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//===--- HexagonHazardRecognizer.h - Hexagon Post RA Hazard Recognizer ----===//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
// This file defines the hazard recognizer for scheduling on Hexagon.
#include "HexagonInstrInfo.h"
#include "HexagonSubtarget.h"
#include "llvm/ADT/SmallSet.h"
#include "llvm/CodeGen/DFAPacketizer.h"
#include "llvm/CodeGen/ScheduleHazardRecognizer.h"
namespace llvm {
class HexagonHazardRecognizer : public ScheduleHazardRecognizer {
DFAPacketizer *Resources;
const HexagonInstrInfo *TII;
unsigned PacketNum = 0;
// If the packet contains a potential dot cur instruction. This is
// used for the scheduling priority function.
SUnit *UsesDotCur = nullptr;
// The packet number when a dor cur is emitted. If its use is not generated
// in the same packet, then try to wait another cycle before emitting.
int DotCurPNum = -1;
// Does the packet contain a load. Used to restrict another load, if possible.
bool UsesLoad = false;
// Check if we should prefer a vector store that will become a .new version.
// The .new store uses different resources than a normal store, and the
// packetizer will not generate the .new if the regular store does not have
// resources available (even if the .new version does). To help, the schedule
// attempts to schedule the .new as soon as possible in the packet.
SUnit *PrefVectorStoreNew = nullptr;
// The set of registers defined by instructions in the current packet.
SmallSet<unsigned, 8> RegDefs;
HexagonHazardRecognizer(const InstrItineraryData *II,
const HexagonInstrInfo *HII,
const HexagonSubtarget &ST)
: Resources(ST.createDFAPacketizer(II)), TII(HII) { }
~HexagonHazardRecognizer() override {
if (Resources)
delete Resources;
/// This callback is invoked when a new block of instructions is about to be
/// scheduled. The hazard state is set to an initialized state.
void Reset() override;
/// Return the hazard type of emitting this node. There are three
/// possible results. Either:
/// * NoHazard: it is legal to issue this instruction on this cycle.
/// * Hazard: issuing this instruction would stall the machine. If some
/// other instruction is available, issue it first.
HazardType getHazardType(SUnit *SU, int stalls) override;
/// This callback is invoked when an instruction is emitted to be scheduled,
/// to advance the hazard state.
void EmitInstruction(SUnit *) override;
/// This callback may be invoked if getHazardType returns NoHazard. If, even
/// though there is no hazard, it would be better to schedule another
/// available instruction, this callback should return true.
bool ShouldPreferAnother(SUnit *) override;
/// This callback is invoked whenever the next top-down instruction to be
/// scheduled cannot issue in the current cycle, either because of latency
/// or resource conflicts. This should increment the internal state of the
/// hazard recognizer so that previously "Hazard" instructions will now not
/// be hazards.
void AdvanceCycle() override;
} // end namespace llvm