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(TheBPFTarget);
27}
28
29// DataLayout --> Little-endian, 64-bit pointer/ABI/alignment
30// The stack is always 8 byte aligned
31// On function prologue, the stack is created by decrementing
32// its pointer. Once decremented, all references are done with positive
33// offset from the stack/frame pointer.
34BPFTargetMachine::BPFTargetMachine(const Target &T, StringRef TT, StringRef CPU,
35                                   StringRef FS, const TargetOptions &Options,
36                                   Reloc::Model RM, CodeModel::Model CM,
37                                   CodeGenOpt::Level OL)
38    : LLVMTargetMachine(T, "e-m:e-p:64:64-i64:64-n32:64-S128", TT, CPU, FS,
39                        Options, RM, CM, OL),
40      TLOF(make_unique<TargetLoweringObjectFileELF>()),
41      Subtarget(TT, CPU, FS, *this) {
42  initAsmInfo();
43}
44namespace {
45// BPF Code Generator Pass Configuration Options.
46class BPFPassConfig : public TargetPassConfig {
47public:
48  BPFPassConfig(BPFTargetMachine *TM, PassManagerBase &PM)
49      : TargetPassConfig(TM, PM) {}
50
51  BPFTargetMachine &getBPFTargetMachine() const {
52    return getTM<BPFTargetMachine>();
53  }
54
55  bool addInstSelector() override;
56};
57}
58
59TargetPassConfig *BPFTargetMachine::createPassConfig(PassManagerBase &PM) {
60  return new BPFPassConfig(this, PM);
61}
62
63// Install an instruction selector pass using
64// the ISelDag to gen BPF code.
65bool BPFPassConfig::addInstSelector() {
66  addPass(createBPFISelDag(getBPFTargetMachine()));
67
68  return false;
69}
70