Bug Summary

File:llvm/lib/Target/AMDGPU/GCNSchedStrategy.cpp
Warning:line 594, column 7
Forming reference to null pointer

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clang -cc1 -cc1 -triple x86_64-pc-linux-gnu -analyze -disable-free -disable-llvm-verifier -discard-value-names -main-file-name GCNSchedStrategy.cpp -analyzer-store=region -analyzer-opt-analyze-nested-blocks -analyzer-checker=core -analyzer-checker=apiModeling -analyzer-checker=unix -analyzer-checker=deadcode -analyzer-checker=cplusplus -analyzer-checker=security.insecureAPI.UncheckedReturn -analyzer-checker=security.insecureAPI.getpw -analyzer-checker=security.insecureAPI.gets -analyzer-checker=security.insecureAPI.mktemp -analyzer-checker=security.insecureAPI.mkstemp -analyzer-checker=security.insecureAPI.vfork -analyzer-checker=nullability.NullPassedToNonnull -analyzer-checker=nullability.NullReturnedFromNonnull -analyzer-output plist -w -setup-static-analyzer -analyzer-config-compatibility-mode=true -mrelocation-model pic -pic-level 2 -mframe-pointer=none -fmath-errno -fno-rounding-math -mconstructor-aliases -munwind-tables -target-cpu x86-64 -fno-split-dwarf-inlining -debugger-tuning=gdb -ffunction-sections -fdata-sections -resource-dir /usr/lib/llvm-12/lib/clang/12.0.0 -D _DEBUG -D _GNU_SOURCE -D __STDC_CONSTANT_MACROS -D __STDC_FORMAT_MACROS -D __STDC_LIMIT_MACROS -I /build/llvm-toolchain-snapshot-12~++20200806111125+5446ec85070/build-llvm/lib/Target/AMDGPU -I /build/llvm-toolchain-snapshot-12~++20200806111125+5446ec85070/llvm/lib/Target/AMDGPU -I /build/llvm-toolchain-snapshot-12~++20200806111125+5446ec85070/build-llvm/include -I /build/llvm-toolchain-snapshot-12~++20200806111125+5446ec85070/llvm/include -U NDEBUG -internal-isystem /usr/lib/gcc/x86_64-linux-gnu/6.3.0/../../../../include/c++/6.3.0 -internal-isystem /usr/lib/gcc/x86_64-linux-gnu/6.3.0/../../../../include/x86_64-linux-gnu/c++/6.3.0 -internal-isystem /usr/lib/gcc/x86_64-linux-gnu/6.3.0/../../../../include/x86_64-linux-gnu/c++/6.3.0 -internal-isystem /usr/lib/gcc/x86_64-linux-gnu/6.3.0/../../../../include/c++/6.3.0/backward -internal-isystem /usr/local/include -internal-isystem /usr/lib/llvm-12/lib/clang/12.0.0/include -internal-externc-isystem /usr/include/x86_64-linux-gnu -internal-externc-isystem /include -internal-externc-isystem /usr/include -O2 -Wno-unused-parameter -Wwrite-strings -Wno-missing-field-initializers -Wno-long-long -Wno-maybe-uninitialized -Wno-comment -std=c++14 -fdeprecated-macro -fdebug-compilation-dir /build/llvm-toolchain-snapshot-12~++20200806111125+5446ec85070/build-llvm/lib/Target/AMDGPU -fdebug-prefix-map=/build/llvm-toolchain-snapshot-12~++20200806111125+5446ec85070=. -ferror-limit 19 -fvisibility hidden -fvisibility-inlines-hidden -stack-protector 2 -fgnuc-version=4.2.1 -vectorize-loops -vectorize-slp -analyzer-output=html -analyzer-config stable-report-filename=true -faddrsig -o /tmp/scan-build-2020-08-06-171148-17323-1 -x c++ /build/llvm-toolchain-snapshot-12~++20200806111125+5446ec85070/llvm/lib/Target/AMDGPU/GCNSchedStrategy.cpp
1//===-- GCNSchedStrategy.cpp - GCN Scheduler Strategy ---------------------===//
2//
3// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4// See https://llvm.org/LICENSE.txt for license information.
5// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6//
7//===----------------------------------------------------------------------===//
8//
9/// \file
10/// This contains a MachineSchedStrategy implementation for maximizing wave
11/// occupancy on GCN hardware.
12//===----------------------------------------------------------------------===//
13
14#include "GCNSchedStrategy.h"
15#include "AMDGPUSubtarget.h"
16#include "SIInstrInfo.h"
17#include "SIMachineFunctionInfo.h"
18#include "SIRegisterInfo.h"
19#include "Utils/AMDGPUBaseInfo.h"
20#include "llvm/CodeGen/RegisterClassInfo.h"
21#include "llvm/Support/MathExtras.h"
22
23#define DEBUG_TYPE"machine-scheduler" "machine-scheduler"
24
25using namespace llvm;
26
27GCNMaxOccupancySchedStrategy::GCNMaxOccupancySchedStrategy(
28 const MachineSchedContext *C) :
29 GenericScheduler(C), TargetOccupancy(0), MF(nullptr) { }
30
31void GCNMaxOccupancySchedStrategy::initialize(ScheduleDAGMI *DAG) {
32 GenericScheduler::initialize(DAG);
33
34 const SIRegisterInfo *SRI = static_cast<const SIRegisterInfo*>(TRI);
35
36 MF = &DAG->MF;
37
38 const GCNSubtarget &ST = MF->getSubtarget<GCNSubtarget>();
39
40 // FIXME: This is also necessary, because some passes that run after
41 // scheduling and before regalloc increase register pressure.
42 const int ErrorMargin = 3;
43
44 SGPRExcessLimit = Context->RegClassInfo
45 ->getNumAllocatableRegs(&AMDGPU::SGPR_32RegClass) - ErrorMargin;
46 VGPRExcessLimit = Context->RegClassInfo
47 ->getNumAllocatableRegs(&AMDGPU::VGPR_32RegClass) - ErrorMargin;
48 if (TargetOccupancy) {
49 SGPRCriticalLimit = ST.getMaxNumSGPRs(TargetOccupancy, true);
50 VGPRCriticalLimit = ST.getMaxNumVGPRs(TargetOccupancy);
51 } else {
52 SGPRCriticalLimit = SRI->getRegPressureSetLimit(DAG->MF,
53 AMDGPU::RegisterPressureSets::SReg_32);
54 VGPRCriticalLimit = SRI->getRegPressureSetLimit(DAG->MF,
55 AMDGPU::RegisterPressureSets::VGPR_32);
56 }
57
58 SGPRCriticalLimit -= ErrorMargin;
59 VGPRCriticalLimit -= ErrorMargin;
60}
61
62void GCNMaxOccupancySchedStrategy::initCandidate(SchedCandidate &Cand, SUnit *SU,
63 bool AtTop, const RegPressureTracker &RPTracker,
64 const SIRegisterInfo *SRI,
65 unsigned SGPRPressure,
66 unsigned VGPRPressure) {
67
68 Cand.SU = SU;
69 Cand.AtTop = AtTop;
70
71 // getDownwardPressure() and getUpwardPressure() make temporary changes to
72 // the tracker, so we need to pass those function a non-const copy.
73 RegPressureTracker &TempTracker = const_cast<RegPressureTracker&>(RPTracker);
74
75 Pressure.clear();
76 MaxPressure.clear();
77
78 if (AtTop)
79 TempTracker.getDownwardPressure(SU->getInstr(), Pressure, MaxPressure);
80 else {
81 // FIXME: I think for bottom up scheduling, the register pressure is cached
82 // and can be retrieved by DAG->getPressureDif(SU).
83 TempTracker.getUpwardPressure(SU->getInstr(), Pressure, MaxPressure);
84 }
85
86 unsigned NewSGPRPressure = Pressure[AMDGPU::RegisterPressureSets::SReg_32];
87 unsigned NewVGPRPressure = Pressure[AMDGPU::RegisterPressureSets::VGPR_32];
88
89 // If two instructions increase the pressure of different register sets
90 // by the same amount, the generic scheduler will prefer to schedule the
91 // instruction that increases the set with the least amount of registers,
92 // which in our case would be SGPRs. This is rarely what we want, so
93 // when we report excess/critical register pressure, we do it either
94 // only for VGPRs or only for SGPRs.
95
96 // FIXME: Better heuristics to determine whether to prefer SGPRs or VGPRs.
97 const unsigned MaxVGPRPressureInc = 16;
98 bool ShouldTrackVGPRs = VGPRPressure + MaxVGPRPressureInc >= VGPRExcessLimit;
99 bool ShouldTrackSGPRs = !ShouldTrackVGPRs && SGPRPressure >= SGPRExcessLimit;
100
101
102 // FIXME: We have to enter REG-EXCESS before we reach the actual threshold
103 // to increase the likelihood we don't go over the limits. We should improve
104 // the analysis to look through dependencies to find the path with the least
105 // register pressure.
106
107 // We only need to update the RPDelta for instructions that increase register
108 // pressure. Instructions that decrease or keep reg pressure the same will be
109 // marked as RegExcess in tryCandidate() when they are compared with
110 // instructions that increase the register pressure.
111 if (ShouldTrackVGPRs && NewVGPRPressure >= VGPRExcessLimit) {
112 Cand.RPDelta.Excess = PressureChange(AMDGPU::RegisterPressureSets::VGPR_32);
113 Cand.RPDelta.Excess.setUnitInc(NewVGPRPressure - VGPRExcessLimit);
114 }
115
116 if (ShouldTrackSGPRs && NewSGPRPressure >= SGPRExcessLimit) {
117 Cand.RPDelta.Excess = PressureChange(AMDGPU::RegisterPressureSets::SReg_32);
118 Cand.RPDelta.Excess.setUnitInc(NewSGPRPressure - SGPRExcessLimit);
119 }
120
121 // Register pressure is considered 'CRITICAL' if it is approaching a value
122 // that would reduce the wave occupancy for the execution unit. When
123 // register pressure is 'CRITICAL', increading SGPR and VGPR pressure both
124 // has the same cost, so we don't need to prefer one over the other.
125
126 int SGPRDelta = NewSGPRPressure - SGPRCriticalLimit;
127 int VGPRDelta = NewVGPRPressure - VGPRCriticalLimit;
128
129 if (SGPRDelta >= 0 || VGPRDelta >= 0) {
130 if (SGPRDelta > VGPRDelta) {
131 Cand.RPDelta.CriticalMax =
132 PressureChange(AMDGPU::RegisterPressureSets::SReg_32);
133 Cand.RPDelta.CriticalMax.setUnitInc(SGPRDelta);
134 } else {
135 Cand.RPDelta.CriticalMax =
136 PressureChange(AMDGPU::RegisterPressureSets::VGPR_32);
137 Cand.RPDelta.CriticalMax.setUnitInc(VGPRDelta);
138 }
139 }
140}
141
142// This function is mostly cut and pasted from
143// GenericScheduler::pickNodeFromQueue()
144void GCNMaxOccupancySchedStrategy::pickNodeFromQueue(SchedBoundary &Zone,
145 const CandPolicy &ZonePolicy,
146 const RegPressureTracker &RPTracker,
147 SchedCandidate &Cand) {
148 const SIRegisterInfo *SRI = static_cast<const SIRegisterInfo*>(TRI);
149 ArrayRef<unsigned> Pressure = RPTracker.getRegSetPressureAtPos();
150 unsigned SGPRPressure = Pressure[AMDGPU::RegisterPressureSets::SReg_32];
151 unsigned VGPRPressure = Pressure[AMDGPU::RegisterPressureSets::VGPR_32];
152 ReadyQueue &Q = Zone.Available;
153 for (SUnit *SU : Q) {
154
155 SchedCandidate TryCand(ZonePolicy);
156 initCandidate(TryCand, SU, Zone.isTop(), RPTracker, SRI,
157 SGPRPressure, VGPRPressure);
158 // Pass SchedBoundary only when comparing nodes from the same boundary.
159 SchedBoundary *ZoneArg = Cand.AtTop == TryCand.AtTop ? &Zone : nullptr;
160 GenericScheduler::tryCandidate(Cand, TryCand, ZoneArg);
161 if (TryCand.Reason != NoCand) {
162 // Initialize resource delta if needed in case future heuristics query it.
163 if (TryCand.ResDelta == SchedResourceDelta())
164 TryCand.initResourceDelta(Zone.DAG, SchedModel);
165 Cand.setBest(TryCand);
166 LLVM_DEBUG(traceCandidate(Cand))do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("machine-scheduler")) { traceCandidate(Cand); } } while (false
);
167 }
168 }
169}
170
171// This function is mostly cut and pasted from
172// GenericScheduler::pickNodeBidirectional()
173SUnit *GCNMaxOccupancySchedStrategy::pickNodeBidirectional(bool &IsTopNode) {
174 // Schedule as far as possible in the direction of no choice. This is most
175 // efficient, but also provides the best heuristics for CriticalPSets.
176 if (SUnit *SU = Bot.pickOnlyChoice()) {
177 IsTopNode = false;
178 return SU;
179 }
180 if (SUnit *SU = Top.pickOnlyChoice()) {
181 IsTopNode = true;
182 return SU;
183 }
184 // Set the bottom-up policy based on the state of the current bottom zone and
185 // the instructions outside the zone, including the top zone.
186 CandPolicy BotPolicy;
187 setPolicy(BotPolicy, /*IsPostRA=*/false, Bot, &Top);
188 // Set the top-down policy based on the state of the current top zone and
189 // the instructions outside the zone, including the bottom zone.
190 CandPolicy TopPolicy;
191 setPolicy(TopPolicy, /*IsPostRA=*/false, Top, &Bot);
192
193 // See if BotCand is still valid (because we previously scheduled from Top).
194 LLVM_DEBUG(dbgs() << "Picking from Bot:\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("machine-scheduler")) { dbgs() << "Picking from Bot:\n"
; } } while (false);
195 if (!BotCand.isValid() || BotCand.SU->isScheduled ||
196 BotCand.Policy != BotPolicy) {
197 BotCand.reset(CandPolicy());
198 pickNodeFromQueue(Bot, BotPolicy, DAG->getBotRPTracker(), BotCand);
199 assert(BotCand.Reason != NoCand && "failed to find the first candidate")((BotCand.Reason != NoCand && "failed to find the first candidate"
) ? static_cast<void> (0) : __assert_fail ("BotCand.Reason != NoCand && \"failed to find the first candidate\""
, "/build/llvm-toolchain-snapshot-12~++20200806111125+5446ec85070/llvm/lib/Target/AMDGPU/GCNSchedStrategy.cpp"
, 199, __PRETTY_FUNCTION__));
200 } else {
201 LLVM_DEBUG(traceCandidate(BotCand))do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("machine-scheduler")) { traceCandidate(BotCand); } } while (
false);
202#ifndef NDEBUG
203 if (VerifyScheduling) {
204 SchedCandidate TCand;
205 TCand.reset(CandPolicy());
206 pickNodeFromQueue(Bot, BotPolicy, DAG->getBotRPTracker(), TCand);
207 assert(TCand.SU == BotCand.SU &&((TCand.SU == BotCand.SU && "Last pick result should correspond to re-picking right now"
) ? static_cast<void> (0) : __assert_fail ("TCand.SU == BotCand.SU && \"Last pick result should correspond to re-picking right now\""
, "/build/llvm-toolchain-snapshot-12~++20200806111125+5446ec85070/llvm/lib/Target/AMDGPU/GCNSchedStrategy.cpp"
, 208, __PRETTY_FUNCTION__))
208 "Last pick result should correspond to re-picking right now")((TCand.SU == BotCand.SU && "Last pick result should correspond to re-picking right now"
) ? static_cast<void> (0) : __assert_fail ("TCand.SU == BotCand.SU && \"Last pick result should correspond to re-picking right now\""
, "/build/llvm-toolchain-snapshot-12~++20200806111125+5446ec85070/llvm/lib/Target/AMDGPU/GCNSchedStrategy.cpp"
, 208, __PRETTY_FUNCTION__));
209 }
210#endif
211 }
212
213 // Check if the top Q has a better candidate.
214 LLVM_DEBUG(dbgs() << "Picking from Top:\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("machine-scheduler")) { dbgs() << "Picking from Top:\n"
; } } while (false);
215 if (!TopCand.isValid() || TopCand.SU->isScheduled ||
216 TopCand.Policy != TopPolicy) {
217 TopCand.reset(CandPolicy());
218 pickNodeFromQueue(Top, TopPolicy, DAG->getTopRPTracker(), TopCand);
219 assert(TopCand.Reason != NoCand && "failed to find the first candidate")((TopCand.Reason != NoCand && "failed to find the first candidate"
) ? static_cast<void> (0) : __assert_fail ("TopCand.Reason != NoCand && \"failed to find the first candidate\""
, "/build/llvm-toolchain-snapshot-12~++20200806111125+5446ec85070/llvm/lib/Target/AMDGPU/GCNSchedStrategy.cpp"
, 219, __PRETTY_FUNCTION__));
220 } else {
221 LLVM_DEBUG(traceCandidate(TopCand))do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("machine-scheduler")) { traceCandidate(TopCand); } } while (
false);
222#ifndef NDEBUG
223 if (VerifyScheduling) {
224 SchedCandidate TCand;
225 TCand.reset(CandPolicy());
226 pickNodeFromQueue(Top, TopPolicy, DAG->getTopRPTracker(), TCand);
227 assert(TCand.SU == TopCand.SU &&((TCand.SU == TopCand.SU && "Last pick result should correspond to re-picking right now"
) ? static_cast<void> (0) : __assert_fail ("TCand.SU == TopCand.SU && \"Last pick result should correspond to re-picking right now\""
, "/build/llvm-toolchain-snapshot-12~++20200806111125+5446ec85070/llvm/lib/Target/AMDGPU/GCNSchedStrategy.cpp"
, 228, __PRETTY_FUNCTION__))
228 "Last pick result should correspond to re-picking right now")((TCand.SU == TopCand.SU && "Last pick result should correspond to re-picking right now"
) ? static_cast<void> (0) : __assert_fail ("TCand.SU == TopCand.SU && \"Last pick result should correspond to re-picking right now\""
, "/build/llvm-toolchain-snapshot-12~++20200806111125+5446ec85070/llvm/lib/Target/AMDGPU/GCNSchedStrategy.cpp"
, 228, __PRETTY_FUNCTION__));
229 }
230#endif
231 }
232
233 // Pick best from BotCand and TopCand.
234 LLVM_DEBUG(dbgs() << "Top Cand: "; traceCandidate(TopCand);do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("machine-scheduler")) { dbgs() << "Top Cand: "; traceCandidate
(TopCand); dbgs() << "Bot Cand: "; traceCandidate(BotCand
);; } } while (false)
235 dbgs() << "Bot Cand: "; traceCandidate(BotCand);)do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("machine-scheduler")) { dbgs() << "Top Cand: "; traceCandidate
(TopCand); dbgs() << "Bot Cand: "; traceCandidate(BotCand
);; } } while (false);
236 SchedCandidate Cand = BotCand;
237 TopCand.Reason = NoCand;
238 GenericScheduler::tryCandidate(Cand, TopCand, nullptr);
239 if (TopCand.Reason != NoCand) {
240 Cand.setBest(TopCand);
241 }
242 LLVM_DEBUG(dbgs() << "Picking: "; traceCandidate(Cand);)do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("machine-scheduler")) { dbgs() << "Picking: "; traceCandidate
(Cand);; } } while (false);
243
244 IsTopNode = Cand.AtTop;
245 return Cand.SU;
246}
247
248// This function is mostly cut and pasted from
249// GenericScheduler::pickNode()
250SUnit *GCNMaxOccupancySchedStrategy::pickNode(bool &IsTopNode) {
251 if (DAG->top() == DAG->bottom()) {
252 assert(Top.Available.empty() && Top.Pending.empty() &&((Top.Available.empty() && Top.Pending.empty() &&
Bot.Available.empty() && Bot.Pending.empty() &&
"ReadyQ garbage") ? static_cast<void> (0) : __assert_fail
("Top.Available.empty() && Top.Pending.empty() && Bot.Available.empty() && Bot.Pending.empty() && \"ReadyQ garbage\""
, "/build/llvm-toolchain-snapshot-12~++20200806111125+5446ec85070/llvm/lib/Target/AMDGPU/GCNSchedStrategy.cpp"
, 253, __PRETTY_FUNCTION__))
253 Bot.Available.empty() && Bot.Pending.empty() && "ReadyQ garbage")((Top.Available.empty() && Top.Pending.empty() &&
Bot.Available.empty() && Bot.Pending.empty() &&
"ReadyQ garbage") ? static_cast<void> (0) : __assert_fail
("Top.Available.empty() && Top.Pending.empty() && Bot.Available.empty() && Bot.Pending.empty() && \"ReadyQ garbage\""
, "/build/llvm-toolchain-snapshot-12~++20200806111125+5446ec85070/llvm/lib/Target/AMDGPU/GCNSchedStrategy.cpp"
, 253, __PRETTY_FUNCTION__));
254 return nullptr;
255 }
256 SUnit *SU;
257 do {
258 if (RegionPolicy.OnlyTopDown) {
259 SU = Top.pickOnlyChoice();
260 if (!SU) {
261 CandPolicy NoPolicy;
262 TopCand.reset(NoPolicy);
263 pickNodeFromQueue(Top, NoPolicy, DAG->getTopRPTracker(), TopCand);
264 assert(TopCand.Reason != NoCand && "failed to find a candidate")((TopCand.Reason != NoCand && "failed to find a candidate"
) ? static_cast<void> (0) : __assert_fail ("TopCand.Reason != NoCand && \"failed to find a candidate\""
, "/build/llvm-toolchain-snapshot-12~++20200806111125+5446ec85070/llvm/lib/Target/AMDGPU/GCNSchedStrategy.cpp"
, 264, __PRETTY_FUNCTION__));
265 SU = TopCand.SU;
266 }
267 IsTopNode = true;
268 } else if (RegionPolicy.OnlyBottomUp) {
269 SU = Bot.pickOnlyChoice();
270 if (!SU) {
271 CandPolicy NoPolicy;
272 BotCand.reset(NoPolicy);
273 pickNodeFromQueue(Bot, NoPolicy, DAG->getBotRPTracker(), BotCand);
274 assert(BotCand.Reason != NoCand && "failed to find a candidate")((BotCand.Reason != NoCand && "failed to find a candidate"
) ? static_cast<void> (0) : __assert_fail ("BotCand.Reason != NoCand && \"failed to find a candidate\""
, "/build/llvm-toolchain-snapshot-12~++20200806111125+5446ec85070/llvm/lib/Target/AMDGPU/GCNSchedStrategy.cpp"
, 274, __PRETTY_FUNCTION__));
275 SU = BotCand.SU;
276 }
277 IsTopNode = false;
278 } else {
279 SU = pickNodeBidirectional(IsTopNode);
280 }
281 } while (SU->isScheduled);
282
283 if (SU->isTopReady())
284 Top.removeReady(SU);
285 if (SU->isBottomReady())
286 Bot.removeReady(SU);
287
288 LLVM_DEBUG(dbgs() << "Scheduling SU(" << SU->NodeNum << ") "do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("machine-scheduler")) { dbgs() << "Scheduling SU(" <<
SU->NodeNum << ") " << *SU->getInstr(); } }
while (false)
289 << *SU->getInstr())do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("machine-scheduler")) { dbgs() << "Scheduling SU(" <<
SU->NodeNum << ") " << *SU->getInstr(); } }
while (false);
290 return SU;
291}
292
293GCNScheduleDAGMILive::GCNScheduleDAGMILive(MachineSchedContext *C,
294 std::unique_ptr<MachineSchedStrategy> S) :
295 ScheduleDAGMILive(C, std::move(S)),
296 ST(MF.getSubtarget<GCNSubtarget>()),
297 MFI(*MF.getInfo<SIMachineFunctionInfo>()),
298 StartingOccupancy(MFI.getOccupancy()),
299 MinOccupancy(StartingOccupancy), Stage(Collect), RegionIdx(0) {
300
301 LLVM_DEBUG(dbgs() << "Starting occupancy is " << StartingOccupancy << ".\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("machine-scheduler")) { dbgs() << "Starting occupancy is "
<< StartingOccupancy << ".\n"; } } while (false);
302}
303
304void GCNScheduleDAGMILive::schedule() {
305 if (Stage == Collect) {
306 // Just record regions at the first pass.
307 Regions.push_back(std::make_pair(RegionBegin, RegionEnd));
308 return;
309 }
310
311 std::vector<MachineInstr*> Unsched;
312 Unsched.reserve(NumRegionInstrs);
313 for (auto &I : *this) {
314 Unsched.push_back(&I);
315 }
316
317 GCNRegPressure PressureBefore;
318 if (LIS) {
319 PressureBefore = Pressure[RegionIdx];
320
321 LLVM_DEBUG(dbgs() << "Pressure before scheduling:\nRegion live-ins:";do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("machine-scheduler")) { dbgs() << "Pressure before scheduling:\nRegion live-ins:"
; GCNRPTracker::printLiveRegs(dbgs(), LiveIns[RegionIdx], MRI
); dbgs() << "Region live-in pressure: "; llvm::getRegPressure
(MRI, LiveIns[RegionIdx]).print(dbgs()); dbgs() << "Region register pressure: "
; PressureBefore.print(dbgs()); } } while (false)
322 GCNRPTracker::printLiveRegs(dbgs(), LiveIns[RegionIdx], MRI);do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("machine-scheduler")) { dbgs() << "Pressure before scheduling:\nRegion live-ins:"
; GCNRPTracker::printLiveRegs(dbgs(), LiveIns[RegionIdx], MRI
); dbgs() << "Region live-in pressure: "; llvm::getRegPressure
(MRI, LiveIns[RegionIdx]).print(dbgs()); dbgs() << "Region register pressure: "
; PressureBefore.print(dbgs()); } } while (false)
323 dbgs() << "Region live-in pressure: ";do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("machine-scheduler")) { dbgs() << "Pressure before scheduling:\nRegion live-ins:"
; GCNRPTracker::printLiveRegs(dbgs(), LiveIns[RegionIdx], MRI
); dbgs() << "Region live-in pressure: "; llvm::getRegPressure
(MRI, LiveIns[RegionIdx]).print(dbgs()); dbgs() << "Region register pressure: "
; PressureBefore.print(dbgs()); } } while (false)
324 llvm::getRegPressure(MRI, LiveIns[RegionIdx]).print(dbgs());do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("machine-scheduler")) { dbgs() << "Pressure before scheduling:\nRegion live-ins:"
; GCNRPTracker::printLiveRegs(dbgs(), LiveIns[RegionIdx], MRI
); dbgs() << "Region live-in pressure: "; llvm::getRegPressure
(MRI, LiveIns[RegionIdx]).print(dbgs()); dbgs() << "Region register pressure: "
; PressureBefore.print(dbgs()); } } while (false)
325 dbgs() << "Region register pressure: ";do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("machine-scheduler")) { dbgs() << "Pressure before scheduling:\nRegion live-ins:"
; GCNRPTracker::printLiveRegs(dbgs(), LiveIns[RegionIdx], MRI
); dbgs() << "Region live-in pressure: "; llvm::getRegPressure
(MRI, LiveIns[RegionIdx]).print(dbgs()); dbgs() << "Region register pressure: "
; PressureBefore.print(dbgs()); } } while (false)
326 PressureBefore.print(dbgs()))do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("machine-scheduler")) { dbgs() << "Pressure before scheduling:\nRegion live-ins:"
; GCNRPTracker::printLiveRegs(dbgs(), LiveIns[RegionIdx], MRI
); dbgs() << "Region live-in pressure: "; llvm::getRegPressure
(MRI, LiveIns[RegionIdx]).print(dbgs()); dbgs() << "Region register pressure: "
; PressureBefore.print(dbgs()); } } while (false);
327 }
328
329 ScheduleDAGMILive::schedule();
330 Regions[RegionIdx] = std::make_pair(RegionBegin, RegionEnd);
331 RescheduleRegions[RegionIdx] = false;
332
333 if (!LIS)
334 return;
335
336 // Check the results of scheduling.
337 GCNMaxOccupancySchedStrategy &S = (GCNMaxOccupancySchedStrategy&)*SchedImpl;
338 auto PressureAfter = getRealRegPressure();
339
340 LLVM_DEBUG(dbgs() << "Pressure after scheduling: ";do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("machine-scheduler")) { dbgs() << "Pressure after scheduling: "
; PressureAfter.print(dbgs()); } } while (false)
341 PressureAfter.print(dbgs()))do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("machine-scheduler")) { dbgs() << "Pressure after scheduling: "
; PressureAfter.print(dbgs()); } } while (false);
342
343 if (PressureAfter.getSGPRNum() <= S.SGPRCriticalLimit &&
344 PressureAfter.getVGPRNum() <= S.VGPRCriticalLimit) {
345 Pressure[RegionIdx] = PressureAfter;
346 LLVM_DEBUG(dbgs() << "Pressure in desired limits, done.\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("machine-scheduler")) { dbgs() << "Pressure in desired limits, done.\n"
; } } while (false);
347 return;
348 }
349 unsigned Occ = MFI.getOccupancy();
350 unsigned WavesAfter = std::min(Occ, PressureAfter.getOccupancy(ST));
351 unsigned WavesBefore = std::min(Occ, PressureBefore.getOccupancy(ST));
352 LLVM_DEBUG(dbgs() << "Occupancy before scheduling: " << WavesBeforedo { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("machine-scheduler")) { dbgs() << "Occupancy before scheduling: "
<< WavesBefore << ", after " << WavesAfter
<< ".\n"; } } while (false)
353 << ", after " << WavesAfter << ".\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("machine-scheduler")) { dbgs() << "Occupancy before scheduling: "
<< WavesBefore << ", after " << WavesAfter
<< ".\n"; } } while (false);
354
355 // We could not keep current target occupancy because of the just scheduled
356 // region. Record new occupancy for next scheduling cycle.
357 unsigned NewOccupancy = std::max(WavesAfter, WavesBefore);
358 // Allow memory bound functions to drop to 4 waves if not limited by an
359 // attribute.
360 if (WavesAfter < WavesBefore && WavesAfter < MinOccupancy &&
361 WavesAfter >= MFI.getMinAllowedOccupancy()) {
362 LLVM_DEBUG(dbgs() << "Function is memory bound, allow occupancy drop up to "do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("machine-scheduler")) { dbgs() << "Function is memory bound, allow occupancy drop up to "
<< MFI.getMinAllowedOccupancy() << " waves\n"; }
} while (false)
363 << MFI.getMinAllowedOccupancy() << " waves\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("machine-scheduler")) { dbgs() << "Function is memory bound, allow occupancy drop up to "
<< MFI.getMinAllowedOccupancy() << " waves\n"; }
} while (false);
364 NewOccupancy = WavesAfter;
365 }
366 if (NewOccupancy < MinOccupancy) {
367 MinOccupancy = NewOccupancy;
368 MFI.limitOccupancy(MinOccupancy);
369 LLVM_DEBUG(dbgs() << "Occupancy lowered for the function to "do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("machine-scheduler")) { dbgs() << "Occupancy lowered for the function to "
<< MinOccupancy << ".\n"; } } while (false)
370 << MinOccupancy << ".\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("machine-scheduler")) { dbgs() << "Occupancy lowered for the function to "
<< MinOccupancy << ".\n"; } } while (false);
371 }
372
373 unsigned MaxVGPRs = ST.getMaxNumVGPRs(MF);
374 unsigned MaxSGPRs = ST.getMaxNumSGPRs(MF);
375 if (PressureAfter.getVGPRNum() > MaxVGPRs ||
376 PressureAfter.getSGPRNum() > MaxSGPRs)
377 RescheduleRegions[RegionIdx] = true;
378
379 if (WavesAfter >= MinOccupancy) {
380 if (Stage == UnclusteredReschedule &&
381 !PressureAfter.less(ST, PressureBefore)) {
382 LLVM_DEBUG(dbgs() << "Unclustered reschedule did not help.\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("machine-scheduler")) { dbgs() << "Unclustered reschedule did not help.\n"
; } } while (false);
383 } else if (WavesAfter > MFI.getMinWavesPerEU() ||
384 PressureAfter.less(ST, PressureBefore) ||
385 !RescheduleRegions[RegionIdx]) {
386 Pressure[RegionIdx] = PressureAfter;
387 return;
388 } else {
389 LLVM_DEBUG(dbgs() << "New pressure will result in more spilling.\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("machine-scheduler")) { dbgs() << "New pressure will result in more spilling.\n"
; } } while (false);
390 }
391 }
392
393 LLVM_DEBUG(dbgs() << "Attempting to revert scheduling.\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("machine-scheduler")) { dbgs() << "Attempting to revert scheduling.\n"
; } } while (false);
394 RescheduleRegions[RegionIdx] = true;
395 RegionEnd = RegionBegin;
396 for (MachineInstr *MI : Unsched) {
397 if (MI->isDebugInstr())
398 continue;
399
400 if (MI->getIterator() != RegionEnd) {
401 BB->remove(MI);
402 BB->insert(RegionEnd, MI);
403 if (!MI->isDebugInstr())
404 LIS->handleMove(*MI, true);
405 }
406 // Reset read-undef flags and update them later.
407 for (auto &Op : MI->operands())
408 if (Op.isReg() && Op.isDef())
409 Op.setIsUndef(false);
410 RegisterOperands RegOpers;
411 RegOpers.collect(*MI, *TRI, MRI, ShouldTrackLaneMasks, false);
412 if (!MI->isDebugInstr()) {
413 if (ShouldTrackLaneMasks) {
414 // Adjust liveness and add missing dead+read-undef flags.
415 SlotIndex SlotIdx = LIS->getInstructionIndex(*MI).getRegSlot();
416 RegOpers.adjustLaneLiveness(*LIS, MRI, SlotIdx, MI);
417 } else {
418 // Adjust for missing dead-def flags.
419 RegOpers.detectDeadDefs(*MI, *LIS);
420 }
421 }
422 RegionEnd = MI->getIterator();
423 ++RegionEnd;
424 LLVM_DEBUG(dbgs() << "Scheduling " << *MI)do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("machine-scheduler")) { dbgs() << "Scheduling " <<
*MI; } } while (false);
425 }
426 RegionBegin = Unsched.front()->getIterator();
427 Regions[RegionIdx] = std::make_pair(RegionBegin, RegionEnd);
428
429 placeDebugValues();
430}
431
432GCNRegPressure GCNScheduleDAGMILive::getRealRegPressure() const {
433 GCNDownwardRPTracker RPTracker(*LIS);
434 RPTracker.advance(begin(), end(), &LiveIns[RegionIdx]);
435 return RPTracker.moveMaxPressure();
436}
437
438void GCNScheduleDAGMILive::computeBlockPressure(const MachineBasicBlock *MBB) {
439 GCNDownwardRPTracker RPTracker(*LIS);
440
441 // If the block has the only successor then live-ins of that successor are
442 // live-outs of the current block. We can reuse calculated live set if the
443 // successor will be sent to scheduling past current block.
444 const MachineBasicBlock *OnlySucc = nullptr;
445 if (MBB->succ_size() == 1 && !(*MBB->succ_begin())->empty()) {
446 SlotIndexes *Ind = LIS->getSlotIndexes();
447 if (Ind->getMBBStartIdx(MBB) < Ind->getMBBStartIdx(*MBB->succ_begin()))
448 OnlySucc = *MBB->succ_begin();
449 }
450
451 // Scheduler sends regions from the end of the block upwards.
452 size_t CurRegion = RegionIdx;
453 for (size_t E = Regions.size(); CurRegion != E; ++CurRegion)
454 if (Regions[CurRegion].first->getParent() != MBB)
455 break;
456 --CurRegion;
457
458 auto I = MBB->begin();
459 auto LiveInIt = MBBLiveIns.find(MBB);
460 if (LiveInIt != MBBLiveIns.end()) {
461 auto LiveIn = std::move(LiveInIt->second);
462 RPTracker.reset(*MBB->begin(), &LiveIn);
463 MBBLiveIns.erase(LiveInIt);
464 } else {
465 auto &Rgn = Regions[CurRegion];
466 I = Rgn.first;
467 auto *NonDbgMI = &*skipDebugInstructionsForward(Rgn.first, Rgn.second);
468 auto LRS = BBLiveInMap.lookup(NonDbgMI);
469 assert(isEqual(getLiveRegsBefore(*NonDbgMI, *LIS), LRS))((isEqual(getLiveRegsBefore(*NonDbgMI, *LIS), LRS)) ? static_cast
<void> (0) : __assert_fail ("isEqual(getLiveRegsBefore(*NonDbgMI, *LIS), LRS)"
, "/build/llvm-toolchain-snapshot-12~++20200806111125+5446ec85070/llvm/lib/Target/AMDGPU/GCNSchedStrategy.cpp"
, 469, __PRETTY_FUNCTION__));
470 RPTracker.reset(*I, &LRS);
471 }
472
473 for ( ; ; ) {
474 I = RPTracker.getNext();
475
476 if (Regions[CurRegion].first == I) {
477 LiveIns[CurRegion] = RPTracker.getLiveRegs();
478 RPTracker.clearMaxPressure();
479 }
480
481 if (Regions[CurRegion].second == I) {
482 Pressure[CurRegion] = RPTracker.moveMaxPressure();
483 if (CurRegion-- == RegionIdx)
484 break;
485 }
486 RPTracker.advanceToNext();
487 RPTracker.advanceBeforeNext();
488 }
489
490 if (OnlySucc) {
491 if (I != MBB->end()) {
492 RPTracker.advanceToNext();
493 RPTracker.advance(MBB->end());
494 }
495 RPTracker.reset(*OnlySucc->begin(), &RPTracker.getLiveRegs());
496 RPTracker.advanceBeforeNext();
497 MBBLiveIns[OnlySucc] = RPTracker.moveLiveRegs();
498 }
499}
500
501DenseMap<MachineInstr *, GCNRPTracker::LiveRegSet>
502GCNScheduleDAGMILive::getBBLiveInMap() const {
503 assert(!Regions.empty())((!Regions.empty()) ? static_cast<void> (0) : __assert_fail
("!Regions.empty()", "/build/llvm-toolchain-snapshot-12~++20200806111125+5446ec85070/llvm/lib/Target/AMDGPU/GCNSchedStrategy.cpp"
, 503, __PRETTY_FUNCTION__));
504 std::vector<MachineInstr *> BBStarters;
505 BBStarters.reserve(Regions.size());
506 auto I = Regions.rbegin(), E = Regions.rend();
507 auto *BB = I->first->getParent();
508 do {
509 auto *MI = &*skipDebugInstructionsForward(I->first, I->second);
510 BBStarters.push_back(MI);
511 do {
512 ++I;
513 } while (I != E && I->first->getParent() == BB);
514 } while (I != E);
515 return getLiveRegMap(BBStarters, false /*After*/, *LIS);
516}
517
518void GCNScheduleDAGMILive::finalizeSchedule() {
519 GCNMaxOccupancySchedStrategy &S = (GCNMaxOccupancySchedStrategy&)*SchedImpl;
520 LLVM_DEBUG(dbgs() << "All regions recorded, starting actual scheduling.\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("machine-scheduler")) { dbgs() << "All regions recorded, starting actual scheduling.\n"
; } } while (false);
1
Assuming 'DebugFlag' is false
→
2
←
Loop condition is false. Exiting loop
→
521
522 LiveIns.resize(Regions.size());
523 Pressure.resize(Regions.size());
524 RescheduleRegions.resize(Regions.size());
525 RescheduleRegions.set();
526
527 if (!Regions.empty())
3
←
Taking true branch
→
528 BBLiveInMap = getBBLiveInMap();
529
530 std::vector<std::unique_ptr<ScheduleDAGMutation>> SavedMutations;
531
532 do {
533 Stage++;
534 RegionIdx = 0;
535 MachineBasicBlock *MBB = nullptr;
4
←
'MBB' initialized to a null pointer value
→
536
537 if (Stage > InitialSchedule) {
5
←
Assuming field 'Stage' is <= InitialSchedule
→
6
←
Taking false branch
→
538 if (!LIS)
539 break;
540
541 // Retry function scheduling if we found resulting occupancy and it is
542 // lower than used for first pass scheduling. This will give more freedom
543 // to schedule low register pressure blocks.
544 // Code is partially copied from MachineSchedulerBase::scheduleRegions().
545
546 if (Stage == UnclusteredReschedule) {
547 if (RescheduleRegions.none())
548 continue;
549 LLVM_DEBUG(dbgs() <<do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("machine-scheduler")) { dbgs() << "Retrying function scheduling without clustering.\n"
; } } while (false)
550 "Retrying function scheduling without clustering.\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("machine-scheduler")) { dbgs() << "Retrying function scheduling without clustering.\n"
; } } while (false);
551 }
552
553 if (Stage == ClusteredLowOccupancyReschedule) {
554 if (StartingOccupancy <= MinOccupancy)
555 break;
556
557 LLVM_DEBUG(do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("machine-scheduler")) { dbgs() << "Retrying function scheduling with lowest recorded occupancy "
<< MinOccupancy << ".\n"; } } while (false)
558 dbgs()do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("machine-scheduler")) { dbgs() << "Retrying function scheduling with lowest recorded occupancy "
<< MinOccupancy << ".\n"; } } while (false)
559 << "Retrying function scheduling with lowest recorded occupancy "do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("machine-scheduler")) { dbgs() << "Retrying function scheduling with lowest recorded occupancy "
<< MinOccupancy << ".\n"; } } while (false)
560 << MinOccupancy << ".\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("machine-scheduler")) { dbgs() << "Retrying function scheduling with lowest recorded occupancy "
<< MinOccupancy << ".\n"; } } while (false);
561
562 S.setTargetOccupancy(MinOccupancy);
563 }
564 }
565
566 if (Stage
6.1
Field 'Stage' is not equal to UnclusteredReschedule
 == UnclusteredReschedule)
7
←
Taking false branch
→
567 SavedMutations.swap(Mutations);
568
569 for (auto Region : Regions) {
8
←
Assuming '__begin2' is not equal to '__end2'
→
570 if (Stage == UnclusteredReschedule && !RescheduleRegions[RegionIdx])
9
←
Assuming field 'Stage' is not equal to UnclusteredReschedule
→
10
←
Taking false branch
→
571 continue;
572
573 RegionBegin = Region.first;
574 RegionEnd = Region.second;
575
576 if (RegionBegin->getParent() != MBB) {
11
←
Assuming the condition is false
→
12
←
Taking false branch
→
577 if (MBB) finishBlock();
578 MBB = RegionBegin->getParent();
579 startBlock(MBB);
580 if (Stage == InitialSchedule)
581 computeBlockPressure(MBB);
582 }
583
584 unsigned NumRegionInstrs = std::distance(begin(), end());
585 enterRegion(MBB, begin(), end(), NumRegionInstrs);
586
587 // Skip empty scheduling regions (0 or 1 schedulable instructions).
588 if (begin() == end() || begin() == std::prev(end())) {
13
←
Taking false branch
→
589 exitRegion();
590 continue;
591 }
592
593 LLVM_DEBUG(dbgs() << "********** MI Scheduling **********\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("machine-scheduler")) { dbgs() << "********** MI Scheduling **********\n"
; } } while (false);
14
←
Assuming 'DebugFlag' is true
→
15
←
Assuming the condition is false
→
16
←
Taking false branch
→
17
←
Loop condition is false. Exiting loop
→
594 LLVM_DEBUG(dbgs() << MF.getName() << ":" << printMBBReference(*MBB) << " "do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("machine-scheduler")) { dbgs() << MF.getName() <<
":" << printMBBReference(*MBB) << " " << MBB
->getName() << "\n From: " << *begin() <<
" To: "; if (RegionEnd != MBB->end()) dbgs() << *
RegionEnd; else dbgs() << "End"; dbgs() << " RegionInstrs: "
<< NumRegionInstrs << '\n'; } } while (false)
18
←
Assuming 'DebugFlag' is true
→
19
←
Assuming the condition is true
→
20
←
Taking true branch
→
21
←
Forming reference to null pointer
595 << MBB->getName() << "\n From: " << *begin()do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("machine-scheduler")) { dbgs() << MF.getName() <<
":" << printMBBReference(*MBB) << " " << MBB
->getName() << "\n From: " << *begin() <<
" To: "; if (RegionEnd != MBB->end()) dbgs() << *
RegionEnd; else dbgs() << "End"; dbgs() << " RegionInstrs: "
<< NumRegionInstrs << '\n'; } } while (false)
596 << " To: ";do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("machine-scheduler")) { dbgs() << MF.getName() <<
":" << printMBBReference(*MBB) << " " << MBB
->getName() << "\n From: " << *begin() <<
" To: "; if (RegionEnd != MBB->end()) dbgs() << *
RegionEnd; else dbgs() << "End"; dbgs() << " RegionInstrs: "
<< NumRegionInstrs << '\n'; } } while (false)
597 if (RegionEnd != MBB->end()) dbgs() << *RegionEnd;do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("machine-scheduler")) { dbgs() << MF.getName() <<
":" << printMBBReference(*MBB) << " " << MBB
->getName() << "\n From: " << *begin() <<
" To: "; if (RegionEnd != MBB->end()) dbgs() << *
RegionEnd; else dbgs() << "End"; dbgs() << " RegionInstrs: "
<< NumRegionInstrs << '\n'; } } while (false)
598 else dbgs() << "End";do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("machine-scheduler")) { dbgs() << MF.getName() <<
":" << printMBBReference(*MBB) << " " << MBB
->getName() << "\n From: " << *begin() <<
" To: "; if (RegionEnd != MBB->end()) dbgs() << *
RegionEnd; else dbgs() << "End"; dbgs() << " RegionInstrs: "
<< NumRegionInstrs << '\n'; } } while (false)
599 dbgs() << " RegionInstrs: " << NumRegionInstrs << '\n')do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("machine-scheduler")) { dbgs() << MF.getName() <<
":" << printMBBReference(*MBB) << " " << MBB
->getName() << "\n From: " << *begin() <<
" To: "; if (RegionEnd != MBB->end()) dbgs() << *
RegionEnd; else dbgs() << "End"; dbgs() << " RegionInstrs: "
<< NumRegionInstrs << '\n'; } } while (false);
600
601 schedule();
602
603 exitRegion();
604 ++RegionIdx;
605 }
606 finishBlock();
607
608 if (Stage == UnclusteredReschedule)
609 SavedMutations.swap(Mutations);
610 } while (Stage != LastStage);
611}