forked from OSchip/llvm-project
118 lines
4.0 KiB
C++
118 lines
4.0 KiB
C++
//===-- BPFTargetMachine.cpp - Define TargetMachine for BPF ---------------===//
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//
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// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
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// See https://llvm.org/LICENSE.txt for license information.
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// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
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//
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//===----------------------------------------------------------------------===//
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//
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// Implements the info about BPF target spec.
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//
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//===----------------------------------------------------------------------===//
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#include "BPFTargetMachine.h"
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#include "BPF.h"
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#include "MCTargetDesc/BPFMCAsmInfo.h"
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#include "TargetInfo/BPFTargetInfo.h"
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#include "llvm/CodeGen/Passes.h"
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#include "llvm/CodeGen/TargetLoweringObjectFileImpl.h"
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#include "llvm/CodeGen/TargetPassConfig.h"
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#include "llvm/IR/LegacyPassManager.h"
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#include "llvm/Support/FormattedStream.h"
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#include "llvm/Support/TargetRegistry.h"
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#include "llvm/Target/TargetOptions.h"
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using namespace llvm;
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static cl::
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opt<bool> DisableMIPeephole("disable-bpf-peephole", cl::Hidden,
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cl::desc("Disable machine peepholes for BPF"));
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extern "C" void LLVMInitializeBPFTarget() {
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// Register the target.
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RegisterTargetMachine<BPFTargetMachine> X(getTheBPFleTarget());
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RegisterTargetMachine<BPFTargetMachine> Y(getTheBPFbeTarget());
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RegisterTargetMachine<BPFTargetMachine> Z(getTheBPFTarget());
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PassRegistry &PR = *PassRegistry::getPassRegistry();
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initializeBPFMIPeepholePass(PR);
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}
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// DataLayout: little or big endian
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static std::string computeDataLayout(const Triple &TT) {
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if (TT.getArch() == Triple::bpfeb)
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return "E-m:e-p:64:64-i64:64-n32:64-S128";
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else
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return "e-m:e-p:64:64-i64:64-n32:64-S128";
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}
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static Reloc::Model getEffectiveRelocModel(Optional<Reloc::Model> RM) {
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if (!RM.hasValue())
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return Reloc::PIC_;
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return *RM;
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}
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BPFTargetMachine::BPFTargetMachine(const Target &T, const Triple &TT,
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StringRef CPU, StringRef FS,
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const TargetOptions &Options,
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Optional<Reloc::Model> RM,
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Optional<CodeModel::Model> CM,
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CodeGenOpt::Level OL, bool JIT)
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: LLVMTargetMachine(T, computeDataLayout(TT), TT, CPU, FS, Options,
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getEffectiveRelocModel(RM),
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getEffectiveCodeModel(CM, CodeModel::Small), OL),
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TLOF(make_unique<TargetLoweringObjectFileELF>()),
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Subtarget(TT, CPU, FS, *this) {
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initAsmInfo();
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BPFMCAsmInfo *MAI =
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static_cast<BPFMCAsmInfo *>(const_cast<MCAsmInfo *>(AsmInfo.get()));
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MAI->setDwarfUsesRelocationsAcrossSections(!Subtarget.getUseDwarfRIS());
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}
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namespace {
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// BPF Code Generator Pass Configuration Options.
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class BPFPassConfig : public TargetPassConfig {
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public:
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BPFPassConfig(BPFTargetMachine &TM, PassManagerBase &PM)
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: TargetPassConfig(TM, PM) {}
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BPFTargetMachine &getBPFTargetMachine() const {
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return getTM<BPFTargetMachine>();
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}
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bool addInstSelector() override;
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void addMachineSSAOptimization() override;
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void addPreEmitPass() override;
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};
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}
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TargetPassConfig *BPFTargetMachine::createPassConfig(PassManagerBase &PM) {
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return new BPFPassConfig(*this, PM);
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}
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// Install an instruction selector pass using
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// the ISelDag to gen BPF code.
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bool BPFPassConfig::addInstSelector() {
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addPass(createBPFISelDag(getBPFTargetMachine()));
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return false;
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}
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void BPFPassConfig::addMachineSSAOptimization() {
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// The default implementation must be called first as we want eBPF
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// Peephole ran at last.
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TargetPassConfig::addMachineSSAOptimization();
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const BPFSubtarget *Subtarget = getBPFTargetMachine().getSubtargetImpl();
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if (Subtarget->getHasAlu32() && !DisableMIPeephole)
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addPass(createBPFMIPeepholePass());
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}
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void BPFPassConfig::addPreEmitPass() {
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const BPFSubtarget *Subtarget = getBPFTargetMachine().getSubtargetImpl();
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addPass(createBPFMIPreEmitCheckingPass());
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if (getOptLevel() != CodeGenOpt::None)
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if (Subtarget->getHasAlu32() && !DisableMIPeephole)
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addPass(createBPFMIPreEmitPeepholePass());
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}
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