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
createBPFMCInstrInfo()36 static MCInstrInfo *createBPFMCInstrInfo() {
37 MCInstrInfo *X = new MCInstrInfo();
38 InitBPFMCInstrInfo(X);
39 return X;
40 }
41
createBPFMCRegisterInfo(const Triple & TT)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
createBPFMCSubtargetInfo(const Triple & TT,StringRef CPU,StringRef FS)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,std::unique_ptr<MCAsmBackend> && MAB,std::unique_ptr<MCObjectWriter> && OW,std::unique_ptr<MCCodeEmitter> && Emitter)54 createBPFMCStreamer(const Triple &T, MCContext &Ctx,
55 std::unique_ptr<MCAsmBackend> &&MAB,
56 std::unique_ptr<MCObjectWriter> &&OW,
57 std::unique_ptr<MCCodeEmitter> &&Emitter) {
58 return createELFStreamer(Ctx, std::move(MAB), std::move(OW),
59 std::move(Emitter));
60 }
61
createBPFMCInstPrinter(const Triple & T,unsigned SyntaxVariant,const MCAsmInfo & MAI,const MCInstrInfo & MII,const MCRegisterInfo & MRI)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:
BPFMCInstrAnalysis(const MCInstrInfo * Info)76 explicit BPFMCInstrAnalysis(const MCInstrInfo *Info)
77 : MCInstrAnalysis(Info) {}
78
evaluateBranch(const MCInst & Inst,uint64_t Addr,uint64_t Size,uint64_t & Target) const79 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 if (Inst.getOpcode() == BPF::JCOND)
85 Imm = (short)Inst.getOperand(0).getImm();
86 else
87 Imm = (short)Inst.getOperand(2).getImm();
88 } else if (isUnconditionalBranch(Inst)) {
89 if (Inst.getOpcode() == BPF::JMP)
90 Imm = (short)Inst.getOperand(0).getImm();
91 else
92 Imm = (int)Inst.getOperand(0).getImm();
93 } else
94 return false;
95
96 Target = Addr + Size + Imm * Size;
97 return true;
98 }
99 };
100
101 } // end anonymous namespace
102
createBPFInstrAnalysis(const MCInstrInfo * Info)103 static MCInstrAnalysis *createBPFInstrAnalysis(const MCInstrInfo *Info) {
104 return new BPFMCInstrAnalysis(Info);
105 }
106
LLVMInitializeBPFTargetMC()107 extern "C" LLVM_EXTERNAL_VISIBILITY void LLVMInitializeBPFTargetMC() {
108 for (Target *T :
109 {&getTheBPFleTarget(), &getTheBPFbeTarget(), &getTheBPFTarget()}) {
110 // Register the MC asm info.
111 RegisterMCAsmInfo<BPFMCAsmInfo> X(*T);
112
113 // Register the MC instruction info.
114 TargetRegistry::RegisterMCInstrInfo(*T, createBPFMCInstrInfo);
115
116 // Register the MC register info.
117 TargetRegistry::RegisterMCRegInfo(*T, createBPFMCRegisterInfo);
118
119 // Register the MC subtarget info.
120 TargetRegistry::RegisterMCSubtargetInfo(*T,
121 createBPFMCSubtargetInfo);
122
123 // Register the object streamer
124 TargetRegistry::RegisterELFStreamer(*T, createBPFMCStreamer);
125
126 // Register the MCInstPrinter.
127 TargetRegistry::RegisterMCInstPrinter(*T, createBPFMCInstPrinter);
128
129 // Register the MC instruction analyzer.
130 TargetRegistry::RegisterMCInstrAnalysis(*T, createBPFInstrAnalysis);
131 }
132
133 // Register the MC code emitter
134 TargetRegistry::RegisterMCCodeEmitter(getTheBPFleTarget(),
135 createBPFMCCodeEmitter);
136 TargetRegistry::RegisterMCCodeEmitter(getTheBPFbeTarget(),
137 createBPFbeMCCodeEmitter);
138
139 // Register the ASM Backend
140 TargetRegistry::RegisterMCAsmBackend(getTheBPFleTarget(),
141 createBPFAsmBackend);
142 TargetRegistry::RegisterMCAsmBackend(getTheBPFbeTarget(),
143 createBPFbeAsmBackend);
144
145 if (sys::IsLittleEndianHost) {
146 TargetRegistry::RegisterMCCodeEmitter(getTheBPFTarget(),
147 createBPFMCCodeEmitter);
148 TargetRegistry::RegisterMCAsmBackend(getTheBPFTarget(),
149 createBPFAsmBackend);
150 } else {
151 TargetRegistry::RegisterMCCodeEmitter(getTheBPFTarget(),
152 createBPFbeMCCodeEmitter);
153 TargetRegistry::RegisterMCAsmBackend(getTheBPFTarget(),
154 createBPFbeAsmBackend);
155 }
156
157 }
158