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
35using namespace llvm;
36
37static MCInstrInfo *createBPFMCInstrInfo() {
38 MCInstrInfo *X = new MCInstrInfo();
39 InitBPFMCInstrInfo(II: X);
40 return X;
41}
42
43static MCRegisterInfo *createBPFMCRegisterInfo(const Triple &TT) {
44 MCRegisterInfo *X = new MCRegisterInfo();
45 InitBPFMCRegisterInfo(RI: X, RA: BPF::R11 /* RAReg doesn't exist */);
46 return X;
47}
48
49static MCSubtargetInfo *createBPFMCSubtargetInfo(const Triple &TT,
50 StringRef CPU, StringRef FS) {
51 return createBPFMCSubtargetInfoImpl(TT, CPU, /*TuneCPU*/ CPU, FS);
52}
53
54static MCStreamer *
55createBPFMCStreamer(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, TAB: std::move(MAB), OW: std::move(OW),
60 CE: std::move(Emitter));
61}
62
63static 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
73namespace {
74
75class BPFMCInstrAnalysis : public MCInstrAnalysis {
76public:
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(i: 0).getImm();
87 else
88 Imm = (short)Inst.getOperand(i: 2).getImm();
89 } else if (isUnconditionalBranch(Inst)) {
90 if (Inst.getOpcode() == BPF::JMP)
91 Imm = (short)Inst.getOperand(i: 0).getImm();
92 else
93 Imm = (int)Inst.getOperand(i: 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
104static MCInstrAnalysis *createBPFInstrAnalysis(const MCInstrInfo *Info) {
105 return new BPFMCInstrAnalysis(Info);
106}
107
108extern "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&: *T, Fn: createBPFMCInstrInfo);
116
117 // Register the MC register info.
118 TargetRegistry::RegisterMCRegInfo(T&: *T, Fn: createBPFMCRegisterInfo);
119
120 // Register the MC subtarget info.
121 TargetRegistry::RegisterMCSubtargetInfo(T&: *T,
122 Fn: createBPFMCSubtargetInfo);
123
124 // Register the object streamer
125 TargetRegistry::RegisterELFStreamer(T&: *T, Fn: createBPFMCStreamer);
126
127 // Register the MCInstPrinter.
128 TargetRegistry::RegisterMCInstPrinter(T&: *T, Fn: createBPFMCInstPrinter);
129
130 // Register the MC instruction analyzer.
131 TargetRegistry::RegisterMCInstrAnalysis(T&: *T, Fn: createBPFInstrAnalysis);
132 }
133
134 // Register the MC code emitter
135 TargetRegistry::RegisterMCCodeEmitter(T&: getTheBPFleTarget(),
136 Fn: createBPFMCCodeEmitter);
137 TargetRegistry::RegisterMCCodeEmitter(T&: getTheBPFbeTarget(),
138 Fn: createBPFbeMCCodeEmitter);
139
140 // Register the ASM Backend
141 TargetRegistry::RegisterMCAsmBackend(T&: getTheBPFleTarget(),
142 Fn: createBPFAsmBackend);
143 TargetRegistry::RegisterMCAsmBackend(T&: getTheBPFbeTarget(),
144 Fn: createBPFbeAsmBackend);
145
146 if (sys::IsLittleEndianHost) {
147 TargetRegistry::RegisterMCCodeEmitter(T&: getTheBPFTarget(),
148 Fn: createBPFMCCodeEmitter);
149 TargetRegistry::RegisterMCAsmBackend(T&: getTheBPFTarget(),
150 Fn: createBPFAsmBackend);
151 } else {
152 TargetRegistry::RegisterMCCodeEmitter(T&: getTheBPFTarget(),
153 Fn: createBPFbeMCCodeEmitter);
154 TargetRegistry::RegisterMCAsmBackend(T&: getTheBPFTarget(),
155 Fn: createBPFbeAsmBackend);
156 }
157}
158