llvm/llvm/lib/Target/ARM/Thumb2ITBlockPass.cpp

//===-- Thumb2ITBlockPass.cpp - Insert Thumb-2 IT blocks ------------------===//
//
// 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
//
//===----------------------------------------------------------------------===//

#include "ARM.h"
#include "ARMMachineFunctionInfo.h"
#include "ARMSubtarget.h"
#include "MCTargetDesc/ARMBaseInfo.h"
#include "Thumb2InstrInfo.h"
#include "llvm/ADT/SmallSet.h"
#include "llvm/ADT/SmallVector.h"
#include "llvm/ADT/Statistic.h"
#include "llvm/ADT/StringRef.h"
#include "llvm/CodeGen/MachineBasicBlock.h"
#include "llvm/CodeGen/MachineFunction.h"
#include "llvm/CodeGen/MachineFunctionPass.h"
#include "llvm/CodeGen/MachineInstr.h"
#include "llvm/CodeGen/MachineInstrBuilder.h"
#include "llvm/CodeGen/MachineInstrBundle.h"
#include "llvm/CodeGen/MachineOperand.h"
#include "llvm/IR/DebugLoc.h"
#include "llvm/MC/MCInstrDesc.h"
#include "llvm/MC/MCRegisterInfo.h"
#include <cassert>
#include <new>

usingnamespacellvm;

#define DEBUG_TYPE …
#define PASS_NAME …

STATISTIC(NumITs,        "Number of IT blocks inserted");
STATISTIC(NumMovedInsts, "Number of predicated instructions moved");

RegisterSet;

namespace {

  class Thumb2ITBlock : public MachineFunctionPass { … };

  char Thumb2ITBlock::ID = …;

} // end anonymous namespace

INITIALIZE_PASS(…)

/// TrackDefUses - Tracking what registers are being defined and used by
/// instructions in the IT block. This also tracks "dependencies", i.e. uses
/// in the IT block that are defined before the IT instruction.
static void TrackDefUses(MachineInstr *MI, RegisterSet &Defs, RegisterSet &Uses,
                         const TargetRegisterInfo *TRI) { … }

/// Clear kill flags for any uses in the given set.  This will likely
/// conservatively remove more kill flags than are necessary, but removing them
/// is safer than incorrect kill flags remaining on instructions.
static void ClearKillFlags(MachineInstr *MI, RegisterSet &Uses) { … }

static bool isCopy(MachineInstr *MI) { … }

bool
Thumb2ITBlock::MoveCopyOutOfITBlock(MachineInstr *MI,
                                    ARMCC::CondCodes CC, ARMCC::CondCodes OCC,
                                    RegisterSet &Defs, RegisterSet &Uses) { … }

bool Thumb2ITBlock::InsertITInstructions(MachineBasicBlock &MBB) { … }

bool Thumb2ITBlock::runOnMachineFunction(MachineFunction &Fn) { … }

/// createThumb2ITBlockPass - Returns an instance of the Thumb2 IT blocks
/// insertion pass.
FunctionPass *llvm::createThumb2ITBlockPass() { … }