1 //===-- BPFMCTargetDesc.cpp - BPF Target Descriptions ---------------------===// 2 // 3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. 4 // See https://llvm.org/LICENSE.txt for license information. 5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception 6 // 7 //===----------------------------------------------------------------------===// 8 // 9 // This file provides BPF specific target descriptions. 10 // 11 //===----------------------------------------------------------------------===// 12 13 #include "MCTargetDesc/BPFMCTargetDesc.h" 14 #include "MCTargetDesc/BPFInstPrinter.h" 15 #include "MCTargetDesc/BPFMCAsmInfo.h" 16 #include "TargetInfo/BPFTargetInfo.h" 17 #include "llvm/MC/MCInstrAnalysis.h" 18 #include "llvm/MC/MCInstrInfo.h" 19 #include "llvm/MC/MCRegisterInfo.h" 20 #include "llvm/MC/MCSubtargetInfo.h" 21 #include "llvm/MC/TargetRegistry.h" 22 #include "llvm/TargetParser/Host.h" 23 24 #define GET_INSTRINFO_MC_DESC 25 #define ENABLE_INSTR_PREDICATE_VERIFIER 26 #include "BPFGenInstrInfo.inc" 27 28 #define GET_SUBTARGETINFO_MC_DESC 29 #include "BPFGenSubtargetInfo.inc" 30 31 #define GET_REGINFO_MC_DESC 32 #include "BPFGenRegisterInfo.inc" 33 34 using namespace llvm; 35 36 static MCInstrInfo *createBPFMCInstrInfo() { 37 MCInstrInfo *X = new MCInstrInfo(); 38 InitBPFMCInstrInfo(X); 39 return X; 40 } 41 42 static MCRegisterInfo *createBPFMCRegisterInfo(const Triple &TT) { 43 MCRegisterInfo *X = new MCRegisterInfo(); 44 InitBPFMCRegisterInfo(X, BPF::R11 /* RAReg doesn't exist */); 45 return X; 46 } 47 48 static MCSubtargetInfo *createBPFMCSubtargetInfo(const Triple &TT, 49 StringRef CPU, StringRef FS) { 50 return createBPFMCSubtargetInfoImpl(TT, CPU, /*TuneCPU*/ CPU, FS); 51 } 52 53 static MCStreamer *createBPFMCStreamer(const Triple &T, MCContext &Ctx, 54 std::unique_ptr<MCAsmBackend> &&MAB, 55 std::unique_ptr<MCObjectWriter> &&OW, 56 std::unique_ptr<MCCodeEmitter> &&Emitter, 57 bool RelaxAll) { 58 return createELFStreamer(Ctx, std::move(MAB), std::move(OW), std::move(Emitter), 59 RelaxAll); 60 } 61 62 static MCInstPrinter *createBPFMCInstPrinter(const Triple &T, 63 unsigned SyntaxVariant, 64 const MCAsmInfo &MAI, 65 const MCInstrInfo &MII, 66 const MCRegisterInfo &MRI) { 67 if (SyntaxVariant == 0) 68 return new BPFInstPrinter(MAI, MII, MRI); 69 return nullptr; 70 } 71 72 namespace { 73 74 class BPFMCInstrAnalysis : public MCInstrAnalysis { 75 public: 76 explicit BPFMCInstrAnalysis(const MCInstrInfo *Info) 77 : MCInstrAnalysis(Info) {} 78 79 bool evaluateBranch(const MCInst &Inst, uint64_t Addr, uint64_t Size, 80 uint64_t &Target) const override { 81 // The target is the 3rd operand of cond inst and the 1st of uncond inst. 82 int16_t Imm; 83 if (isConditionalBranch(Inst)) { 84 Imm = Inst.getOperand(2).getImm(); 85 } else if (isUnconditionalBranch(Inst)) 86 Imm = Inst.getOperand(0).getImm(); 87 else 88 return false; 89 90 Target = Addr + Size + Imm * Size; 91 return true; 92 } 93 }; 94 95 } // end anonymous namespace 96 97 static MCInstrAnalysis *createBPFInstrAnalysis(const MCInstrInfo *Info) { 98 return new BPFMCInstrAnalysis(Info); 99 } 100 101 extern "C" LLVM_EXTERNAL_VISIBILITY void LLVMInitializeBPFTargetMC() { 102 for (Target *T : 103 {&getTheBPFleTarget(), &getTheBPFbeTarget(), &getTheBPFTarget()}) { 104 // Register the MC asm info. 105 RegisterMCAsmInfo<BPFMCAsmInfo> X(*T); 106 107 // Register the MC instruction info. 108 TargetRegistry::RegisterMCInstrInfo(*T, createBPFMCInstrInfo); 109 110 // Register the MC register info. 111 TargetRegistry::RegisterMCRegInfo(*T, createBPFMCRegisterInfo); 112 113 // Register the MC subtarget info. 114 TargetRegistry::RegisterMCSubtargetInfo(*T, 115 createBPFMCSubtargetInfo); 116 117 // Register the object streamer 118 TargetRegistry::RegisterELFStreamer(*T, createBPFMCStreamer); 119 120 // Register the MCInstPrinter. 121 TargetRegistry::RegisterMCInstPrinter(*T, createBPFMCInstPrinter); 122 123 // Register the MC instruction analyzer. 124 TargetRegistry::RegisterMCInstrAnalysis(*T, createBPFInstrAnalysis); 125 } 126 127 // Register the MC code emitter 128 TargetRegistry::RegisterMCCodeEmitter(getTheBPFleTarget(), 129 createBPFMCCodeEmitter); 130 TargetRegistry::RegisterMCCodeEmitter(getTheBPFbeTarget(), 131 createBPFbeMCCodeEmitter); 132 133 // Register the ASM Backend 134 TargetRegistry::RegisterMCAsmBackend(getTheBPFleTarget(), 135 createBPFAsmBackend); 136 TargetRegistry::RegisterMCAsmBackend(getTheBPFbeTarget(), 137 createBPFbeAsmBackend); 138 139 if (sys::IsLittleEndianHost) { 140 TargetRegistry::RegisterMCCodeEmitter(getTheBPFTarget(), 141 createBPFMCCodeEmitter); 142 TargetRegistry::RegisterMCAsmBackend(getTheBPFTarget(), 143 createBPFAsmBackend); 144 } else { 145 TargetRegistry::RegisterMCCodeEmitter(getTheBPFTarget(), 146 createBPFbeMCCodeEmitter); 147 TargetRegistry::RegisterMCAsmBackend(getTheBPFTarget(), 148 createBPFbeAsmBackend); 149 } 150 151 } 152