llvm/llvm/lib/Target/AMDGPU/GCNVOPDUtils.cpp

//===- GCNVOPDUtils.cpp - GCN VOPD Utils  ------------------------===//
//
// 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
//
//===----------------------------------------------------------------------===//
//
/// \file This file contains the AMDGPU DAG scheduling
/// mutation to pair VOPD instructions back to back. It also contains
//  subroutines useful in the creation of VOPD instructions
//
//===----------------------------------------------------------------------===//

#include "GCNVOPDUtils.h"
#include "AMDGPUSubtarget.h"
#include "GCNSubtarget.h"
#include "MCTargetDesc/AMDGPUMCTargetDesc.h"
#include "SIInstrInfo.h"
#include "Utils/AMDGPUBaseInfo.h"
#include "llvm/ADT/STLExtras.h"
#include "llvm/ADT/SmallVector.h"
#include "llvm/CodeGen/MachineBasicBlock.h"
#include "llvm/CodeGen/MachineInstr.h"
#include "llvm/CodeGen/MachineOperand.h"
#include "llvm/CodeGen/MachineRegisterInfo.h"
#include "llvm/CodeGen/MacroFusion.h"
#include "llvm/CodeGen/ScheduleDAG.h"
#include "llvm/CodeGen/ScheduleDAGMutation.h"
#include "llvm/CodeGen/TargetInstrInfo.h"
#include "llvm/MC/MCInst.h"

usingnamespacellvm;

#define DEBUG_TYPE …

bool llvm::checkVOPDRegConstraints(const SIInstrInfo &TII,
                                   const MachineInstr &FirstMI,
                                   const MachineInstr &SecondMI) { … }

/// Check if the instr pair, FirstMI and SecondMI, should be scheduled
/// together. Given SecondMI, when FirstMI is unspecified, then check if
/// SecondMI may be part of a fused pair at all.
static bool shouldScheduleVOPDAdjacent(const TargetInstrInfo &TII,
                                       const TargetSubtargetInfo &TSI,
                                       const MachineInstr *FirstMI,
                                       const MachineInstr &SecondMI) { … }

namespace {
/// Adapts design from MacroFusion
/// Puts valid candidate instructions back-to-back so they can easily
/// be turned into VOPD instructions
/// Greedily pairs instruction candidates. O(n^2) algorithm.
struct VOPDPairingMutation : ScheduleDAGMutation { … };
} // namespace

std::unique_ptr<ScheduleDAGMutation> llvm::createVOPDPairingMutation() { … }