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/Support/Compiler.h" 23 #include "llvm/TargetParser/Host.h" 24 25 #define GET_INSTRINFO_MC_DESC 26 #define ENABLE_INSTR_PREDICATE_VERIFIER 27 #include "BPFGenInstrInfo.inc" 28 29 #define GET_SUBTARGETINFO_MC_DESC 30 #include "BPFGenSubtargetInfo.inc" 31 32 #define GET_REGINFO_MC_DESC 33 #include "BPFGenRegisterInfo.inc" 34 35 using namespace llvm; 36 37 static MCInstrInfo *createBPFMCInstrInfo() { 38 MCInstrInfo *X = new MCInstrInfo(); 39 InitBPFMCInstrInfo(X); 40 return X; 41 } 42 43 static MCRegisterInfo *createBPFMCRegisterInfo(const Triple &TT) { 44 MCRegisterInfo *X = new MCRegisterInfo(); 45 InitBPFMCRegisterInfo(X, BPF::R11 /* RAReg doesn't exist */); 46 return X; 47 } 48 49 static MCSubtargetInfo *createBPFMCSubtargetInfo(const Triple &TT, 50 StringRef CPU, StringRef FS) { 51 return createBPFMCSubtargetInfoImpl(TT, CPU, /*TuneCPU*/ CPU, FS); 52 } 53 54 static MCStreamer * 55 createBPFMCStreamer(const Triple &T, MCContext &Ctx, 56 std::unique_ptr<MCAsmBackend> &&MAB, 57 std::unique_ptr<MCObjectWriter> &&OW, 58 std::unique_ptr<MCCodeEmitter> &&Emitter) { 59 return createELFStreamer(Ctx, std::move(MAB), std::move(OW), 60 std::move(Emitter)); 61 } 62 63 static MCInstPrinter *createBPFMCInstPrinter(const Triple &T, 64 unsigned SyntaxVariant, 65 const MCAsmInfo &MAI, 66 const MCInstrInfo &MII, 67 const MCRegisterInfo &MRI) { 68 if (SyntaxVariant == 0) 69 return new BPFInstPrinter(MAI, MII, MRI); 70 return nullptr; 71 } 72 73 namespace { 74 75 class BPFMCInstrAnalysis : public MCInstrAnalysis { 76 public: 77 explicit BPFMCInstrAnalysis(const MCInstrInfo *Info) 78 : MCInstrAnalysis(Info) {} 79 80 bool evaluateBranch(const MCInst &Inst, uint64_t Addr, uint64_t Size, 81 uint64_t &Target) const override { 82 // The target is the 3rd operand of cond inst and the 1st of uncond inst. 83 int32_t Imm; 84 if (isConditionalBranch(Inst)) { 85 if (Inst.getOpcode() == BPF::JCOND) 86 Imm = (short)Inst.getOperand(0).getImm(); 87 else 88 Imm = (short)Inst.getOperand(2).getImm(); 89 } else if (isUnconditionalBranch(Inst)) { 90 if (Inst.getOpcode() == BPF::JMP) 91 Imm = (short)Inst.getOperand(0).getImm(); 92 else 93 Imm = (int)Inst.getOperand(0).getImm(); 94 } else 95 return false; 96 97 Target = Addr + Size + Imm * Size; 98 return true; 99 } 100 }; 101 102 } // end anonymous namespace 103 104 static MCInstrAnalysis *createBPFInstrAnalysis(const MCInstrInfo *Info) { 105 return new BPFMCInstrAnalysis(Info); 106 } 107 108 extern "C" LLVM_ABI LLVM_EXTERNAL_VISIBILITY void LLVMInitializeBPFTargetMC() { 109 for (Target *T : 110 {&getTheBPFleTarget(), &getTheBPFbeTarget(), &getTheBPFTarget()}) { 111 // Register the MC asm info. 112 RegisterMCAsmInfo<BPFMCAsmInfo> X(*T); 113 114 // Register the MC instruction info. 115 TargetRegistry::RegisterMCInstrInfo(*T, createBPFMCInstrInfo); 116 117 // Register the MC register info. 118 TargetRegistry::RegisterMCRegInfo(*T, createBPFMCRegisterInfo); 119 120 // Register the MC subtarget info. 121 TargetRegistry::RegisterMCSubtargetInfo(*T, 122 createBPFMCSubtargetInfo); 123 124 // Register the object streamer 125 TargetRegistry::RegisterELFStreamer(*T, createBPFMCStreamer); 126 127 // Register the MCInstPrinter. 128 TargetRegistry::RegisterMCInstPrinter(*T, createBPFMCInstPrinter); 129 130 // Register the MC instruction analyzer. 131 TargetRegistry::RegisterMCInstrAnalysis(*T, createBPFInstrAnalysis); 132 } 133 134 // Register the MC code emitter 135 TargetRegistry::RegisterMCCodeEmitter(getTheBPFleTarget(), 136 createBPFMCCodeEmitter); 137 TargetRegistry::RegisterMCCodeEmitter(getTheBPFbeTarget(), 138 createBPFbeMCCodeEmitter); 139 140 // Register the ASM Backend 141 TargetRegistry::RegisterMCAsmBackend(getTheBPFleTarget(), 142 createBPFAsmBackend); 143 TargetRegistry::RegisterMCAsmBackend(getTheBPFbeTarget(), 144 createBPFbeAsmBackend); 145 146 if (sys::IsLittleEndianHost) { 147 TargetRegistry::RegisterMCCodeEmitter(getTheBPFTarget(), 148 createBPFMCCodeEmitter); 149 TargetRegistry::RegisterMCAsmBackend(getTheBPFTarget(), 150 createBPFAsmBackend); 151 } else { 152 TargetRegistry::RegisterMCCodeEmitter(getTheBPFTarget(), 153 createBPFbeMCCodeEmitter); 154 TargetRegistry::RegisterMCAsmBackend(getTheBPFTarget(), 155 createBPFbeAsmBackend); 156 } 157 } 158