llvm/llvm/include/llvm/CodeGen/MachineInstrBundle.h

//===- llvm/CodeGen/MachineInstrBundle.h - MI bundle utilities --*- C++ -*-===//
//
// 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
//
//===----------------------------------------------------------------------===//
//
// This file provide utility functions to manipulate machine instruction
// bundles.
//
//===----------------------------------------------------------------------===//

#ifndef LLVM_CODEGEN_MACHINEINSTRBUNDLE_H
#define LLVM_CODEGEN_MACHINEINSTRBUNDLE_H

#include "llvm/CodeGen/MachineBasicBlock.h"

namespace llvm {

/// finalizeBundle - Finalize a machine instruction bundle which includes
/// a sequence of instructions starting from FirstMI to LastMI (exclusive).
/// This routine adds a BUNDLE instruction to represent the bundle, it adds
/// IsInternalRead markers to MachineOperands which are defined inside the
/// bundle, and it copies externally visible defs and uses to the BUNDLE
/// instruction.
void finalizeBundle(MachineBasicBlock &MBB,
                    MachineBasicBlock::instr_iterator FirstMI,
                    MachineBasicBlock::instr_iterator LastMI);

/// finalizeBundle - Same functionality as the previous finalizeBundle except
/// the last instruction in the bundle is not provided as an input. This is
/// used in cases where bundles are pre-determined by marking instructions
/// with 'InsideBundle' marker. It returns the MBB instruction iterator that
/// points to the end of the bundle.
MachineBasicBlock::instr_iterator finalizeBundle(MachineBasicBlock &MBB,
                    MachineBasicBlock::instr_iterator FirstMI);

/// finalizeBundles - Finalize instruction bundles in the specified
/// MachineFunction. Return true if any bundles are finalized.
bool finalizeBundles(MachineFunction &MF);

/// Returns an iterator to the first instruction in the bundle containing \p I.
inline MachineBasicBlock::instr_iterator getBundleStart(
    MachineBasicBlock::instr_iterator I) { … }

/// Returns an iterator to the first instruction in the bundle containing \p I.
inline MachineBasicBlock::const_instr_iterator getBundleStart(
    MachineBasicBlock::const_instr_iterator I) { … }

/// Returns an iterator pointing beyond the bundle containing \p I.
inline MachineBasicBlock::instr_iterator getBundleEnd(
    MachineBasicBlock::instr_iterator I) { … }

/// Returns an iterator pointing beyond the bundle containing \p I.
inline MachineBasicBlock::const_instr_iterator getBundleEnd(
    MachineBasicBlock::const_instr_iterator I) { … }

//===----------------------------------------------------------------------===//
// MachineBundleOperand iterator
//

/// MIBundleOperandIteratorBase - Iterator that visits all operands in a bundle
/// of MachineInstrs. This class is not intended to be used directly, use one
/// of the sub-classes instead.
///
/// Intended use:
///
///   for (MIBundleOperands MIO(MI); MIO.isValid(); ++MIO) {
///     if (!MIO->isReg())
///       continue;
///     ...
///   }
///
template <typename ValueT>
class MIBundleOperandIteratorBase
    : public iterator_facade_base<MIBundleOperandIteratorBase<ValueT>,
                                  std::forward_iterator_tag, ValueT> { … };

/// MIBundleOperands - Iterate over all operands in a bundle of machine
/// instructions.
///
class MIBundleOperands : public MIBundleOperandIteratorBase<MachineOperand> { … };

/// ConstMIBundleOperands - Iterate over all operands in a const bundle of
/// machine instructions.
///
class ConstMIBundleOperands
    : public MIBundleOperandIteratorBase<const MachineOperand> { … };

inline iterator_range<ConstMIBundleOperands>
const_mi_bundle_ops(const MachineInstr &MI) { … }

inline iterator_range<MIBundleOperands> mi_bundle_ops(MachineInstr &MI) { … }

/// VirtRegInfo - Information about a virtual register used by a set of
/// operands.
///
struct VirtRegInfo { … };

/// AnalyzeVirtRegInBundle - Analyze how the current instruction or bundle uses
/// a virtual register.  This function should not be called after operator++(),
/// it expects a fresh iterator.
///
/// @param Reg The virtual register to analyze.
/// @param Ops When set, this vector will receive an (MI, OpNum) entry for
///            each operand referring to Reg.
/// @returns A filled-in RegInfo struct.
VirtRegInfo AnalyzeVirtRegInBundle(
    MachineInstr &MI, Register Reg,
    SmallVectorImpl<std::pair<MachineInstr *, unsigned>> *Ops = nullptr);

/// Return a pair of lane masks (reads, writes) indicating which lanes this
/// instruction uses with Reg.
std::pair<LaneBitmask, LaneBitmask>
AnalyzeVirtRegLanesInBundle(const MachineInstr &MI, Register Reg,
                            const MachineRegisterInfo &MRI,
                            const TargetRegisterInfo &TRI);

/// Information about how a physical register Reg is used by a set of
/// operands.
struct PhysRegInfo { … };

/// AnalyzePhysRegInBundle - Analyze how the current instruction or bundle uses
/// a physical register.  This function should not be called after operator++(),
/// it expects a fresh iterator.
///
/// @param Reg The physical register to analyze.
/// @returns A filled-in PhysRegInfo struct.
PhysRegInfo AnalyzePhysRegInBundle(const MachineInstr &MI, Register Reg,
                                   const TargetRegisterInfo *TRI);

} // End llvm namespace

#endif