70 lines
2.4 KiB
C++
70 lines
2.4 KiB
C++
//===- ARMMacroFusion.cpp - ARM Macro Fusion ----------------------===//
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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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/// \file This file contains the ARM implementation of the DAG scheduling
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/// mutation to pair instructions back to back.
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//
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//===----------------------------------------------------------------------===//
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#include "ARMMacroFusion.h"
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#include "ARMSubtarget.h"
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#include "llvm/CodeGen/MacroFusion.h"
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#include "llvm/CodeGen/TargetInstrInfo.h"
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namespace llvm {
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// Fuse AES crypto encoding or decoding.
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static bool isAESPair(const MachineInstr *FirstMI,
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const MachineInstr &SecondMI) {
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// Assume the 1st instr to be a wildcard if it is unspecified.
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switch(SecondMI.getOpcode()) {
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// AES encode.
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case ARM::AESMC :
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return FirstMI == nullptr || FirstMI->getOpcode() == ARM::AESE;
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// AES decode.
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case ARM::AESIMC:
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return FirstMI == nullptr || FirstMI->getOpcode() == ARM::AESD;
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}
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return false;
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}
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// Fuse literal generation.
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static bool isLiteralsPair(const MachineInstr *FirstMI,
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const MachineInstr &SecondMI) {
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// Assume the 1st instr to be a wildcard if it is unspecified.
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if ((FirstMI == nullptr || FirstMI->getOpcode() == ARM::MOVi16) &&
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SecondMI.getOpcode() == ARM::MOVTi16)
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return true;
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return false;
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}
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/// Check if the instr pair, FirstMI and SecondMI, should be fused
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/// together. Given SecondMI, when FirstMI is unspecified, then check if
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/// SecondMI may be part of a fused pair at all.
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static bool shouldScheduleAdjacent(const TargetInstrInfo &TII,
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const TargetSubtargetInfo &TSI,
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const MachineInstr *FirstMI,
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const MachineInstr &SecondMI) {
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const ARMSubtarget &ST = static_cast<const ARMSubtarget&>(TSI);
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if (ST.hasFuseAES() && isAESPair(FirstMI, SecondMI))
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return true;
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if (ST.hasFuseLiterals() && isLiteralsPair(FirstMI, SecondMI))
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return true;
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return false;
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}
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std::unique_ptr<ScheduleDAGMutation> createARMMacroFusionDAGMutation () {
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return createMacroFusionDAGMutation(shouldScheduleAdjacent);
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}
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} // end namespace llvm
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