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 int32_t Imm; 83 if (isConditionalBranch(Inst)) { 84 Imm = (short)Inst.getOperand(2).getImm(); 85 } else if (isUnconditionalBranch(Inst)) { 86 if (Inst.getOpcode() == BPF::JMP) 87 Imm = (short)Inst.getOperand(0).getImm(); 88 else 89 Imm = (int)Inst.getOperand(0).getImm(); 90 } else 91 return false; 92 93 Target = Addr + Size + Imm * Size; 94 return true; 95 } 96 }; 97 98 } // end anonymous namespace 99 100 static MCInstrAnalysis *createBPFInstrAnalysis(const MCInstrInfo *Info) { 101 return new BPFMCInstrAnalysis(Info); 102 } 103 104 extern "C" LLVM_EXTERNAL_VISIBILITY void LLVMInitializeBPFTargetMC() { 105 for (Target *T : 106 {&getTheBPFleTarget(), &getTheBPFbeTarget(), &getTheBPFTarget()}) { 107 // Register the MC asm info. 108 RegisterMCAsmInfo<BPFMCAsmInfo> X(*T); 109 110 // Register the MC instruction info. 111 TargetRegistry::RegisterMCInstrInfo(*T, createBPFMCInstrInfo); 112 113 // Register the MC register info. 114 TargetRegistry::RegisterMCRegInfo(*T, createBPFMCRegisterInfo); 115 116 // Register the MC subtarget info. 117 TargetRegistry::RegisterMCSubtargetInfo(*T, 118 createBPFMCSubtargetInfo); 119 120 // Register the object streamer 121 TargetRegistry::RegisterELFStreamer(*T, createBPFMCStreamer); 122 123 // Register the MCInstPrinter. 124 TargetRegistry::RegisterMCInstPrinter(*T, createBPFMCInstPrinter); 125 126 // Register the MC instruction analyzer. 127 TargetRegistry::RegisterMCInstrAnalysis(*T, createBPFInstrAnalysis); 128 } 129 130 // Register the MC code emitter 131 TargetRegistry::RegisterMCCodeEmitter(getTheBPFleTarget(), 132 createBPFMCCodeEmitter); 133 TargetRegistry::RegisterMCCodeEmitter(getTheBPFbeTarget(), 134 createBPFbeMCCodeEmitter); 135 136 // Register the ASM Backend 137 TargetRegistry::RegisterMCAsmBackend(getTheBPFleTarget(), 138 createBPFAsmBackend); 139 TargetRegistry::RegisterMCAsmBackend(getTheBPFbeTarget(), 140 createBPFbeAsmBackend); 141 142 if (sys::IsLittleEndianHost) { 143 TargetRegistry::RegisterMCCodeEmitter(getTheBPFTarget(), 144 createBPFMCCodeEmitter); 145 TargetRegistry::RegisterMCAsmBackend(getTheBPFTarget(), 146 createBPFAsmBackend); 147 } else { 148 TargetRegistry::RegisterMCCodeEmitter(getTheBPFTarget(), 149 createBPFbeMCCodeEmitter); 150 TargetRegistry::RegisterMCAsmBackend(getTheBPFTarget(), 151 createBPFbeAsmBackend); 152 } 153 154 } 155