(NewOpCode >= 0 && "Invalid New opcode\n"); + MIB = BuildMI(*BB, InsertPt, OldMI->getDebugLoc(), HII->get(NewOpCode)); + MIB.add(OldMI->getOperand(1)); + MIB.add(OldMI->getOperand(2)); + MIB.add(ImmOp); + MIB.add(OldMI->getOperand(3)); + OpStart = 4; + } else if (HII->getAddrMode(*OldMI) == HexagonII::BaseImmOffset) { + short NewOpCode = HII->changeAddrMode_io_abs(*OldMI); + assert(NewOpCode >= 0 && "Invalid New opcode\n"); + MIB = BuildMI(*BB, InsertPt, OldMI->getDebugLoc(), HII->get(NewOpCode)); + const GlobalValue *GV = ImmOp.getGlobal(); + int64_t Offset = ImmOp.getOffset() + OldMI->getOperand(1).getImm(); + MIB.addGlobalAddress(GV, Offset, ImmOp.getTargetFlags()); + MIB.add(OldMI->getOperand(2)); + OpStart = 3; + } + Changed = true; + LLVM_DEBUG(dbgs() << "[Changing]: " << *OldMI << "\n"); + LLVM_DEBUG(dbgs() << "[TO]: " << *MIB << "\n"); + } else if (ImmOpNum == 1 && OldMI->getOperand(2).getImm() == 0) { + short NewOpCode = HII->changeAddrMode_rr_io(*OldMI); + assert(NewOpCode >= 0 && "Invalid New opcode\n"); + MIB = BuildMI(*BB, InsertPt, OldMI->getDebugLoc(), HII->get(NewOpCode)); + MIB.add(OldMI->getOperand(0)); + MIB.add(ImmOp); + OpStart = 3; + Changed = true; + LLVM_DEBUG(dbgs() << "[Changing]: " << *OldMI << "\n"); + LLVM_DEBUG(dbgs() << "[TO]: " << *MIB << "\n"); + } + if (Changed) + for (unsigned i = OpStart; i < OpEnd; ++i) + MIB.add(OldMI->getOperand(i)); + + return Changed; +} + +short HexagonOptAddrMode::getBaseWithLongOffset(const MachineInstr &MI) const { + if (HII->getAddrMode(MI) == HexagonII::BaseImmOffset) { + short TempOpCode = HII->changeAddrMode_io_rr(MI); + return HII->changeAddrMode_rr_ur(TempOpCode); + } + return HII->changeAddrMode_rr_ur(MI); +} + +bool HexagonOptAddrMode::changeAddAsl(NodeAddr<UseNode *> AddAslUN, + MachineInstr *AddAslMI, + const MachineOperand &ImmOp, + unsigned ImmOpNum) { + NodeAddr<StmtNode *> SA = AddAslUN.Addr->getOwner(*DFG); + + LLVM_DEBUG(dbgs() << "Processing addasl :" << *AddAslMI << "\n"); + + NodeList UNodeList; + getAllRealUses(SA, UNodeList); + + for (auto I = UNodeList.rbegin(), E = UNodeList.rend(); I != E; ++I) { + NodeAddr<UseNode *> UseUN = *I; + assert(!(UseUN.Addr->getFlags() & NodeAttrs::PhiRef) && + "Can't transform this 'AddAsl' instruction!"); + + NodeAddr<StmtNode *> UseIA = UseUN.Addr->getOwner(*DFG); + LLVM_DEBUG(dbgs() << "[InstrNode]: " + << Print<NodeAddr<InstrNode *>>(UseIA, *DFG) << "\n"); + MachineInstr *UseMI = UseIA.Addr->getCode(); + LLVM_DEBUG(dbgs() << "[MI <" << printMBBReference(*UseMI->getParent()) + << ">]: " << *UseMI << "\n"); + const MCInstrDesc &UseMID = UseMI->getDesc(); + assert(HII->getAddrMode(*UseMI) == HexagonII::BaseImmOffset); + + auto UsePos = MachineBasicBlock::iterator(UseMI); + MachineBasicBlock::instr_iterator InsertPt = UsePos.getInstrIterator(); + short NewOpCode = getBaseWithLongOffset(*UseMI); + assert(NewOpCode >= 0 && "Invalid New opcode\n"); + + unsigned OpStart; + unsigned OpEnd = UseMI->getNumOperands(); + + MachineBasicBlock *BB = UseMI->getParent(); + MachineInstrBuilder MIB = + BuildMI(*BB, InsertPt, UseMI->getDebugLoc(), HII->get(NewOpCode)); + // change mem(Rs + # ) -> mem(Rt << # + ##) + if (UseMID.mayLoad()) { + MIB.add(UseMI->getOperand(0)); + MIB.add(AddAslMI->getOperand(2)); + MIB.add(AddAslMI->getOperand(3)); + const GlobalValue *GV = ImmOp.getGlobal(); + MIB.addGlobalAddress(GV, UseMI->getOperand(2).getImm()+ImmOp.getOffset(), + ImmOp.getTargetFlags()); + OpStart = 3; + } else if (UseMID.mayStore()) { + MIB.add(AddAslMI->getOperand(2)); + MIB.add(AddAslMI->getOperand(3)); + const GlobalValue *GV = ImmOp.getGlobal(); + MIB.addGlobalAddress(GV, UseMI->getOperand(1).getImm()+ImmOp.getOffset(), + ImmOp.getTargetFlags()); + MIB.add(UseMI->getOperand(2)); + OpStart = 3; + } else + llvm_unreachable("Unhandled instruction"); + + for (unsigned i = OpStart; i < OpEnd; ++i) + MIB.add(UseMI->getOperand(i)); + + Deleted.insert(UseMI); + } + + return true; +} + +bool HexagonOptAddrMode::xformUseMI(MachineInstr *TfrMI, MachineInstr *UseMI, + NodeAddr<UseNode *> UseN, + unsigned UseMOnum) { + const MachineOperand ImmOp = TfrMI->getOperand(1); + const MCInstrDesc &MID = UseMI->getDesc(); + unsigned Changed = false; + if (MID.mayLoad()) + Changed = changeLoad(UseMI, ImmOp, UseMOnum); + else if (MID.mayStore()) + Changed = changeStore(UseMI, ImmOp, UseMOnum); + else if (UseMI->getOpcode() == Hexagon::S2_addasl_rrri) + Changed = changeAddAsl(UseN, UseMI, ImmOp, UseMOnum); + + if (Changed) + Deleted.insert(UseMI); + + return Changed; +} + +bool HexagonOptAddrMode::processBlock(NodeAddr<BlockNode *> BA) { + bool Changed = false; + + for (auto IA : BA.Addr->members(*DFG)) { + if (!DFG->IsCode<NodeAttrs::Stmt>(IA)) + continue; + + NodeAddr<StmtNode *> SA = IA; + MachineInstr *MI = SA.Addr->getCode(); + if ((MI->getOpcode() != Hexagon::A2_tfrsi || + !MI->getOperand(1).isGlobal()) && + (MI->getOpcode() != Hexagon::A2_addi || + !MI->getOperand(2).isImm() || HII->isConstExtended(*MI))) + continue; + + LLVM_DEBUG(dbgs() << "[Analyzing " << HII->getName(MI->getOpcode()) + << "]: " << *MI << "\n\t[InstrNode]: " + << Print<NodeAddr<InstrNode *>>(IA, *DFG) << '\n'); + + NodeList UNodeList; + getAllRealUses(SA, UNodeList); + + if (!allValidCandidates(SA, UNodeList)) + continue; + + // Analyze all uses of 'add'. If the output of 'add' is used as an address + // in the base+immediate addressing mode load/store instructions, see if + // they can be updated to use the immediate value as an offet. Thus, + // providing us the opportunity to eliminate 'add'. + // Ex: Rx= add(Rt,#12) + // memw(Rx+#0) = Rs + // This can be replaced with memw(Rt+#12) = Rs + // + // This transformation is only performed if all uses can be updated and + // the offset isn't required to be constant extended. + if (MI->getOpcode() == Hexagon::A2_addi) { + Changed |= processAddUses(SA, MI, UNodeList); + continue; + } + + short SizeInc = 0; + unsigned DefR = MI->getOperand(0).getReg(); + InstrEvalMap InstrEvalResult; + + // Analyze all uses and calculate increase in size. Perform the optimization + // only if there is no increase in size. + if (!analyzeUses(DefR, UNodeList, InstrEvalResult, SizeInc)) + continue; + if (SizeInc > CodeGrowthLimit) + continue; + + bool KeepTfr = false; + + LLVM_DEBUG(dbgs() << "\t[Total reached uses] : " << UNodeList.size() + << "\n"); + LLVM_DEBUG(dbgs() << "\t[Processing Reached Uses] ===\n"); + for (auto I = UNodeList.rbegin(), E = UNodeList.rend(); I != E; ++I) { + NodeAddr<UseNode *> UseN = *I; + assert(!(UseN.Addr->getFlags() & NodeAttrs::PhiRef) && + "Found a PhiRef node as a real reached use!!"); + + NodeAddr<StmtNode *> OwnerN = UseN.Addr->getOwner(*DFG); + MachineInstr *UseMI = OwnerN.Addr->getCode(); + LLVM_DEBUG(dbgs() << "\t\t[MI <" << printMBBReference(*UseMI->getParent()) + << ">]: " << *UseMI << "\n"); + + int UseMOnum = -1; + unsigned NumOperands = UseMI->getNumOperands(); + for (unsigned j = 0; j < NumOperands - 1; ++j) { + const MachineOperand &op = UseMI->getOperand(j); + if (op.isReg() && op.isUse() && DefR == op.getReg()) + UseMOnum = j; + } + // It is possible that the register will not be found in any operand. + // This could happen, for example, when DefR = R4, but the used + // register is D2. + + // Change UseMI if replacement is possible. If any replacement failed, + // or wasn't attempted, make sure to keep the TFR. + bool Xformed = false; + if (UseMOnum >= 0 && InstrEvalResult[UseMI]) + Xformed = xformUseMI(MI, UseMI, UseN, UseMOnum); + Changed |= Xformed; + KeepTfr |= !Xformed; + } + if (!KeepTfr) + Deleted.insert(MI); + } + return Changed; +} + +bool HexagonOptAddrMode::runOnMachineFunction(MachineFunction &MF) { + if (skipFunction(MF.getFunction())) + return false; + + bool Changed = false; + auto &HST = MF.getSubtarget<HexagonSubtarget>(); + MRI = &MF.getRegInfo(); + HII = HST.getInstrInfo(); + HRI = HST.getRegisterInfo(); + const auto &MDF = getAnalysis<MachineDominanceFrontier>(); + MDT = &getAnalysis<MachineDominatorTree>(); + const TargetOperandInfo TOI(*HII); + + DataFlowGraph G(MF, *HII, *HRI, *MDT, MDF, TOI); + // Need to keep dead phis because we can propagate uses of registers into + // nodes dominated by those would-be phis. + G.build(BuildOptions::KeepDeadPhis); + DFG = &G; + + Liveness L(*MRI, *DFG); + L.computePhiInfo(); + LV = &L; + + Deleted.clear(); + NodeAddr<FuncNode *> FA = DFG->getFunc(); + LLVM_DEBUG(dbgs() << "==== [RefMap#]=====:\n " + << Print<NodeAddr<FuncNode *>>(FA, *DFG) << "\n"); + + for (NodeAddr<BlockNode *> BA : FA.Addr->members(*DFG)) + Changed |= processBlock(BA); + + for (auto MI : Deleted) + MI->eraseFromParent(); + + if (Changed) { + G.build(); + L.computeLiveIns(); + L.resetLiveIns(); + L.resetKills(); + } + + return Changed; +} + +//===----------------------------------------------------------------------===// +// Public Constructor Functions +//===----------------------------------------------------------------------===// + +FunctionPass *llvm::createHexagonOptAddrMode() { + return new HexagonOptAddrMode(); +} |
