forked from OSchip/llvm-project
612 lines
22 KiB
C++
612 lines
22 KiB
C++
//===-- GCNSchedStrategy.cpp - GCN Scheduler Strategy ---------------------===//
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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
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/// This contains a MachineSchedStrategy implementation for maximizing wave
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/// occupancy on GCN hardware.
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//===----------------------------------------------------------------------===//
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#include "GCNSchedStrategy.h"
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#include "AMDGPUSubtarget.h"
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#include "SIInstrInfo.h"
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#include "SIMachineFunctionInfo.h"
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#include "SIRegisterInfo.h"
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#include "Utils/AMDGPUBaseInfo.h"
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#include "llvm/CodeGen/RegisterClassInfo.h"
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#include "llvm/Support/MathExtras.h"
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#define DEBUG_TYPE "machine-scheduler"
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using namespace llvm;
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GCNMaxOccupancySchedStrategy::GCNMaxOccupancySchedStrategy(
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const MachineSchedContext *C) :
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GenericScheduler(C), TargetOccupancy(0), MF(nullptr) { }
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void GCNMaxOccupancySchedStrategy::initialize(ScheduleDAGMI *DAG) {
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GenericScheduler::initialize(DAG);
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const SIRegisterInfo *SRI = static_cast<const SIRegisterInfo*>(TRI);
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MF = &DAG->MF;
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const GCNSubtarget &ST = MF->getSubtarget<GCNSubtarget>();
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// FIXME: This is also necessary, because some passes that run after
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// scheduling and before regalloc increase register pressure.
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const int ErrorMargin = 3;
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SGPRExcessLimit = Context->RegClassInfo
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->getNumAllocatableRegs(&AMDGPU::SGPR_32RegClass) - ErrorMargin;
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VGPRExcessLimit = Context->RegClassInfo
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->getNumAllocatableRegs(&AMDGPU::VGPR_32RegClass) - ErrorMargin;
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if (TargetOccupancy) {
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SGPRCriticalLimit = ST.getMaxNumSGPRs(TargetOccupancy, true);
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VGPRCriticalLimit = ST.getMaxNumVGPRs(TargetOccupancy);
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} else {
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SGPRCriticalLimit = SRI->getRegPressureSetLimit(DAG->MF,
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AMDGPU::RegisterPressureSets::SReg_32);
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VGPRCriticalLimit = SRI->getRegPressureSetLimit(DAG->MF,
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AMDGPU::RegisterPressureSets::VGPR_32);
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}
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SGPRCriticalLimit -= ErrorMargin;
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VGPRCriticalLimit -= ErrorMargin;
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}
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void GCNMaxOccupancySchedStrategy::initCandidate(SchedCandidate &Cand, SUnit *SU,
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bool AtTop, const RegPressureTracker &RPTracker,
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const SIRegisterInfo *SRI,
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unsigned SGPRPressure,
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unsigned VGPRPressure) {
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Cand.SU = SU;
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Cand.AtTop = AtTop;
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// getDownwardPressure() and getUpwardPressure() make temporary changes to
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// the tracker, so we need to pass those function a non-const copy.
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RegPressureTracker &TempTracker = const_cast<RegPressureTracker&>(RPTracker);
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Pressure.clear();
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MaxPressure.clear();
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if (AtTop)
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TempTracker.getDownwardPressure(SU->getInstr(), Pressure, MaxPressure);
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else {
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// FIXME: I think for bottom up scheduling, the register pressure is cached
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// and can be retrieved by DAG->getPressureDif(SU).
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TempTracker.getUpwardPressure(SU->getInstr(), Pressure, MaxPressure);
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}
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unsigned NewSGPRPressure = Pressure[AMDGPU::RegisterPressureSets::SReg_32];
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unsigned NewVGPRPressure = Pressure[AMDGPU::RegisterPressureSets::VGPR_32];
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// If two instructions increase the pressure of different register sets
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// by the same amount, the generic scheduler will prefer to schedule the
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// instruction that increases the set with the least amount of registers,
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// which in our case would be SGPRs. This is rarely what we want, so
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// when we report excess/critical register pressure, we do it either
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// only for VGPRs or only for SGPRs.
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// FIXME: Better heuristics to determine whether to prefer SGPRs or VGPRs.
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const unsigned MaxVGPRPressureInc = 16;
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bool ShouldTrackVGPRs = VGPRPressure + MaxVGPRPressureInc >= VGPRExcessLimit;
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bool ShouldTrackSGPRs = !ShouldTrackVGPRs && SGPRPressure >= SGPRExcessLimit;
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// FIXME: We have to enter REG-EXCESS before we reach the actual threshold
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// to increase the likelihood we don't go over the limits. We should improve
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// the analysis to look through dependencies to find the path with the least
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// register pressure.
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// We only need to update the RPDelta for instructions that increase register
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// pressure. Instructions that decrease or keep reg pressure the same will be
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// marked as RegExcess in tryCandidate() when they are compared with
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// instructions that increase the register pressure.
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if (ShouldTrackVGPRs && NewVGPRPressure >= VGPRExcessLimit) {
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Cand.RPDelta.Excess = PressureChange(AMDGPU::RegisterPressureSets::VGPR_32);
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Cand.RPDelta.Excess.setUnitInc(NewVGPRPressure - VGPRExcessLimit);
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}
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if (ShouldTrackSGPRs && NewSGPRPressure >= SGPRExcessLimit) {
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Cand.RPDelta.Excess = PressureChange(AMDGPU::RegisterPressureSets::SReg_32);
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Cand.RPDelta.Excess.setUnitInc(NewSGPRPressure - SGPRExcessLimit);
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}
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// Register pressure is considered 'CRITICAL' if it is approaching a value
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// that would reduce the wave occupancy for the execution unit. When
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// register pressure is 'CRITICAL', increading SGPR and VGPR pressure both
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// has the same cost, so we don't need to prefer one over the other.
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int SGPRDelta = NewSGPRPressure - SGPRCriticalLimit;
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int VGPRDelta = NewVGPRPressure - VGPRCriticalLimit;
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if (SGPRDelta >= 0 || VGPRDelta >= 0) {
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if (SGPRDelta > VGPRDelta) {
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Cand.RPDelta.CriticalMax =
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PressureChange(AMDGPU::RegisterPressureSets::SReg_32);
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Cand.RPDelta.CriticalMax.setUnitInc(SGPRDelta);
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} else {
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Cand.RPDelta.CriticalMax =
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PressureChange(AMDGPU::RegisterPressureSets::VGPR_32);
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Cand.RPDelta.CriticalMax.setUnitInc(VGPRDelta);
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}
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}
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}
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// This function is mostly cut and pasted from
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// GenericScheduler::pickNodeFromQueue()
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void GCNMaxOccupancySchedStrategy::pickNodeFromQueue(SchedBoundary &Zone,
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const CandPolicy &ZonePolicy,
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const RegPressureTracker &RPTracker,
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SchedCandidate &Cand) {
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const SIRegisterInfo *SRI = static_cast<const SIRegisterInfo*>(TRI);
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ArrayRef<unsigned> Pressure = RPTracker.getRegSetPressureAtPos();
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unsigned SGPRPressure = Pressure[AMDGPU::RegisterPressureSets::SReg_32];
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unsigned VGPRPressure = Pressure[AMDGPU::RegisterPressureSets::VGPR_32];
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ReadyQueue &Q = Zone.Available;
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for (SUnit *SU : Q) {
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SchedCandidate TryCand(ZonePolicy);
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initCandidate(TryCand, SU, Zone.isTop(), RPTracker, SRI,
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SGPRPressure, VGPRPressure);
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// Pass SchedBoundary only when comparing nodes from the same boundary.
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SchedBoundary *ZoneArg = Cand.AtTop == TryCand.AtTop ? &Zone : nullptr;
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GenericScheduler::tryCandidate(Cand, TryCand, ZoneArg);
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if (TryCand.Reason != NoCand) {
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// Initialize resource delta if needed in case future heuristics query it.
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if (TryCand.ResDelta == SchedResourceDelta())
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TryCand.initResourceDelta(Zone.DAG, SchedModel);
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Cand.setBest(TryCand);
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LLVM_DEBUG(traceCandidate(Cand));
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}
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}
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}
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// This function is mostly cut and pasted from
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// GenericScheduler::pickNodeBidirectional()
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SUnit *GCNMaxOccupancySchedStrategy::pickNodeBidirectional(bool &IsTopNode) {
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// Schedule as far as possible in the direction of no choice. This is most
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// efficient, but also provides the best heuristics for CriticalPSets.
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if (SUnit *SU = Bot.pickOnlyChoice()) {
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IsTopNode = false;
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return SU;
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}
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if (SUnit *SU = Top.pickOnlyChoice()) {
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IsTopNode = true;
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return SU;
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}
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// Set the bottom-up policy based on the state of the current bottom zone and
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// the instructions outside the zone, including the top zone.
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CandPolicy BotPolicy;
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setPolicy(BotPolicy, /*IsPostRA=*/false, Bot, &Top);
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// Set the top-down policy based on the state of the current top zone and
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// the instructions outside the zone, including the bottom zone.
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CandPolicy TopPolicy;
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setPolicy(TopPolicy, /*IsPostRA=*/false, Top, &Bot);
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// See if BotCand is still valid (because we previously scheduled from Top).
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LLVM_DEBUG(dbgs() << "Picking from Bot:\n");
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if (!BotCand.isValid() || BotCand.SU->isScheduled ||
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BotCand.Policy != BotPolicy) {
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BotCand.reset(CandPolicy());
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pickNodeFromQueue(Bot, BotPolicy, DAG->getBotRPTracker(), BotCand);
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assert(BotCand.Reason != NoCand && "failed to find the first candidate");
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} else {
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LLVM_DEBUG(traceCandidate(BotCand));
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#ifndef NDEBUG
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if (VerifyScheduling) {
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SchedCandidate TCand;
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TCand.reset(CandPolicy());
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pickNodeFromQueue(Bot, BotPolicy, DAG->getBotRPTracker(), TCand);
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assert(TCand.SU == BotCand.SU &&
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"Last pick result should correspond to re-picking right now");
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}
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#endif
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}
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// Check if the top Q has a better candidate.
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LLVM_DEBUG(dbgs() << "Picking from Top:\n");
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if (!TopCand.isValid() || TopCand.SU->isScheduled ||
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TopCand.Policy != TopPolicy) {
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TopCand.reset(CandPolicy());
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pickNodeFromQueue(Top, TopPolicy, DAG->getTopRPTracker(), TopCand);
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assert(TopCand.Reason != NoCand && "failed to find the first candidate");
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} else {
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LLVM_DEBUG(traceCandidate(TopCand));
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#ifndef NDEBUG
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if (VerifyScheduling) {
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SchedCandidate TCand;
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TCand.reset(CandPolicy());
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pickNodeFromQueue(Top, TopPolicy, DAG->getTopRPTracker(), TCand);
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assert(TCand.SU == TopCand.SU &&
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"Last pick result should correspond to re-picking right now");
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}
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#endif
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}
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// Pick best from BotCand and TopCand.
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LLVM_DEBUG(dbgs() << "Top Cand: "; traceCandidate(TopCand);
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dbgs() << "Bot Cand: "; traceCandidate(BotCand););
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SchedCandidate Cand = BotCand;
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TopCand.Reason = NoCand;
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GenericScheduler::tryCandidate(Cand, TopCand, nullptr);
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if (TopCand.Reason != NoCand) {
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Cand.setBest(TopCand);
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}
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LLVM_DEBUG(dbgs() << "Picking: "; traceCandidate(Cand););
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IsTopNode = Cand.AtTop;
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return Cand.SU;
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}
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// This function is mostly cut and pasted from
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// GenericScheduler::pickNode()
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SUnit *GCNMaxOccupancySchedStrategy::pickNode(bool &IsTopNode) {
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if (DAG->top() == DAG->bottom()) {
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assert(Top.Available.empty() && Top.Pending.empty() &&
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Bot.Available.empty() && Bot.Pending.empty() && "ReadyQ garbage");
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return nullptr;
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}
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SUnit *SU;
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do {
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if (RegionPolicy.OnlyTopDown) {
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SU = Top.pickOnlyChoice();
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if (!SU) {
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CandPolicy NoPolicy;
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TopCand.reset(NoPolicy);
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pickNodeFromQueue(Top, NoPolicy, DAG->getTopRPTracker(), TopCand);
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assert(TopCand.Reason != NoCand && "failed to find a candidate");
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SU = TopCand.SU;
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}
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IsTopNode = true;
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} else if (RegionPolicy.OnlyBottomUp) {
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SU = Bot.pickOnlyChoice();
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if (!SU) {
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CandPolicy NoPolicy;
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BotCand.reset(NoPolicy);
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pickNodeFromQueue(Bot, NoPolicy, DAG->getBotRPTracker(), BotCand);
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assert(BotCand.Reason != NoCand && "failed to find a candidate");
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SU = BotCand.SU;
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}
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IsTopNode = false;
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} else {
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SU = pickNodeBidirectional(IsTopNode);
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}
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} while (SU->isScheduled);
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if (SU->isTopReady())
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Top.removeReady(SU);
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if (SU->isBottomReady())
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Bot.removeReady(SU);
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LLVM_DEBUG(dbgs() << "Scheduling SU(" << SU->NodeNum << ") "
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<< *SU->getInstr());
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return SU;
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}
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GCNScheduleDAGMILive::GCNScheduleDAGMILive(MachineSchedContext *C,
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std::unique_ptr<MachineSchedStrategy> S) :
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ScheduleDAGMILive(C, std::move(S)),
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ST(MF.getSubtarget<GCNSubtarget>()),
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MFI(*MF.getInfo<SIMachineFunctionInfo>()),
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StartingOccupancy(MFI.getOccupancy()),
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MinOccupancy(StartingOccupancy), Stage(Collect), RegionIdx(0) {
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LLVM_DEBUG(dbgs() << "Starting occupancy is " << StartingOccupancy << ".\n");
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}
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void GCNScheduleDAGMILive::schedule() {
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if (Stage == Collect) {
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// Just record regions at the first pass.
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Regions.push_back(std::make_pair(RegionBegin, RegionEnd));
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return;
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}
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std::vector<MachineInstr*> Unsched;
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Unsched.reserve(NumRegionInstrs);
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for (auto &I : *this) {
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Unsched.push_back(&I);
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}
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GCNRegPressure PressureBefore;
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if (LIS) {
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PressureBefore = Pressure[RegionIdx];
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LLVM_DEBUG(dbgs() << "Pressure before scheduling:\nRegion live-ins:";
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GCNRPTracker::printLiveRegs(dbgs(), LiveIns[RegionIdx], MRI);
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dbgs() << "Region live-in pressure: ";
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llvm::getRegPressure(MRI, LiveIns[RegionIdx]).print(dbgs());
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dbgs() << "Region register pressure: ";
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PressureBefore.print(dbgs()));
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}
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ScheduleDAGMILive::schedule();
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Regions[RegionIdx] = std::make_pair(RegionBegin, RegionEnd);
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RescheduleRegions[RegionIdx] = false;
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if (!LIS)
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return;
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// Check the results of scheduling.
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GCNMaxOccupancySchedStrategy &S = (GCNMaxOccupancySchedStrategy&)*SchedImpl;
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auto PressureAfter = getRealRegPressure();
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LLVM_DEBUG(dbgs() << "Pressure after scheduling: ";
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PressureAfter.print(dbgs()));
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if (PressureAfter.getSGPRNum() <= S.SGPRCriticalLimit &&
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PressureAfter.getVGPRNum() <= S.VGPRCriticalLimit) {
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Pressure[RegionIdx] = PressureAfter;
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LLVM_DEBUG(dbgs() << "Pressure in desired limits, done.\n");
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return;
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}
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unsigned Occ = MFI.getOccupancy();
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unsigned WavesAfter = std::min(Occ, PressureAfter.getOccupancy(ST));
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unsigned WavesBefore = std::min(Occ, PressureBefore.getOccupancy(ST));
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LLVM_DEBUG(dbgs() << "Occupancy before scheduling: " << WavesBefore
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<< ", after " << WavesAfter << ".\n");
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// We could not keep current target occupancy because of the just scheduled
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// region. Record new occupancy for next scheduling cycle.
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unsigned NewOccupancy = std::max(WavesAfter, WavesBefore);
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// Allow memory bound functions to drop to 4 waves if not limited by an
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// attribute.
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if (WavesAfter < WavesBefore && WavesAfter < MinOccupancy &&
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WavesAfter >= MFI.getMinAllowedOccupancy()) {
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LLVM_DEBUG(dbgs() << "Function is memory bound, allow occupancy drop up to "
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<< MFI.getMinAllowedOccupancy() << " waves\n");
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NewOccupancy = WavesAfter;
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}
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if (NewOccupancy < MinOccupancy) {
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MinOccupancy = NewOccupancy;
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MFI.limitOccupancy(MinOccupancy);
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LLVM_DEBUG(dbgs() << "Occupancy lowered for the function to "
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<< MinOccupancy << ".\n");
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}
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unsigned MaxVGPRs = ST.getMaxNumVGPRs(MF);
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unsigned MaxSGPRs = ST.getMaxNumSGPRs(MF);
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if (PressureAfter.getVGPRNum() > MaxVGPRs ||
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PressureAfter.getSGPRNum() > MaxSGPRs)
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RescheduleRegions[RegionIdx] = true;
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if (WavesAfter >= MinOccupancy) {
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if (Stage == UnclusteredReschedule &&
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!PressureAfter.less(ST, PressureBefore)) {
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LLVM_DEBUG(dbgs() << "Unclustered reschedule did not help.\n");
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} else if (WavesAfter > MFI.getMinWavesPerEU() ||
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PressureAfter.less(ST, PressureBefore) ||
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!RescheduleRegions[RegionIdx]) {
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Pressure[RegionIdx] = PressureAfter;
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return;
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} else {
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LLVM_DEBUG(dbgs() << "New pressure will result in more spilling.\n");
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}
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}
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LLVM_DEBUG(dbgs() << "Attempting to revert scheduling.\n");
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RescheduleRegions[RegionIdx] = true;
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RegionEnd = RegionBegin;
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for (MachineInstr *MI : Unsched) {
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if (MI->isDebugInstr())
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continue;
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if (MI->getIterator() != RegionEnd) {
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BB->remove(MI);
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BB->insert(RegionEnd, MI);
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if (!MI->isDebugInstr())
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LIS->handleMove(*MI, true);
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}
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// Reset read-undef flags and update them later.
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for (auto &Op : MI->operands())
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if (Op.isReg() && Op.isDef())
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Op.setIsUndef(false);
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RegisterOperands RegOpers;
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RegOpers.collect(*MI, *TRI, MRI, ShouldTrackLaneMasks, false);
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if (!MI->isDebugInstr()) {
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if (ShouldTrackLaneMasks) {
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// Adjust liveness and add missing dead+read-undef flags.
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SlotIndex SlotIdx = LIS->getInstructionIndex(*MI).getRegSlot();
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RegOpers.adjustLaneLiveness(*LIS, MRI, SlotIdx, MI);
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} else {
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// Adjust for missing dead-def flags.
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RegOpers.detectDeadDefs(*MI, *LIS);
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}
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}
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RegionEnd = MI->getIterator();
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++RegionEnd;
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LLVM_DEBUG(dbgs() << "Scheduling " << *MI);
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}
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RegionBegin = Unsched.front()->getIterator();
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Regions[RegionIdx] = std::make_pair(RegionBegin, RegionEnd);
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placeDebugValues();
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}
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GCNRegPressure GCNScheduleDAGMILive::getRealRegPressure() const {
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GCNDownwardRPTracker RPTracker(*LIS);
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RPTracker.advance(begin(), end(), &LiveIns[RegionIdx]);
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return RPTracker.moveMaxPressure();
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}
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void GCNScheduleDAGMILive::computeBlockPressure(const MachineBasicBlock *MBB) {
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GCNDownwardRPTracker RPTracker(*LIS);
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// If the block has the only successor then live-ins of that successor are
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// live-outs of the current block. We can reuse calculated live set if the
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// successor will be sent to scheduling past current block.
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const MachineBasicBlock *OnlySucc = nullptr;
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if (MBB->succ_size() == 1 && !(*MBB->succ_begin())->empty()) {
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SlotIndexes *Ind = LIS->getSlotIndexes();
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if (Ind->getMBBStartIdx(MBB) < Ind->getMBBStartIdx(*MBB->succ_begin()))
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OnlySucc = *MBB->succ_begin();
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}
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// Scheduler sends regions from the end of the block upwards.
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size_t CurRegion = RegionIdx;
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for (size_t E = Regions.size(); CurRegion != E; ++CurRegion)
|
|
if (Regions[CurRegion].first->getParent() != MBB)
|
|
break;
|
|
--CurRegion;
|
|
|
|
auto I = MBB->begin();
|
|
auto LiveInIt = MBBLiveIns.find(MBB);
|
|
if (LiveInIt != MBBLiveIns.end()) {
|
|
auto LiveIn = std::move(LiveInIt->second);
|
|
RPTracker.reset(*MBB->begin(), &LiveIn);
|
|
MBBLiveIns.erase(LiveInIt);
|
|
} else {
|
|
auto &Rgn = Regions[CurRegion];
|
|
I = Rgn.first;
|
|
auto *NonDbgMI = &*skipDebugInstructionsForward(Rgn.first, Rgn.second);
|
|
auto LRS = BBLiveInMap.lookup(NonDbgMI);
|
|
assert(isEqual(getLiveRegsBefore(*NonDbgMI, *LIS), LRS));
|
|
RPTracker.reset(*I, &LRS);
|
|
}
|
|
|
|
for ( ; ; ) {
|
|
I = RPTracker.getNext();
|
|
|
|
if (Regions[CurRegion].first == I) {
|
|
LiveIns[CurRegion] = RPTracker.getLiveRegs();
|
|
RPTracker.clearMaxPressure();
|
|
}
|
|
|
|
if (Regions[CurRegion].second == I) {
|
|
Pressure[CurRegion] = RPTracker.moveMaxPressure();
|
|
if (CurRegion-- == RegionIdx)
|
|
break;
|
|
}
|
|
RPTracker.advanceToNext();
|
|
RPTracker.advanceBeforeNext();
|
|
}
|
|
|
|
if (OnlySucc) {
|
|
if (I != MBB->end()) {
|
|
RPTracker.advanceToNext();
|
|
RPTracker.advance(MBB->end());
|
|
}
|
|
RPTracker.reset(*OnlySucc->begin(), &RPTracker.getLiveRegs());
|
|
RPTracker.advanceBeforeNext();
|
|
MBBLiveIns[OnlySucc] = RPTracker.moveLiveRegs();
|
|
}
|
|
}
|
|
|
|
DenseMap<MachineInstr *, GCNRPTracker::LiveRegSet>
|
|
GCNScheduleDAGMILive::getBBLiveInMap() const {
|
|
assert(!Regions.empty());
|
|
std::vector<MachineInstr *> BBStarters;
|
|
BBStarters.reserve(Regions.size());
|
|
auto I = Regions.rbegin(), E = Regions.rend();
|
|
auto *BB = I->first->getParent();
|
|
do {
|
|
auto *MI = &*skipDebugInstructionsForward(I->first, I->second);
|
|
BBStarters.push_back(MI);
|
|
do {
|
|
++I;
|
|
} while (I != E && I->first->getParent() == BB);
|
|
} while (I != E);
|
|
return getLiveRegMap(BBStarters, false /*After*/, *LIS);
|
|
}
|
|
|
|
void GCNScheduleDAGMILive::finalizeSchedule() {
|
|
GCNMaxOccupancySchedStrategy &S = (GCNMaxOccupancySchedStrategy&)*SchedImpl;
|
|
LLVM_DEBUG(dbgs() << "All regions recorded, starting actual scheduling.\n");
|
|
|
|
LiveIns.resize(Regions.size());
|
|
Pressure.resize(Regions.size());
|
|
RescheduleRegions.resize(Regions.size());
|
|
RescheduleRegions.set();
|
|
|
|
if (!Regions.empty())
|
|
BBLiveInMap = getBBLiveInMap();
|
|
|
|
std::vector<std::unique_ptr<ScheduleDAGMutation>> SavedMutations;
|
|
|
|
do {
|
|
Stage++;
|
|
RegionIdx = 0;
|
|
MachineBasicBlock *MBB = nullptr;
|
|
|
|
if (Stage > InitialSchedule) {
|
|
if (!LIS)
|
|
break;
|
|
|
|
// Retry function scheduling if we found resulting occupancy and it is
|
|
// lower than used for first pass scheduling. This will give more freedom
|
|
// to schedule low register pressure blocks.
|
|
// Code is partially copied from MachineSchedulerBase::scheduleRegions().
|
|
|
|
if (Stage == UnclusteredReschedule) {
|
|
if (RescheduleRegions.none())
|
|
continue;
|
|
LLVM_DEBUG(dbgs() <<
|
|
"Retrying function scheduling without clustering.\n");
|
|
}
|
|
|
|
if (Stage == ClusteredLowOccupancyReschedule) {
|
|
if (StartingOccupancy <= MinOccupancy)
|
|
break;
|
|
|
|
LLVM_DEBUG(
|
|
dbgs()
|
|
<< "Retrying function scheduling with lowest recorded occupancy "
|
|
<< MinOccupancy << ".\n");
|
|
|
|
S.setTargetOccupancy(MinOccupancy);
|
|
}
|
|
}
|
|
|
|
if (Stage == UnclusteredReschedule)
|
|
SavedMutations.swap(Mutations);
|
|
|
|
for (auto Region : Regions) {
|
|
if (Stage == UnclusteredReschedule && !RescheduleRegions[RegionIdx])
|
|
continue;
|
|
|
|
RegionBegin = Region.first;
|
|
RegionEnd = Region.second;
|
|
|
|
if (RegionBegin->getParent() != MBB) {
|
|
if (MBB) finishBlock();
|
|
MBB = RegionBegin->getParent();
|
|
startBlock(MBB);
|
|
if (Stage == InitialSchedule)
|
|
computeBlockPressure(MBB);
|
|
}
|
|
|
|
unsigned NumRegionInstrs = std::distance(begin(), end());
|
|
enterRegion(MBB, begin(), end(), NumRegionInstrs);
|
|
|
|
// Skip empty scheduling regions (0 or 1 schedulable instructions).
|
|
if (begin() == end() || begin() == std::prev(end())) {
|
|
exitRegion();
|
|
continue;
|
|
}
|
|
|
|
LLVM_DEBUG(dbgs() << "********** MI Scheduling **********\n");
|
|
LLVM_DEBUG(dbgs() << MF.getName() << ":" << printMBBReference(*MBB) << " "
|
|
<< MBB->getName() << "\n From: " << *begin()
|
|
<< " To: ";
|
|
if (RegionEnd != MBB->end()) dbgs() << *RegionEnd;
|
|
else dbgs() << "End";
|
|
dbgs() << " RegionInstrs: " << NumRegionInstrs << '\n');
|
|
|
|
schedule();
|
|
|
|
exitRegion();
|
|
++RegionIdx;
|
|
}
|
|
finishBlock();
|
|
|
|
if (Stage == UnclusteredReschedule)
|
|
SavedMutations.swap(Mutations);
|
|
} while (Stage != LastStage);
|
|
}
|