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
34using namespace llvm;
35
36static MCInstrInfo *createBPFMCInstrInfo() {
37 MCInstrInfo *X = new MCInstrInfo();
38 InitBPFMCInstrInfo(II: X);
39 return X;
40}
41
42static MCRegisterInfo *createBPFMCRegisterInfo(const Triple &TT) {
43 MCRegisterInfo *X = new MCRegisterInfo();
44 InitBPFMCRegisterInfo(RI: X, RA: BPF::R11 /* RAReg doesn't exist */);
45 return X;
46}
47
48static MCSubtargetInfo *createBPFMCSubtargetInfo(const Triple &TT,
49 StringRef CPU, StringRef FS) {
50 return createBPFMCSubtargetInfoImpl(TT, CPU, /*TuneCPU*/ CPU, FS);
51}
52
53static MCStreamer *
54createBPFMCStreamer(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, TAB: std::move(MAB), OW: std::move(OW),
59 CE: std::move(Emitter));
60}
61
62static 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
72namespace {
73
74class BPFMCInstrAnalysis : public MCInstrAnalysis {
75public:
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 if (Inst.getOpcode() == BPF::JCOND)
85 Imm = (short)Inst.getOperand(i: 0).getImm();
86 else
87 Imm = (short)Inst.getOperand(i: 2).getImm();
88 } else if (isUnconditionalBranch(Inst)) {
89 if (Inst.getOpcode() == BPF::JMP)
90 Imm = (short)Inst.getOperand(i: 0).getImm();
91 else
92 Imm = (int)Inst.getOperand(i: 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
103static MCInstrAnalysis *createBPFInstrAnalysis(const MCInstrInfo *Info) {
104 return new BPFMCInstrAnalysis(Info);
105}
106
107extern "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&: *T, Fn: createBPFMCInstrInfo);
115
116 // Register the MC register info.
117 TargetRegistry::RegisterMCRegInfo(T&: *T, Fn: createBPFMCRegisterInfo);
118
119 // Register the MC subtarget info.
120 TargetRegistry::RegisterMCSubtargetInfo(T&: *T,
121 Fn: createBPFMCSubtargetInfo);
122
123 // Register the object streamer
124 TargetRegistry::RegisterELFStreamer(T&: *T, Fn: createBPFMCStreamer);
125
126 // Register the MCInstPrinter.
127 TargetRegistry::RegisterMCInstPrinter(T&: *T, Fn: createBPFMCInstPrinter);
128
129 // Register the MC instruction analyzer.
130 TargetRegistry::RegisterMCInstrAnalysis(T&: *T, Fn: createBPFInstrAnalysis);
131 }
132
133 // Register the MC code emitter
134 TargetRegistry::RegisterMCCodeEmitter(T&: getTheBPFleTarget(),
135 Fn: createBPFMCCodeEmitter);
136 TargetRegistry::RegisterMCCodeEmitter(T&: getTheBPFbeTarget(),
137 Fn: createBPFbeMCCodeEmitter);
138
139 // Register the ASM Backend
140 TargetRegistry::RegisterMCAsmBackend(T&: getTheBPFleTarget(),
141 Fn: createBPFAsmBackend);
142 TargetRegistry::RegisterMCAsmBackend(T&: getTheBPFbeTarget(),
143 Fn: createBPFbeAsmBackend);
144
145 if (sys::IsLittleEndianHost) {
146 TargetRegistry::RegisterMCCodeEmitter(T&: getTheBPFTarget(),
147 Fn: createBPFMCCodeEmitter);
148 TargetRegistry::RegisterMCAsmBackend(T&: getTheBPFTarget(),
149 Fn: createBPFAsmBackend);
150 } else {
151 TargetRegistry::RegisterMCCodeEmitter(T&: getTheBPFTarget(),
152 Fn: createBPFbeMCCodeEmitter);
153 TargetRegistry::RegisterMCAsmBackend(T&: getTheBPFTarget(),
154 Fn: createBPFbeAsmBackend);
155 }
156
157}
158