llvm/llvm/lib/Target/RISCV/RISCVIndirectBranchTracking.cpp

//===------ RISCVIndirectBranchTracking.cpp - Enables lpad mechanism ------===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
//
// The pass adds LPAD (AUIPC with rs1 = X0) machine instructions at the
// beginning of each basic block or function that is referenced by an indrect
// jump/call instruction.
//
//===----------------------------------------------------------------------===//

#include "RISCV.h"
#include "RISCVInstrInfo.h"
#include "RISCVSubtarget.h"
#include "RISCVTargetMachine.h"
#include "llvm/ADT/Statistic.h"
#include "llvm/CodeGen/MachineFunctionPass.h"
#include "llvm/CodeGen/MachineInstrBuilder.h"
#include "llvm/CodeGen/MachineModuleInfo.h"

usingnamespacellvm;

cl::opt<uint32_t> PreferredLandingPadLabel(
    "riscv-landing-pad-label", cl::ReallyHidden,
    cl::desc("Use preferred fixed label for all labels"));

namespace {
class RISCVIndirectBranchTrackingPass : public MachineFunctionPass { … };

} // end anonymous namespace

char RISCVIndirectBranchTrackingPass::ID = …;

FunctionPass *llvm::createRISCVIndirectBranchTrackingPass() { … }

static void emitLpad(MachineBasicBlock &MBB, const RISCVInstrInfo *TII,
                     uint32_t Label) { … }

bool RISCVIndirectBranchTrackingPass::runOnMachineFunction(
    MachineFunction &MF) { … }