LLVM  9.0.0svn
BPFTargetMachine.cpp
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1 //===-- BPFTargetMachine.cpp - Define TargetMachine for BPF ---------------===//
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 // Implements the info about BPF target spec.
10 //
11 //===----------------------------------------------------------------------===//
12 
13 #include "BPFTargetMachine.h"
14 #include "BPF.h"
17 #include "llvm/CodeGen/Passes.h"
24 using namespace llvm;
25 
26 static cl::
27 opt<bool> DisableMIPeephole("disable-bpf-peephole", cl::Hidden,
28  cl::desc("Disable machine peepholes for BPF"));
29 
30 extern "C" void LLVMInitializeBPFTarget() {
31  // Register the target.
35 
38 }
39 
40 // DataLayout: little or big endian
41 static std::string computeDataLayout(const Triple &TT) {
42  if (TT.getArch() == Triple::bpfeb)
43  return "E-m:e-p:64:64-i64:64-n32:64-S128";
44  else
45  return "e-m:e-p:64:64-i64:64-n32:64-S128";
46 }
47 
49  if (!RM.hasValue())
50  return Reloc::PIC_;
51  return *RM;
52 }
53 
55  StringRef CPU, StringRef FS,
56  const TargetOptions &Options,
59  CodeGenOpt::Level OL, bool JIT)
60  : LLVMTargetMachine(T, computeDataLayout(TT), TT, CPU, FS, Options,
62  getEffectiveCodeModel(CM, CodeModel::Small), OL),
64  Subtarget(TT, CPU, FS, *this) {
65  initAsmInfo();
66 
67  BPFMCAsmInfo *MAI =
68  static_cast<BPFMCAsmInfo *>(const_cast<MCAsmInfo *>(AsmInfo.get()));
70 }
71 namespace {
72 // BPF Code Generator Pass Configuration Options.
73 class BPFPassConfig : public TargetPassConfig {
74 public:
75  BPFPassConfig(BPFTargetMachine &TM, PassManagerBase &PM)
76  : TargetPassConfig(TM, PM) {}
77 
78  BPFTargetMachine &getBPFTargetMachine() const {
79  return getTM<BPFTargetMachine>();
80  }
81 
82  bool addInstSelector() override;
83  void addMachineSSAOptimization() override;
84  void addPreEmitPass() override;
85 };
86 }
87 
89  return new BPFPassConfig(*this, PM);
90 }
91 
92 // Install an instruction selector pass using
93 // the ISelDag to gen BPF code.
94 bool BPFPassConfig::addInstSelector() {
95  addPass(createBPFISelDag(getBPFTargetMachine()));
96 
97  return false;
98 }
99 
100 void BPFPassConfig::addMachineSSAOptimization() {
101  // The default implementation must be called first as we want eBPF
102  // Peephole ran at last.
104 
105  const BPFSubtarget *Subtarget = getBPFTargetMachine().getSubtargetImpl();
106  if (Subtarget->getHasAlu32() && !DisableMIPeephole)
107  addPass(createBPFMIPeepholePass());
108 }
109 
110 void BPFPassConfig::addPreEmitPass() {
111  const BPFSubtarget *Subtarget = getBPFTargetMachine().getSubtargetImpl();
112 
114  if (getOptLevel() != CodeGenOpt::None)
115  if (Subtarget->getHasAlu32() && !DisableMIPeephole)
117 }
static GCMetadataPrinterRegistry::Add< ErlangGCPrinter > X("erlang", "erlang-compatible garbage collector")
CodeModel::Model getEffectiveCodeModel(Optional< CodeModel::Model > CM, CodeModel::Model Default)
Helper method for getting the code model, returning Default if CM does not have a value...
static PassRegistry * getPassRegistry()
getPassRegistry - Access the global registry object, which is automatically initialized at applicatio...
void initializeBPFMIPeepholePass(PassRegistry &)
This class represents lattice values for constants.
Definition: AllocatorList.h:23
FunctionPass * createBPFMIPreEmitPeepholePass()
FunctionPass * createBPFMIPreEmitCheckingPass()
std::enable_if<!std::is_array< T >::value, std::unique_ptr< T > >::type make_unique(Args &&... args)
Constructs a new T() with the given args and returns a unique_ptr<T> which owns the object...
Definition: STLExtras.h:1437
virtual void addMachineSSAOptimization()
addMachineSSAOptimization - Add standard passes that optimize machine instructions in SSA form...
static GCMetadataPrinterRegistry::Add< OcamlGCMetadataPrinter > Y("ocaml", "ocaml 3.10-compatible collector")
void setDwarfUsesRelocationsAcrossSections(bool enable)
Definition: BPFMCAsmInfo.h:47
Target-Independent Code Generator Pass Configuration Options.
TargetPassConfig * createPassConfig(PassManagerBase &PM) override
Create a pass configuration object to be used by addPassToEmitX methods for generating a pipeline of ...
RegisterTargetMachine - Helper template for registering a target machine implementation, for use in the target machine initialization function.
ArchType getArch() const
getArch - Get the parsed architecture type of this triple.
Definition: Triple.h:295
static cl::opt< bool > DisableMIPeephole("disable-bpf-peephole", cl::Hidden, cl::desc("Disable machine peepholes for BPF"))
This class is intended to be used as a base class for asm properties and features specific to the tar...
Definition: MCAsmInfo.h:56
bool getUseDwarfRIS() const
Definition: BPFSubtarget.h:74
CodeGenOpt::Level getOptLevel() const
Returns the optimization level: None, Less, Default, or Aggressive.
static Reloc::Model getEffectiveRelocModel(Optional< Reloc::Model > RM)
std::unique_ptr< const MCAsmInfo > AsmInfo
Contains target specific asm information.
Definition: TargetMachine.h:93
This class describes a target machine that is implemented with the LLVM target-independent code gener...
FunctionPass * createBPFMIPeepholePass()
Triple - Helper class for working with autoconf configuration names.
Definition: Triple.h:43
PassManagerBase - An abstract interface to allow code to add passes to a pass manager without having ...
BPFTargetMachine(const Target &T, const Triple &TT, StringRef CPU, StringRef FS, const TargetOptions &Options, Optional< Reloc::Model > RM, Optional< CodeModel::Model > CM, CodeGenOpt::Level OL, bool JIT)
Target - Wrapper for Target specific information.
bool hasValue() const
Definition: Optional.h:259
bool getHasAlu32() const
Definition: BPFSubtarget.h:73
void LLVMInitializeBPFTarget()
static std::string computeDataLayout(const Triple &TT)
Target & getTheBPFleTarget()
StringRef - Represent a constant reference to a string, i.e.
Definition: StringRef.h:48
PassRegistry - This class manages the registration and intitialization of the pass subsystem as appli...
Definition: PassRegistry.h:38
Target & getTheBPFbeTarget()
FunctionPass * createBPFISelDag(BPFTargetMachine &TM)
Target & getTheBPFTarget()