BPFTargetMachine.cpp revision 6948897e478cbd66626159776a8017b3c18579b9 
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/Support/FormattedStream.h"
20#include "llvm/Support/TargetRegistry.h"
21#include "llvm/Target/TargetOptions.h"
22using namespace llvm;
23
24extern "C" void LLVMInitializeBPFTarget() {
25  // Register the target.
26  RegisterTargetMachine<BPFTargetMachine> X(TheBPFleTarget);
27  RegisterTargetMachine<BPFTargetMachine> Y(TheBPFbeTarget);
28  RegisterTargetMachine<BPFTargetMachine> Z(TheBPFTarget);
29}
30
31// DataLayout: little or big endian
32static std::string computeDataLayout(const Triple &TT) {
33  if (TT.getArch() == Triple::bpfeb)
34    return "E-m:e-p:64:64-i64:64-n32:64-S128";
35  else
36    return "e-m:e-p:64:64-i64:64-n32:64-S128";
37}
38
39BPFTargetMachine::BPFTargetMachine(const Target &T, const Triple &TT,
40                                   StringRef CPU, StringRef FS,
41                                   const TargetOptions &Options,
42                                   Reloc::Model RM, CodeModel::Model CM,
43                                   CodeGenOpt::Level OL)
44    : LLVMTargetMachine(T, computeDataLayout(TT), TT, CPU, FS,
45                        Options, RM, CM, OL),
46      TLOF(make_unique<TargetLoweringObjectFileELF>()),
47      Subtarget(Triple(TT), CPU, FS, *this) {
48  initAsmInfo();
49}
50namespace {
51// BPF Code Generator Pass Configuration Options.
52class BPFPassConfig : public TargetPassConfig {
53public:
54  BPFPassConfig(BPFTargetMachine *TM, PassManagerBase &PM)
55      : TargetPassConfig(TM, PM) {}
56
57  BPFTargetMachine &getBPFTargetMachine() const {
58    return getTM<BPFTargetMachine>();
59  }
60
61  bool addInstSelector() override;
62};
63}
64
65TargetPassConfig *BPFTargetMachine::createPassConfig(PassManagerBase &PM) {
66  return new BPFPassConfig(this, PM);
67}
68
69// Install an instruction selector pass using
70// the ISelDag to gen BPF code.
71bool BPFPassConfig::addInstSelector() {
72  addPass(createBPFISelDag(getBPFTargetMachine()));
73
74  return false;
75}
76