1//===-- BPFTargetMachine.cpp - Define TargetMachine for BPF ---------------===//
2//
3//                     The LLVM Compiler Infrastructure
4//
5// This file is distributed under the University of Illinois Open Source
6// License. See LICENSE.TXT for details.
7//
8//===----------------------------------------------------------------------===//
9//
10// Implements the info about BPF target spec.
11//
12//===----------------------------------------------------------------------===//
13
14#include "BPF.h"
15#include "BPFTargetMachine.h"
16#include "llvm/CodeGen/TargetLoweringObjectFileImpl.h"
17#include "llvm/IR/LegacyPassManager.h"
18#include "llvm/CodeGen/Passes.h"
19#include "llvm/CodeGen/TargetPassConfig.h"
20#include "llvm/Support/FormattedStream.h"
21#include "llvm/Support/TargetRegistry.h"
22#include "llvm/Target/TargetOptions.h"
23using namespace llvm;
24
25extern "C" void LLVMInitializeBPFTarget() {
26  // Register the target.
27  RegisterTargetMachine<BPFTargetMachine> X(TheBPFleTarget);
28  RegisterTargetMachine<BPFTargetMachine> Y(TheBPFbeTarget);
29  RegisterTargetMachine<BPFTargetMachine> Z(TheBPFTarget);
30}
31
32// DataLayout: little or big endian
33static std::string computeDataLayout(const Triple &TT) {
34  if (TT.getArch() == Triple::bpfeb)
35    return "E-m:e-p:64:64-i64:64-n32:64-S128";
36  else
37    return "e-m:e-p:64:64-i64:64-n32:64-S128";
38}
39
40static Reloc::Model getEffectiveRelocModel(Optional<Reloc::Model> RM) {
41  if (!RM.hasValue())
42    return Reloc::PIC_;
43  return *RM;
44}
45
46BPFTargetMachine::BPFTargetMachine(const Target &T, const Triple &TT,
47                                   StringRef CPU, StringRef FS,
48                                   const TargetOptions &Options,
49                                   Optional<Reloc::Model> RM,
50                                   CodeModel::Model CM, CodeGenOpt::Level OL)
51    : LLVMTargetMachine(T, computeDataLayout(TT), TT, CPU, FS, Options,
52                        getEffectiveRelocModel(RM), CM, OL),
53      TLOF(make_unique<TargetLoweringObjectFileELF>()),
54      Subtarget(TT, CPU, FS, *this) {
55  initAsmInfo();
56}
57namespace {
58// BPF Code Generator Pass Configuration Options.
59class BPFPassConfig : public TargetPassConfig {
60public:
61  BPFPassConfig(BPFTargetMachine *TM, PassManagerBase &PM)
62      : TargetPassConfig(TM, PM) {}
63
64  BPFTargetMachine &getBPFTargetMachine() const {
65    return getTM<BPFTargetMachine>();
66  }
67
68  bool addInstSelector() override;
69};
70}
71
72TargetPassConfig *BPFTargetMachine::createPassConfig(PassManagerBase &PM) {
73  return new BPFPassConfig(this, PM);
74}
75
76// Install an instruction selector pass using
77// the ISelDag to gen BPF code.
78bool BPFPassConfig::addInstSelector() {
79  addPass(createBPFISelDag(getBPFTargetMachine()));
80
81  return false;
82}
83