|  | //===---------- AArch64CollectLOH.cpp - AArch64 collect LOH pass --*- C++ -*-=// | 
|  | // | 
|  | //                     The LLVM Compiler Infrastructure | 
|  | // | 
|  | // This file is distributed under the University of Illinois Open Source | 
|  | // License. See LICENSE.TXT for details. | 
|  | // | 
|  | //===----------------------------------------------------------------------===// | 
|  | // | 
|  | // This file contains a pass that collect the Linker Optimization Hint (LOH). | 
|  | // This pass should be run at the very end of the compilation flow, just before | 
|  | // assembly printer. | 
|  | // To be useful for the linker, the LOH must be printed into the assembly file. | 
|  | // | 
|  | // A LOH describes a sequence of instructions that may be optimized by the | 
|  | // linker. | 
|  | // This same sequence cannot be optimized by the compiler because some of | 
|  | // the information will be known at link time. | 
|  | // For instance, consider the following sequence: | 
|  | //     L1: adrp xA, sym@PAGE | 
|  | //     L2: add xB, xA, sym@PAGEOFF | 
|  | //     L3: ldr xC, [xB, #imm] | 
|  | // This sequence can be turned into: | 
|  | // A literal load if sym@PAGE + sym@PAGEOFF + #imm - address(L3) is < 1MB: | 
|  | //     L3: ldr xC, sym+#imm | 
|  | // It may also be turned into either the following more efficient | 
|  | // code sequences: | 
|  | // - If sym@PAGEOFF + #imm fits the encoding space of L3. | 
|  | //     L1: adrp xA, sym@PAGE | 
|  | //     L3: ldr xC, [xB, sym@PAGEOFF + #imm] | 
|  | // - If sym@PAGE + sym@PAGEOFF - address(L1) < 1MB: | 
|  | //     L1: adr xA, sym | 
|  | //     L3: ldr xC, [xB, #imm] | 
|  | // | 
|  | // To be valid a LOH must meet all the requirements needed by all the related | 
|  | // possible linker transformations. | 
|  | // For instance, using the running example, the constraints to emit | 
|  | // ".loh AdrpAddLdr" are: | 
|  | // - L1, L2, and L3 instructions are of the expected type, i.e., | 
|  | //   respectively ADRP, ADD (immediate), and LD. | 
|  | // - The result of L1 is used only by L2. | 
|  | // - The register argument (xA) used in the ADD instruction is defined | 
|  | //   only by L1. | 
|  | // - The result of L2 is used only by L3. | 
|  | // - The base address (xB) in L3 is defined only L2. | 
|  | // - The ADRP in L1 and the ADD in L2 must reference the same symbol using | 
|  | //   @PAGE/@PAGEOFF with no additional constants | 
|  | // | 
|  | // Currently supported LOHs are: | 
|  | // * So called non-ADRP-related: | 
|  | //   - .loh AdrpAddLdr L1, L2, L3: | 
|  | //     L1: adrp xA, sym@PAGE | 
|  | //     L2: add xB, xA, sym@PAGEOFF | 
|  | //     L3: ldr xC, [xB, #imm] | 
|  | //   - .loh AdrpLdrGotLdr L1, L2, L3: | 
|  | //     L1: adrp xA, sym@GOTPAGE | 
|  | //     L2: ldr xB, [xA, sym@GOTPAGEOFF] | 
|  | //     L3: ldr xC, [xB, #imm] | 
|  | //   - .loh AdrpLdr L1, L3: | 
|  | //     L1: adrp xA, sym@PAGE | 
|  | //     L3: ldr xC, [xA, sym@PAGEOFF] | 
|  | //   - .loh AdrpAddStr L1, L2, L3: | 
|  | //     L1: adrp xA, sym@PAGE | 
|  | //     L2: add xB, xA, sym@PAGEOFF | 
|  | //     L3: str xC, [xB, #imm] | 
|  | //   - .loh AdrpLdrGotStr L1, L2, L3: | 
|  | //     L1: adrp xA, sym@GOTPAGE | 
|  | //     L2: ldr xB, [xA, sym@GOTPAGEOFF] | 
|  | //     L3: str xC, [xB, #imm] | 
|  | //   - .loh AdrpAdd L1, L2: | 
|  | //     L1: adrp xA, sym@PAGE | 
|  | //     L2: add xB, xA, sym@PAGEOFF | 
|  | //   For all these LOHs, L1, L2, L3 form a simple chain: | 
|  | //   L1 result is used only by L2 and L2 result by L3. | 
|  | //   L3 LOH-related argument is defined only by L2 and L2 LOH-related argument | 
|  | //   by L1. | 
|  | // All these LOHs aim at using more efficient load/store patterns by folding | 
|  | // some instructions used to compute the address directly into the load/store. | 
|  | // | 
|  | // * So called ADRP-related: | 
|  | //  - .loh AdrpAdrp L2, L1: | 
|  | //    L2: ADRP xA, sym1@PAGE | 
|  | //    L1: ADRP xA, sym2@PAGE | 
|  | //    L2 dominates L1 and xA is not redifined between L2 and L1 | 
|  | // This LOH aims at getting rid of redundant ADRP instructions. | 
|  | // | 
|  | // The overall design for emitting the LOHs is: | 
|  | // 1. AArch64CollectLOH (this pass) records the LOHs in the AArch64FunctionInfo. | 
|  | // 2. AArch64AsmPrinter reads the LOHs from AArch64FunctionInfo and it: | 
|  | //     1. Associates them a label. | 
|  | //     2. Emits them in a MCStreamer (EmitLOHDirective). | 
|  | //         - The MCMachOStreamer records them into the MCAssembler. | 
|  | //         - The MCAsmStreamer prints them. | 
|  | //         - Other MCStreamers ignore them. | 
|  | //     3. Closes the MCStreamer: | 
|  | //         - The MachObjectWriter gets them from the MCAssembler and writes | 
|  | //           them in the object file. | 
|  | //         - Other ObjectWriters ignore them. | 
|  | //===----------------------------------------------------------------------===// | 
|  |  | 
|  | #include "AArch64.h" | 
|  | #include "AArch64InstrInfo.h" | 
|  | #include "AArch64MachineFunctionInfo.h" | 
|  | #include "AArch64Subtarget.h" | 
|  | #include "MCTargetDesc/AArch64AddressingModes.h" | 
|  | #include "llvm/ADT/BitVector.h" | 
|  | #include "llvm/ADT/DenseMap.h" | 
|  | #include "llvm/ADT/MapVector.h" | 
|  | #include "llvm/ADT/SetVector.h" | 
|  | #include "llvm/ADT/SmallVector.h" | 
|  | #include "llvm/ADT/Statistic.h" | 
|  | #include "llvm/CodeGen/MachineBasicBlock.h" | 
|  | #include "llvm/CodeGen/MachineDominators.h" | 
|  | #include "llvm/CodeGen/MachineFunctionPass.h" | 
|  | #include "llvm/CodeGen/MachineInstr.h" | 
|  | #include "llvm/CodeGen/MachineInstrBuilder.h" | 
|  | #include "llvm/Support/CommandLine.h" | 
|  | #include "llvm/Support/Debug.h" | 
|  | #include "llvm/Support/ErrorHandling.h" | 
|  | #include "llvm/Support/raw_ostream.h" | 
|  | #include "llvm/Target/TargetInstrInfo.h" | 
|  | #include "llvm/Target/TargetMachine.h" | 
|  | #include "llvm/Target/TargetRegisterInfo.h" | 
|  | using namespace llvm; | 
|  |  | 
|  | #define DEBUG_TYPE "aarch64-collect-loh" | 
|  |  | 
|  | static cl::opt<bool> | 
|  | PreCollectRegister("aarch64-collect-loh-pre-collect-register", cl::Hidden, | 
|  | cl::desc("Restrict analysis to registers invovled" | 
|  | " in LOHs"), | 
|  | cl::init(true)); | 
|  |  | 
|  | static cl::opt<bool> | 
|  | BasicBlockScopeOnly("aarch64-collect-loh-bb-only", cl::Hidden, | 
|  | cl::desc("Restrict analysis at basic block scope"), | 
|  | cl::init(true)); | 
|  |  | 
|  | STATISTIC(NumADRPSimpleCandidate, | 
|  | "Number of simplifiable ADRP dominate by another"); | 
|  | STATISTIC(NumADRPComplexCandidate2, | 
|  | "Number of simplifiable ADRP reachable by 2 defs"); | 
|  | STATISTIC(NumADRPComplexCandidate3, | 
|  | "Number of simplifiable ADRP reachable by 3 defs"); | 
|  | STATISTIC(NumADRPComplexCandidateOther, | 
|  | "Number of simplifiable ADRP reachable by 4 or more defs"); | 
|  | STATISTIC(NumADDToSTRWithImm, | 
|  | "Number of simplifiable STR with imm reachable by ADD"); | 
|  | STATISTIC(NumLDRToSTRWithImm, | 
|  | "Number of simplifiable STR with imm reachable by LDR"); | 
|  | STATISTIC(NumADDToSTR, "Number of simplifiable STR reachable by ADD"); | 
|  | STATISTIC(NumLDRToSTR, "Number of simplifiable STR reachable by LDR"); | 
|  | STATISTIC(NumADDToLDRWithImm, | 
|  | "Number of simplifiable LDR with imm reachable by ADD"); | 
|  | STATISTIC(NumLDRToLDRWithImm, | 
|  | "Number of simplifiable LDR with imm reachable by LDR"); | 
|  | STATISTIC(NumADDToLDR, "Number of simplifiable LDR reachable by ADD"); | 
|  | STATISTIC(NumLDRToLDR, "Number of simplifiable LDR reachable by LDR"); | 
|  | STATISTIC(NumADRPToLDR, "Number of simplifiable LDR reachable by ADRP"); | 
|  | STATISTIC(NumCplxLvl1, "Number of complex case of level 1"); | 
|  | STATISTIC(NumTooCplxLvl1, "Number of too complex case of level 1"); | 
|  | STATISTIC(NumCplxLvl2, "Number of complex case of level 2"); | 
|  | STATISTIC(NumTooCplxLvl2, "Number of too complex case of level 2"); | 
|  | STATISTIC(NumADRSimpleCandidate, "Number of simplifiable ADRP + ADD"); | 
|  | STATISTIC(NumADRComplexCandidate, "Number of too complex ADRP + ADD"); | 
|  |  | 
|  | namespace llvm { | 
|  | void initializeAArch64CollectLOHPass(PassRegistry &); | 
|  | } | 
|  |  | 
|  | #define AARCH64_COLLECT_LOH_NAME "AArch64 Collect Linker Optimization Hint (LOH)" | 
|  |  | 
|  | namespace { | 
|  | struct AArch64CollectLOH : public MachineFunctionPass { | 
|  | static char ID; | 
|  | AArch64CollectLOH() : MachineFunctionPass(ID) { | 
|  | initializeAArch64CollectLOHPass(*PassRegistry::getPassRegistry()); | 
|  | } | 
|  |  | 
|  | bool runOnMachineFunction(MachineFunction &MF) override; | 
|  |  | 
|  | const char *getPassName() const override { | 
|  | return AARCH64_COLLECT_LOH_NAME; | 
|  | } | 
|  |  | 
|  | void getAnalysisUsage(AnalysisUsage &AU) const override { | 
|  | AU.setPreservesAll(); | 
|  | MachineFunctionPass::getAnalysisUsage(AU); | 
|  | AU.addRequired<MachineDominatorTree>(); | 
|  | } | 
|  |  | 
|  | private: | 
|  | }; | 
|  |  | 
|  | /// A set of MachineInstruction. | 
|  | typedef SetVector<const MachineInstr *> SetOfMachineInstr; | 
|  | /// Map a basic block to a set of instructions per register. | 
|  | /// This is used to represent the exposed uses of a basic block | 
|  | /// per register. | 
|  | typedef MapVector<const MachineBasicBlock *, | 
|  | std::unique_ptr<SetOfMachineInstr[]>> | 
|  | BlockToSetOfInstrsPerColor; | 
|  | /// Map a basic block to an instruction per register. | 
|  | /// This is used to represent the live-out definitions of a basic block | 
|  | /// per register. | 
|  | typedef MapVector<const MachineBasicBlock *, | 
|  | std::unique_ptr<const MachineInstr *[]>> | 
|  | BlockToInstrPerColor; | 
|  | /// Map an instruction to a set of instructions. Used to represent the | 
|  | /// mapping def to reachable uses or use to definitions. | 
|  | typedef MapVector<const MachineInstr *, SetOfMachineInstr> InstrToInstrs; | 
|  | /// Map a basic block to a BitVector. | 
|  | /// This is used to record the kill registers per basic block. | 
|  | typedef MapVector<const MachineBasicBlock *, BitVector> BlockToRegSet; | 
|  |  | 
|  | /// Map a register to a dense id. | 
|  | typedef DenseMap<unsigned, unsigned> MapRegToId; | 
|  | /// Map a dense id to a register. Used for debug purposes. | 
|  | typedef SmallVector<unsigned, 32> MapIdToReg; | 
|  | } // end anonymous namespace. | 
|  |  | 
|  | char AArch64CollectLOH::ID = 0; | 
|  |  | 
|  | INITIALIZE_PASS_BEGIN(AArch64CollectLOH, "aarch64-collect-loh", | 
|  | AARCH64_COLLECT_LOH_NAME, false, false) | 
|  | INITIALIZE_PASS_DEPENDENCY(MachineDominatorTree) | 
|  | INITIALIZE_PASS_END(AArch64CollectLOH, "aarch64-collect-loh", | 
|  | AARCH64_COLLECT_LOH_NAME, false, false) | 
|  |  | 
|  | /// Given a couple (MBB, reg) get the corresponding set of instruction from | 
|  | /// the given "sets". | 
|  | /// If this couple does not reference any set, an empty set is added to "sets" | 
|  | /// for this couple and returned. | 
|  | /// \param nbRegs is used internally allocate some memory. It must be consistent | 
|  | /// with the way sets is used. | 
|  | static SetOfMachineInstr &getSet(BlockToSetOfInstrsPerColor &sets, | 
|  | const MachineBasicBlock &MBB, unsigned reg, | 
|  | unsigned nbRegs) { | 
|  | SetOfMachineInstr *result; | 
|  | BlockToSetOfInstrsPerColor::iterator it = sets.find(&MBB); | 
|  | if (it != sets.end()) | 
|  | result = it->second.get(); | 
|  | else | 
|  | result = (sets[&MBB] = make_unique<SetOfMachineInstr[]>(nbRegs)).get(); | 
|  |  | 
|  | return result[reg]; | 
|  | } | 
|  |  | 
|  | /// Given a couple (reg, MI) get the corresponding set of instructions from the | 
|  | /// the given "sets". | 
|  | /// This is used to get the uses record in sets of a definition identified by | 
|  | /// MI and reg, i.e., MI defines reg. | 
|  | /// If the couple does not reference anything, an empty set is added to | 
|  | /// "sets[reg]". | 
|  | /// \pre set[reg] is valid. | 
|  | static SetOfMachineInstr &getUses(InstrToInstrs *sets, unsigned reg, | 
|  | const MachineInstr &MI) { | 
|  | return sets[reg][&MI]; | 
|  | } | 
|  |  | 
|  | /// Same as getUses but does not modify the input map: sets. | 
|  | /// \return NULL if the couple (reg, MI) is not in sets. | 
|  | static const SetOfMachineInstr *getUses(const InstrToInstrs *sets, unsigned reg, | 
|  | const MachineInstr &MI) { | 
|  | InstrToInstrs::const_iterator Res = sets[reg].find(&MI); | 
|  | if (Res != sets[reg].end()) | 
|  | return &(Res->second); | 
|  | return nullptr; | 
|  | } | 
|  |  | 
|  | /// Initialize the reaching definition algorithm: | 
|  | /// For each basic block BB in MF, record: | 
|  | /// - its kill set. | 
|  | /// - its reachable uses (uses that are exposed to BB's predecessors). | 
|  | /// - its the generated definitions. | 
|  | /// \param DummyOp if not NULL, specifies a Dummy Operation to be added to | 
|  | /// the list of uses of exposed defintions. | 
|  | /// \param ADRPMode specifies to only consider ADRP instructions for generated | 
|  | /// definition. It also consider definitions of ADRP instructions as uses and | 
|  | /// ignore other uses. The ADRPMode is used to collect the information for LHO | 
|  | /// that involve ADRP operation only. | 
|  | static void initReachingDef(const MachineFunction &MF, | 
|  | InstrToInstrs *ColorOpToReachedUses, | 
|  | BlockToInstrPerColor &Gen, BlockToRegSet &Kill, | 
|  | BlockToSetOfInstrsPerColor &ReachableUses, | 
|  | const MapRegToId &RegToId, | 
|  | const MachineInstr *DummyOp, bool ADRPMode) { | 
|  | const TargetRegisterInfo *TRI = MF.getSubtarget().getRegisterInfo(); | 
|  | unsigned NbReg = RegToId.size(); | 
|  |  | 
|  | for (const MachineBasicBlock &MBB : MF) { | 
|  | auto &BBGen = Gen[&MBB]; | 
|  | BBGen = make_unique<const MachineInstr *[]>(NbReg); | 
|  | std::fill(BBGen.get(), BBGen.get() + NbReg, nullptr); | 
|  |  | 
|  | BitVector &BBKillSet = Kill[&MBB]; | 
|  | BBKillSet.resize(NbReg); | 
|  | for (const MachineInstr &MI : MBB) { | 
|  | bool IsADRP = MI.getOpcode() == AArch64::ADRP; | 
|  |  | 
|  | // Process uses first. | 
|  | if (IsADRP || !ADRPMode) | 
|  | for (const MachineOperand &MO : MI.operands()) { | 
|  | // Treat ADRP def as use, as the goal of the analysis is to find | 
|  | // ADRP defs reached by other ADRP defs. | 
|  | if (!MO.isReg() || (!ADRPMode && !MO.isUse()) || | 
|  | (ADRPMode && (!IsADRP || !MO.isDef()))) | 
|  | continue; | 
|  | unsigned CurReg = MO.getReg(); | 
|  | MapRegToId::const_iterator ItCurRegId = RegToId.find(CurReg); | 
|  | if (ItCurRegId == RegToId.end()) | 
|  | continue; | 
|  | CurReg = ItCurRegId->second; | 
|  |  | 
|  | // if CurReg has not been defined, this use is reachable. | 
|  | if (!BBGen[CurReg] && !BBKillSet.test(CurReg)) | 
|  | getSet(ReachableUses, MBB, CurReg, NbReg).insert(&MI); | 
|  | // current basic block definition for this color, if any, is in Gen. | 
|  | if (BBGen[CurReg]) | 
|  | getUses(ColorOpToReachedUses, CurReg, *BBGen[CurReg]).insert(&MI); | 
|  | } | 
|  |  | 
|  | // Process clobbers. | 
|  | for (const MachineOperand &MO : MI.operands()) { | 
|  | if (!MO.isRegMask()) | 
|  | continue; | 
|  | // Clobbers kill the related colors. | 
|  | const uint32_t *PreservedRegs = MO.getRegMask(); | 
|  |  | 
|  | // Set generated regs. | 
|  | for (const auto &Entry : RegToId) { | 
|  | unsigned Reg = Entry.second; | 
|  | // Use the global register ID when querying APIs external to this | 
|  | // pass. | 
|  | if (MachineOperand::clobbersPhysReg(PreservedRegs, Entry.first)) { | 
|  | // Do not register clobbered definition for no ADRP. | 
|  | // This definition is not used anyway (otherwise register | 
|  | // allocation is wrong). | 
|  | BBGen[Reg] = ADRPMode ? &MI : nullptr; | 
|  | BBKillSet.set(Reg); | 
|  | } | 
|  | } | 
|  | } | 
|  |  | 
|  | // Process register defs. | 
|  | for (const MachineOperand &MO : MI.operands()) { | 
|  | if (!MO.isReg() || !MO.isDef()) | 
|  | continue; | 
|  | unsigned CurReg = MO.getReg(); | 
|  | MapRegToId::const_iterator ItCurRegId = RegToId.find(CurReg); | 
|  | if (ItCurRegId == RegToId.end()) | 
|  | continue; | 
|  |  | 
|  | for (MCRegAliasIterator AI(CurReg, TRI, true); AI.isValid(); ++AI) { | 
|  | MapRegToId::const_iterator ItRegId = RegToId.find(*AI); | 
|  | // If this alias has not been recorded, then it is not interesting | 
|  | // for the current analysis. | 
|  | // We can end up in this situation because of tuple registers. | 
|  | // E.g., Let say we are interested in S1. When we register | 
|  | // S1, we will also register its aliases and in particular | 
|  | // the tuple Q1_Q2. | 
|  | // Now, when we encounter Q1_Q2, we will look through its aliases | 
|  | // and will find that S2 is not registered. | 
|  | if (ItRegId == RegToId.end()) | 
|  | continue; | 
|  |  | 
|  | BBKillSet.set(ItRegId->second); | 
|  | BBGen[ItRegId->second] = &MI; | 
|  | } | 
|  | BBGen[ItCurRegId->second] = &MI; | 
|  | } | 
|  | } | 
|  |  | 
|  | // If we restrict our analysis to basic block scope, conservatively add a | 
|  | // dummy | 
|  | // use for each generated value. | 
|  | if (!ADRPMode && DummyOp && !MBB.succ_empty()) | 
|  | for (unsigned CurReg = 0; CurReg < NbReg; ++CurReg) | 
|  | if (BBGen[CurReg]) | 
|  | getUses(ColorOpToReachedUses, CurReg, *BBGen[CurReg]).insert(DummyOp); | 
|  | } | 
|  | } | 
|  |  | 
|  | /// Reaching def core algorithm: | 
|  | /// while an Out has changed | 
|  | ///    for each bb | 
|  | ///       for each color | 
|  | ///           In[bb][color] = U Out[bb.predecessors][color] | 
|  | ///           insert reachableUses[bb][color] in each in[bb][color] | 
|  | ///                 op.reachedUses | 
|  | /// | 
|  | ///           Out[bb] = Gen[bb] U (In[bb] - Kill[bb]) | 
|  | static void reachingDefAlgorithm(const MachineFunction &MF, | 
|  | InstrToInstrs *ColorOpToReachedUses, | 
|  | BlockToSetOfInstrsPerColor &In, | 
|  | BlockToSetOfInstrsPerColor &Out, | 
|  | BlockToInstrPerColor &Gen, BlockToRegSet &Kill, | 
|  | BlockToSetOfInstrsPerColor &ReachableUses, | 
|  | unsigned NbReg) { | 
|  | bool HasChanged; | 
|  | do { | 
|  | HasChanged = false; | 
|  | for (const MachineBasicBlock &MBB : MF) { | 
|  | unsigned CurReg; | 
|  | for (CurReg = 0; CurReg < NbReg; ++CurReg) { | 
|  | SetOfMachineInstr &BBInSet = getSet(In, MBB, CurReg, NbReg); | 
|  | SetOfMachineInstr &BBReachableUses = | 
|  | getSet(ReachableUses, MBB, CurReg, NbReg); | 
|  | SetOfMachineInstr &BBOutSet = getSet(Out, MBB, CurReg, NbReg); | 
|  | unsigned Size = BBOutSet.size(); | 
|  | //   In[bb][color] = U Out[bb.predecessors][color] | 
|  | for (const MachineBasicBlock *PredMBB : MBB.predecessors()) { | 
|  | SetOfMachineInstr &PredOutSet = getSet(Out, *PredMBB, CurReg, NbReg); | 
|  | BBInSet.insert(PredOutSet.begin(), PredOutSet.end()); | 
|  | } | 
|  | //   insert reachableUses[bb][color] in each in[bb][color] op.reachedses | 
|  | for (const MachineInstr *MI : BBInSet) { | 
|  | SetOfMachineInstr &OpReachedUses = | 
|  | getUses(ColorOpToReachedUses, CurReg, *MI); | 
|  | OpReachedUses.insert(BBReachableUses.begin(), BBReachableUses.end()); | 
|  | } | 
|  | //           Out[bb] = Gen[bb] U (In[bb] - Kill[bb]) | 
|  | if (!Kill[&MBB].test(CurReg)) | 
|  | BBOutSet.insert(BBInSet.begin(), BBInSet.end()); | 
|  | if (Gen[&MBB][CurReg]) | 
|  | BBOutSet.insert(Gen[&MBB][CurReg]); | 
|  | HasChanged |= BBOutSet.size() != Size; | 
|  | } | 
|  | } | 
|  | } while (HasChanged); | 
|  | } | 
|  |  | 
|  | /// Reaching definition algorithm. | 
|  | /// \param MF function on which the algorithm will operate. | 
|  | /// \param[out] ColorOpToReachedUses will contain the result of the reaching | 
|  | /// def algorithm. | 
|  | /// \param ADRPMode specify whether the reaching def algorithm should be tuned | 
|  | /// for ADRP optimization. \see initReachingDef for more details. | 
|  | /// \param DummyOp if not NULL, the algorithm will work at | 
|  | /// basic block scope and will set for every exposed definition a use to | 
|  | /// @p DummyOp. | 
|  | /// \pre ColorOpToReachedUses is an array of at least number of registers of | 
|  | /// InstrToInstrs. | 
|  | static void reachingDef(const MachineFunction &MF, | 
|  | InstrToInstrs *ColorOpToReachedUses, | 
|  | const MapRegToId &RegToId, bool ADRPMode = false, | 
|  | const MachineInstr *DummyOp = nullptr) { | 
|  | // structures: | 
|  | // For each basic block. | 
|  | // Out: a set per color of definitions that reach the | 
|  | //      out boundary of this block. | 
|  | // In: Same as Out but for in boundary. | 
|  | // Gen: generated color in this block (one operation per color). | 
|  | // Kill: register set of killed color in this block. | 
|  | // ReachableUses: a set per color of uses (operation) reachable | 
|  | //                for "In" definitions. | 
|  | BlockToSetOfInstrsPerColor Out, In, ReachableUses; | 
|  | BlockToInstrPerColor Gen; | 
|  | BlockToRegSet Kill; | 
|  |  | 
|  | // Initialize Gen, kill and reachableUses. | 
|  | initReachingDef(MF, ColorOpToReachedUses, Gen, Kill, ReachableUses, RegToId, | 
|  | DummyOp, ADRPMode); | 
|  |  | 
|  | // Algo. | 
|  | if (!DummyOp) | 
|  | reachingDefAlgorithm(MF, ColorOpToReachedUses, In, Out, Gen, Kill, | 
|  | ReachableUses, RegToId.size()); | 
|  | } | 
|  |  | 
|  | #ifndef NDEBUG | 
|  | /// print the result of the reaching definition algorithm. | 
|  | static void printReachingDef(const InstrToInstrs *ColorOpToReachedUses, | 
|  | unsigned NbReg, const TargetRegisterInfo *TRI, | 
|  | const MapIdToReg &IdToReg) { | 
|  | unsigned CurReg; | 
|  | for (CurReg = 0; CurReg < NbReg; ++CurReg) { | 
|  | if (ColorOpToReachedUses[CurReg].empty()) | 
|  | continue; | 
|  | DEBUG(dbgs() << "*** Reg " << PrintReg(IdToReg[CurReg], TRI) << " ***\n"); | 
|  |  | 
|  | for (const auto &DefsIt : ColorOpToReachedUses[CurReg]) { | 
|  | DEBUG(dbgs() << "Def:\n"); | 
|  | DEBUG(DefsIt.first->print(dbgs())); | 
|  | DEBUG(dbgs() << "Reachable uses:\n"); | 
|  | for (const MachineInstr *MI : DefsIt.second) { | 
|  | DEBUG(MI->print(dbgs())); | 
|  | } | 
|  | } | 
|  | } | 
|  | } | 
|  | #endif // NDEBUG | 
|  |  | 
|  | /// Answer the following question: Can Def be one of the definition | 
|  | /// involved in a part of a LOH? | 
|  | static bool canDefBePartOfLOH(const MachineInstr *Def) { | 
|  | unsigned Opc = Def->getOpcode(); | 
|  | // Accept ADRP, ADDLow and LOADGot. | 
|  | switch (Opc) { | 
|  | default: | 
|  | return false; | 
|  | case AArch64::ADRP: | 
|  | return true; | 
|  | case AArch64::ADDXri: | 
|  | // Check immediate to see if the immediate is an address. | 
|  | switch (Def->getOperand(2).getType()) { | 
|  | default: | 
|  | return false; | 
|  | case MachineOperand::MO_GlobalAddress: | 
|  | case MachineOperand::MO_JumpTableIndex: | 
|  | case MachineOperand::MO_ConstantPoolIndex: | 
|  | case MachineOperand::MO_BlockAddress: | 
|  | return true; | 
|  | } | 
|  | case AArch64::LDRXui: | 
|  | // Check immediate to see if the immediate is an address. | 
|  | switch (Def->getOperand(2).getType()) { | 
|  | default: | 
|  | return false; | 
|  | case MachineOperand::MO_GlobalAddress: | 
|  | return true; | 
|  | } | 
|  | } | 
|  | // Unreachable. | 
|  | return false; | 
|  | } | 
|  |  | 
|  | /// Check whether the given instruction can the end of a LOH chain involving a | 
|  | /// store. | 
|  | static bool isCandidateStore(const MachineInstr *Instr) { | 
|  | switch (Instr->getOpcode()) { | 
|  | default: | 
|  | return false; | 
|  | case AArch64::STRBBui: | 
|  | case AArch64::STRHHui: | 
|  | case AArch64::STRBui: | 
|  | case AArch64::STRHui: | 
|  | case AArch64::STRWui: | 
|  | case AArch64::STRXui: | 
|  | case AArch64::STRSui: | 
|  | case AArch64::STRDui: | 
|  | case AArch64::STRQui: | 
|  | // In case we have str xA, [xA, #imm], this is two different uses | 
|  | // of xA and we cannot fold, otherwise the xA stored may be wrong, | 
|  | // even if #imm == 0. | 
|  | if (Instr->getOperand(0).getReg() != Instr->getOperand(1).getReg()) | 
|  | return true; | 
|  | } | 
|  | return false; | 
|  | } | 
|  |  | 
|  | /// Given the result of a reaching definition algorithm in ColorOpToReachedUses, | 
|  | /// Build the Use to Defs information and filter out obvious non-LOH candidates. | 
|  | /// In ADRPMode, non-LOH candidates are "uses" with non-ADRP definitions. | 
|  | /// In non-ADRPMode, non-LOH candidates are "uses" with several definition, | 
|  | /// i.e., no simple chain. | 
|  | /// \param ADRPMode -- \see initReachingDef. | 
|  | static void reachedUsesToDefs(InstrToInstrs &UseToReachingDefs, | 
|  | const InstrToInstrs *ColorOpToReachedUses, | 
|  | const MapRegToId &RegToId, | 
|  | bool ADRPMode = false) { | 
|  |  | 
|  | SetOfMachineInstr NotCandidate; | 
|  | unsigned NbReg = RegToId.size(); | 
|  | MapRegToId::const_iterator EndIt = RegToId.end(); | 
|  | for (unsigned CurReg = 0; CurReg < NbReg; ++CurReg) { | 
|  | // If this color is never defined, continue. | 
|  | if (ColorOpToReachedUses[CurReg].empty()) | 
|  | continue; | 
|  |  | 
|  | for (const auto &DefsIt : ColorOpToReachedUses[CurReg]) { | 
|  | for (const MachineInstr *MI : DefsIt.second) { | 
|  | const MachineInstr *Def = DefsIt.first; | 
|  | MapRegToId::const_iterator It; | 
|  | // if all the reaching defs are not adrp, this use will not be | 
|  | // simplifiable. | 
|  | if ((ADRPMode && Def->getOpcode() != AArch64::ADRP) || | 
|  | (!ADRPMode && !canDefBePartOfLOH(Def)) || | 
|  | (!ADRPMode && isCandidateStore(MI) && | 
|  | // store are LOH candidate iff the end of the chain is used as | 
|  | // base. | 
|  | ((It = RegToId.find((MI)->getOperand(1).getReg())) == EndIt || | 
|  | It->second != CurReg))) { | 
|  | NotCandidate.insert(MI); | 
|  | continue; | 
|  | } | 
|  | // Do not consider self reaching as a simplifiable case for ADRP. | 
|  | if (!ADRPMode || MI != DefsIt.first) { | 
|  | UseToReachingDefs[MI].insert(DefsIt.first); | 
|  | // If UsesIt has several reaching definitions, it is not | 
|  | // candidate for simplificaton in non-ADRPMode. | 
|  | if (!ADRPMode && UseToReachingDefs[MI].size() > 1) | 
|  | NotCandidate.insert(MI); | 
|  | } | 
|  | } | 
|  | } | 
|  | } | 
|  | for (const MachineInstr *Elem : NotCandidate) { | 
|  | DEBUG(dbgs() << "Too many reaching defs: " << *Elem << "\n"); | 
|  | // It would have been better if we could just remove the entry | 
|  | // from the map.  Because of that, we have to filter the garbage | 
|  | // (second.empty) in the subsequence analysis. | 
|  | UseToReachingDefs[Elem].clear(); | 
|  | } | 
|  | } | 
|  |  | 
|  | /// Based on the use to defs information (in ADRPMode), compute the | 
|  | /// opportunities of LOH ADRP-related. | 
|  | static void computeADRP(const InstrToInstrs &UseToDefs, | 
|  | AArch64FunctionInfo &AArch64FI, | 
|  | const MachineDominatorTree *MDT) { | 
|  | DEBUG(dbgs() << "*** Compute LOH for ADRP\n"); | 
|  | for (const auto &Entry : UseToDefs) { | 
|  | unsigned Size = Entry.second.size(); | 
|  | if (Size == 0) | 
|  | continue; | 
|  | if (Size == 1) { | 
|  | const MachineInstr *L2 = *Entry.second.begin(); | 
|  | const MachineInstr *L1 = Entry.first; | 
|  | if (!MDT->dominates(L2, L1)) { | 
|  | DEBUG(dbgs() << "Dominance check failed:\n" << *L2 << '\n' << *L1 | 
|  | << '\n'); | 
|  | continue; | 
|  | } | 
|  | DEBUG(dbgs() << "Record AdrpAdrp:\n" << *L2 << '\n' << *L1 << '\n'); | 
|  | SmallVector<const MachineInstr *, 2> Args; | 
|  | Args.push_back(L2); | 
|  | Args.push_back(L1); | 
|  | AArch64FI.addLOHDirective(MCLOH_AdrpAdrp, Args); | 
|  | ++NumADRPSimpleCandidate; | 
|  | } | 
|  | #ifdef DEBUG | 
|  | else if (Size == 2) | 
|  | ++NumADRPComplexCandidate2; | 
|  | else if (Size == 3) | 
|  | ++NumADRPComplexCandidate3; | 
|  | else | 
|  | ++NumADRPComplexCandidateOther; | 
|  | #endif | 
|  | // if Size < 1, the use should have been removed from the candidates | 
|  | assert(Size >= 1 && "No reaching defs for that use!"); | 
|  | } | 
|  | } | 
|  |  | 
|  | /// Check whether the given instruction can be the end of a LOH chain | 
|  | /// involving a load. | 
|  | static bool isCandidateLoad(const MachineInstr *Instr) { | 
|  | switch (Instr->getOpcode()) { | 
|  | default: | 
|  | return false; | 
|  | case AArch64::LDRSBWui: | 
|  | case AArch64::LDRSBXui: | 
|  | case AArch64::LDRSHWui: | 
|  | case AArch64::LDRSHXui: | 
|  | case AArch64::LDRSWui: | 
|  | case AArch64::LDRBui: | 
|  | case AArch64::LDRHui: | 
|  | case AArch64::LDRWui: | 
|  | case AArch64::LDRXui: | 
|  | case AArch64::LDRSui: | 
|  | case AArch64::LDRDui: | 
|  | case AArch64::LDRQui: | 
|  | if (Instr->getOperand(2).getTargetFlags() & AArch64II::MO_GOT) | 
|  | return false; | 
|  | return true; | 
|  | } | 
|  | // Unreachable. | 
|  | return false; | 
|  | } | 
|  |  | 
|  | /// Check whether the given instruction can load a litteral. | 
|  | static bool supportLoadFromLiteral(const MachineInstr *Instr) { | 
|  | switch (Instr->getOpcode()) { | 
|  | default: | 
|  | return false; | 
|  | case AArch64::LDRSWui: | 
|  | case AArch64::LDRWui: | 
|  | case AArch64::LDRXui: | 
|  | case AArch64::LDRSui: | 
|  | case AArch64::LDRDui: | 
|  | case AArch64::LDRQui: | 
|  | return true; | 
|  | } | 
|  | // Unreachable. | 
|  | return false; | 
|  | } | 
|  |  | 
|  | /// Check whether the given instruction is a LOH candidate. | 
|  | /// \param UseToDefs is used to check that Instr is at the end of LOH supported | 
|  | /// chain. | 
|  | /// \pre UseToDefs contains only on def per use, i.e., obvious non candidate are | 
|  | /// already been filtered out. | 
|  | static bool isCandidate(const MachineInstr *Instr, | 
|  | const InstrToInstrs &UseToDefs, | 
|  | const MachineDominatorTree *MDT) { | 
|  | if (!isCandidateLoad(Instr) && !isCandidateStore(Instr)) | 
|  | return false; | 
|  |  | 
|  | const MachineInstr *Def = *UseToDefs.find(Instr)->second.begin(); | 
|  | if (Def->getOpcode() != AArch64::ADRP) { | 
|  | // At this point, Def is ADDXri or LDRXui of the right type of | 
|  | // symbol, because we filtered out the uses that were not defined | 
|  | // by these kind of instructions (+ ADRP). | 
|  |  | 
|  | // Check if this forms a simple chain: each intermediate node must | 
|  | // dominates the next one. | 
|  | if (!MDT->dominates(Def, Instr)) | 
|  | return false; | 
|  | // Move one node up in the simple chain. | 
|  | if (UseToDefs.find(Def) == | 
|  | UseToDefs.end() | 
|  | // The map may contain garbage we have to ignore. | 
|  | || | 
|  | UseToDefs.find(Def)->second.empty()) | 
|  | return false; | 
|  | Instr = Def; | 
|  | Def = *UseToDefs.find(Def)->second.begin(); | 
|  | } | 
|  | // Check if we reached the top of the simple chain: | 
|  | // - top is ADRP. | 
|  | // - check the simple chain property: each intermediate node must | 
|  | // dominates the next one. | 
|  | if (Def->getOpcode() == AArch64::ADRP) | 
|  | return MDT->dominates(Def, Instr); | 
|  | return false; | 
|  | } | 
|  |  | 
|  | static bool registerADRCandidate(const MachineInstr &Use, | 
|  | const InstrToInstrs &UseToDefs, | 
|  | const InstrToInstrs *DefsPerColorToUses, | 
|  | AArch64FunctionInfo &AArch64FI, | 
|  | SetOfMachineInstr *InvolvedInLOHs, | 
|  | const MapRegToId &RegToId) { | 
|  | // Look for opportunities to turn ADRP -> ADD or | 
|  | // ADRP -> LDR GOTPAGEOFF into ADR. | 
|  | // If ADRP has more than one use. Give up. | 
|  | if (Use.getOpcode() != AArch64::ADDXri && | 
|  | (Use.getOpcode() != AArch64::LDRXui || | 
|  | !(Use.getOperand(2).getTargetFlags() & AArch64II::MO_GOT))) | 
|  | return false; | 
|  | InstrToInstrs::const_iterator It = UseToDefs.find(&Use); | 
|  | // The map may contain garbage that we need to ignore. | 
|  | if (It == UseToDefs.end() || It->second.empty()) | 
|  | return false; | 
|  | const MachineInstr &Def = **It->second.begin(); | 
|  | if (Def.getOpcode() != AArch64::ADRP) | 
|  | return false; | 
|  | // Check the number of users of ADRP. | 
|  | const SetOfMachineInstr *Users = | 
|  | getUses(DefsPerColorToUses, | 
|  | RegToId.find(Def.getOperand(0).getReg())->second, Def); | 
|  | if (Users->size() > 1) { | 
|  | ++NumADRComplexCandidate; | 
|  | return false; | 
|  | } | 
|  | ++NumADRSimpleCandidate; | 
|  | assert((!InvolvedInLOHs || InvolvedInLOHs->insert(&Def)) && | 
|  | "ADRP already involved in LOH."); | 
|  | assert((!InvolvedInLOHs || InvolvedInLOHs->insert(&Use)) && | 
|  | "ADD already involved in LOH."); | 
|  | DEBUG(dbgs() << "Record AdrpAdd\n" << Def << '\n' << Use << '\n'); | 
|  |  | 
|  | SmallVector<const MachineInstr *, 2> Args; | 
|  | Args.push_back(&Def); | 
|  | Args.push_back(&Use); | 
|  |  | 
|  | AArch64FI.addLOHDirective(Use.getOpcode() == AArch64::ADDXri ? MCLOH_AdrpAdd | 
|  | : MCLOH_AdrpLdrGot, | 
|  | Args); | 
|  | return true; | 
|  | } | 
|  |  | 
|  | /// Based on the use to defs information (in non-ADRPMode), compute the | 
|  | /// opportunities of LOH non-ADRP-related | 
|  | static void computeOthers(const InstrToInstrs &UseToDefs, | 
|  | const InstrToInstrs *DefsPerColorToUses, | 
|  | AArch64FunctionInfo &AArch64FI, const MapRegToId &RegToId, | 
|  | const MachineDominatorTree *MDT) { | 
|  | SetOfMachineInstr *InvolvedInLOHs = nullptr; | 
|  | #ifdef DEBUG | 
|  | SetOfMachineInstr InvolvedInLOHsStorage; | 
|  | InvolvedInLOHs = &InvolvedInLOHsStorage; | 
|  | #endif // DEBUG | 
|  | DEBUG(dbgs() << "*** Compute LOH for Others\n"); | 
|  | // ADRP -> ADD/LDR -> LDR/STR pattern. | 
|  | // Fall back to ADRP -> ADD pattern if we fail to catch the bigger pattern. | 
|  |  | 
|  | // FIXME: When the statistics are not important, | 
|  | // This initial filtering loop can be merged into the next loop. | 
|  | // Currently, we didn't do it to have the same code for both DEBUG and | 
|  | // NDEBUG builds. Indeed, the iterator of the second loop would need | 
|  | // to be changed. | 
|  | SetOfMachineInstr PotentialCandidates; | 
|  | SetOfMachineInstr PotentialADROpportunities; | 
|  | for (auto &Use : UseToDefs) { | 
|  | // If no definition is available, this is a non candidate. | 
|  | if (Use.second.empty()) | 
|  | continue; | 
|  | // Keep only instructions that are load or store and at the end of | 
|  | // a ADRP -> ADD/LDR/Nothing chain. | 
|  | // We already filtered out the no-chain cases. | 
|  | if (!isCandidate(Use.first, UseToDefs, MDT)) { | 
|  | PotentialADROpportunities.insert(Use.first); | 
|  | continue; | 
|  | } | 
|  | PotentialCandidates.insert(Use.first); | 
|  | } | 
|  |  | 
|  | // Make the following distinctions for statistics as the linker does | 
|  | // know how to decode instructions: | 
|  | // - ADD/LDR/Nothing make there different patterns. | 
|  | // - LDR/STR make two different patterns. | 
|  | // Hence, 6 - 1 base patterns. | 
|  | // (because ADRP-> Nothing -> STR is not simplifiable) | 
|  |  | 
|  | // The linker is only able to have a simple semantic, i.e., if pattern A | 
|  | // do B. | 
|  | // However, we want to see the opportunity we may miss if we were able to | 
|  | // catch more complex cases. | 
|  |  | 
|  | // PotentialCandidates are result of a chain ADRP -> ADD/LDR -> | 
|  | // A potential candidate becomes a candidate, if its current immediate | 
|  | // operand is zero and all nodes of the chain have respectively only one user | 
|  | #ifdef DEBUG | 
|  | SetOfMachineInstr DefsOfPotentialCandidates; | 
|  | #endif | 
|  | for (const MachineInstr *Candidate : PotentialCandidates) { | 
|  | // Get the definition of the candidate i.e., ADD or LDR. | 
|  | const MachineInstr *Def = *UseToDefs.find(Candidate)->second.begin(); | 
|  | // Record the elements of the chain. | 
|  | const MachineInstr *L1 = Def; | 
|  | const MachineInstr *L2 = nullptr; | 
|  | unsigned ImmediateDefOpc = Def->getOpcode(); | 
|  | if (Def->getOpcode() != AArch64::ADRP) { | 
|  | // Check the number of users of this node. | 
|  | const SetOfMachineInstr *Users = | 
|  | getUses(DefsPerColorToUses, | 
|  | RegToId.find(Def->getOperand(0).getReg())->second, *Def); | 
|  | if (Users->size() > 1) { | 
|  | #ifdef DEBUG | 
|  | // if all the uses of this def are in potential candidate, this is | 
|  | // a complex candidate of level 2. | 
|  | bool IsLevel2 = true; | 
|  | for (const MachineInstr *MI : *Users) { | 
|  | if (!PotentialCandidates.count(MI)) { | 
|  | ++NumTooCplxLvl2; | 
|  | IsLevel2 = false; | 
|  | break; | 
|  | } | 
|  | } | 
|  | if (IsLevel2) | 
|  | ++NumCplxLvl2; | 
|  | #endif // DEBUG | 
|  | PotentialADROpportunities.insert(Def); | 
|  | continue; | 
|  | } | 
|  | L2 = Def; | 
|  | Def = *UseToDefs.find(Def)->second.begin(); | 
|  | L1 = Def; | 
|  | } // else the element in the middle of the chain is nothing, thus | 
|  | // Def already contains the first element of the chain. | 
|  |  | 
|  | // Check the number of users of the first node in the chain, i.e., ADRP | 
|  | const SetOfMachineInstr *Users = | 
|  | getUses(DefsPerColorToUses, | 
|  | RegToId.find(Def->getOperand(0).getReg())->second, *Def); | 
|  | if (Users->size() > 1) { | 
|  | #ifdef DEBUG | 
|  | // if all the uses of this def are in the defs of the potential candidate, | 
|  | // this is a complex candidate of level 1 | 
|  | if (DefsOfPotentialCandidates.empty()) { | 
|  | // lazy init | 
|  | DefsOfPotentialCandidates = PotentialCandidates; | 
|  | for (const MachineInstr *Candidate : PotentialCandidates) { | 
|  | if (!UseToDefs.find(Candidate)->second.empty()) | 
|  | DefsOfPotentialCandidates.insert( | 
|  | *UseToDefs.find(Candidate)->second.begin()); | 
|  | } | 
|  | } | 
|  | bool Found = false; | 
|  | for (auto &Use : *Users) { | 
|  | if (!DefsOfPotentialCandidates.count(Use)) { | 
|  | ++NumTooCplxLvl1; | 
|  | Found = true; | 
|  | break; | 
|  | } | 
|  | } | 
|  | if (!Found) | 
|  | ++NumCplxLvl1; | 
|  | #endif // DEBUG | 
|  | continue; | 
|  | } | 
|  |  | 
|  | bool IsL2Add = (ImmediateDefOpc == AArch64::ADDXri); | 
|  | // If the chain is three instructions long and ldr is the second element, | 
|  | // then this ldr must load form GOT, otherwise this is not a correct chain. | 
|  | if (L2 && !IsL2Add && | 
|  | !(L2->getOperand(2).getTargetFlags() & AArch64II::MO_GOT)) | 
|  | continue; | 
|  | SmallVector<const MachineInstr *, 3> Args; | 
|  | MCLOHType Kind; | 
|  | if (isCandidateLoad(Candidate)) { | 
|  | if (!L2) { | 
|  | // At this point, the candidate LOH indicates that the ldr instruction | 
|  | // may use a direct access to the symbol. There is not such encoding | 
|  | // for loads of byte and half. | 
|  | if (!supportLoadFromLiteral(Candidate)) | 
|  | continue; | 
|  |  | 
|  | DEBUG(dbgs() << "Record AdrpLdr:\n" << *L1 << '\n' << *Candidate | 
|  | << '\n'); | 
|  | Kind = MCLOH_AdrpLdr; | 
|  | Args.push_back(L1); | 
|  | Args.push_back(Candidate); | 
|  | assert((!InvolvedInLOHs || InvolvedInLOHs->insert(L1)) && | 
|  | "L1 already involved in LOH."); | 
|  | assert((!InvolvedInLOHs || InvolvedInLOHs->insert(Candidate)) && | 
|  | "Candidate already involved in LOH."); | 
|  | ++NumADRPToLDR; | 
|  | } else { | 
|  | DEBUG(dbgs() << "Record Adrp" << (IsL2Add ? "Add" : "LdrGot") | 
|  | << "Ldr:\n" << *L1 << '\n' << *L2 << '\n' << *Candidate | 
|  | << '\n'); | 
|  |  | 
|  | Kind = IsL2Add ? MCLOH_AdrpAddLdr : MCLOH_AdrpLdrGotLdr; | 
|  | Args.push_back(L1); | 
|  | Args.push_back(L2); | 
|  | Args.push_back(Candidate); | 
|  |  | 
|  | PotentialADROpportunities.remove(L2); | 
|  | assert((!InvolvedInLOHs || InvolvedInLOHs->insert(L1)) && | 
|  | "L1 already involved in LOH."); | 
|  | assert((!InvolvedInLOHs || InvolvedInLOHs->insert(L2)) && | 
|  | "L2 already involved in LOH."); | 
|  | assert((!InvolvedInLOHs || InvolvedInLOHs->insert(Candidate)) && | 
|  | "Candidate already involved in LOH."); | 
|  | #ifdef DEBUG | 
|  | // get the immediate of the load | 
|  | if (Candidate->getOperand(2).getImm() == 0) | 
|  | if (ImmediateDefOpc == AArch64::ADDXri) | 
|  | ++NumADDToLDR; | 
|  | else | 
|  | ++NumLDRToLDR; | 
|  | else if (ImmediateDefOpc == AArch64::ADDXri) | 
|  | ++NumADDToLDRWithImm; | 
|  | else | 
|  | ++NumLDRToLDRWithImm; | 
|  | #endif // DEBUG | 
|  | } | 
|  | } else { | 
|  | if (ImmediateDefOpc == AArch64::ADRP) | 
|  | continue; | 
|  | else { | 
|  |  | 
|  | DEBUG(dbgs() << "Record Adrp" << (IsL2Add ? "Add" : "LdrGot") | 
|  | << "Str:\n" << *L1 << '\n' << *L2 << '\n' << *Candidate | 
|  | << '\n'); | 
|  |  | 
|  | Kind = IsL2Add ? MCLOH_AdrpAddStr : MCLOH_AdrpLdrGotStr; | 
|  | Args.push_back(L1); | 
|  | Args.push_back(L2); | 
|  | Args.push_back(Candidate); | 
|  |  | 
|  | PotentialADROpportunities.remove(L2); | 
|  | assert((!InvolvedInLOHs || InvolvedInLOHs->insert(L1)) && | 
|  | "L1 already involved in LOH."); | 
|  | assert((!InvolvedInLOHs || InvolvedInLOHs->insert(L2)) && | 
|  | "L2 already involved in LOH."); | 
|  | assert((!InvolvedInLOHs || InvolvedInLOHs->insert(Candidate)) && | 
|  | "Candidate already involved in LOH."); | 
|  | #ifdef DEBUG | 
|  | // get the immediate of the store | 
|  | if (Candidate->getOperand(2).getImm() == 0) | 
|  | if (ImmediateDefOpc == AArch64::ADDXri) | 
|  | ++NumADDToSTR; | 
|  | else | 
|  | ++NumLDRToSTR; | 
|  | else if (ImmediateDefOpc == AArch64::ADDXri) | 
|  | ++NumADDToSTRWithImm; | 
|  | else | 
|  | ++NumLDRToSTRWithImm; | 
|  | #endif // DEBUG | 
|  | } | 
|  | } | 
|  | AArch64FI.addLOHDirective(Kind, Args); | 
|  | } | 
|  |  | 
|  | // Now, we grabbed all the big patterns, check ADR opportunities. | 
|  | for (const MachineInstr *Candidate : PotentialADROpportunities) | 
|  | registerADRCandidate(*Candidate, UseToDefs, DefsPerColorToUses, AArch64FI, | 
|  | InvolvedInLOHs, RegToId); | 
|  | } | 
|  |  | 
|  | /// Look for every register defined by potential LOHs candidates. | 
|  | /// Map these registers with dense id in @p RegToId and vice-versa in | 
|  | /// @p IdToReg. @p IdToReg is populated only in DEBUG mode. | 
|  | static void collectInvolvedReg(const MachineFunction &MF, MapRegToId &RegToId, | 
|  | MapIdToReg &IdToReg, | 
|  | const TargetRegisterInfo *TRI) { | 
|  | unsigned CurRegId = 0; | 
|  | if (!PreCollectRegister) { | 
|  | unsigned NbReg = TRI->getNumRegs(); | 
|  | for (; CurRegId < NbReg; ++CurRegId) { | 
|  | RegToId[CurRegId] = CurRegId; | 
|  | DEBUG(IdToReg.push_back(CurRegId)); | 
|  | DEBUG(assert(IdToReg[CurRegId] == CurRegId && "Reg index mismatches")); | 
|  | } | 
|  | return; | 
|  | } | 
|  |  | 
|  | DEBUG(dbgs() << "** Collect Involved Register\n"); | 
|  | for (const auto &MBB : MF) { | 
|  | for (const MachineInstr &MI : MBB) { | 
|  | if (!canDefBePartOfLOH(&MI) && | 
|  | !isCandidateLoad(&MI) && !isCandidateStore(&MI)) | 
|  | continue; | 
|  |  | 
|  | // Process defs | 
|  | for (MachineInstr::const_mop_iterator IO = MI.operands_begin(), | 
|  | IOEnd = MI.operands_end(); | 
|  | IO != IOEnd; ++IO) { | 
|  | if (!IO->isReg() || !IO->isDef()) | 
|  | continue; | 
|  | unsigned CurReg = IO->getReg(); | 
|  | for (MCRegAliasIterator AI(CurReg, TRI, true); AI.isValid(); ++AI) | 
|  | if (RegToId.find(*AI) == RegToId.end()) { | 
|  | DEBUG(IdToReg.push_back(*AI); | 
|  | assert(IdToReg[CurRegId] == *AI && | 
|  | "Reg index mismatches insertion index.")); | 
|  | RegToId[*AI] = CurRegId++; | 
|  | DEBUG(dbgs() << "Register: " << PrintReg(*AI, TRI) << '\n'); | 
|  | } | 
|  | } | 
|  | } | 
|  | } | 
|  | } | 
|  |  | 
|  | bool AArch64CollectLOH::runOnMachineFunction(MachineFunction &MF) { | 
|  | const TargetRegisterInfo *TRI = MF.getSubtarget().getRegisterInfo(); | 
|  | const MachineDominatorTree *MDT = &getAnalysis<MachineDominatorTree>(); | 
|  |  | 
|  | MapRegToId RegToId; | 
|  | MapIdToReg IdToReg; | 
|  | AArch64FunctionInfo *AArch64FI = MF.getInfo<AArch64FunctionInfo>(); | 
|  | assert(AArch64FI && "No MachineFunctionInfo for this function!"); | 
|  |  | 
|  | DEBUG(dbgs() << "Looking for LOH in " << MF.getName() << '\n'); | 
|  |  | 
|  | collectInvolvedReg(MF, RegToId, IdToReg, TRI); | 
|  | if (RegToId.empty()) | 
|  | return false; | 
|  |  | 
|  | MachineInstr *DummyOp = nullptr; | 
|  | if (BasicBlockScopeOnly) { | 
|  | const TargetInstrInfo *TII = MF.getSubtarget().getInstrInfo(); | 
|  | // For local analysis, create a dummy operation to record uses that are not | 
|  | // local. | 
|  | DummyOp = MF.CreateMachineInstr(TII->get(AArch64::COPY), DebugLoc()); | 
|  | } | 
|  |  | 
|  | unsigned NbReg = RegToId.size(); | 
|  | bool Modified = false; | 
|  |  | 
|  | // Start with ADRP. | 
|  | InstrToInstrs *ColorOpToReachedUses = new InstrToInstrs[NbReg]; | 
|  |  | 
|  | // Compute the reaching def in ADRP mode, meaning ADRP definitions | 
|  | // are first considered as uses. | 
|  | reachingDef(MF, ColorOpToReachedUses, RegToId, true, DummyOp); | 
|  | DEBUG(dbgs() << "ADRP reaching defs\n"); | 
|  | DEBUG(printReachingDef(ColorOpToReachedUses, NbReg, TRI, IdToReg)); | 
|  |  | 
|  | // Translate the definition to uses map into a use to definitions map to ease | 
|  | // statistic computation. | 
|  | InstrToInstrs ADRPToReachingDefs; | 
|  | reachedUsesToDefs(ADRPToReachingDefs, ColorOpToReachedUses, RegToId, true); | 
|  |  | 
|  | // Compute LOH for ADRP. | 
|  | computeADRP(ADRPToReachingDefs, *AArch64FI, MDT); | 
|  | delete[] ColorOpToReachedUses; | 
|  |  | 
|  | // Continue with general ADRP -> ADD/LDR -> LDR/STR pattern. | 
|  | ColorOpToReachedUses = new InstrToInstrs[NbReg]; | 
|  |  | 
|  | // first perform a regular reaching def analysis. | 
|  | reachingDef(MF, ColorOpToReachedUses, RegToId, false, DummyOp); | 
|  | DEBUG(dbgs() << "All reaching defs\n"); | 
|  | DEBUG(printReachingDef(ColorOpToReachedUses, NbReg, TRI, IdToReg)); | 
|  |  | 
|  | // Turn that into a use to defs to ease statistic computation. | 
|  | InstrToInstrs UsesToReachingDefs; | 
|  | reachedUsesToDefs(UsesToReachingDefs, ColorOpToReachedUses, RegToId, false); | 
|  |  | 
|  | // Compute other than AdrpAdrp LOH. | 
|  | computeOthers(UsesToReachingDefs, ColorOpToReachedUses, *AArch64FI, RegToId, | 
|  | MDT); | 
|  | delete[] ColorOpToReachedUses; | 
|  |  | 
|  | if (BasicBlockScopeOnly) | 
|  | MF.DeleteMachineInstr(DummyOp); | 
|  |  | 
|  | return Modified; | 
|  | } | 
|  |  | 
|  | /// createAArch64CollectLOHPass - returns an instance of the Statistic for | 
|  | /// linker optimization pass. | 
|  | FunctionPass *llvm::createAArch64CollectLOHPass() { | 
|  | return new AArch64CollectLOH(); | 
|  | } |