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
createBPFMCInstrInfo()37 static MCInstrInfo *createBPFMCInstrInfo() {
38 MCInstrInfo *X = new MCInstrInfo();
39 InitBPFMCInstrInfo(X);
40 return X;
41 }
42
createBPFMCRegisterInfo(const Triple & TT)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
createBPFMCSubtargetInfo(const Triple & TT,StringRef CPU,StringRef FS)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 *
createBPFMCStreamer(const Triple & T,MCContext & Ctx,std::unique_ptr<MCAsmBackend> && MAB,std::unique_ptr<MCObjectWriter> && OW,std::unique_ptr<MCCodeEmitter> && Emitter)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
createBPFMCInstPrinter(const Triple & T,unsigned SyntaxVariant,const MCAsmInfo & MAI,const MCInstrInfo & MII,const MCRegisterInfo & MRI)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:
BPFMCInstrAnalysis(const MCInstrInfo * Info)77 explicit BPFMCInstrAnalysis(const MCInstrInfo *Info)
78 : MCInstrAnalysis(Info) {}
79
evaluateBranch(const MCInst & Inst,uint64_t Addr,uint64_t Size,uint64_t & Target) const80 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
createBPFInstrAnalysis(const MCInstrInfo * Info)104 static MCInstrAnalysis *createBPFInstrAnalysis(const MCInstrInfo *Info) {
105 return new BPFMCInstrAnalysis(Info);
106 }
107
LLVMInitializeBPFTargetMC()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