| File: | llvm/lib/Target/AMDGPU/SIMachineScheduler.cpp |
| Warning: | line 770, column 9 Value stored to 'ProposedColor' is never read |
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| 1 | //===-- SIMachineScheduler.cpp - SI Scheduler Interface -------------------===// |
| 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 | /// SI Machine Scheduler interface |
| 11 | // |
| 12 | //===----------------------------------------------------------------------===// |
| 13 | |
| 14 | #include "SIMachineScheduler.h" |
| 15 | #include "SIInstrInfo.h" |
| 16 | #include "MCTargetDesc/AMDGPUMCTargetDesc.h" |
| 17 | #include "llvm/CodeGen/LiveIntervals.h" |
| 18 | #include "llvm/CodeGen/MachineRegisterInfo.h" |
| 19 | |
| 20 | using namespace llvm; |
| 21 | |
| 22 | #define DEBUG_TYPE"machine-scheduler" "machine-scheduler" |
| 23 | |
| 24 | // This scheduler implements a different scheduling algorithm than |
| 25 | // GenericScheduler. |
| 26 | // |
| 27 | // There are several specific architecture behaviours that can't be modelled |
| 28 | // for GenericScheduler: |
| 29 | // . When accessing the result of an SGPR load instruction, you have to wait |
| 30 | // for all the SGPR load instructions before your current instruction to |
| 31 | // have finished. |
| 32 | // . When accessing the result of an VGPR load instruction, you have to wait |
| 33 | // for all the VGPR load instructions previous to the VGPR load instruction |
| 34 | // you are interested in to finish. |
| 35 | // . The less the register pressure, the best load latencies are hidden |
| 36 | // |
| 37 | // Moreover some specifities (like the fact a lot of instructions in the shader |
| 38 | // have few dependencies) makes the generic scheduler have some unpredictable |
| 39 | // behaviours. For example when register pressure becomes high, it can either |
| 40 | // manage to prevent register pressure from going too high, or it can |
| 41 | // increase register pressure even more than if it hadn't taken register |
| 42 | // pressure into account. |
| 43 | // |
| 44 | // Also some other bad behaviours are generated, like loading at the beginning |
| 45 | // of the shader a constant in VGPR you won't need until the end of the shader. |
| 46 | // |
| 47 | // The scheduling problem for SI can distinguish three main parts: |
| 48 | // . Hiding high latencies (texture sampling, etc) |
| 49 | // . Hiding low latencies (SGPR constant loading, etc) |
| 50 | // . Keeping register usage low for better latency hiding and general |
| 51 | // performance |
| 52 | // |
| 53 | // Some other things can also affect performance, but are hard to predict |
| 54 | // (cache usage, the fact the HW can issue several instructions from different |
| 55 | // wavefronts if different types, etc) |
| 56 | // |
| 57 | // This scheduler tries to solve the scheduling problem by dividing it into |
| 58 | // simpler sub-problems. It divides the instructions into blocks, schedules |
| 59 | // locally inside the blocks where it takes care of low latencies, and then |
| 60 | // chooses the order of the blocks by taking care of high latencies. |
| 61 | // Dividing the instructions into blocks helps control keeping register |
| 62 | // usage low. |
| 63 | // |
| 64 | // First the instructions are put into blocks. |
| 65 | // We want the blocks help control register usage and hide high latencies |
| 66 | // later. To help control register usage, we typically want all local |
| 67 | // computations, when for example you create a result that can be comsummed |
| 68 | // right away, to be contained in a block. Block inputs and outputs would |
| 69 | // typically be important results that are needed in several locations of |
| 70 | // the shader. Since we do want blocks to help hide high latencies, we want |
| 71 | // the instructions inside the block to have a minimal set of dependencies |
| 72 | // on high latencies. It will make it easy to pick blocks to hide specific |
| 73 | // high latencies. |
| 74 | // The block creation algorithm is divided into several steps, and several |
| 75 | // variants can be tried during the scheduling process. |
| 76 | // |
| 77 | // Second the order of the instructions inside the blocks is chosen. |
| 78 | // At that step we do take into account only register usage and hiding |
| 79 | // low latency instructions |
| 80 | // |
| 81 | // Third the block order is chosen, there we try to hide high latencies |
| 82 | // and keep register usage low. |
| 83 | // |
| 84 | // After the third step, a pass is done to improve the hiding of low |
| 85 | // latencies. |
| 86 | // |
| 87 | // Actually when talking about 'low latency' or 'high latency' it includes |
| 88 | // both the latency to get the cache (or global mem) data go to the register, |
| 89 | // and the bandwidth limitations. |
| 90 | // Increasing the number of active wavefronts helps hide the former, but it |
| 91 | // doesn't solve the latter, thus why even if wavefront count is high, we have |
| 92 | // to try have as many instructions hiding high latencies as possible. |
| 93 | // The OpenCL doc says for example latency of 400 cycles for a global mem access, |
| 94 | // which is hidden by 10 instructions if the wavefront count is 10. |
| 95 | |
| 96 | // Some figures taken from AMD docs: |
| 97 | // Both texture and constant L1 caches are 4-way associative with 64 bytes |
| 98 | // lines. |
| 99 | // Constant cache is shared with 4 CUs. |
| 100 | // For texture sampling, the address generation unit receives 4 texture |
| 101 | // addresses per cycle, thus we could expect texture sampling latency to be |
| 102 | // equivalent to 4 instructions in the very best case (a VGPR is 64 work items, |
| 103 | // instructions in a wavefront group are executed every 4 cycles), |
| 104 | // or 16 instructions if the other wavefronts associated to the 3 other VALUs |
| 105 | // of the CU do texture sampling too. (Don't take these figures too seriously, |
| 106 | // as I'm not 100% sure of the computation) |
| 107 | // Data exports should get similar latency. |
| 108 | // For constant loading, the cache is shader with 4 CUs. |
| 109 | // The doc says "a throughput of 16B/cycle for each of the 4 Compute Unit" |
| 110 | // I guess if the other CU don't read the cache, it can go up to 64B/cycle. |
| 111 | // It means a simple s_buffer_load should take one instruction to hide, as |
| 112 | // well as a s_buffer_loadx2 and potentially a s_buffer_loadx8 if on the same |
| 113 | // cache line. |
| 114 | // |
| 115 | // As of today the driver doesn't preload the constants in cache, thus the |
| 116 | // first loads get extra latency. The doc says global memory access can be |
| 117 | // 300-600 cycles. We do not specially take that into account when scheduling |
| 118 | // As we expect the driver to be able to preload the constants soon. |
| 119 | |
| 120 | // common code // |
| 121 | |
| 122 | #ifndef NDEBUG |
| 123 | |
| 124 | static const char *getReasonStr(SIScheduleCandReason Reason) { |
| 125 | switch (Reason) { |
| 126 | case NoCand: return "NOCAND"; |
| 127 | case RegUsage: return "REGUSAGE"; |
| 128 | case Latency: return "LATENCY"; |
| 129 | case Successor: return "SUCCESSOR"; |
| 130 | case Depth: return "DEPTH"; |
| 131 | case NodeOrder: return "ORDER"; |
| 132 | } |
| 133 | llvm_unreachable("Unknown reason!")::llvm::llvm_unreachable_internal("Unknown reason!", "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/llvm/lib/Target/AMDGPU/SIMachineScheduler.cpp" , 133); |
| 134 | } |
| 135 | |
| 136 | #endif |
| 137 | |
| 138 | namespace llvm { |
| 139 | namespace SISched { |
| 140 | static bool tryLess(int TryVal, int CandVal, |
| 141 | SISchedulerCandidate &TryCand, |
| 142 | SISchedulerCandidate &Cand, |
| 143 | SIScheduleCandReason Reason) { |
| 144 | if (TryVal < CandVal) { |
| 145 | TryCand.Reason = Reason; |
| 146 | return true; |
| 147 | } |
| 148 | if (TryVal > CandVal) { |
| 149 | if (Cand.Reason > Reason) |
| 150 | Cand.Reason = Reason; |
| 151 | return true; |
| 152 | } |
| 153 | Cand.setRepeat(Reason); |
| 154 | return false; |
| 155 | } |
| 156 | |
| 157 | static bool tryGreater(int TryVal, int CandVal, |
| 158 | SISchedulerCandidate &TryCand, |
| 159 | SISchedulerCandidate &Cand, |
| 160 | SIScheduleCandReason Reason) { |
| 161 | if (TryVal > CandVal) { |
| 162 | TryCand.Reason = Reason; |
| 163 | return true; |
| 164 | } |
| 165 | if (TryVal < CandVal) { |
| 166 | if (Cand.Reason > Reason) |
| 167 | Cand.Reason = Reason; |
| 168 | return true; |
| 169 | } |
| 170 | Cand.setRepeat(Reason); |
| 171 | return false; |
| 172 | } |
| 173 | } // end namespace SISched |
| 174 | } // end namespace llvm |
| 175 | |
| 176 | // SIScheduleBlock // |
| 177 | |
| 178 | void SIScheduleBlock::addUnit(SUnit *SU) { |
| 179 | NodeNum2Index[SU->NodeNum] = SUnits.size(); |
| 180 | SUnits.push_back(SU); |
| 181 | } |
| 182 | |
| 183 | #ifndef NDEBUG |
| 184 | void SIScheduleBlock::traceCandidate(const SISchedCandidate &Cand) { |
| 185 | |
| 186 | dbgs() << " SU(" << Cand.SU->NodeNum << ") " << getReasonStr(Cand.Reason); |
| 187 | dbgs() << '\n'; |
| 188 | } |
| 189 | #endif |
| 190 | |
| 191 | void SIScheduleBlock::tryCandidateTopDown(SISchedCandidate &Cand, |
| 192 | SISchedCandidate &TryCand) { |
| 193 | // Initialize the candidate if needed. |
| 194 | if (!Cand.isValid()) { |
| 195 | TryCand.Reason = NodeOrder; |
| 196 | return; |
| 197 | } |
| 198 | |
| 199 | if (Cand.SGPRUsage > 60 && |
| 200 | SISched::tryLess(TryCand.SGPRUsage, Cand.SGPRUsage, |
| 201 | TryCand, Cand, RegUsage)) |
| 202 | return; |
| 203 | |
| 204 | // Schedule low latency instructions as top as possible. |
| 205 | // Order of priority is: |
| 206 | // . Low latency instructions which do not depend on other low latency |
| 207 | // instructions we haven't waited for |
| 208 | // . Other instructions which do not depend on low latency instructions |
| 209 | // we haven't waited for |
| 210 | // . Low latencies |
| 211 | // . All other instructions |
| 212 | // Goal is to get: low latency instructions - independent instructions |
| 213 | // - (eventually some more low latency instructions) |
| 214 | // - instructions that depend on the first low latency instructions. |
| 215 | // If in the block there is a lot of constant loads, the SGPR usage |
| 216 | // could go quite high, thus above the arbitrary limit of 60 will encourage |
| 217 | // use the already loaded constants (in order to release some SGPRs) before |
| 218 | // loading more. |
| 219 | if (SISched::tryLess(TryCand.HasLowLatencyNonWaitedParent, |
| 220 | Cand.HasLowLatencyNonWaitedParent, |
| 221 | TryCand, Cand, SIScheduleCandReason::Depth)) |
| 222 | return; |
| 223 | |
| 224 | if (SISched::tryGreater(TryCand.IsLowLatency, Cand.IsLowLatency, |
| 225 | TryCand, Cand, SIScheduleCandReason::Depth)) |
| 226 | return; |
| 227 | |
| 228 | if (TryCand.IsLowLatency && |
| 229 | SISched::tryLess(TryCand.LowLatencyOffset, Cand.LowLatencyOffset, |
| 230 | TryCand, Cand, SIScheduleCandReason::Depth)) |
| 231 | return; |
| 232 | |
| 233 | if (SISched::tryLess(TryCand.VGPRUsage, Cand.VGPRUsage, |
| 234 | TryCand, Cand, RegUsage)) |
| 235 | return; |
| 236 | |
| 237 | // Fall through to original instruction order. |
| 238 | if (TryCand.SU->NodeNum < Cand.SU->NodeNum) { |
| 239 | TryCand.Reason = NodeOrder; |
| 240 | } |
| 241 | } |
| 242 | |
| 243 | SUnit* SIScheduleBlock::pickNode() { |
| 244 | SISchedCandidate TopCand; |
| 245 | |
| 246 | for (SUnit* SU : TopReadySUs) { |
| 247 | SISchedCandidate TryCand; |
| 248 | std::vector<unsigned> pressure; |
| 249 | std::vector<unsigned> MaxPressure; |
| 250 | // Predict register usage after this instruction. |
| 251 | TryCand.SU = SU; |
| 252 | TopRPTracker.getDownwardPressure(SU->getInstr(), pressure, MaxPressure); |
| 253 | TryCand.SGPRUsage = pressure[AMDGPU::RegisterPressureSets::SReg_32]; |
| 254 | TryCand.VGPRUsage = pressure[AMDGPU::RegisterPressureSets::VGPR_32]; |
| 255 | TryCand.IsLowLatency = DAG->IsLowLatencySU[SU->NodeNum]; |
| 256 | TryCand.LowLatencyOffset = DAG->LowLatencyOffset[SU->NodeNum]; |
| 257 | TryCand.HasLowLatencyNonWaitedParent = |
| 258 | HasLowLatencyNonWaitedParent[NodeNum2Index[SU->NodeNum]]; |
| 259 | tryCandidateTopDown(TopCand, TryCand); |
| 260 | if (TryCand.Reason != NoCand) |
| 261 | TopCand.setBest(TryCand); |
| 262 | } |
| 263 | |
| 264 | return TopCand.SU; |
| 265 | } |
| 266 | |
| 267 | |
| 268 | // Schedule something valid. |
| 269 | void SIScheduleBlock::fastSchedule() { |
| 270 | TopReadySUs.clear(); |
| 271 | if (Scheduled) |
| 272 | undoSchedule(); |
| 273 | |
| 274 | for (SUnit* SU : SUnits) { |
| 275 | if (!SU->NumPredsLeft) |
| 276 | TopReadySUs.push_back(SU); |
| 277 | } |
| 278 | |
| 279 | while (!TopReadySUs.empty()) { |
| 280 | SUnit *SU = TopReadySUs[0]; |
| 281 | ScheduledSUnits.push_back(SU); |
| 282 | nodeScheduled(SU); |
| 283 | } |
| 284 | |
| 285 | Scheduled = true; |
| 286 | } |
| 287 | |
| 288 | // Returns if the register was set between first and last. |
| 289 | static bool isDefBetween(unsigned Reg, |
| 290 | SlotIndex First, SlotIndex Last, |
| 291 | const MachineRegisterInfo *MRI, |
| 292 | const LiveIntervals *LIS) { |
| 293 | for (MachineRegisterInfo::def_instr_iterator |
| 294 | UI = MRI->def_instr_begin(Reg), |
| 295 | UE = MRI->def_instr_end(); UI != UE; ++UI) { |
| 296 | const MachineInstr* MI = &*UI; |
| 297 | if (MI->isDebugValue()) |
| 298 | continue; |
| 299 | SlotIndex InstSlot = LIS->getInstructionIndex(*MI).getRegSlot(); |
| 300 | if (InstSlot >= First && InstSlot <= Last) |
| 301 | return true; |
| 302 | } |
| 303 | return false; |
| 304 | } |
| 305 | |
| 306 | void SIScheduleBlock::initRegPressure(MachineBasicBlock::iterator BeginBlock, |
| 307 | MachineBasicBlock::iterator EndBlock) { |
| 308 | IntervalPressure Pressure, BotPressure; |
| 309 | RegPressureTracker RPTracker(Pressure), BotRPTracker(BotPressure); |
| 310 | LiveIntervals *LIS = DAG->getLIS(); |
| 311 | MachineRegisterInfo *MRI = DAG->getMRI(); |
| 312 | DAG->initRPTracker(TopRPTracker); |
| 313 | DAG->initRPTracker(BotRPTracker); |
| 314 | DAG->initRPTracker(RPTracker); |
| 315 | |
| 316 | // Goes though all SU. RPTracker captures what had to be alive for the SUs |
| 317 | // to execute, and what is still alive at the end. |
| 318 | for (SUnit* SU : ScheduledSUnits) { |
| 319 | RPTracker.setPos(SU->getInstr()); |
| 320 | RPTracker.advance(); |
| 321 | } |
| 322 | |
| 323 | // Close the RPTracker to finalize live ins/outs. |
| 324 | RPTracker.closeRegion(); |
| 325 | |
| 326 | // Initialize the live ins and live outs. |
| 327 | TopRPTracker.addLiveRegs(RPTracker.getPressure().LiveInRegs); |
| 328 | BotRPTracker.addLiveRegs(RPTracker.getPressure().LiveOutRegs); |
| 329 | |
| 330 | // Do not Track Physical Registers, because it messes up. |
| 331 | for (const auto &RegMaskPair : RPTracker.getPressure().LiveInRegs) { |
| 332 | if (Register::isVirtualRegister(RegMaskPair.RegUnit)) |
| 333 | LiveInRegs.insert(RegMaskPair.RegUnit); |
| 334 | } |
| 335 | LiveOutRegs.clear(); |
| 336 | // There is several possibilities to distinguish: |
| 337 | // 1) Reg is not input to any instruction in the block, but is output of one |
| 338 | // 2) 1) + read in the block and not needed after it |
| 339 | // 3) 1) + read in the block but needed in another block |
| 340 | // 4) Reg is input of an instruction but another block will read it too |
| 341 | // 5) Reg is input of an instruction and then rewritten in the block. |
| 342 | // result is not read in the block (implies used in another block) |
| 343 | // 6) Reg is input of an instruction and then rewritten in the block. |
| 344 | // result is read in the block and not needed in another block |
| 345 | // 7) Reg is input of an instruction and then rewritten in the block. |
| 346 | // result is read in the block but also needed in another block |
| 347 | // LiveInRegs will contains all the regs in situation 4, 5, 6, 7 |
| 348 | // We want LiveOutRegs to contain only Regs whose content will be read after |
| 349 | // in another block, and whose content was written in the current block, |
| 350 | // that is we want it to get 1, 3, 5, 7 |
| 351 | // Since we made the MIs of a block to be packed all together before |
| 352 | // scheduling, then the LiveIntervals were correct, and the RPTracker was |
| 353 | // able to correctly handle 5 vs 6, 2 vs 3. |
| 354 | // (Note: This is not sufficient for RPTracker to not do mistakes for case 4) |
| 355 | // The RPTracker's LiveOutRegs has 1, 3, (some correct or incorrect)4, 5, 7 |
| 356 | // Comparing to LiveInRegs is not sufficient to differenciate 4 vs 5, 7 |
| 357 | // The use of findDefBetween removes the case 4. |
| 358 | for (const auto &RegMaskPair : RPTracker.getPressure().LiveOutRegs) { |
| 359 | Register Reg = RegMaskPair.RegUnit; |
| 360 | if (Reg.isVirtual() && |
| 361 | isDefBetween(Reg, LIS->getInstructionIndex(*BeginBlock).getRegSlot(), |
| 362 | LIS->getInstructionIndex(*EndBlock).getRegSlot(), MRI, |
| 363 | LIS)) { |
| 364 | LiveOutRegs.insert(Reg); |
| 365 | } |
| 366 | } |
| 367 | |
| 368 | // Pressure = sum_alive_registers register size |
| 369 | // Internally llvm will represent some registers as big 128 bits registers |
| 370 | // for example, but they actually correspond to 4 actual 32 bits registers. |
| 371 | // Thus Pressure is not equal to num_alive_registers * constant. |
| 372 | LiveInPressure = TopPressure.MaxSetPressure; |
| 373 | LiveOutPressure = BotPressure.MaxSetPressure; |
| 374 | |
| 375 | // Prepares TopRPTracker for top down scheduling. |
| 376 | TopRPTracker.closeTop(); |
| 377 | } |
| 378 | |
| 379 | void SIScheduleBlock::schedule(MachineBasicBlock::iterator BeginBlock, |
| 380 | MachineBasicBlock::iterator EndBlock) { |
| 381 | if (!Scheduled) |
| 382 | fastSchedule(); |
| 383 | |
| 384 | // PreScheduling phase to set LiveIn and LiveOut. |
| 385 | initRegPressure(BeginBlock, EndBlock); |
| 386 | undoSchedule(); |
| 387 | |
| 388 | // Schedule for real now. |
| 389 | |
| 390 | TopReadySUs.clear(); |
| 391 | |
| 392 | for (SUnit* SU : SUnits) { |
| 393 | if (!SU->NumPredsLeft) |
| 394 | TopReadySUs.push_back(SU); |
| 395 | } |
| 396 | |
| 397 | while (!TopReadySUs.empty()) { |
| 398 | SUnit *SU = pickNode(); |
| 399 | ScheduledSUnits.push_back(SU); |
| 400 | TopRPTracker.setPos(SU->getInstr()); |
| 401 | TopRPTracker.advance(); |
| 402 | nodeScheduled(SU); |
| 403 | } |
| 404 | |
| 405 | // TODO: compute InternalAdditionnalPressure. |
| 406 | InternalAdditionnalPressure.resize(TopPressure.MaxSetPressure.size()); |
| 407 | |
| 408 | // Check everything is right. |
| 409 | #ifndef NDEBUG |
| 410 | assert(SUnits.size() == ScheduledSUnits.size() &&(static_cast <bool> (SUnits.size() == ScheduledSUnits.size () && TopReadySUs.empty()) ? void (0) : __assert_fail ("SUnits.size() == ScheduledSUnits.size() && TopReadySUs.empty()" , "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/llvm/lib/Target/AMDGPU/SIMachineScheduler.cpp" , 411, __extension__ __PRETTY_FUNCTION__)) |
| 411 | TopReadySUs.empty())(static_cast <bool> (SUnits.size() == ScheduledSUnits.size () && TopReadySUs.empty()) ? void (0) : __assert_fail ("SUnits.size() == ScheduledSUnits.size() && TopReadySUs.empty()" , "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/llvm/lib/Target/AMDGPU/SIMachineScheduler.cpp" , 411, __extension__ __PRETTY_FUNCTION__)); |
| 412 | for (SUnit* SU : SUnits) { |
| 413 | assert(SU->isScheduled &&(static_cast <bool> (SU->isScheduled && SU-> NumPredsLeft == 0) ? void (0) : __assert_fail ("SU->isScheduled && SU->NumPredsLeft == 0" , "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/llvm/lib/Target/AMDGPU/SIMachineScheduler.cpp" , 414, __extension__ __PRETTY_FUNCTION__)) |
| 414 | SU->NumPredsLeft == 0)(static_cast <bool> (SU->isScheduled && SU-> NumPredsLeft == 0) ? void (0) : __assert_fail ("SU->isScheduled && SU->NumPredsLeft == 0" , "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/llvm/lib/Target/AMDGPU/SIMachineScheduler.cpp" , 414, __extension__ __PRETTY_FUNCTION__)); |
| 415 | } |
| 416 | #endif |
| 417 | |
| 418 | Scheduled = true; |
| 419 | } |
| 420 | |
| 421 | void SIScheduleBlock::undoSchedule() { |
| 422 | for (SUnit* SU : SUnits) { |
| 423 | SU->isScheduled = false; |
| 424 | for (SDep& Succ : SU->Succs) { |
| 425 | if (BC->isSUInBlock(Succ.getSUnit(), ID)) |
| 426 | undoReleaseSucc(SU, &Succ); |
| 427 | } |
| 428 | } |
| 429 | HasLowLatencyNonWaitedParent.assign(SUnits.size(), 0); |
| 430 | ScheduledSUnits.clear(); |
| 431 | Scheduled = false; |
| 432 | } |
| 433 | |
| 434 | void SIScheduleBlock::undoReleaseSucc(SUnit *SU, SDep *SuccEdge) { |
| 435 | SUnit *SuccSU = SuccEdge->getSUnit(); |
| 436 | |
| 437 | if (SuccEdge->isWeak()) { |
| 438 | ++SuccSU->WeakPredsLeft; |
| 439 | return; |
| 440 | } |
| 441 | ++SuccSU->NumPredsLeft; |
| 442 | } |
| 443 | |
| 444 | void SIScheduleBlock::releaseSucc(SUnit *SU, SDep *SuccEdge) { |
| 445 | SUnit *SuccSU = SuccEdge->getSUnit(); |
| 446 | |
| 447 | if (SuccEdge->isWeak()) { |
| 448 | --SuccSU->WeakPredsLeft; |
| 449 | return; |
| 450 | } |
| 451 | #ifndef NDEBUG |
| 452 | if (SuccSU->NumPredsLeft == 0) { |
| 453 | dbgs() << "*** Scheduling failed! ***\n"; |
| 454 | DAG->dumpNode(*SuccSU); |
| 455 | dbgs() << " has been released too many times!\n"; |
| 456 | llvm_unreachable(nullptr)::llvm::llvm_unreachable_internal(nullptr, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/llvm/lib/Target/AMDGPU/SIMachineScheduler.cpp" , 456); |
| 457 | } |
| 458 | #endif |
| 459 | |
| 460 | --SuccSU->NumPredsLeft; |
| 461 | } |
| 462 | |
| 463 | /// Release Successors of the SU that are in the block or not. |
| 464 | void SIScheduleBlock::releaseSuccessors(SUnit *SU, bool InOrOutBlock) { |
| 465 | for (SDep& Succ : SU->Succs) { |
| 466 | SUnit *SuccSU = Succ.getSUnit(); |
| 467 | |
| 468 | if (SuccSU->NodeNum >= DAG->SUnits.size()) |
| 469 | continue; |
| 470 | |
| 471 | if (BC->isSUInBlock(SuccSU, ID) != InOrOutBlock) |
| 472 | continue; |
| 473 | |
| 474 | releaseSucc(SU, &Succ); |
| 475 | if (SuccSU->NumPredsLeft == 0 && InOrOutBlock) |
| 476 | TopReadySUs.push_back(SuccSU); |
| 477 | } |
| 478 | } |
| 479 | |
| 480 | void SIScheduleBlock::nodeScheduled(SUnit *SU) { |
| 481 | // Is in TopReadySUs |
| 482 | assert (!SU->NumPredsLeft)(static_cast <bool> (!SU->NumPredsLeft) ? void (0) : __assert_fail ("!SU->NumPredsLeft", "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/llvm/lib/Target/AMDGPU/SIMachineScheduler.cpp" , 482, __extension__ __PRETTY_FUNCTION__)); |
| 483 | std::vector<SUnit *>::iterator I = llvm::find(TopReadySUs, SU); |
| 484 | if (I == TopReadySUs.end()) { |
| 485 | dbgs() << "Data Structure Bug in SI Scheduler\n"; |
| 486 | llvm_unreachable(nullptr)::llvm::llvm_unreachable_internal(nullptr, "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/llvm/lib/Target/AMDGPU/SIMachineScheduler.cpp" , 486); |
| 487 | } |
| 488 | TopReadySUs.erase(I); |
| 489 | |
| 490 | releaseSuccessors(SU, true); |
| 491 | // Scheduling this node will trigger a wait, |
| 492 | // thus propagate to other instructions that they do not need to wait either. |
| 493 | if (HasLowLatencyNonWaitedParent[NodeNum2Index[SU->NodeNum]]) |
| 494 | HasLowLatencyNonWaitedParent.assign(SUnits.size(), 0); |
| 495 | |
| 496 | if (DAG->IsLowLatencySU[SU->NodeNum]) { |
| 497 | for (SDep& Succ : SU->Succs) { |
| 498 | std::map<unsigned, unsigned>::iterator I = |
| 499 | NodeNum2Index.find(Succ.getSUnit()->NodeNum); |
| 500 | if (I != NodeNum2Index.end()) |
| 501 | HasLowLatencyNonWaitedParent[I->second] = 1; |
| 502 | } |
| 503 | } |
| 504 | SU->isScheduled = true; |
| 505 | } |
| 506 | |
| 507 | void SIScheduleBlock::finalizeUnits() { |
| 508 | // We remove links from outside blocks to enable scheduling inside the block. |
| 509 | for (SUnit* SU : SUnits) { |
| 510 | releaseSuccessors(SU, false); |
| 511 | if (DAG->IsHighLatencySU[SU->NodeNum]) |
| 512 | HighLatencyBlock = true; |
| 513 | } |
| 514 | HasLowLatencyNonWaitedParent.resize(SUnits.size(), 0); |
| 515 | } |
| 516 | |
| 517 | // we maintain ascending order of IDs |
| 518 | void SIScheduleBlock::addPred(SIScheduleBlock *Pred) { |
| 519 | unsigned PredID = Pred->getID(); |
| 520 | |
| 521 | // Check if not already predecessor. |
| 522 | for (SIScheduleBlock* P : Preds) { |
| 523 | if (PredID == P->getID()) |
| 524 | return; |
| 525 | } |
| 526 | Preds.push_back(Pred); |
| 527 | |
| 528 | assert(none_of(Succs,(static_cast <bool> (none_of(Succs, [=](std::pair<SIScheduleBlock *, SIScheduleBlockLinkKind> S) { return PredID == S.first-> getID(); }) && "Loop in the Block Graph!") ? void (0) : __assert_fail ("none_of(Succs, [=](std::pair<SIScheduleBlock*, SIScheduleBlockLinkKind> S) { return PredID == S.first->getID(); }) && \"Loop in the Block Graph!\"" , "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/llvm/lib/Target/AMDGPU/SIMachineScheduler.cpp" , 533, __extension__ __PRETTY_FUNCTION__)) |
| 529 | [=](std::pair<SIScheduleBlock*,(static_cast <bool> (none_of(Succs, [=](std::pair<SIScheduleBlock *, SIScheduleBlockLinkKind> S) { return PredID == S.first-> getID(); }) && "Loop in the Block Graph!") ? void (0) : __assert_fail ("none_of(Succs, [=](std::pair<SIScheduleBlock*, SIScheduleBlockLinkKind> S) { return PredID == S.first->getID(); }) && \"Loop in the Block Graph!\"" , "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/llvm/lib/Target/AMDGPU/SIMachineScheduler.cpp" , 533, __extension__ __PRETTY_FUNCTION__)) |
| 530 | SIScheduleBlockLinkKind> S) {(static_cast <bool> (none_of(Succs, [=](std::pair<SIScheduleBlock *, SIScheduleBlockLinkKind> S) { return PredID == S.first-> getID(); }) && "Loop in the Block Graph!") ? void (0) : __assert_fail ("none_of(Succs, [=](std::pair<SIScheduleBlock*, SIScheduleBlockLinkKind> S) { return PredID == S.first->getID(); }) && \"Loop in the Block Graph!\"" , "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/llvm/lib/Target/AMDGPU/SIMachineScheduler.cpp" , 533, __extension__ __PRETTY_FUNCTION__)) |
| 531 | return PredID == S.first->getID();(static_cast <bool> (none_of(Succs, [=](std::pair<SIScheduleBlock *, SIScheduleBlockLinkKind> S) { return PredID == S.first-> getID(); }) && "Loop in the Block Graph!") ? void (0) : __assert_fail ("none_of(Succs, [=](std::pair<SIScheduleBlock*, SIScheduleBlockLinkKind> S) { return PredID == S.first->getID(); }) && \"Loop in the Block Graph!\"" , "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/llvm/lib/Target/AMDGPU/SIMachineScheduler.cpp" , 533, __extension__ __PRETTY_FUNCTION__)) |
| 532 | }) &&(static_cast <bool> (none_of(Succs, [=](std::pair<SIScheduleBlock *, SIScheduleBlockLinkKind> S) { return PredID == S.first-> getID(); }) && "Loop in the Block Graph!") ? void (0) : __assert_fail ("none_of(Succs, [=](std::pair<SIScheduleBlock*, SIScheduleBlockLinkKind> S) { return PredID == S.first->getID(); }) && \"Loop in the Block Graph!\"" , "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/llvm/lib/Target/AMDGPU/SIMachineScheduler.cpp" , 533, __extension__ __PRETTY_FUNCTION__)) |
| 533 | "Loop in the Block Graph!")(static_cast <bool> (none_of(Succs, [=](std::pair<SIScheduleBlock *, SIScheduleBlockLinkKind> S) { return PredID == S.first-> getID(); }) && "Loop in the Block Graph!") ? void (0) : __assert_fail ("none_of(Succs, [=](std::pair<SIScheduleBlock*, SIScheduleBlockLinkKind> S) { return PredID == S.first->getID(); }) && \"Loop in the Block Graph!\"" , "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/llvm/lib/Target/AMDGPU/SIMachineScheduler.cpp" , 533, __extension__ __PRETTY_FUNCTION__)); |
| 534 | } |
| 535 | |
| 536 | void SIScheduleBlock::addSucc(SIScheduleBlock *Succ, |
| 537 | SIScheduleBlockLinkKind Kind) { |
| 538 | unsigned SuccID = Succ->getID(); |
| 539 | |
| 540 | // Check if not already predecessor. |
| 541 | for (std::pair<SIScheduleBlock*, SIScheduleBlockLinkKind> &S : Succs) { |
| 542 | if (SuccID == S.first->getID()) { |
| 543 | if (S.second == SIScheduleBlockLinkKind::NoData && |
| 544 | Kind == SIScheduleBlockLinkKind::Data) |
| 545 | S.second = Kind; |
| 546 | return; |
| 547 | } |
| 548 | } |
| 549 | if (Succ->isHighLatencyBlock()) |
| 550 | ++NumHighLatencySuccessors; |
| 551 | Succs.push_back(std::make_pair(Succ, Kind)); |
| 552 | |
| 553 | assert(none_of(Preds,(static_cast <bool> (none_of(Preds, [=](SIScheduleBlock *P) { return SuccID == P->getID(); }) && "Loop in the Block Graph!" ) ? void (0) : __assert_fail ("none_of(Preds, [=](SIScheduleBlock *P) { return SuccID == P->getID(); }) && \"Loop in the Block Graph!\"" , "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/llvm/lib/Target/AMDGPU/SIMachineScheduler.cpp" , 555, __extension__ __PRETTY_FUNCTION__)) |
| 554 | [=](SIScheduleBlock *P) { return SuccID == P->getID(); }) &&(static_cast <bool> (none_of(Preds, [=](SIScheduleBlock *P) { return SuccID == P->getID(); }) && "Loop in the Block Graph!" ) ? void (0) : __assert_fail ("none_of(Preds, [=](SIScheduleBlock *P) { return SuccID == P->getID(); }) && \"Loop in the Block Graph!\"" , "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/llvm/lib/Target/AMDGPU/SIMachineScheduler.cpp" , 555, __extension__ __PRETTY_FUNCTION__)) |
| 555 | "Loop in the Block Graph!")(static_cast <bool> (none_of(Preds, [=](SIScheduleBlock *P) { return SuccID == P->getID(); }) && "Loop in the Block Graph!" ) ? void (0) : __assert_fail ("none_of(Preds, [=](SIScheduleBlock *P) { return SuccID == P->getID(); }) && \"Loop in the Block Graph!\"" , "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/llvm/lib/Target/AMDGPU/SIMachineScheduler.cpp" , 555, __extension__ __PRETTY_FUNCTION__)); |
| 556 | } |
| 557 | |
| 558 | #ifndef NDEBUG |
| 559 | void SIScheduleBlock::printDebug(bool full) { |
| 560 | dbgs() << "Block (" << ID << ")\n"; |
| 561 | if (!full) |
| 562 | return; |
| 563 | |
| 564 | dbgs() << "\nContains High Latency Instruction: " |
| 565 | << HighLatencyBlock << '\n'; |
| 566 | dbgs() << "\nDepends On:\n"; |
| 567 | for (SIScheduleBlock* P : Preds) { |
| 568 | P->printDebug(false); |
| 569 | } |
| 570 | |
| 571 | dbgs() << "\nSuccessors:\n"; |
| 572 | for (std::pair<SIScheduleBlock*, SIScheduleBlockLinkKind> S : Succs) { |
| 573 | if (S.second == SIScheduleBlockLinkKind::Data) |
| 574 | dbgs() << "(Data Dep) "; |
| 575 | S.first->printDebug(false); |
| 576 | } |
| 577 | |
| 578 | if (Scheduled) { |
| 579 | dbgs() << "LiveInPressure " |
| 580 | << LiveInPressure[AMDGPU::RegisterPressureSets::SReg_32] << ' ' |
| 581 | << LiveInPressure[AMDGPU::RegisterPressureSets::VGPR_32] << '\n'; |
| 582 | dbgs() << "LiveOutPressure " |
| 583 | << LiveOutPressure[AMDGPU::RegisterPressureSets::SReg_32] << ' ' |
| 584 | << LiveOutPressure[AMDGPU::RegisterPressureSets::VGPR_32] << "\n\n"; |
| 585 | dbgs() << "LiveIns:\n"; |
| 586 | for (unsigned Reg : LiveInRegs) |
| 587 | dbgs() << printVRegOrUnit(Reg, DAG->getTRI()) << ' '; |
| 588 | |
| 589 | dbgs() << "\nLiveOuts:\n"; |
| 590 | for (unsigned Reg : LiveOutRegs) |
| 591 | dbgs() << printVRegOrUnit(Reg, DAG->getTRI()) << ' '; |
| 592 | } |
| 593 | |
| 594 | dbgs() << "\nInstructions:\n"; |
| 595 | for (const SUnit* SU : SUnits) |
| 596 | DAG->dumpNode(*SU); |
| 597 | |
| 598 | dbgs() << "///////////////////////\n"; |
| 599 | } |
| 600 | #endif |
| 601 | |
| 602 | // SIScheduleBlockCreator // |
| 603 | |
| 604 | SIScheduleBlockCreator::SIScheduleBlockCreator(SIScheduleDAGMI *DAG) |
| 605 | : DAG(DAG) {} |
| 606 | |
| 607 | SIScheduleBlocks |
| 608 | SIScheduleBlockCreator::getBlocks(SISchedulerBlockCreatorVariant BlockVariant) { |
| 609 | std::map<SISchedulerBlockCreatorVariant, SIScheduleBlocks>::iterator B = |
| 610 | Blocks.find(BlockVariant); |
| 611 | if (B == Blocks.end()) { |
| 612 | SIScheduleBlocks Res; |
| 613 | createBlocksForVariant(BlockVariant); |
| 614 | topologicalSort(); |
| 615 | scheduleInsideBlocks(); |
| 616 | fillStats(); |
| 617 | Res.Blocks = CurrentBlocks; |
| 618 | Res.TopDownIndex2Block = TopDownIndex2Block; |
| 619 | Res.TopDownBlock2Index = TopDownBlock2Index; |
| 620 | Blocks[BlockVariant] = Res; |
| 621 | return Res; |
| 622 | } else { |
| 623 | return B->second; |
| 624 | } |
| 625 | } |
| 626 | |
| 627 | bool SIScheduleBlockCreator::isSUInBlock(SUnit *SU, unsigned ID) { |
| 628 | if (SU->NodeNum >= DAG->SUnits.size()) |
| 629 | return false; |
| 630 | return CurrentBlocks[Node2CurrentBlock[SU->NodeNum]]->getID() == ID; |
| 631 | } |
| 632 | |
| 633 | void SIScheduleBlockCreator::colorHighLatenciesAlone() { |
| 634 | unsigned DAGSize = DAG->SUnits.size(); |
| 635 | |
| 636 | for (unsigned i = 0, e = DAGSize; i != e; ++i) { |
| 637 | SUnit *SU = &DAG->SUnits[i]; |
| 638 | if (DAG->IsHighLatencySU[SU->NodeNum]) { |
| 639 | CurrentColoring[SU->NodeNum] = NextReservedID++; |
| 640 | } |
| 641 | } |
| 642 | } |
| 643 | |
| 644 | static bool |
| 645 | hasDataDependencyPred(const SUnit &SU, const SUnit &FromSU) { |
| 646 | for (const auto &PredDep : SU.Preds) { |
| 647 | if (PredDep.getSUnit() == &FromSU && |
| 648 | PredDep.getKind() == llvm::SDep::Data) |
| 649 | return true; |
| 650 | } |
| 651 | return false; |
| 652 | } |
| 653 | |
| 654 | void SIScheduleBlockCreator::colorHighLatenciesGroups() { |
| 655 | unsigned DAGSize = DAG->SUnits.size(); |
| 656 | unsigned NumHighLatencies = 0; |
| 657 | unsigned GroupSize; |
| 658 | int Color = NextReservedID; |
| 659 | unsigned Count = 0; |
| 660 | std::set<unsigned> FormingGroup; |
| 661 | |
| 662 | for (unsigned i = 0, e = DAGSize; i != e; ++i) { |
| 663 | SUnit *SU = &DAG->SUnits[i]; |
| 664 | if (DAG->IsHighLatencySU[SU->NodeNum]) |
| 665 | ++NumHighLatencies; |
| 666 | } |
| 667 | |
| 668 | if (NumHighLatencies == 0) |
| 669 | return; |
| 670 | |
| 671 | if (NumHighLatencies <= 6) |
| 672 | GroupSize = 2; |
| 673 | else if (NumHighLatencies <= 12) |
| 674 | GroupSize = 3; |
| 675 | else |
| 676 | GroupSize = 4; |
| 677 | |
| 678 | for (unsigned SUNum : DAG->TopDownIndex2SU) { |
| 679 | const SUnit &SU = DAG->SUnits[SUNum]; |
| 680 | if (DAG->IsHighLatencySU[SU.NodeNum]) { |
| 681 | unsigned CompatibleGroup = true; |
| 682 | int ProposedColor = Color; |
| 683 | std::vector<int> AdditionalElements; |
| 684 | |
| 685 | // We don't want to put in the same block |
| 686 | // two high latency instructions that depend |
| 687 | // on each other. |
| 688 | // One way would be to check canAddEdge |
| 689 | // in both directions, but that currently is not |
| 690 | // enough because there the high latency order is |
| 691 | // enforced (via links). |
| 692 | // Instead, look at the dependencies between the |
| 693 | // high latency instructions and deduce if it is |
| 694 | // a data dependency or not. |
| 695 | for (unsigned j : FormingGroup) { |
| 696 | bool HasSubGraph; |
| 697 | std::vector<int> SubGraph; |
| 698 | // By construction (topological order), if SU and |
| 699 | // DAG->SUnits[j] are linked, DAG->SUnits[j] is neccessary |
| 700 | // in the parent graph of SU. |
| 701 | #ifndef NDEBUG |
| 702 | SubGraph = DAG->GetTopo()->GetSubGraph(SU, DAG->SUnits[j], |
| 703 | HasSubGraph); |
| 704 | assert(!HasSubGraph)(static_cast <bool> (!HasSubGraph) ? void (0) : __assert_fail ("!HasSubGraph", "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/llvm/lib/Target/AMDGPU/SIMachineScheduler.cpp" , 704, __extension__ __PRETTY_FUNCTION__)); |
| 705 | #endif |
| 706 | SubGraph = DAG->GetTopo()->GetSubGraph(DAG->SUnits[j], SU, |
| 707 | HasSubGraph); |
| 708 | if (!HasSubGraph) |
| 709 | continue; // No dependencies between each other |
| 710 | else if (SubGraph.size() > 5) { |
| 711 | // Too many elements would be required to be added to the block. |
| 712 | CompatibleGroup = false; |
| 713 | break; |
| 714 | } |
| 715 | else { |
| 716 | // Check the type of dependency |
| 717 | for (unsigned k : SubGraph) { |
| 718 | // If in the path to join the two instructions, |
| 719 | // there is another high latency instruction, |
| 720 | // or instructions colored for another block |
| 721 | // abort the merge. |
| 722 | if (DAG->IsHighLatencySU[k] || |
| 723 | (CurrentColoring[k] != ProposedColor && |
| 724 | CurrentColoring[k] != 0)) { |
| 725 | CompatibleGroup = false; |
| 726 | break; |
| 727 | } |
| 728 | // If one of the SU in the subgraph depends on the result of SU j, |
| 729 | // there'll be a data dependency. |
| 730 | if (hasDataDependencyPred(DAG->SUnits[k], DAG->SUnits[j])) { |
| 731 | CompatibleGroup = false; |
| 732 | break; |
| 733 | } |
| 734 | } |
| 735 | if (!CompatibleGroup) |
| 736 | break; |
| 737 | // Same check for the SU |
| 738 | if (hasDataDependencyPred(SU, DAG->SUnits[j])) { |
| 739 | CompatibleGroup = false; |
| 740 | break; |
| 741 | } |
| 742 | // Add all the required instructions to the block |
| 743 | // These cannot live in another block (because they |
| 744 | // depend (order dependency) on one of the |
| 745 | // instruction in the block, and are required for the |
| 746 | // high latency instruction we add. |
| 747 | llvm::append_range(AdditionalElements, SubGraph); |
| 748 | } |
| 749 | } |
| 750 | if (CompatibleGroup) { |
| 751 | FormingGroup.insert(SU.NodeNum); |
| 752 | for (unsigned j : AdditionalElements) |
| 753 | CurrentColoring[j] = ProposedColor; |
| 754 | CurrentColoring[SU.NodeNum] = ProposedColor; |
| 755 | ++Count; |
| 756 | } |
| 757 | // Found one incompatible instruction, |
| 758 | // or has filled a big enough group. |
| 759 | // -> start a new one. |
| 760 | if (!CompatibleGroup) { |
| 761 | FormingGroup.clear(); |
| 762 | Color = ++NextReservedID; |
| 763 | ProposedColor = Color; |
| 764 | FormingGroup.insert(SU.NodeNum); |
| 765 | CurrentColoring[SU.NodeNum] = ProposedColor; |
| 766 | Count = 0; |
| 767 | } else if (Count == GroupSize) { |
| 768 | FormingGroup.clear(); |
| 769 | Color = ++NextReservedID; |
| 770 | ProposedColor = Color; |
Value stored to 'ProposedColor' is never read | |
| 771 | Count = 0; |
| 772 | } |
| 773 | } |
| 774 | } |
| 775 | } |
| 776 | |
| 777 | void SIScheduleBlockCreator::colorComputeReservedDependencies() { |
| 778 | unsigned DAGSize = DAG->SUnits.size(); |
| 779 | std::map<std::set<unsigned>, unsigned> ColorCombinations; |
| 780 | |
| 781 | CurrentTopDownReservedDependencyColoring.clear(); |
| 782 | CurrentBottomUpReservedDependencyColoring.clear(); |
| 783 | |
| 784 | CurrentTopDownReservedDependencyColoring.resize(DAGSize, 0); |
| 785 | CurrentBottomUpReservedDependencyColoring.resize(DAGSize, 0); |
| 786 | |
| 787 | // Traverse TopDown, and give different colors to SUs depending |
| 788 | // on which combination of High Latencies they depend on. |
| 789 | |
| 790 | for (unsigned SUNum : DAG->TopDownIndex2SU) { |
| 791 | SUnit *SU = &DAG->SUnits[SUNum]; |
| 792 | std::set<unsigned> SUColors; |
| 793 | |
| 794 | // Already given. |
| 795 | if (CurrentColoring[SU->NodeNum]) { |
| 796 | CurrentTopDownReservedDependencyColoring[SU->NodeNum] = |
| 797 | CurrentColoring[SU->NodeNum]; |
| 798 | continue; |
| 799 | } |
| 800 | |
| 801 | for (SDep& PredDep : SU->Preds) { |
| 802 | SUnit *Pred = PredDep.getSUnit(); |
| 803 | if (PredDep.isWeak() || Pred->NodeNum >= DAGSize) |
| 804 | continue; |
| 805 | if (CurrentTopDownReservedDependencyColoring[Pred->NodeNum] > 0) |
| 806 | SUColors.insert(CurrentTopDownReservedDependencyColoring[Pred->NodeNum]); |
| 807 | } |
| 808 | // Color 0 by default. |
| 809 | if (SUColors.empty()) |
| 810 | continue; |
| 811 | // Same color than parents. |
| 812 | if (SUColors.size() == 1 && *SUColors.begin() > DAGSize) |
| 813 | CurrentTopDownReservedDependencyColoring[SU->NodeNum] = |
| 814 | *SUColors.begin(); |
| 815 | else { |
| 816 | std::map<std::set<unsigned>, unsigned>::iterator Pos = |
| 817 | ColorCombinations.find(SUColors); |
| 818 | if (Pos != ColorCombinations.end()) { |
| 819 | CurrentTopDownReservedDependencyColoring[SU->NodeNum] = Pos->second; |
| 820 | } else { |
| 821 | CurrentTopDownReservedDependencyColoring[SU->NodeNum] = |
| 822 | NextNonReservedID; |
| 823 | ColorCombinations[SUColors] = NextNonReservedID++; |
| 824 | } |
| 825 | } |
| 826 | } |
| 827 | |
| 828 | ColorCombinations.clear(); |
| 829 | |
| 830 | // Same as before, but BottomUp. |
| 831 | |
| 832 | for (unsigned SUNum : DAG->BottomUpIndex2SU) { |
| 833 | SUnit *SU = &DAG->SUnits[SUNum]; |
| 834 | std::set<unsigned> SUColors; |
| 835 | |
| 836 | // Already given. |
| 837 | if (CurrentColoring[SU->NodeNum]) { |
| 838 | CurrentBottomUpReservedDependencyColoring[SU->NodeNum] = |
| 839 | CurrentColoring[SU->NodeNum]; |
| 840 | continue; |
| 841 | } |
| 842 | |
| 843 | for (SDep& SuccDep : SU->Succs) { |
| 844 | SUnit *Succ = SuccDep.getSUnit(); |
| 845 | if (SuccDep.isWeak() || Succ->NodeNum >= DAGSize) |
| 846 | continue; |
| 847 | if (CurrentBottomUpReservedDependencyColoring[Succ->NodeNum] > 0) |
| 848 | SUColors.insert(CurrentBottomUpReservedDependencyColoring[Succ->NodeNum]); |
| 849 | } |
| 850 | // Keep color 0. |
| 851 | if (SUColors.empty()) |
| 852 | continue; |
| 853 | // Same color than parents. |
| 854 | if (SUColors.size() == 1 && *SUColors.begin() > DAGSize) |
| 855 | CurrentBottomUpReservedDependencyColoring[SU->NodeNum] = |
| 856 | *SUColors.begin(); |
| 857 | else { |
| 858 | std::map<std::set<unsigned>, unsigned>::iterator Pos = |
| 859 | ColorCombinations.find(SUColors); |
| 860 | if (Pos != ColorCombinations.end()) { |
| 861 | CurrentBottomUpReservedDependencyColoring[SU->NodeNum] = Pos->second; |
| 862 | } else { |
| 863 | CurrentBottomUpReservedDependencyColoring[SU->NodeNum] = |
| 864 | NextNonReservedID; |
| 865 | ColorCombinations[SUColors] = NextNonReservedID++; |
| 866 | } |
| 867 | } |
| 868 | } |
| 869 | } |
| 870 | |
| 871 | void SIScheduleBlockCreator::colorAccordingToReservedDependencies() { |
| 872 | unsigned DAGSize = DAG->SUnits.size(); |
| 873 | std::map<std::pair<unsigned, unsigned>, unsigned> ColorCombinations; |
| 874 | |
| 875 | // Every combination of colors given by the top down |
| 876 | // and bottom up Reserved node dependency |
| 877 | |
| 878 | for (unsigned i = 0, e = DAGSize; i != e; ++i) { |
| 879 | SUnit *SU = &DAG->SUnits[i]; |
| 880 | std::pair<unsigned, unsigned> SUColors; |
| 881 | |
| 882 | // High latency instructions: already given. |
| 883 | if (CurrentColoring[SU->NodeNum]) |
| 884 | continue; |
| 885 | |
| 886 | SUColors.first = CurrentTopDownReservedDependencyColoring[SU->NodeNum]; |
| 887 | SUColors.second = CurrentBottomUpReservedDependencyColoring[SU->NodeNum]; |
| 888 | |
| 889 | std::map<std::pair<unsigned, unsigned>, unsigned>::iterator Pos = |
| 890 | ColorCombinations.find(SUColors); |
| 891 | if (Pos != ColorCombinations.end()) { |
| 892 | CurrentColoring[SU->NodeNum] = Pos->second; |
| 893 | } else { |
| 894 | CurrentColoring[SU->NodeNum] = NextNonReservedID; |
| 895 | ColorCombinations[SUColors] = NextNonReservedID++; |
| 896 | } |
| 897 | } |
| 898 | } |
| 899 | |
| 900 | void SIScheduleBlockCreator::colorEndsAccordingToDependencies() { |
| 901 | unsigned DAGSize = DAG->SUnits.size(); |
| 902 | std::vector<int> PendingColoring = CurrentColoring; |
| 903 | |
| 904 | assert(DAGSize >= 1 &&(static_cast <bool> (DAGSize >= 1 && CurrentBottomUpReservedDependencyColoring .size() == DAGSize && CurrentTopDownReservedDependencyColoring .size() == DAGSize) ? void (0) : __assert_fail ("DAGSize >= 1 && CurrentBottomUpReservedDependencyColoring.size() == DAGSize && CurrentTopDownReservedDependencyColoring.size() == DAGSize" , "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/llvm/lib/Target/AMDGPU/SIMachineScheduler.cpp" , 906, __extension__ __PRETTY_FUNCTION__)) |
| 905 | CurrentBottomUpReservedDependencyColoring.size() == DAGSize &&(static_cast <bool> (DAGSize >= 1 && CurrentBottomUpReservedDependencyColoring .size() == DAGSize && CurrentTopDownReservedDependencyColoring .size() == DAGSize) ? void (0) : __assert_fail ("DAGSize >= 1 && CurrentBottomUpReservedDependencyColoring.size() == DAGSize && CurrentTopDownReservedDependencyColoring.size() == DAGSize" , "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/llvm/lib/Target/AMDGPU/SIMachineScheduler.cpp" , 906, __extension__ __PRETTY_FUNCTION__)) |
| 906 | CurrentTopDownReservedDependencyColoring.size() == DAGSize)(static_cast <bool> (DAGSize >= 1 && CurrentBottomUpReservedDependencyColoring .size() == DAGSize && CurrentTopDownReservedDependencyColoring .size() == DAGSize) ? void (0) : __assert_fail ("DAGSize >= 1 && CurrentBottomUpReservedDependencyColoring.size() == DAGSize && CurrentTopDownReservedDependencyColoring.size() == DAGSize" , "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/llvm/lib/Target/AMDGPU/SIMachineScheduler.cpp" , 906, __extension__ __PRETTY_FUNCTION__)); |
| 907 | // If there is no reserved block at all, do nothing. We don't want |
| 908 | // everything in one block. |
| 909 | if (*std::max_element(CurrentBottomUpReservedDependencyColoring.begin(), |
| 910 | CurrentBottomUpReservedDependencyColoring.end()) == 0 && |
| 911 | *std::max_element(CurrentTopDownReservedDependencyColoring.begin(), |
| 912 | CurrentTopDownReservedDependencyColoring.end()) == 0) |
| 913 | return; |
| 914 | |
| 915 | for (unsigned SUNum : DAG->BottomUpIndex2SU) { |
| 916 | SUnit *SU = &DAG->SUnits[SUNum]; |
| 917 | std::set<unsigned> SUColors; |
| 918 | std::set<unsigned> SUColorsPending; |
| 919 | |
| 920 | if (CurrentColoring[SU->NodeNum] <= (int)DAGSize) |
| 921 | continue; |
| 922 | |
| 923 | if (CurrentBottomUpReservedDependencyColoring[SU->NodeNum] > 0 || |
| 924 | CurrentTopDownReservedDependencyColoring[SU->NodeNum] > 0) |
| 925 | continue; |
| 926 | |
| 927 | for (SDep& SuccDep : SU->Succs) { |
| 928 | SUnit *Succ = SuccDep.getSUnit(); |
| 929 | if (SuccDep.isWeak() || Succ->NodeNum >= DAGSize) |
| 930 | continue; |
| 931 | if (CurrentBottomUpReservedDependencyColoring[Succ->NodeNum] > 0 || |
| 932 | CurrentTopDownReservedDependencyColoring[Succ->NodeNum] > 0) |
| 933 | SUColors.insert(CurrentColoring[Succ->NodeNum]); |
| 934 | SUColorsPending.insert(PendingColoring[Succ->NodeNum]); |
| 935 | } |
| 936 | // If there is only one child/parent block, and that block |
| 937 | // is not among the ones we are removing in this path, then |
| 938 | // merge the instruction to that block |
| 939 | if (SUColors.size() == 1 && SUColorsPending.size() == 1) |
| 940 | PendingColoring[SU->NodeNum] = *SUColors.begin(); |
| 941 | else // TODO: Attribute new colors depending on color |
| 942 | // combination of children. |
| 943 | PendingColoring[SU->NodeNum] = NextNonReservedID++; |
| 944 | } |
| 945 | CurrentColoring = PendingColoring; |
| 946 | } |
| 947 | |
| 948 | |
| 949 | void SIScheduleBlockCreator::colorForceConsecutiveOrderInGroup() { |
| 950 | unsigned DAGSize = DAG->SUnits.size(); |
| 951 | unsigned PreviousColor; |
| 952 | std::set<unsigned> SeenColors; |
| 953 | |
| 954 | if (DAGSize <= 1) |
| 955 | return; |
| 956 | |
| 957 | PreviousColor = CurrentColoring[0]; |
| 958 | |
| 959 | for (unsigned i = 1, e = DAGSize; i != e; ++i) { |
| 960 | SUnit *SU = &DAG->SUnits[i]; |
| 961 | unsigned CurrentColor = CurrentColoring[i]; |
| 962 | unsigned PreviousColorSave = PreviousColor; |
| 963 | assert(i == SU->NodeNum)(static_cast <bool> (i == SU->NodeNum) ? void (0) : __assert_fail ("i == SU->NodeNum", "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/llvm/lib/Target/AMDGPU/SIMachineScheduler.cpp" , 963, __extension__ __PRETTY_FUNCTION__)); |
| 964 | |
| 965 | if (CurrentColor != PreviousColor) |
| 966 | SeenColors.insert(PreviousColor); |
| 967 | PreviousColor = CurrentColor; |
| 968 | |
| 969 | if (CurrentColoring[SU->NodeNum] <= (int)DAGSize) |
| 970 | continue; |
| 971 | |
| 972 | if (SeenColors.find(CurrentColor) == SeenColors.end()) |
| 973 | continue; |
| 974 | |
| 975 | if (PreviousColorSave != CurrentColor) |
| 976 | CurrentColoring[i] = NextNonReservedID++; |
| 977 | else |
| 978 | CurrentColoring[i] = CurrentColoring[i-1]; |
| 979 | } |
| 980 | } |
| 981 | |
| 982 | void SIScheduleBlockCreator::colorMergeConstantLoadsNextGroup() { |
| 983 | unsigned DAGSize = DAG->SUnits.size(); |
| 984 | |
| 985 | for (unsigned SUNum : DAG->BottomUpIndex2SU) { |
| 986 | SUnit *SU = &DAG->SUnits[SUNum]; |
| 987 | std::set<unsigned> SUColors; |
| 988 | |
| 989 | if (CurrentColoring[SU->NodeNum] <= (int)DAGSize) |
| 990 | continue; |
| 991 | |
| 992 | // No predecessor: Vgpr constant loading. |
| 993 | // Low latency instructions usually have a predecessor (the address) |
| 994 | if (SU->Preds.size() > 0 && !DAG->IsLowLatencySU[SU->NodeNum]) |
| 995 | continue; |
| 996 | |
| 997 | for (SDep& SuccDep : SU->Succs) { |
| 998 | SUnit *Succ = SuccDep.getSUnit(); |
| 999 | if (SuccDep.isWeak() || Succ->NodeNum >= DAGSize) |
| 1000 | continue; |
| 1001 | SUColors.insert(CurrentColoring[Succ->NodeNum]); |
| 1002 | } |
| 1003 | if (SUColors.size() == 1) |
| 1004 | CurrentColoring[SU->NodeNum] = *SUColors.begin(); |
| 1005 | } |
| 1006 | } |
| 1007 | |
| 1008 | void SIScheduleBlockCreator::colorMergeIfPossibleNextGroup() { |
| 1009 | unsigned DAGSize = DAG->SUnits.size(); |
| 1010 | |
| 1011 | for (unsigned SUNum : DAG->BottomUpIndex2SU) { |
| 1012 | SUnit *SU = &DAG->SUnits[SUNum]; |
| 1013 | std::set<unsigned> SUColors; |
| 1014 | |
| 1015 | if (CurrentColoring[SU->NodeNum] <= (int)DAGSize) |
| 1016 | continue; |
| 1017 | |
| 1018 | for (SDep& SuccDep : SU->Succs) { |
| 1019 | SUnit *Succ = SuccDep.getSUnit(); |
| 1020 | if (SuccDep.isWeak() || Succ->NodeNum >= DAGSize) |
| 1021 | continue; |
| 1022 | SUColors.insert(CurrentColoring[Succ->NodeNum]); |
| 1023 | } |
| 1024 | if (SUColors.size() == 1) |
| 1025 | CurrentColoring[SU->NodeNum] = *SUColors.begin(); |
| 1026 | } |
| 1027 | } |
| 1028 | |
| 1029 | void SIScheduleBlockCreator::colorMergeIfPossibleNextGroupOnlyForReserved() { |
| 1030 | unsigned DAGSize = DAG->SUnits.size(); |
| 1031 | |
| 1032 | for (unsigned SUNum : DAG->BottomUpIndex2SU) { |
| 1033 | SUnit *SU = &DAG->SUnits[SUNum]; |
| 1034 | std::set<unsigned> SUColors; |
| 1035 | |
| 1036 | if (CurrentColoring[SU->NodeNum] <= (int)DAGSize) |
| 1037 | continue; |
| 1038 | |
| 1039 | for (SDep& SuccDep : SU->Succs) { |
| 1040 | SUnit *Succ = SuccDep.getSUnit(); |
| 1041 | if (SuccDep.isWeak() || Succ->NodeNum >= DAGSize) |
| 1042 | continue; |
| 1043 | SUColors.insert(CurrentColoring[Succ->NodeNum]); |
| 1044 | } |
| 1045 | if (SUColors.size() == 1 && *SUColors.begin() <= DAGSize) |
| 1046 | CurrentColoring[SU->NodeNum] = *SUColors.begin(); |
| 1047 | } |
| 1048 | } |
| 1049 | |
| 1050 | void SIScheduleBlockCreator::colorMergeIfPossibleSmallGroupsToNextGroup() { |
| 1051 | unsigned DAGSize = DAG->SUnits.size(); |
| 1052 | std::map<unsigned, unsigned> ColorCount; |
| 1053 | |
| 1054 | for (unsigned SUNum : DAG->BottomUpIndex2SU) { |
| 1055 | SUnit *SU = &DAG->SUnits[SUNum]; |
| 1056 | unsigned color = CurrentColoring[SU->NodeNum]; |
| 1057 | ++ColorCount[color]; |
| 1058 | } |
| 1059 | |
| 1060 | for (unsigned SUNum : DAG->BottomUpIndex2SU) { |
| 1061 | SUnit *SU = &DAG->SUnits[SUNum]; |
| 1062 | unsigned color = CurrentColoring[SU->NodeNum]; |
| 1063 | std::set<unsigned> SUColors; |
| 1064 | |
| 1065 | if (CurrentColoring[SU->NodeNum] <= (int)DAGSize) |
| 1066 | continue; |
| 1067 | |
| 1068 | if (ColorCount[color] > 1) |
| 1069 | continue; |
| 1070 | |
| 1071 | for (SDep& SuccDep : SU->Succs) { |
| 1072 | SUnit *Succ = SuccDep.getSUnit(); |
| 1073 | if (SuccDep.isWeak() || Succ->NodeNum >= DAGSize) |
| 1074 | continue; |
| 1075 | SUColors.insert(CurrentColoring[Succ->NodeNum]); |
| 1076 | } |
| 1077 | if (SUColors.size() == 1 && *SUColors.begin() != color) { |
| 1078 | --ColorCount[color]; |
| 1079 | CurrentColoring[SU->NodeNum] = *SUColors.begin(); |
| 1080 | ++ColorCount[*SUColors.begin()]; |
| 1081 | } |
| 1082 | } |
| 1083 | } |
| 1084 | |
| 1085 | void SIScheduleBlockCreator::cutHugeBlocks() { |
| 1086 | // TODO |
| 1087 | } |
| 1088 | |
| 1089 | void SIScheduleBlockCreator::regroupNoUserInstructions() { |
| 1090 | unsigned DAGSize = DAG->SUnits.size(); |
| 1091 | int GroupID = NextNonReservedID++; |
| 1092 | |
| 1093 | for (unsigned SUNum : DAG->BottomUpIndex2SU) { |
| 1094 | SUnit *SU = &DAG->SUnits[SUNum]; |
| 1095 | bool hasSuccessor = false; |
| 1096 | |
| 1097 | if (CurrentColoring[SU->NodeNum] <= (int)DAGSize) |
| 1098 | continue; |
| 1099 | |
| 1100 | for (SDep& SuccDep : SU->Succs) { |
| 1101 | SUnit *Succ = SuccDep.getSUnit(); |
| 1102 | if (SuccDep.isWeak() || Succ->NodeNum >= DAGSize) |
| 1103 | continue; |
| 1104 | hasSuccessor = true; |
| 1105 | } |
| 1106 | if (!hasSuccessor) |
| 1107 | CurrentColoring[SU->NodeNum] = GroupID; |
| 1108 | } |
| 1109 | } |
| 1110 | |
| 1111 | void SIScheduleBlockCreator::colorExports() { |
| 1112 | unsigned ExportColor = NextNonReservedID++; |
| 1113 | SmallVector<unsigned, 8> ExpGroup; |
| 1114 | |
| 1115 | // Put all exports together in a block. |
| 1116 | // The block will naturally end up being scheduled last, |
| 1117 | // thus putting exports at the end of the schedule, which |
| 1118 | // is better for performance. |
| 1119 | // However we must ensure, for safety, the exports can be put |
| 1120 | // together in the same block without any other instruction. |
| 1121 | // This could happen, for example, when scheduling after regalloc |
| 1122 | // if reloading a spilled register from memory using the same |
| 1123 | // register than used in a previous export. |
| 1124 | // If that happens, do not regroup the exports. |
| 1125 | for (unsigned SUNum : DAG->TopDownIndex2SU) { |
| 1126 | const SUnit &SU = DAG->SUnits[SUNum]; |
| 1127 | if (SIInstrInfo::isEXP(*SU.getInstr())) { |
| 1128 | // Check the EXP can be added to the group safely, |
| 1129 | // ie without needing any other instruction. |
| 1130 | // The EXP is allowed to depend on other EXP |
| 1131 | // (they will be in the same group). |
| 1132 | for (unsigned j : ExpGroup) { |
| 1133 | bool HasSubGraph; |
| 1134 | std::vector<int> SubGraph; |
| 1135 | // By construction (topological order), if SU and |
| 1136 | // DAG->SUnits[j] are linked, DAG->SUnits[j] is neccessary |
| 1137 | // in the parent graph of SU. |
| 1138 | #ifndef NDEBUG |
| 1139 | SubGraph = DAG->GetTopo()->GetSubGraph(SU, DAG->SUnits[j], |
| 1140 | HasSubGraph); |
| 1141 | assert(!HasSubGraph)(static_cast <bool> (!HasSubGraph) ? void (0) : __assert_fail ("!HasSubGraph", "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/llvm/lib/Target/AMDGPU/SIMachineScheduler.cpp" , 1141, __extension__ __PRETTY_FUNCTION__)); |
| 1142 | #endif |
| 1143 | SubGraph = DAG->GetTopo()->GetSubGraph(DAG->SUnits[j], SU, |
| 1144 | HasSubGraph); |
| 1145 | if (!HasSubGraph) |
| 1146 | continue; // No dependencies between each other |
| 1147 | |
| 1148 | // SubGraph contains all the instructions required |
| 1149 | // between EXP SUnits[j] and EXP SU. |
| 1150 | for (unsigned k : SubGraph) { |
| 1151 | if (!SIInstrInfo::isEXP(*DAG->SUnits[k].getInstr())) |
| 1152 | // Other instructions than EXP would be required in the group. |
| 1153 | // Abort the groupping. |
| 1154 | return; |
| 1155 | } |
| 1156 | } |
| 1157 | |
| 1158 | ExpGroup.push_back(SUNum); |
| 1159 | } |
| 1160 | } |
| 1161 | |
| 1162 | // The group can be formed. Give the color. |
| 1163 | for (unsigned j : ExpGroup) |
| 1164 | CurrentColoring[j] = ExportColor; |
| 1165 | } |
| 1166 | |
| 1167 | void SIScheduleBlockCreator::createBlocksForVariant(SISchedulerBlockCreatorVariant BlockVariant) { |
| 1168 | unsigned DAGSize = DAG->SUnits.size(); |
| 1169 | std::map<unsigned,unsigned> RealID; |
| 1170 | |
| 1171 | CurrentBlocks.clear(); |
| 1172 | CurrentColoring.clear(); |
| 1173 | CurrentColoring.resize(DAGSize, 0); |
| 1174 | Node2CurrentBlock.clear(); |
| 1175 | |
| 1176 | // Restore links previous scheduling variant has overridden. |
| 1177 | DAG->restoreSULinksLeft(); |
| 1178 | |
| 1179 | NextReservedID = 1; |
| 1180 | NextNonReservedID = DAGSize + 1; |
| 1181 | |
| 1182 | LLVM_DEBUG(dbgs() << "Coloring the graph\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("machine-scheduler")) { dbgs() << "Coloring the graph\n" ; } } while (false); |
| 1183 | |
| 1184 | if (BlockVariant == SISchedulerBlockCreatorVariant::LatenciesGrouped) |
| 1185 | colorHighLatenciesGroups(); |
| 1186 | else |
| 1187 | colorHighLatenciesAlone(); |
| 1188 | colorComputeReservedDependencies(); |
| 1189 | colorAccordingToReservedDependencies(); |
| 1190 | colorEndsAccordingToDependencies(); |
| 1191 | if (BlockVariant == SISchedulerBlockCreatorVariant::LatenciesAlonePlusConsecutive) |
| 1192 | colorForceConsecutiveOrderInGroup(); |
| 1193 | regroupNoUserInstructions(); |
| 1194 | colorMergeConstantLoadsNextGroup(); |
| 1195 | colorMergeIfPossibleNextGroupOnlyForReserved(); |
| 1196 | colorExports(); |
| 1197 | |
| 1198 | // Put SUs of same color into same block |
| 1199 | Node2CurrentBlock.resize(DAGSize, -1); |
| 1200 | for (unsigned i = 0, e = DAGSize; i != e; ++i) { |
| 1201 | SUnit *SU = &DAG->SUnits[i]; |
| 1202 | unsigned Color = CurrentColoring[SU->NodeNum]; |
| 1203 | if (RealID.find(Color) == RealID.end()) { |
| 1204 | int ID = CurrentBlocks.size(); |
| 1205 | BlockPtrs.push_back(std::make_unique<SIScheduleBlock>(DAG, this, ID)); |
| 1206 | CurrentBlocks.push_back(BlockPtrs.rbegin()->get()); |
| 1207 | RealID[Color] = ID; |
| 1208 | } |
| 1209 | CurrentBlocks[RealID[Color]]->addUnit(SU); |
| 1210 | Node2CurrentBlock[SU->NodeNum] = RealID[Color]; |
| 1211 | } |
| 1212 | |
| 1213 | // Build dependencies between blocks. |
| 1214 | for (unsigned i = 0, e = DAGSize; i != e; ++i) { |
| 1215 | SUnit *SU = &DAG->SUnits[i]; |
| 1216 | int SUID = Node2CurrentBlock[i]; |
| 1217 | for (SDep& SuccDep : SU->Succs) { |
| 1218 | SUnit *Succ = SuccDep.getSUnit(); |
| 1219 | if (SuccDep.isWeak() || Succ->NodeNum >= DAGSize) |
| 1220 | continue; |
| 1221 | if (Node2CurrentBlock[Succ->NodeNum] != SUID) |
| 1222 | CurrentBlocks[SUID]->addSucc(CurrentBlocks[Node2CurrentBlock[Succ->NodeNum]], |
| 1223 | SuccDep.isCtrl() ? NoData : Data); |
| 1224 | } |
| 1225 | for (SDep& PredDep : SU->Preds) { |
| 1226 | SUnit *Pred = PredDep.getSUnit(); |
| 1227 | if (PredDep.isWeak() || Pred->NodeNum >= DAGSize) |
| 1228 | continue; |
| 1229 | if (Node2CurrentBlock[Pred->NodeNum] != SUID) |
| 1230 | CurrentBlocks[SUID]->addPred(CurrentBlocks[Node2CurrentBlock[Pred->NodeNum]]); |
| 1231 | } |
| 1232 | } |
| 1233 | |
| 1234 | // Free root and leafs of all blocks to enable scheduling inside them. |
| 1235 | for (unsigned i = 0, e = CurrentBlocks.size(); i != e; ++i) { |
| 1236 | SIScheduleBlock *Block = CurrentBlocks[i]; |
| 1237 | Block->finalizeUnits(); |
| 1238 | } |
| 1239 | LLVM_DEBUG(dbgs() << "Blocks created:\n\n";do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("machine-scheduler")) { dbgs() << "Blocks created:\n\n" ; for (unsigned i = 0, e = CurrentBlocks.size(); i != e; ++i) { SIScheduleBlock *Block = CurrentBlocks[i]; Block->printDebug (true); }; } } while (false) |
| 1240 | for (unsigned i = 0, e = CurrentBlocks.size(); i != e; ++i) {do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("machine-scheduler")) { dbgs() << "Blocks created:\n\n" ; for (unsigned i = 0, e = CurrentBlocks.size(); i != e; ++i) { SIScheduleBlock *Block = CurrentBlocks[i]; Block->printDebug (true); }; } } while (false) |
| 1241 | SIScheduleBlock *Block = CurrentBlocks[i];do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("machine-scheduler")) { dbgs() << "Blocks created:\n\n" ; for (unsigned i = 0, e = CurrentBlocks.size(); i != e; ++i) { SIScheduleBlock *Block = CurrentBlocks[i]; Block->printDebug (true); }; } } while (false) |
| 1242 | Block->printDebug(true);do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("machine-scheduler")) { dbgs() << "Blocks created:\n\n" ; for (unsigned i = 0, e = CurrentBlocks.size(); i != e; ++i) { SIScheduleBlock *Block = CurrentBlocks[i]; Block->printDebug (true); }; } } while (false) |
| 1243 | })do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("machine-scheduler")) { dbgs() << "Blocks created:\n\n" ; for (unsigned i = 0, e = CurrentBlocks.size(); i != e; ++i) { SIScheduleBlock *Block = CurrentBlocks[i]; Block->printDebug (true); }; } } while (false); |
| 1244 | } |
| 1245 | |
| 1246 | // Two functions taken from Codegen/MachineScheduler.cpp |
| 1247 | |
| 1248 | /// Non-const version. |
| 1249 | static MachineBasicBlock::iterator |
| 1250 | nextIfDebug(MachineBasicBlock::iterator I, |
| 1251 | MachineBasicBlock::const_iterator End) { |
| 1252 | for (; I != End; ++I) { |
| 1253 | if (!I->isDebugInstr()) |
| 1254 | break; |
| 1255 | } |
| 1256 | return I; |
| 1257 | } |
| 1258 | |
| 1259 | void SIScheduleBlockCreator::topologicalSort() { |
| 1260 | unsigned DAGSize = CurrentBlocks.size(); |
| 1261 | std::vector<int> WorkList; |
| 1262 | |
| 1263 | LLVM_DEBUG(dbgs() << "Topological Sort\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("machine-scheduler")) { dbgs() << "Topological Sort\n" ; } } while (false); |
| 1264 | |
| 1265 | WorkList.reserve(DAGSize); |
| 1266 | TopDownIndex2Block.resize(DAGSize); |
| 1267 | TopDownBlock2Index.resize(DAGSize); |
| 1268 | BottomUpIndex2Block.resize(DAGSize); |
| 1269 | |
| 1270 | for (unsigned i = 0, e = DAGSize; i != e; ++i) { |
| 1271 | SIScheduleBlock *Block = CurrentBlocks[i]; |
| 1272 | unsigned Degree = Block->getSuccs().size(); |
| 1273 | TopDownBlock2Index[i] = Degree; |
| 1274 | if (Degree == 0) { |
| 1275 | WorkList.push_back(i); |
| 1276 | } |
| 1277 | } |
| 1278 | |
| 1279 | int Id = DAGSize; |
| 1280 | while (!WorkList.empty()) { |
| 1281 | int i = WorkList.back(); |
| 1282 | SIScheduleBlock *Block = CurrentBlocks[i]; |
| 1283 | WorkList.pop_back(); |
| 1284 | TopDownBlock2Index[i] = --Id; |
| 1285 | TopDownIndex2Block[Id] = i; |
| 1286 | for (SIScheduleBlock* Pred : Block->getPreds()) { |
| 1287 | if (!--TopDownBlock2Index[Pred->getID()]) |
| 1288 | WorkList.push_back(Pred->getID()); |
| 1289 | } |
| 1290 | } |
| 1291 | |
| 1292 | #ifndef NDEBUG |
| 1293 | // Check correctness of the ordering. |
| 1294 | for (unsigned i = 0, e = DAGSize; i != e; ++i) { |
| 1295 | SIScheduleBlock *Block = CurrentBlocks[i]; |
| 1296 | for (SIScheduleBlock* Pred : Block->getPreds()) { |
| 1297 | assert(TopDownBlock2Index[i] > TopDownBlock2Index[Pred->getID()] &&(static_cast <bool> (TopDownBlock2Index[i] > TopDownBlock2Index [Pred->getID()] && "Wrong Top Down topological sorting" ) ? void (0) : __assert_fail ("TopDownBlock2Index[i] > TopDownBlock2Index[Pred->getID()] && \"Wrong Top Down topological sorting\"" , "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/llvm/lib/Target/AMDGPU/SIMachineScheduler.cpp" , 1298, __extension__ __PRETTY_FUNCTION__)) |
| 1298 | "Wrong Top Down topological sorting")(static_cast <bool> (TopDownBlock2Index[i] > TopDownBlock2Index [Pred->getID()] && "Wrong Top Down topological sorting" ) ? void (0) : __assert_fail ("TopDownBlock2Index[i] > TopDownBlock2Index[Pred->getID()] && \"Wrong Top Down topological sorting\"" , "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/llvm/lib/Target/AMDGPU/SIMachineScheduler.cpp" , 1298, __extension__ __PRETTY_FUNCTION__)); |
| 1299 | } |
| 1300 | } |
| 1301 | #endif |
| 1302 | |
| 1303 | BottomUpIndex2Block = std::vector<int>(TopDownIndex2Block.rbegin(), |
| 1304 | TopDownIndex2Block.rend()); |
| 1305 | } |
| 1306 | |
| 1307 | void SIScheduleBlockCreator::scheduleInsideBlocks() { |
| 1308 | unsigned DAGSize = CurrentBlocks.size(); |
| 1309 | |
| 1310 | LLVM_DEBUG(dbgs() << "\nScheduling Blocks\n\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("machine-scheduler")) { dbgs() << "\nScheduling Blocks\n\n" ; } } while (false); |
| 1311 | |
| 1312 | // We do schedule a valid scheduling such that a Block corresponds |
| 1313 | // to a range of instructions. |
| 1314 | LLVM_DEBUG(dbgs() << "First phase: Fast scheduling for Reg Liveness\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("machine-scheduler")) { dbgs() << "First phase: Fast scheduling for Reg Liveness\n" ; } } while (false); |
| 1315 | for (unsigned i = 0, e = DAGSize; i != e; ++i) { |
| 1316 | SIScheduleBlock *Block = CurrentBlocks[i]; |
| 1317 | Block->fastSchedule(); |
| 1318 | } |
| 1319 | |
| 1320 | // Note: the following code, and the part restoring previous position |
| 1321 | // is by far the most expensive operation of the Scheduler. |
| 1322 | |
| 1323 | // Do not update CurrentTop. |
| 1324 | MachineBasicBlock::iterator CurrentTopFastSched = DAG->getCurrentTop(); |
| 1325 | std::vector<MachineBasicBlock::iterator> PosOld; |
| 1326 | std::vector<MachineBasicBlock::iterator> PosNew; |
| 1327 | PosOld.reserve(DAG->SUnits.size()); |
| 1328 | PosNew.reserve(DAG->SUnits.size()); |
| 1329 | |
| 1330 | for (unsigned i = 0, e = DAGSize; i != e; ++i) { |
| 1331 | int BlockIndice = TopDownIndex2Block[i]; |
| 1332 | SIScheduleBlock *Block = CurrentBlocks[BlockIndice]; |
| 1333 | std::vector<SUnit*> SUs = Block->getScheduledUnits(); |
| 1334 | |
| 1335 | for (SUnit* SU : SUs) { |
| 1336 | MachineInstr *MI = SU->getInstr(); |
| 1337 | MachineBasicBlock::iterator Pos = MI; |
| 1338 | PosOld.push_back(Pos); |
| 1339 | if (&*CurrentTopFastSched == MI) { |
| 1340 | PosNew.push_back(Pos); |
| 1341 | CurrentTopFastSched = nextIfDebug(++CurrentTopFastSched, |
| 1342 | DAG->getCurrentBottom()); |
| 1343 | } else { |
| 1344 | // Update the instruction stream. |
| 1345 | DAG->getBB()->splice(CurrentTopFastSched, DAG->getBB(), MI); |
| 1346 | |
| 1347 | // Update LiveIntervals. |
| 1348 | // Note: Moving all instructions and calling handleMove every time |
| 1349 | // is the most cpu intensive operation of the scheduler. |
| 1350 | // It would gain a lot if there was a way to recompute the |
| 1351 | // LiveIntervals for the entire scheduling region. |
| 1352 | DAG->getLIS()->handleMove(*MI, /*UpdateFlags=*/true); |
| 1353 | PosNew.push_back(CurrentTopFastSched); |
| 1354 | } |
| 1355 | } |
| 1356 | } |
| 1357 | |
| 1358 | // Now we have Block of SUs == Block of MI. |
| 1359 | // We do the final schedule for the instructions inside the block. |
| 1360 | // The property that all the SUs of the Block are grouped together as MI |
| 1361 | // is used for correct reg usage tracking. |
| 1362 | for (unsigned i = 0, e = DAGSize; i != e; ++i) { |
| 1363 | SIScheduleBlock *Block = CurrentBlocks[i]; |
| 1364 | std::vector<SUnit*> SUs = Block->getScheduledUnits(); |
| 1365 | Block->schedule((*SUs.begin())->getInstr(), (*SUs.rbegin())->getInstr()); |
| 1366 | } |
| 1367 | |
| 1368 | LLVM_DEBUG(dbgs() << "Restoring MI Pos\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("machine-scheduler")) { dbgs() << "Restoring MI Pos\n" ; } } while (false); |
| 1369 | // Restore old ordering (which prevents a LIS->handleMove bug). |
| 1370 | for (unsigned i = PosOld.size(), e = 0; i != e; --i) { |
| 1371 | MachineBasicBlock::iterator POld = PosOld[i-1]; |
| 1372 | MachineBasicBlock::iterator PNew = PosNew[i-1]; |
| 1373 | if (PNew != POld) { |
| 1374 | // Update the instruction stream. |
| 1375 | DAG->getBB()->splice(POld, DAG->getBB(), PNew); |
| 1376 | |
| 1377 | // Update LiveIntervals. |
| 1378 | DAG->getLIS()->handleMove(*POld, /*UpdateFlags=*/true); |
| 1379 | } |
| 1380 | } |
| 1381 | |
| 1382 | LLVM_DEBUG(for (unsigned i = 0, e = CurrentBlocks.size(); i != e; ++i) {do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("machine-scheduler")) { for (unsigned i = 0, e = CurrentBlocks .size(); i != e; ++i) { SIScheduleBlock *Block = CurrentBlocks [i]; Block->printDebug(true); }; } } while (false) |
| 1383 | SIScheduleBlock *Block = CurrentBlocks[i];do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("machine-scheduler")) { for (unsigned i = 0, e = CurrentBlocks .size(); i != e; ++i) { SIScheduleBlock *Block = CurrentBlocks [i]; Block->printDebug(true); }; } } while (false) |
| 1384 | Block->printDebug(true);do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("machine-scheduler")) { for (unsigned i = 0, e = CurrentBlocks .size(); i != e; ++i) { SIScheduleBlock *Block = CurrentBlocks [i]; Block->printDebug(true); }; } } while (false) |
| 1385 | })do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("machine-scheduler")) { for (unsigned i = 0, e = CurrentBlocks .size(); i != e; ++i) { SIScheduleBlock *Block = CurrentBlocks [i]; Block->printDebug(true); }; } } while (false); |
| 1386 | } |
| 1387 | |
| 1388 | void SIScheduleBlockCreator::fillStats() { |
| 1389 | unsigned DAGSize = CurrentBlocks.size(); |
| 1390 | |
| 1391 | for (unsigned i = 0, e = DAGSize; i != e; ++i) { |
| 1392 | int BlockIndice = TopDownIndex2Block[i]; |
| 1393 | SIScheduleBlock *Block = CurrentBlocks[BlockIndice]; |
| 1394 | if (Block->getPreds().empty()) |
| 1395 | Block->Depth = 0; |
| 1396 | else { |
| 1397 | unsigned Depth = 0; |
| 1398 | for (SIScheduleBlock *Pred : Block->getPreds()) { |
| 1399 | if (Depth < Pred->Depth + Pred->getCost()) |
| 1400 | Depth = Pred->Depth + Pred->getCost(); |
| 1401 | } |
| 1402 | Block->Depth = Depth; |
| 1403 | } |
| 1404 | } |
| 1405 | |
| 1406 | for (unsigned i = 0, e = DAGSize; i != e; ++i) { |
| 1407 | int BlockIndice = BottomUpIndex2Block[i]; |
| 1408 | SIScheduleBlock *Block = CurrentBlocks[BlockIndice]; |
| 1409 | if (Block->getSuccs().empty()) |
| 1410 | Block->Height = 0; |
| 1411 | else { |
| 1412 | unsigned Height = 0; |
| 1413 | for (const auto &Succ : Block->getSuccs()) |
| 1414 | Height = std::max(Height, Succ.first->Height + Succ.first->getCost()); |
| 1415 | Block->Height = Height; |
| 1416 | } |
| 1417 | } |
| 1418 | } |
| 1419 | |
| 1420 | // SIScheduleBlockScheduler // |
| 1421 | |
| 1422 | SIScheduleBlockScheduler::SIScheduleBlockScheduler(SIScheduleDAGMI *DAG, |
| 1423 | SISchedulerBlockSchedulerVariant Variant, |
| 1424 | SIScheduleBlocks BlocksStruct) : |
| 1425 | DAG(DAG), Variant(Variant), Blocks(BlocksStruct.Blocks), |
| 1426 | LastPosWaitedHighLatency(0), NumBlockScheduled(0), VregCurrentUsage(0), |
| 1427 | SregCurrentUsage(0), maxVregUsage(0), maxSregUsage(0) { |
| 1428 | |
| 1429 | // Fill the usage of every output |
| 1430 | // Warning: while by construction we always have a link between two blocks |
| 1431 | // when one needs a result from the other, the number of users of an output |
| 1432 | // is not the sum of child blocks having as input the same virtual register. |
| 1433 | // Here is an example. A produces x and y. B eats x and produces x'. |
| 1434 | // C eats x' and y. The register coalescer may have attributed the same |
| 1435 | // virtual register to x and x'. |
| 1436 | // To count accurately, we do a topological sort. In case the register is |
| 1437 | // found for several parents, we increment the usage of the one with the |
| 1438 | // highest topological index. |
| 1439 | LiveOutRegsNumUsages.resize(Blocks.size()); |
| 1440 | for (unsigned i = 0, e = Blocks.size(); i != e; ++i) { |
| 1441 | SIScheduleBlock *Block = Blocks[i]; |
| 1442 | for (unsigned Reg : Block->getInRegs()) { |
| 1443 | bool Found = false; |
| 1444 | int topoInd = -1; |
| 1445 | for (SIScheduleBlock* Pred: Block->getPreds()) { |
| 1446 | std::set<unsigned> PredOutRegs = Pred->getOutRegs(); |
| 1447 | std::set<unsigned>::iterator RegPos = PredOutRegs.find(Reg); |
| 1448 | |
| 1449 | if (RegPos != PredOutRegs.end()) { |
| 1450 | Found = true; |
| 1451 | if (topoInd < BlocksStruct.TopDownBlock2Index[Pred->getID()]) { |
| 1452 | topoInd = BlocksStruct.TopDownBlock2Index[Pred->getID()]; |
| 1453 | } |
| 1454 | } |
| 1455 | } |
| 1456 | |
| 1457 | if (!Found) |
| 1458 | continue; |
| 1459 | |
| 1460 | int PredID = BlocksStruct.TopDownIndex2Block[topoInd]; |
| 1461 | ++LiveOutRegsNumUsages[PredID][Reg]; |
| 1462 | } |
| 1463 | } |
| 1464 | |
| 1465 | LastPosHighLatencyParentScheduled.resize(Blocks.size(), 0); |
| 1466 | BlockNumPredsLeft.resize(Blocks.size()); |
| 1467 | BlockNumSuccsLeft.resize(Blocks.size()); |
| 1468 | |
| 1469 | for (unsigned i = 0, e = Blocks.size(); i != e; ++i) { |
| 1470 | SIScheduleBlock *Block = Blocks[i]; |
| 1471 | BlockNumPredsLeft[i] = Block->getPreds().size(); |
| 1472 | BlockNumSuccsLeft[i] = Block->getSuccs().size(); |
| 1473 | } |
| 1474 | |
| 1475 | #ifndef NDEBUG |
| 1476 | for (unsigned i = 0, e = Blocks.size(); i != e; ++i) { |
| 1477 | SIScheduleBlock *Block = Blocks[i]; |
| 1478 | assert(Block->getID() == i)(static_cast <bool> (Block->getID() == i) ? void (0) : __assert_fail ("Block->getID() == i", "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/llvm/lib/Target/AMDGPU/SIMachineScheduler.cpp" , 1478, __extension__ __PRETTY_FUNCTION__)); |
| 1479 | } |
| 1480 | #endif |
| 1481 | |
| 1482 | std::set<unsigned> InRegs = DAG->getInRegs(); |
| 1483 | addLiveRegs(InRegs); |
| 1484 | |
| 1485 | // Increase LiveOutRegsNumUsages for blocks |
| 1486 | // producing registers consumed in another |
| 1487 | // scheduling region. |
| 1488 | for (unsigned Reg : DAG->getOutRegs()) { |
| 1489 | for (unsigned i = 0, e = Blocks.size(); i != e; ++i) { |
| 1490 | // Do reverse traversal |
| 1491 | int ID = BlocksStruct.TopDownIndex2Block[Blocks.size()-1-i]; |
| 1492 | SIScheduleBlock *Block = Blocks[ID]; |
| 1493 | const std::set<unsigned> &OutRegs = Block->getOutRegs(); |
| 1494 | |
| 1495 | if (OutRegs.find(Reg) == OutRegs.end()) |
| 1496 | continue; |
| 1497 | |
| 1498 | ++LiveOutRegsNumUsages[ID][Reg]; |
| 1499 | break; |
| 1500 | } |
| 1501 | } |
| 1502 | |
| 1503 | // Fill LiveRegsConsumers for regs that were already |
| 1504 | // defined before scheduling. |
| 1505 | for (unsigned i = 0, e = Blocks.size(); i != e; ++i) { |
| 1506 | SIScheduleBlock *Block = Blocks[i]; |
| 1507 | for (unsigned Reg : Block->getInRegs()) { |
| 1508 | bool Found = false; |
| 1509 | for (SIScheduleBlock* Pred: Block->getPreds()) { |
| 1510 | std::set<unsigned> PredOutRegs = Pred->getOutRegs(); |
| 1511 | std::set<unsigned>::iterator RegPos = PredOutRegs.find(Reg); |
| 1512 | |
| 1513 | if (RegPos != PredOutRegs.end()) { |
| 1514 | Found = true; |
| 1515 | break; |
| 1516 | } |
| 1517 | } |
| 1518 | |
| 1519 | if (!Found) |
| 1520 | ++LiveRegsConsumers[Reg]; |
| 1521 | } |
| 1522 | } |
| 1523 | |
| 1524 | for (unsigned i = 0, e = Blocks.size(); i != e; ++i) { |
| 1525 | SIScheduleBlock *Block = Blocks[i]; |
| 1526 | if (BlockNumPredsLeft[i] == 0) { |
| 1527 | ReadyBlocks.push_back(Block); |
| 1528 | } |
| 1529 | } |
| 1530 | |
| 1531 | while (SIScheduleBlock *Block = pickBlock()) { |
| 1532 | BlocksScheduled.push_back(Block); |
| 1533 | blockScheduled(Block); |
| 1534 | } |
| 1535 | |
| 1536 | LLVM_DEBUG(dbgs() << "Block Order:"; for (SIScheduleBlock *Blockdo { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("machine-scheduler")) { dbgs() << "Block Order:"; for ( SIScheduleBlock *Block : BlocksScheduled) { dbgs() << ' ' << Block->getID(); } dbgs() << '\n';; } } while (false) |
| 1537 | : BlocksScheduled) {do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("machine-scheduler")) { dbgs() << "Block Order:"; for ( SIScheduleBlock *Block : BlocksScheduled) { dbgs() << ' ' << Block->getID(); } dbgs() << '\n';; } } while (false) |
| 1538 | dbgs() << ' ' << Block->getID();do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("machine-scheduler")) { dbgs() << "Block Order:"; for ( SIScheduleBlock *Block : BlocksScheduled) { dbgs() << ' ' << Block->getID(); } dbgs() << '\n';; } } while (false) |
| 1539 | } dbgs() << '\n';)do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("machine-scheduler")) { dbgs() << "Block Order:"; for ( SIScheduleBlock *Block : BlocksScheduled) { dbgs() << ' ' << Block->getID(); } dbgs() << '\n';; } } while (false); |
| 1540 | } |
| 1541 | |
| 1542 | bool SIScheduleBlockScheduler::tryCandidateLatency(SIBlockSchedCandidate &Cand, |
| 1543 | SIBlockSchedCandidate &TryCand) { |
| 1544 | if (!Cand.isValid()) { |
| 1545 | TryCand.Reason = NodeOrder; |
| 1546 | return true; |
| 1547 | } |
| 1548 | |
| 1549 | // Try to hide high latencies. |
| 1550 | if (SISched::tryLess(TryCand.LastPosHighLatParentScheduled, |
| 1551 | Cand.LastPosHighLatParentScheduled, TryCand, Cand, Latency)) |
| 1552 | return true; |
| 1553 | // Schedule high latencies early so you can hide them better. |
| 1554 | if (SISched::tryGreater(TryCand.IsHighLatency, Cand.IsHighLatency, |
| 1555 | TryCand, Cand, Latency)) |
| 1556 | return true; |
| 1557 | if (TryCand.IsHighLatency && SISched::tryGreater(TryCand.Height, Cand.Height, |
| 1558 | TryCand, Cand, Depth)) |
| 1559 | return true; |
| 1560 | if (SISched::tryGreater(TryCand.NumHighLatencySuccessors, |
| 1561 | Cand.NumHighLatencySuccessors, |
| 1562 | TryCand, Cand, Successor)) |
| 1563 | return true; |
| 1564 | return false; |
| 1565 | } |
| 1566 | |
| 1567 | bool SIScheduleBlockScheduler::tryCandidateRegUsage(SIBlockSchedCandidate &Cand, |
| 1568 | SIBlockSchedCandidate &TryCand) { |
| 1569 | if (!Cand.isValid()) { |
| 1570 | TryCand.Reason = NodeOrder; |
| 1571 | return true; |
| 1572 | } |
| 1573 | |
| 1574 | if (SISched::tryLess(TryCand.VGPRUsageDiff > 0, Cand.VGPRUsageDiff > 0, |
| 1575 | TryCand, Cand, RegUsage)) |
| 1576 | return true; |
| 1577 | if (SISched::tryGreater(TryCand.NumSuccessors > 0, |
| 1578 | Cand.NumSuccessors > 0, |
| 1579 | TryCand, Cand, Successor)) |
| 1580 | return true; |
| 1581 | if (SISched::tryGreater(TryCand.Height, Cand.Height, TryCand, Cand, Depth)) |
| 1582 | return true; |
| 1583 | if (SISched::tryLess(TryCand.VGPRUsageDiff, Cand.VGPRUsageDiff, |
| 1584 | TryCand, Cand, RegUsage)) |
| 1585 | return true; |
| 1586 | return false; |
| 1587 | } |
| 1588 | |
| 1589 | SIScheduleBlock *SIScheduleBlockScheduler::pickBlock() { |
| 1590 | SIBlockSchedCandidate Cand; |
| 1591 | std::vector<SIScheduleBlock*>::iterator Best; |
| 1592 | SIScheduleBlock *Block; |
| 1593 | if (ReadyBlocks.empty()) |
| 1594 | return nullptr; |
| 1595 | |
| 1596 | DAG->fillVgprSgprCost(LiveRegs.begin(), LiveRegs.end(), |
| 1597 | VregCurrentUsage, SregCurrentUsage); |
| 1598 | if (VregCurrentUsage > maxVregUsage) |
| 1599 | maxVregUsage = VregCurrentUsage; |
| 1600 | if (SregCurrentUsage > maxSregUsage) |
| 1601 | maxSregUsage = SregCurrentUsage; |
| 1602 | LLVM_DEBUG(dbgs() << "Picking New Blocks\n"; dbgs() << "Available: ";do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("machine-scheduler")) { dbgs() << "Picking New Blocks\n" ; dbgs() << "Available: "; for (SIScheduleBlock *Block : ReadyBlocks) dbgs() << Block->getID() << ' '; dbgs() << "\nCurrent Live:\n"; for (unsigned Reg : LiveRegs ) dbgs() << printVRegOrUnit(Reg, DAG->getTRI()) << ' '; dbgs() << '\n'; dbgs() << "Current VGPRs: " << VregCurrentUsage << '\n'; dbgs() << "Current SGPRs: " << SregCurrentUsage << '\n';; } } while (false) |
| 1603 | for (SIScheduleBlock *Blockdo { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("machine-scheduler")) { dbgs() << "Picking New Blocks\n" ; dbgs() << "Available: "; for (SIScheduleBlock *Block : ReadyBlocks) dbgs() << Block->getID() << ' '; dbgs() << "\nCurrent Live:\n"; for (unsigned Reg : LiveRegs ) dbgs() << printVRegOrUnit(Reg, DAG->getTRI()) << ' '; dbgs() << '\n'; dbgs() << "Current VGPRs: " << VregCurrentUsage << '\n'; dbgs() << "Current SGPRs: " << SregCurrentUsage << '\n';; } } while (false) |
| 1604 | : ReadyBlocks) dbgs()do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("machine-scheduler")) { dbgs() << "Picking New Blocks\n" ; dbgs() << "Available: "; for (SIScheduleBlock *Block : ReadyBlocks) dbgs() << Block->getID() << ' '; dbgs() << "\nCurrent Live:\n"; for (unsigned Reg : LiveRegs ) dbgs() << printVRegOrUnit(Reg, DAG->getTRI()) << ' '; dbgs() << '\n'; dbgs() << "Current VGPRs: " << VregCurrentUsage << '\n'; dbgs() << "Current SGPRs: " << SregCurrentUsage << '\n';; } } while (false) |
| 1605 | << Block->getID() << ' ';do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("machine-scheduler")) { dbgs() << "Picking New Blocks\n" ; dbgs() << "Available: "; for (SIScheduleBlock *Block : ReadyBlocks) dbgs() << Block->getID() << ' '; dbgs() << "\nCurrent Live:\n"; for (unsigned Reg : LiveRegs ) dbgs() << printVRegOrUnit(Reg, DAG->getTRI()) << ' '; dbgs() << '\n'; dbgs() << "Current VGPRs: " << VregCurrentUsage << '\n'; dbgs() << "Current SGPRs: " << SregCurrentUsage << '\n';; } } while (false) |
| 1606 | dbgs() << "\nCurrent Live:\n";do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("machine-scheduler")) { dbgs() << "Picking New Blocks\n" ; dbgs() << "Available: "; for (SIScheduleBlock *Block : ReadyBlocks) dbgs() << Block->getID() << ' '; dbgs() << "\nCurrent Live:\n"; for (unsigned Reg : LiveRegs ) dbgs() << printVRegOrUnit(Reg, DAG->getTRI()) << ' '; dbgs() << '\n'; dbgs() << "Current VGPRs: " << VregCurrentUsage << '\n'; dbgs() << "Current SGPRs: " << SregCurrentUsage << '\n';; } } while (false) |
| 1607 | for (unsigned Regdo { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("machine-scheduler")) { dbgs() << "Picking New Blocks\n" ; dbgs() << "Available: "; for (SIScheduleBlock *Block : ReadyBlocks) dbgs() << Block->getID() << ' '; dbgs() << "\nCurrent Live:\n"; for (unsigned Reg : LiveRegs ) dbgs() << printVRegOrUnit(Reg, DAG->getTRI()) << ' '; dbgs() << '\n'; dbgs() << "Current VGPRs: " << VregCurrentUsage << '\n'; dbgs() << "Current SGPRs: " << SregCurrentUsage << '\n';; } } while (false) |
| 1608 | : LiveRegs) dbgs()do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("machine-scheduler")) { dbgs() << "Picking New Blocks\n" ; dbgs() << "Available: "; for (SIScheduleBlock *Block : ReadyBlocks) dbgs() << Block->getID() << ' '; dbgs() << "\nCurrent Live:\n"; for (unsigned Reg : LiveRegs ) dbgs() << printVRegOrUnit(Reg, DAG->getTRI()) << ' '; dbgs() << '\n'; dbgs() << "Current VGPRs: " << VregCurrentUsage << '\n'; dbgs() << "Current SGPRs: " << SregCurrentUsage << '\n';; } } while (false) |
| 1609 | << printVRegOrUnit(Reg, DAG->getTRI()) << ' ';do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("machine-scheduler")) { dbgs() << "Picking New Blocks\n" ; dbgs() << "Available: "; for (SIScheduleBlock *Block : ReadyBlocks) dbgs() << Block->getID() << ' '; dbgs() << "\nCurrent Live:\n"; for (unsigned Reg : LiveRegs ) dbgs() << printVRegOrUnit(Reg, DAG->getTRI()) << ' '; dbgs() << '\n'; dbgs() << "Current VGPRs: " << VregCurrentUsage << '\n'; dbgs() << "Current SGPRs: " << SregCurrentUsage << '\n';; } } while (false) |
| 1610 | dbgs() << '\n';do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("machine-scheduler")) { dbgs() << "Picking New Blocks\n" ; dbgs() << "Available: "; for (SIScheduleBlock *Block : ReadyBlocks) dbgs() << Block->getID() << ' '; dbgs() << "\nCurrent Live:\n"; for (unsigned Reg : LiveRegs ) dbgs() << printVRegOrUnit(Reg, DAG->getTRI()) << ' '; dbgs() << '\n'; dbgs() << "Current VGPRs: " << VregCurrentUsage << '\n'; dbgs() << "Current SGPRs: " << SregCurrentUsage << '\n';; } } while (false) |
| 1611 | dbgs() << "Current VGPRs: " << VregCurrentUsage << '\n';do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("machine-scheduler")) { dbgs() << "Picking New Blocks\n" ; dbgs() << "Available: "; for (SIScheduleBlock *Block : ReadyBlocks) dbgs() << Block->getID() << ' '; dbgs() << "\nCurrent Live:\n"; for (unsigned Reg : LiveRegs ) dbgs() << printVRegOrUnit(Reg, DAG->getTRI()) << ' '; dbgs() << '\n'; dbgs() << "Current VGPRs: " << VregCurrentUsage << '\n'; dbgs() << "Current SGPRs: " << SregCurrentUsage << '\n';; } } while (false) |
| 1612 | dbgs() << "Current SGPRs: " << SregCurrentUsage << '\n';)do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("machine-scheduler")) { dbgs() << "Picking New Blocks\n" ; dbgs() << "Available: "; for (SIScheduleBlock *Block : ReadyBlocks) dbgs() << Block->getID() << ' '; dbgs() << "\nCurrent Live:\n"; for (unsigned Reg : LiveRegs ) dbgs() << printVRegOrUnit(Reg, DAG->getTRI()) << ' '; dbgs() << '\n'; dbgs() << "Current VGPRs: " << VregCurrentUsage << '\n'; dbgs() << "Current SGPRs: " << SregCurrentUsage << '\n';; } } while (false); |
| 1613 | |
| 1614 | Cand.Block = nullptr; |
| 1615 | for (std::vector<SIScheduleBlock*>::iterator I = ReadyBlocks.begin(), |
| 1616 | E = ReadyBlocks.end(); I != E; ++I) { |
| 1617 | SIBlockSchedCandidate TryCand; |
| 1618 | TryCand.Block = *I; |
| 1619 | TryCand.IsHighLatency = TryCand.Block->isHighLatencyBlock(); |
| 1620 | TryCand.VGPRUsageDiff = |
| 1621 | checkRegUsageImpact(TryCand.Block->getInRegs(), |
| 1622 | TryCand.Block->getOutRegs())[AMDGPU::RegisterPressureSets::VGPR_32]; |
| 1623 | TryCand.NumSuccessors = TryCand.Block->getSuccs().size(); |
| 1624 | TryCand.NumHighLatencySuccessors = |
| 1625 | TryCand.Block->getNumHighLatencySuccessors(); |
| 1626 | TryCand.LastPosHighLatParentScheduled = |
| 1627 | (unsigned int) std::max<int> (0, |
| 1628 | LastPosHighLatencyParentScheduled[TryCand.Block->getID()] - |
| 1629 | LastPosWaitedHighLatency); |
| 1630 | TryCand.Height = TryCand.Block->Height; |
| 1631 | // Try not to increase VGPR usage too much, else we may spill. |
| 1632 | if (VregCurrentUsage > 120 || |
| 1633 | Variant != SISchedulerBlockSchedulerVariant::BlockLatencyRegUsage) { |
| 1634 | if (!tryCandidateRegUsage(Cand, TryCand) && |
| 1635 | Variant != SISchedulerBlockSchedulerVariant::BlockRegUsage) |
| 1636 | tryCandidateLatency(Cand, TryCand); |
| 1637 | } else { |
| 1638 | if (!tryCandidateLatency(Cand, TryCand)) |
| 1639 | tryCandidateRegUsage(Cand, TryCand); |
| 1640 | } |
| 1641 | if (TryCand.Reason != NoCand) { |
| 1642 | Cand.setBest(TryCand); |
| 1643 | Best = I; |
| 1644 | LLVM_DEBUG(dbgs() << "Best Current Choice: " << Cand.Block->getID() << ' 'do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("machine-scheduler")) { dbgs() << "Best Current Choice: " << Cand.Block->getID() << ' ' << getReasonStr (Cand.Reason) << '\n'; } } while (false) |
| 1645 | << getReasonStr(Cand.Reason) << '\n')do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("machine-scheduler")) { dbgs() << "Best Current Choice: " << Cand.Block->getID() << ' ' << getReasonStr (Cand.Reason) << '\n'; } } while (false); |
| 1646 | } |
| 1647 | } |
| 1648 | |
| 1649 | LLVM_DEBUG(dbgs() << "Picking: " << Cand.Block->getID() << '\n';do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("machine-scheduler")) { dbgs() << "Picking: " << Cand.Block->getID() << '\n'; dbgs() << "Is a block with high latency instruction: " << (Cand.IsHighLatency ? "yes\n" : "no\n"); dbgs() << "Position of last high latency dependency: " << Cand.LastPosHighLatParentScheduled << '\n'; dbgs() << "VGPRUsageDiff: " << Cand .VGPRUsageDiff << '\n'; dbgs() << '\n';; } } while (false) |
| 1650 | dbgs() << "Is a block with high latency instruction: "do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("machine-scheduler")) { dbgs() << "Picking: " << Cand.Block->getID() << '\n'; dbgs() << "Is a block with high latency instruction: " << (Cand.IsHighLatency ? "yes\n" : "no\n"); dbgs() << "Position of last high latency dependency: " << Cand.LastPosHighLatParentScheduled << '\n'; dbgs() << "VGPRUsageDiff: " << Cand .VGPRUsageDiff << '\n'; dbgs() << '\n';; } } while (false) |
| 1651 | << (Cand.IsHighLatency ? "yes\n" : "no\n");do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("machine-scheduler")) { dbgs() << "Picking: " << Cand.Block->getID() << '\n'; dbgs() << "Is a block with high latency instruction: " << (Cand.IsHighLatency ? "yes\n" : "no\n"); dbgs() << "Position of last high latency dependency: " << Cand.LastPosHighLatParentScheduled << '\n'; dbgs() << "VGPRUsageDiff: " << Cand .VGPRUsageDiff << '\n'; dbgs() << '\n';; } } while (false) |
| 1652 | dbgs() << "Position of last high latency dependency: "do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("machine-scheduler")) { dbgs() << "Picking: " << Cand.Block->getID() << '\n'; dbgs() << "Is a block with high latency instruction: " << (Cand.IsHighLatency ? "yes\n" : "no\n"); dbgs() << "Position of last high latency dependency: " << Cand.LastPosHighLatParentScheduled << '\n'; dbgs() << "VGPRUsageDiff: " << Cand .VGPRUsageDiff << '\n'; dbgs() << '\n';; } } while (false) |
| 1653 | << Cand.LastPosHighLatParentScheduled << '\n';do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("machine-scheduler")) { dbgs() << "Picking: " << Cand.Block->getID() << '\n'; dbgs() << "Is a block with high latency instruction: " << (Cand.IsHighLatency ? "yes\n" : "no\n"); dbgs() << "Position of last high latency dependency: " << Cand.LastPosHighLatParentScheduled << '\n'; dbgs() << "VGPRUsageDiff: " << Cand .VGPRUsageDiff << '\n'; dbgs() << '\n';; } } while (false) |
| 1654 | dbgs() << "VGPRUsageDiff: " << Cand.VGPRUsageDiff << '\n';do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("machine-scheduler")) { dbgs() << "Picking: " << Cand.Block->getID() << '\n'; dbgs() << "Is a block with high latency instruction: " << (Cand.IsHighLatency ? "yes\n" : "no\n"); dbgs() << "Position of last high latency dependency: " << Cand.LastPosHighLatParentScheduled << '\n'; dbgs() << "VGPRUsageDiff: " << Cand .VGPRUsageDiff << '\n'; dbgs() << '\n';; } } while (false) |
| 1655 | dbgs() << '\n';)do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("machine-scheduler")) { dbgs() << "Picking: " << Cand.Block->getID() << '\n'; dbgs() << "Is a block with high latency instruction: " << (Cand.IsHighLatency ? "yes\n" : "no\n"); dbgs() << "Position of last high latency dependency: " << Cand.LastPosHighLatParentScheduled << '\n'; dbgs() << "VGPRUsageDiff: " << Cand .VGPRUsageDiff << '\n'; dbgs() << '\n';; } } while (false); |
| 1656 | |
| 1657 | Block = Cand.Block; |
| 1658 | ReadyBlocks.erase(Best); |
| 1659 | return Block; |
| 1660 | } |
| 1661 | |
| 1662 | // Tracking of currently alive registers to determine VGPR Usage. |
| 1663 | |
| 1664 | void SIScheduleBlockScheduler::addLiveRegs(std::set<unsigned> &Regs) { |
| 1665 | for (Register Reg : Regs) { |
| 1666 | // For now only track virtual registers. |
| 1667 | if (!Reg.isVirtual()) |
| 1668 | continue; |
| 1669 | // If not already in the live set, then add it. |
| 1670 | (void) LiveRegs.insert(Reg); |
| 1671 | } |
| 1672 | } |
| 1673 | |
| 1674 | void SIScheduleBlockScheduler::decreaseLiveRegs(SIScheduleBlock *Block, |
| 1675 | std::set<unsigned> &Regs) { |
| 1676 | for (unsigned Reg : Regs) { |
| 1677 | // For now only track virtual registers. |
| 1678 | std::set<unsigned>::iterator Pos = LiveRegs.find(Reg); |
| 1679 | assert (Pos != LiveRegs.end() && // Reg must be live.(static_cast <bool> (Pos != LiveRegs.end() && LiveRegsConsumers .find(Reg) != LiveRegsConsumers.end() && LiveRegsConsumers [Reg] >= 1) ? void (0) : __assert_fail ("Pos != LiveRegs.end() && LiveRegsConsumers.find(Reg) != LiveRegsConsumers.end() && LiveRegsConsumers[Reg] >= 1" , "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/llvm/lib/Target/AMDGPU/SIMachineScheduler.cpp" , 1681, __extension__ __PRETTY_FUNCTION__)) |
| 1680 | LiveRegsConsumers.find(Reg) != LiveRegsConsumers.end() &&(static_cast <bool> (Pos != LiveRegs.end() && LiveRegsConsumers .find(Reg) != LiveRegsConsumers.end() && LiveRegsConsumers [Reg] >= 1) ? void (0) : __assert_fail ("Pos != LiveRegs.end() && LiveRegsConsumers.find(Reg) != LiveRegsConsumers.end() && LiveRegsConsumers[Reg] >= 1" , "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/llvm/lib/Target/AMDGPU/SIMachineScheduler.cpp" , 1681, __extension__ __PRETTY_FUNCTION__)) |
| 1681 | LiveRegsConsumers[Reg] >= 1)(static_cast <bool> (Pos != LiveRegs.end() && LiveRegsConsumers .find(Reg) != LiveRegsConsumers.end() && LiveRegsConsumers [Reg] >= 1) ? void (0) : __assert_fail ("Pos != LiveRegs.end() && LiveRegsConsumers.find(Reg) != LiveRegsConsumers.end() && LiveRegsConsumers[Reg] >= 1" , "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/llvm/lib/Target/AMDGPU/SIMachineScheduler.cpp" , 1681, __extension__ __PRETTY_FUNCTION__)); |
| 1682 | --LiveRegsConsumers[Reg]; |
| 1683 | if (LiveRegsConsumers[Reg] == 0) |
| 1684 | LiveRegs.erase(Pos); |
| 1685 | } |
| 1686 | } |
| 1687 | |
| 1688 | void SIScheduleBlockScheduler::releaseBlockSuccs(SIScheduleBlock *Parent) { |
| 1689 | for (const auto &Block : Parent->getSuccs()) { |
| 1690 | if (--BlockNumPredsLeft[Block.first->getID()] == 0) |
| 1691 | ReadyBlocks.push_back(Block.first); |
| 1692 | |
| 1693 | if (Parent->isHighLatencyBlock() && |
| 1694 | Block.second == SIScheduleBlockLinkKind::Data) |
| 1695 | LastPosHighLatencyParentScheduled[Block.first->getID()] = NumBlockScheduled; |
| 1696 | } |
| 1697 | } |
| 1698 | |
| 1699 | void SIScheduleBlockScheduler::blockScheduled(SIScheduleBlock *Block) { |
| 1700 | decreaseLiveRegs(Block, Block->getInRegs()); |
| 1701 | addLiveRegs(Block->getOutRegs()); |
| 1702 | releaseBlockSuccs(Block); |
| 1703 | for (std::map<unsigned, unsigned>::iterator RegI = |
| 1704 | LiveOutRegsNumUsages[Block->getID()].begin(), |
| 1705 | E = LiveOutRegsNumUsages[Block->getID()].end(); RegI != E; ++RegI) { |
| 1706 | std::pair<unsigned, unsigned> RegP = *RegI; |
| 1707 | // We produce this register, thus it must not be previously alive. |
| 1708 | assert(LiveRegsConsumers.find(RegP.first) == LiveRegsConsumers.end() ||(static_cast <bool> (LiveRegsConsumers.find(RegP.first) == LiveRegsConsumers.end() || LiveRegsConsumers[RegP.first] == 0) ? void (0) : __assert_fail ("LiveRegsConsumers.find(RegP.first) == LiveRegsConsumers.end() || LiveRegsConsumers[RegP.first] == 0" , "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/llvm/lib/Target/AMDGPU/SIMachineScheduler.cpp" , 1709, __extension__ __PRETTY_FUNCTION__)) |
| 1709 | LiveRegsConsumers[RegP.first] == 0)(static_cast <bool> (LiveRegsConsumers.find(RegP.first) == LiveRegsConsumers.end() || LiveRegsConsumers[RegP.first] == 0) ? void (0) : __assert_fail ("LiveRegsConsumers.find(RegP.first) == LiveRegsConsumers.end() || LiveRegsConsumers[RegP.first] == 0" , "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/llvm/lib/Target/AMDGPU/SIMachineScheduler.cpp" , 1709, __extension__ __PRETTY_FUNCTION__)); |
| 1710 | LiveRegsConsumers[RegP.first] += RegP.second; |
| 1711 | } |
| 1712 | if (LastPosHighLatencyParentScheduled[Block->getID()] > |
| 1713 | (unsigned)LastPosWaitedHighLatency) |
| 1714 | LastPosWaitedHighLatency = |
| 1715 | LastPosHighLatencyParentScheduled[Block->getID()]; |
| 1716 | ++NumBlockScheduled; |
| 1717 | } |
| 1718 | |
| 1719 | std::vector<int> |
| 1720 | SIScheduleBlockScheduler::checkRegUsageImpact(std::set<unsigned> &InRegs, |
| 1721 | std::set<unsigned> &OutRegs) { |
| 1722 | std::vector<int> DiffSetPressure; |
| 1723 | DiffSetPressure.assign(DAG->getTRI()->getNumRegPressureSets(), 0); |
| 1724 | |
| 1725 | for (Register Reg : InRegs) { |
| 1726 | // For now only track virtual registers. |
| 1727 | if (!Reg.isVirtual()) |
| 1728 | continue; |
| 1729 | if (LiveRegsConsumers[Reg] > 1) |
| 1730 | continue; |
| 1731 | PSetIterator PSetI = DAG->getMRI()->getPressureSets(Reg); |
| 1732 | for (; PSetI.isValid(); ++PSetI) { |
| 1733 | DiffSetPressure[*PSetI] -= PSetI.getWeight(); |
| 1734 | } |
| 1735 | } |
| 1736 | |
| 1737 | for (Register Reg : OutRegs) { |
| 1738 | // For now only track virtual registers. |
| 1739 | if (!Reg.isVirtual()) |
| 1740 | continue; |
| 1741 | PSetIterator PSetI = DAG->getMRI()->getPressureSets(Reg); |
| 1742 | for (; PSetI.isValid(); ++PSetI) { |
| 1743 | DiffSetPressure[*PSetI] += PSetI.getWeight(); |
| 1744 | } |
| 1745 | } |
| 1746 | |
| 1747 | return DiffSetPressure; |
| 1748 | } |
| 1749 | |
| 1750 | // SIScheduler // |
| 1751 | |
| 1752 | struct SIScheduleBlockResult |
| 1753 | SIScheduler::scheduleVariant(SISchedulerBlockCreatorVariant BlockVariant, |
| 1754 | SISchedulerBlockSchedulerVariant ScheduleVariant) { |
| 1755 | SIScheduleBlocks Blocks = BlockCreator.getBlocks(BlockVariant); |
| 1756 | SIScheduleBlockScheduler Scheduler(DAG, ScheduleVariant, Blocks); |
| 1757 | std::vector<SIScheduleBlock*> ScheduledBlocks; |
| 1758 | struct SIScheduleBlockResult Res; |
| 1759 | |
| 1760 | ScheduledBlocks = Scheduler.getBlocks(); |
| 1761 | |
| 1762 | for (unsigned b = 0; b < ScheduledBlocks.size(); ++b) { |
| 1763 | SIScheduleBlock *Block = ScheduledBlocks[b]; |
| 1764 | std::vector<SUnit*> SUs = Block->getScheduledUnits(); |
| 1765 | |
| 1766 | for (SUnit* SU : SUs) |
| 1767 | Res.SUs.push_back(SU->NodeNum); |
| 1768 | } |
| 1769 | |
| 1770 | Res.MaxSGPRUsage = Scheduler.getSGPRUsage(); |
| 1771 | Res.MaxVGPRUsage = Scheduler.getVGPRUsage(); |
| 1772 | return Res; |
| 1773 | } |
| 1774 | |
| 1775 | // SIScheduleDAGMI // |
| 1776 | |
| 1777 | SIScheduleDAGMI::SIScheduleDAGMI(MachineSchedContext *C) : |
| 1778 | ScheduleDAGMILive(C, std::make_unique<GenericScheduler>(C)) { |
| 1779 | SITII = static_cast<const SIInstrInfo*>(TII); |
| 1780 | SITRI = static_cast<const SIRegisterInfo*>(TRI); |
| 1781 | } |
| 1782 | |
| 1783 | SIScheduleDAGMI::~SIScheduleDAGMI() = default; |
| 1784 | |
| 1785 | // Code adapted from scheduleDAG.cpp |
| 1786 | // Does a topological sort over the SUs. |
| 1787 | // Both TopDown and BottomUp |
| 1788 | void SIScheduleDAGMI::topologicalSort() { |
| 1789 | Topo.InitDAGTopologicalSorting(); |
| 1790 | |
| 1791 | TopDownIndex2SU = std::vector<int>(Topo.begin(), Topo.end()); |
| 1792 | BottomUpIndex2SU = std::vector<int>(Topo.rbegin(), Topo.rend()); |
| 1793 | } |
| 1794 | |
| 1795 | // Move low latencies further from their user without |
| 1796 | // increasing SGPR usage (in general) |
| 1797 | // This is to be replaced by a better pass that would |
| 1798 | // take into account SGPR usage (based on VGPR Usage |
| 1799 | // and the corresponding wavefront count), that would |
| 1800 | // try to merge groups of loads if it make sense, etc |
| 1801 | void SIScheduleDAGMI::moveLowLatencies() { |
| 1802 | unsigned DAGSize = SUnits.size(); |
| 1803 | int LastLowLatencyUser = -1; |
| 1804 | int LastLowLatencyPos = -1; |
| 1805 | |
| 1806 | for (unsigned i = 0, e = ScheduledSUnits.size(); i != e; ++i) { |
| 1807 | SUnit *SU = &SUnits[ScheduledSUnits[i]]; |
| 1808 | bool IsLowLatencyUser = false; |
| 1809 | unsigned MinPos = 0; |
| 1810 | |
| 1811 | for (SDep& PredDep : SU->Preds) { |
| 1812 | SUnit *Pred = PredDep.getSUnit(); |
| 1813 | if (SITII->isLowLatencyInstruction(*Pred->getInstr())) { |
| 1814 | IsLowLatencyUser = true; |
| 1815 | } |
| 1816 | if (Pred->NodeNum >= DAGSize) |
| 1817 | continue; |
| 1818 | unsigned PredPos = ScheduledSUnitsInv[Pred->NodeNum]; |
| 1819 | if (PredPos >= MinPos) |
| 1820 | MinPos = PredPos + 1; |
| 1821 | } |
| 1822 | |
| 1823 | if (SITII->isLowLatencyInstruction(*SU->getInstr())) { |
| 1824 | unsigned BestPos = LastLowLatencyUser + 1; |
| 1825 | if ((int)BestPos <= LastLowLatencyPos) |
| 1826 | BestPos = LastLowLatencyPos + 1; |
| 1827 | if (BestPos < MinPos) |
| 1828 | BestPos = MinPos; |
| 1829 | if (BestPos < i) { |
| 1830 | for (unsigned u = i; u > BestPos; --u) { |
| 1831 | ++ScheduledSUnitsInv[ScheduledSUnits[u-1]]; |
| 1832 | ScheduledSUnits[u] = ScheduledSUnits[u-1]; |
| 1833 | } |
| 1834 | ScheduledSUnits[BestPos] = SU->NodeNum; |
| 1835 | ScheduledSUnitsInv[SU->NodeNum] = BestPos; |
| 1836 | } |
| 1837 | LastLowLatencyPos = BestPos; |
| 1838 | if (IsLowLatencyUser) |
| 1839 | LastLowLatencyUser = BestPos; |
| 1840 | } else if (IsLowLatencyUser) { |
| 1841 | LastLowLatencyUser = i; |
| 1842 | // Moves COPY instructions on which depends |
| 1843 | // the low latency instructions too. |
| 1844 | } else if (SU->getInstr()->getOpcode() == AMDGPU::COPY) { |
| 1845 | bool CopyForLowLat = false; |
| 1846 | for (SDep& SuccDep : SU->Succs) { |
| 1847 | SUnit *Succ = SuccDep.getSUnit(); |
| 1848 | if (SuccDep.isWeak() || Succ->NodeNum >= DAGSize) |
| 1849 | continue; |
| 1850 | if (SITII->isLowLatencyInstruction(*Succ->getInstr())) { |
| 1851 | CopyForLowLat = true; |
| 1852 | } |
| 1853 | } |
| 1854 | if (!CopyForLowLat) |
| 1855 | continue; |
| 1856 | if (MinPos < i) { |
| 1857 | for (unsigned u = i; u > MinPos; --u) { |
| 1858 | ++ScheduledSUnitsInv[ScheduledSUnits[u-1]]; |
| 1859 | ScheduledSUnits[u] = ScheduledSUnits[u-1]; |
| 1860 | } |
| 1861 | ScheduledSUnits[MinPos] = SU->NodeNum; |
| 1862 | ScheduledSUnitsInv[SU->NodeNum] = MinPos; |
| 1863 | } |
| 1864 | } |
| 1865 | } |
| 1866 | } |
| 1867 | |
| 1868 | void SIScheduleDAGMI::restoreSULinksLeft() { |
| 1869 | for (unsigned i = 0, e = SUnits.size(); i != e; ++i) { |
| 1870 | SUnits[i].isScheduled = false; |
| 1871 | SUnits[i].WeakPredsLeft = SUnitsLinksBackup[i].WeakPredsLeft; |
| 1872 | SUnits[i].NumPredsLeft = SUnitsLinksBackup[i].NumPredsLeft; |
| 1873 | SUnits[i].WeakSuccsLeft = SUnitsLinksBackup[i].WeakSuccsLeft; |
| 1874 | SUnits[i].NumSuccsLeft = SUnitsLinksBackup[i].NumSuccsLeft; |
| 1875 | } |
| 1876 | } |
| 1877 | |
| 1878 | // Return the Vgpr and Sgpr usage corresponding to some virtual registers. |
| 1879 | template<typename _Iterator> void |
| 1880 | SIScheduleDAGMI::fillVgprSgprCost(_Iterator First, _Iterator End, |
| 1881 | unsigned &VgprUsage, unsigned &SgprUsage) { |
| 1882 | VgprUsage = 0; |
| 1883 | SgprUsage = 0; |
| 1884 | for (_Iterator RegI = First; RegI != End; ++RegI) { |
| 1885 | Register Reg = *RegI; |
| 1886 | // For now only track virtual registers |
| 1887 | if (!Reg.isVirtual()) |
| 1888 | continue; |
| 1889 | PSetIterator PSetI = MRI.getPressureSets(Reg); |
| 1890 | for (; PSetI.isValid(); ++PSetI) { |
| 1891 | if (*PSetI == AMDGPU::RegisterPressureSets::VGPR_32) |
| 1892 | VgprUsage += PSetI.getWeight(); |
| 1893 | else if (*PSetI == AMDGPU::RegisterPressureSets::SReg_32) |
| 1894 | SgprUsage += PSetI.getWeight(); |
| 1895 | } |
| 1896 | } |
| 1897 | } |
| 1898 | |
| 1899 | void SIScheduleDAGMI::schedule() |
| 1900 | { |
| 1901 | SmallVector<SUnit*, 8> TopRoots, BotRoots; |
| 1902 | SIScheduleBlockResult Best, Temp; |
| 1903 | LLVM_DEBUG(dbgs() << "Preparing Scheduling\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("machine-scheduler")) { dbgs() << "Preparing Scheduling\n" ; } } while (false); |
| 1904 | |
| 1905 | buildDAGWithRegPressure(); |
| 1906 | LLVM_DEBUG(dump())do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("machine-scheduler")) { dump(); } } while (false); |
| 1907 | |
| 1908 | topologicalSort(); |
| 1909 | findRootsAndBiasEdges(TopRoots, BotRoots); |
| 1910 | // We reuse several ScheduleDAGMI and ScheduleDAGMILive |
| 1911 | // functions, but to make them happy we must initialize |
| 1912 | // the default Scheduler implementation (even if we do not |
| 1913 | // run it) |
| 1914 | SchedImpl->initialize(this); |
| 1915 | initQueues(TopRoots, BotRoots); |
| 1916 | |
| 1917 | // Fill some stats to help scheduling. |
| 1918 | |
| 1919 | SUnitsLinksBackup = SUnits; |
| 1920 | IsLowLatencySU.clear(); |
| 1921 | LowLatencyOffset.clear(); |
| 1922 | IsHighLatencySU.clear(); |
| 1923 | |
| 1924 | IsLowLatencySU.resize(SUnits.size(), 0); |
| 1925 | LowLatencyOffset.resize(SUnits.size(), 0); |
| 1926 | IsHighLatencySU.resize(SUnits.size(), 0); |
| 1927 | |
| 1928 | for (unsigned i = 0, e = (unsigned)SUnits.size(); i != e; ++i) { |
| 1929 | SUnit *SU = &SUnits[i]; |
| 1930 | const MachineOperand *BaseLatOp; |
| 1931 | int64_t OffLatReg; |
| 1932 | if (SITII->isLowLatencyInstruction(*SU->getInstr())) { |
| 1933 | IsLowLatencySU[i] = 1; |
| 1934 | bool OffsetIsScalable; |
| 1935 | if (SITII->getMemOperandWithOffset(*SU->getInstr(), BaseLatOp, OffLatReg, |
| 1936 | OffsetIsScalable, TRI)) |
| 1937 | LowLatencyOffset[i] = OffLatReg; |
| 1938 | } else if (SITII->isHighLatencyDef(SU->getInstr()->getOpcode())) |
| 1939 | IsHighLatencySU[i] = 1; |
| 1940 | } |
| 1941 | |
| 1942 | SIScheduler Scheduler(this); |
| 1943 | Best = Scheduler.scheduleVariant(SISchedulerBlockCreatorVariant::LatenciesAlone, |
| 1944 | SISchedulerBlockSchedulerVariant::BlockLatencyRegUsage); |
| 1945 | |
| 1946 | // if VGPR usage is extremely high, try other good performing variants |
| 1947 | // which could lead to lower VGPR usage |
| 1948 | if (Best.MaxVGPRUsage > 180) { |
| 1949 | static const std::pair<SISchedulerBlockCreatorVariant, |
| 1950 | SISchedulerBlockSchedulerVariant> |
| 1951 | Variants[] = { |
| 1952 | { LatenciesAlone, BlockRegUsageLatency }, |
| 1953 | // { LatenciesAlone, BlockRegUsage }, |
| 1954 | { LatenciesGrouped, BlockLatencyRegUsage }, |
| 1955 | // { LatenciesGrouped, BlockRegUsageLatency }, |
| 1956 | // { LatenciesGrouped, BlockRegUsage }, |
| 1957 | { LatenciesAlonePlusConsecutive, BlockLatencyRegUsage }, |
| 1958 | // { LatenciesAlonePlusConsecutive, BlockRegUsageLatency }, |
| 1959 | // { LatenciesAlonePlusConsecutive, BlockRegUsage } |
| 1960 | }; |
| 1961 | for (std::pair<SISchedulerBlockCreatorVariant, SISchedulerBlockSchedulerVariant> v : Variants) { |
| 1962 | Temp = Scheduler.scheduleVariant(v.first, v.second); |
| 1963 | if (Temp.MaxVGPRUsage < Best.MaxVGPRUsage) |
| 1964 | Best = Temp; |
| 1965 | } |
| 1966 | } |
| 1967 | // if VGPR usage is still extremely high, we may spill. Try other variants |
| 1968 | // which are less performing, but that could lead to lower VGPR usage. |
| 1969 | if (Best.MaxVGPRUsage > 200) { |
| 1970 | static const std::pair<SISchedulerBlockCreatorVariant, |
| 1971 | SISchedulerBlockSchedulerVariant> |
| 1972 | Variants[] = { |
| 1973 | // { LatenciesAlone, BlockRegUsageLatency }, |
| 1974 | { LatenciesAlone, BlockRegUsage }, |
| 1975 | // { LatenciesGrouped, BlockLatencyRegUsage }, |
| 1976 | { LatenciesGrouped, BlockRegUsageLatency }, |
| 1977 | { LatenciesGrouped, BlockRegUsage }, |
| 1978 | // { LatenciesAlonePlusConsecutive, BlockLatencyRegUsage }, |
| 1979 | { LatenciesAlonePlusConsecutive, BlockRegUsageLatency }, |
| 1980 | { LatenciesAlonePlusConsecutive, BlockRegUsage } |
| 1981 | }; |
| 1982 | for (std::pair<SISchedulerBlockCreatorVariant, SISchedulerBlockSchedulerVariant> v : Variants) { |
| 1983 | Temp = Scheduler.scheduleVariant(v.first, v.second); |
| 1984 | if (Temp.MaxVGPRUsage < Best.MaxVGPRUsage) |
| 1985 | Best = Temp; |
| 1986 | } |
| 1987 | } |
| 1988 | |
| 1989 | ScheduledSUnits = Best.SUs; |
| 1990 | ScheduledSUnitsInv.resize(SUnits.size()); |
| 1991 | |
| 1992 | for (unsigned i = 0, e = (unsigned)SUnits.size(); i != e; ++i) { |
| 1993 | ScheduledSUnitsInv[ScheduledSUnits[i]] = i; |
| 1994 | } |
| 1995 | |
| 1996 | moveLowLatencies(); |
| 1997 | |
| 1998 | // Tell the outside world about the result of the scheduling. |
| 1999 | |
| 2000 | assert(TopRPTracker.getPos() == RegionBegin && "bad initial Top tracker")(static_cast <bool> (TopRPTracker.getPos() == RegionBegin && "bad initial Top tracker") ? void (0) : __assert_fail ("TopRPTracker.getPos() == RegionBegin && \"bad initial Top tracker\"" , "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/llvm/lib/Target/AMDGPU/SIMachineScheduler.cpp" , 2000, __extension__ __PRETTY_FUNCTION__)); |
| 2001 | TopRPTracker.setPos(CurrentTop); |
| 2002 | |
| 2003 | for (std::vector<unsigned>::iterator I = ScheduledSUnits.begin(), |
| 2004 | E = ScheduledSUnits.end(); I != E; ++I) { |
| 2005 | SUnit *SU = &SUnits[*I]; |
| 2006 | |
| 2007 | scheduleMI(SU, true); |
| 2008 | |
| 2009 | LLVM_DEBUG(dbgs() << "Scheduling SU(" << SU->NodeNum << ") "do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("machine-scheduler")) { dbgs() << "Scheduling SU(" << SU->NodeNum << ") " << *SU->getInstr(); } } while (false) |
| 2010 | << *SU->getInstr())do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("machine-scheduler")) { dbgs() << "Scheduling SU(" << SU->NodeNum << ") " << *SU->getInstr(); } } while (false); |
| 2011 | } |
| 2012 | |
| 2013 | assert(CurrentTop == CurrentBottom && "Nonempty unscheduled zone.")(static_cast <bool> (CurrentTop == CurrentBottom && "Nonempty unscheduled zone.") ? void (0) : __assert_fail ("CurrentTop == CurrentBottom && \"Nonempty unscheduled zone.\"" , "/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/llvm/lib/Target/AMDGPU/SIMachineScheduler.cpp" , 2013, __extension__ __PRETTY_FUNCTION__)); |
| 2014 | |
| 2015 | placeDebugValues(); |
| 2016 | |
| 2017 | LLVM_DEBUG({do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("machine-scheduler")) { { dbgs() << "*** Final schedule for " << printMBBReference(*begin()->getParent()) << " ***\n"; dumpSchedule(); dbgs() << '\n'; }; } } while (false) |
| 2018 | dbgs() << "*** Final schedule for "do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("machine-scheduler")) { { dbgs() << "*** Final schedule for " << printMBBReference(*begin()->getParent()) << " ***\n"; dumpSchedule(); dbgs() << '\n'; }; } } while (false) |
| 2019 | << printMBBReference(*begin()->getParent()) << " ***\n";do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("machine-scheduler")) { { dbgs() << "*** Final schedule for " << printMBBReference(*begin()->getParent()) << " ***\n"; dumpSchedule(); dbgs() << '\n'; }; } } while (false) |
| 2020 | dumpSchedule();do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("machine-scheduler")) { { dbgs() << "*** Final schedule for " << printMBBReference(*begin()->getParent()) << " ***\n"; dumpSchedule(); dbgs() << '\n'; }; } } while (false) |
| 2021 | dbgs() << '\n';do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("machine-scheduler")) { { dbgs() << "*** Final schedule for " << printMBBReference(*begin()->getParent()) << " ***\n"; dumpSchedule(); dbgs() << '\n'; }; } } while (false) |
| 2022 | })do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("machine-scheduler")) { { dbgs() << "*** Final schedule for " << printMBBReference(*begin()->getParent()) << " ***\n"; dumpSchedule(); dbgs() << '\n'; }; } } while (false); |
| 2023 | } |