| File: | src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/lib/CodeGen/MachinePipeliner.cpp |
| Warning: | line 1978, column 13 Value stored to 'Order' is never read |
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| 1 | //===- MachinePipeliner.cpp - Machine Software Pipeliner Pass -------------===// |
| 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 | // An implementation of the Swing Modulo Scheduling (SMS) software pipeliner. |
| 10 | // |
| 11 | // This SMS implementation is a target-independent back-end pass. When enabled, |
| 12 | // the pass runs just prior to the register allocation pass, while the machine |
| 13 | // IR is in SSA form. If software pipelining is successful, then the original |
| 14 | // loop is replaced by the optimized loop. The optimized loop contains one or |
| 15 | // more prolog blocks, the pipelined kernel, and one or more epilog blocks. If |
| 16 | // the instructions cannot be scheduled in a given MII, we increase the MII by |
| 17 | // one and try again. |
| 18 | // |
| 19 | // The SMS implementation is an extension of the ScheduleDAGInstrs class. We |
| 20 | // represent loop carried dependences in the DAG as order edges to the Phi |
| 21 | // nodes. We also perform several passes over the DAG to eliminate unnecessary |
| 22 | // edges that inhibit the ability to pipeline. The implementation uses the |
| 23 | // DFAPacketizer class to compute the minimum initiation interval and the check |
| 24 | // where an instruction may be inserted in the pipelined schedule. |
| 25 | // |
| 26 | // In order for the SMS pass to work, several target specific hooks need to be |
| 27 | // implemented to get information about the loop structure and to rewrite |
| 28 | // instructions. |
| 29 | // |
| 30 | //===----------------------------------------------------------------------===// |
| 31 | |
| 32 | #include "llvm/ADT/ArrayRef.h" |
| 33 | #include "llvm/ADT/BitVector.h" |
| 34 | #include "llvm/ADT/DenseMap.h" |
| 35 | #include "llvm/ADT/MapVector.h" |
| 36 | #include "llvm/ADT/PriorityQueue.h" |
| 37 | #include "llvm/ADT/SetOperations.h" |
| 38 | #include "llvm/ADT/SetVector.h" |
| 39 | #include "llvm/ADT/SmallPtrSet.h" |
| 40 | #include "llvm/ADT/SmallSet.h" |
| 41 | #include "llvm/ADT/SmallVector.h" |
| 42 | #include "llvm/ADT/Statistic.h" |
| 43 | #include "llvm/ADT/iterator_range.h" |
| 44 | #include "llvm/Analysis/AliasAnalysis.h" |
| 45 | #include "llvm/Analysis/MemoryLocation.h" |
| 46 | #include "llvm/Analysis/ValueTracking.h" |
| 47 | #include "llvm/CodeGen/DFAPacketizer.h" |
| 48 | #include "llvm/CodeGen/LiveIntervals.h" |
| 49 | #include "llvm/CodeGen/MachineBasicBlock.h" |
| 50 | #include "llvm/CodeGen/MachineDominators.h" |
| 51 | #include "llvm/CodeGen/MachineFunction.h" |
| 52 | #include "llvm/CodeGen/MachineFunctionPass.h" |
| 53 | #include "llvm/CodeGen/MachineInstr.h" |
| 54 | #include "llvm/CodeGen/MachineInstrBuilder.h" |
| 55 | #include "llvm/CodeGen/MachineLoopInfo.h" |
| 56 | #include "llvm/CodeGen/MachineMemOperand.h" |
| 57 | #include "llvm/CodeGen/MachineOperand.h" |
| 58 | #include "llvm/CodeGen/MachinePipeliner.h" |
| 59 | #include "llvm/CodeGen/MachineRegisterInfo.h" |
| 60 | #include "llvm/CodeGen/ModuloSchedule.h" |
| 61 | #include "llvm/CodeGen/RegisterPressure.h" |
| 62 | #include "llvm/CodeGen/ScheduleDAG.h" |
| 63 | #include "llvm/CodeGen/ScheduleDAGMutation.h" |
| 64 | #include "llvm/CodeGen/TargetOpcodes.h" |
| 65 | #include "llvm/CodeGen/TargetRegisterInfo.h" |
| 66 | #include "llvm/CodeGen/TargetSubtargetInfo.h" |
| 67 | #include "llvm/Config/llvm-config.h" |
| 68 | #include "llvm/IR/Attributes.h" |
| 69 | #include "llvm/IR/DebugLoc.h" |
| 70 | #include "llvm/IR/Function.h" |
| 71 | #include "llvm/MC/LaneBitmask.h" |
| 72 | #include "llvm/MC/MCInstrDesc.h" |
| 73 | #include "llvm/MC/MCInstrItineraries.h" |
| 74 | #include "llvm/MC/MCRegisterInfo.h" |
| 75 | #include "llvm/Pass.h" |
| 76 | #include "llvm/Support/CommandLine.h" |
| 77 | #include "llvm/Support/Compiler.h" |
| 78 | #include "llvm/Support/Debug.h" |
| 79 | #include "llvm/Support/MathExtras.h" |
| 80 | #include "llvm/Support/raw_ostream.h" |
| 81 | #include <algorithm> |
| 82 | #include <cassert> |
| 83 | #include <climits> |
| 84 | #include <cstdint> |
| 85 | #include <deque> |
| 86 | #include <functional> |
| 87 | #include <iterator> |
| 88 | #include <map> |
| 89 | #include <memory> |
| 90 | #include <tuple> |
| 91 | #include <utility> |
| 92 | #include <vector> |
| 93 | |
| 94 | using namespace llvm; |
| 95 | |
| 96 | #define DEBUG_TYPE"pipeliner" "pipeliner" |
| 97 | |
| 98 | STATISTIC(NumTrytoPipeline, "Number of loops that we attempt to pipeline")static llvm::Statistic NumTrytoPipeline = {"pipeliner", "NumTrytoPipeline" , "Number of loops that we attempt to pipeline"}; |
| 99 | STATISTIC(NumPipelined, "Number of loops software pipelined")static llvm::Statistic NumPipelined = {"pipeliner", "NumPipelined" , "Number of loops software pipelined"}; |
| 100 | STATISTIC(NumNodeOrderIssues, "Number of node order issues found")static llvm::Statistic NumNodeOrderIssues = {"pipeliner", "NumNodeOrderIssues" , "Number of node order issues found"}; |
| 101 | STATISTIC(NumFailBranch, "Pipeliner abort due to unknown branch")static llvm::Statistic NumFailBranch = {"pipeliner", "NumFailBranch" , "Pipeliner abort due to unknown branch"}; |
| 102 | STATISTIC(NumFailLoop, "Pipeliner abort due to unsupported loop")static llvm::Statistic NumFailLoop = {"pipeliner", "NumFailLoop" , "Pipeliner abort due to unsupported loop"}; |
| 103 | STATISTIC(NumFailPreheader, "Pipeliner abort due to missing preheader")static llvm::Statistic NumFailPreheader = {"pipeliner", "NumFailPreheader" , "Pipeliner abort due to missing preheader"}; |
| 104 | STATISTIC(NumFailLargeMaxMII, "Pipeliner abort due to MaxMII too large")static llvm::Statistic NumFailLargeMaxMII = {"pipeliner", "NumFailLargeMaxMII" , "Pipeliner abort due to MaxMII too large"}; |
| 105 | STATISTIC(NumFailZeroMII, "Pipeliner abort due to zero MII")static llvm::Statistic NumFailZeroMII = {"pipeliner", "NumFailZeroMII" , "Pipeliner abort due to zero MII"}; |
| 106 | STATISTIC(NumFailNoSchedule, "Pipeliner abort due to no schedule found")static llvm::Statistic NumFailNoSchedule = {"pipeliner", "NumFailNoSchedule" , "Pipeliner abort due to no schedule found"}; |
| 107 | STATISTIC(NumFailZeroStage, "Pipeliner abort due to zero stage")static llvm::Statistic NumFailZeroStage = {"pipeliner", "NumFailZeroStage" , "Pipeliner abort due to zero stage"}; |
| 108 | STATISTIC(NumFailLargeMaxStage, "Pipeliner abort due to too many stages")static llvm::Statistic NumFailLargeMaxStage = {"pipeliner", "NumFailLargeMaxStage" , "Pipeliner abort due to too many stages"}; |
| 109 | |
| 110 | /// A command line option to turn software pipelining on or off. |
| 111 | static cl::opt<bool> EnableSWP("enable-pipeliner", cl::Hidden, cl::init(true), |
| 112 | cl::ZeroOrMore, |
| 113 | cl::desc("Enable Software Pipelining")); |
| 114 | |
| 115 | /// A command line option to enable SWP at -Os. |
| 116 | static cl::opt<bool> EnableSWPOptSize("enable-pipeliner-opt-size", |
| 117 | cl::desc("Enable SWP at Os."), cl::Hidden, |
| 118 | cl::init(false)); |
| 119 | |
| 120 | /// A command line argument to limit minimum initial interval for pipelining. |
| 121 | static cl::opt<int> SwpMaxMii("pipeliner-max-mii", |
| 122 | cl::desc("Size limit for the MII."), |
| 123 | cl::Hidden, cl::init(27)); |
| 124 | |
| 125 | /// A command line argument to limit the number of stages in the pipeline. |
| 126 | static cl::opt<int> |
| 127 | SwpMaxStages("pipeliner-max-stages", |
| 128 | cl::desc("Maximum stages allowed in the generated scheduled."), |
| 129 | cl::Hidden, cl::init(3)); |
| 130 | |
| 131 | /// A command line option to disable the pruning of chain dependences due to |
| 132 | /// an unrelated Phi. |
| 133 | static cl::opt<bool> |
| 134 | SwpPruneDeps("pipeliner-prune-deps", |
| 135 | cl::desc("Prune dependences between unrelated Phi nodes."), |
| 136 | cl::Hidden, cl::init(true)); |
| 137 | |
| 138 | /// A command line option to disable the pruning of loop carried order |
| 139 | /// dependences. |
| 140 | static cl::opt<bool> |
| 141 | SwpPruneLoopCarried("pipeliner-prune-loop-carried", |
| 142 | cl::desc("Prune loop carried order dependences."), |
| 143 | cl::Hidden, cl::init(true)); |
| 144 | |
| 145 | #ifndef NDEBUG1 |
| 146 | static cl::opt<int> SwpLoopLimit("pipeliner-max", cl::Hidden, cl::init(-1)); |
| 147 | #endif |
| 148 | |
| 149 | static cl::opt<bool> SwpIgnoreRecMII("pipeliner-ignore-recmii", |
| 150 | cl::ReallyHidden, cl::init(false), |
| 151 | cl::ZeroOrMore, cl::desc("Ignore RecMII")); |
| 152 | |
| 153 | static cl::opt<bool> SwpShowResMask("pipeliner-show-mask", cl::Hidden, |
| 154 | cl::init(false)); |
| 155 | static cl::opt<bool> SwpDebugResource("pipeliner-dbg-res", cl::Hidden, |
| 156 | cl::init(false)); |
| 157 | |
| 158 | static cl::opt<bool> EmitTestAnnotations( |
| 159 | "pipeliner-annotate-for-testing", cl::Hidden, cl::init(false), |
| 160 | cl::desc("Instead of emitting the pipelined code, annotate instructions " |
| 161 | "with the generated schedule for feeding into the " |
| 162 | "-modulo-schedule-test pass")); |
| 163 | |
| 164 | static cl::opt<bool> ExperimentalCodeGen( |
| 165 | "pipeliner-experimental-cg", cl::Hidden, cl::init(false), |
| 166 | cl::desc( |
| 167 | "Use the experimental peeling code generator for software pipelining")); |
| 168 | |
| 169 | namespace llvm { |
| 170 | |
| 171 | // A command line option to enable the CopyToPhi DAG mutation. |
| 172 | cl::opt<bool> |
| 173 | SwpEnableCopyToPhi("pipeliner-enable-copytophi", cl::ReallyHidden, |
| 174 | cl::init(true), cl::ZeroOrMore, |
| 175 | cl::desc("Enable CopyToPhi DAG Mutation")); |
| 176 | |
| 177 | } // end namespace llvm |
| 178 | |
| 179 | unsigned SwingSchedulerDAG::Circuits::MaxPaths = 5; |
| 180 | char MachinePipeliner::ID = 0; |
| 181 | #ifndef NDEBUG1 |
| 182 | int MachinePipeliner::NumTries = 0; |
| 183 | #endif |
| 184 | char &llvm::MachinePipelinerID = MachinePipeliner::ID; |
| 185 | |
| 186 | INITIALIZE_PASS_BEGIN(MachinePipeliner, DEBUG_TYPE,static void *initializeMachinePipelinerPassOnce(PassRegistry & Registry) { |
| 187 | "Modulo Software Pipelining", false, false)static void *initializeMachinePipelinerPassOnce(PassRegistry & Registry) { |
| 188 | INITIALIZE_PASS_DEPENDENCY(AAResultsWrapperPass)initializeAAResultsWrapperPassPass(Registry); |
| 189 | INITIALIZE_PASS_DEPENDENCY(MachineLoopInfo)initializeMachineLoopInfoPass(Registry); |
| 190 | INITIALIZE_PASS_DEPENDENCY(MachineDominatorTree)initializeMachineDominatorTreePass(Registry); |
| 191 | INITIALIZE_PASS_DEPENDENCY(LiveIntervals)initializeLiveIntervalsPass(Registry); |
| 192 | INITIALIZE_PASS_END(MachinePipeliner, DEBUG_TYPE,PassInfo *PI = new PassInfo( "Modulo Software Pipelining", "pipeliner" , &MachinePipeliner::ID, PassInfo::NormalCtor_t(callDefaultCtor <MachinePipeliner>), false, false); Registry.registerPass (*PI, true); return PI; } static llvm::once_flag InitializeMachinePipelinerPassFlag ; void llvm::initializeMachinePipelinerPass(PassRegistry & Registry) { llvm::call_once(InitializeMachinePipelinerPassFlag , initializeMachinePipelinerPassOnce, std::ref(Registry)); } |
| 193 | "Modulo Software Pipelining", false, false)PassInfo *PI = new PassInfo( "Modulo Software Pipelining", "pipeliner" , &MachinePipeliner::ID, PassInfo::NormalCtor_t(callDefaultCtor <MachinePipeliner>), false, false); Registry.registerPass (*PI, true); return PI; } static llvm::once_flag InitializeMachinePipelinerPassFlag ; void llvm::initializeMachinePipelinerPass(PassRegistry & Registry) { llvm::call_once(InitializeMachinePipelinerPassFlag , initializeMachinePipelinerPassOnce, std::ref(Registry)); } |
| 194 | |
| 195 | /// The "main" function for implementing Swing Modulo Scheduling. |
| 196 | bool MachinePipeliner::runOnMachineFunction(MachineFunction &mf) { |
| 197 | if (skipFunction(mf.getFunction())) |
| 198 | return false; |
| 199 | |
| 200 | if (!EnableSWP) |
| 201 | return false; |
| 202 | |
| 203 | if (mf.getFunction().getAttributes().hasAttribute( |
| 204 | AttributeList::FunctionIndex, Attribute::OptimizeForSize) && |
| 205 | !EnableSWPOptSize.getPosition()) |
| 206 | return false; |
| 207 | |
| 208 | if (!mf.getSubtarget().enableMachinePipeliner()) |
| 209 | return false; |
| 210 | |
| 211 | // Cannot pipeline loops without instruction itineraries if we are using |
| 212 | // DFA for the pipeliner. |
| 213 | if (mf.getSubtarget().useDFAforSMS() && |
| 214 | (!mf.getSubtarget().getInstrItineraryData() || |
| 215 | mf.getSubtarget().getInstrItineraryData()->isEmpty())) |
| 216 | return false; |
| 217 | |
| 218 | MF = &mf; |
| 219 | MLI = &getAnalysis<MachineLoopInfo>(); |
| 220 | MDT = &getAnalysis<MachineDominatorTree>(); |
| 221 | ORE = &getAnalysis<MachineOptimizationRemarkEmitterPass>().getORE(); |
| 222 | TII = MF->getSubtarget().getInstrInfo(); |
| 223 | RegClassInfo.runOnMachineFunction(*MF); |
| 224 | |
| 225 | for (auto &L : *MLI) |
| 226 | scheduleLoop(*L); |
| 227 | |
| 228 | return false; |
| 229 | } |
| 230 | |
| 231 | /// Attempt to perform the SMS algorithm on the specified loop. This function is |
| 232 | /// the main entry point for the algorithm. The function identifies candidate |
| 233 | /// loops, calculates the minimum initiation interval, and attempts to schedule |
| 234 | /// the loop. |
| 235 | bool MachinePipeliner::scheduleLoop(MachineLoop &L) { |
| 236 | bool Changed = false; |
| 237 | for (auto &InnerLoop : L) |
| 238 | Changed |= scheduleLoop(*InnerLoop); |
| 239 | |
| 240 | #ifndef NDEBUG1 |
| 241 | // Stop trying after reaching the limit (if any). |
| 242 | int Limit = SwpLoopLimit; |
| 243 | if (Limit >= 0) { |
| 244 | if (NumTries >= SwpLoopLimit) |
| 245 | return Changed; |
| 246 | NumTries++; |
| 247 | } |
| 248 | #endif |
| 249 | |
| 250 | setPragmaPipelineOptions(L); |
| 251 | if (!canPipelineLoop(L)) { |
| 252 | LLVM_DEBUG(dbgs() << "\n!!! Can not pipeline loop.\n")do { } while (false); |
| 253 | ORE->emit([&]() { |
| 254 | return MachineOptimizationRemarkMissed(DEBUG_TYPE"pipeliner", "canPipelineLoop", |
| 255 | L.getStartLoc(), L.getHeader()) |
| 256 | << "Failed to pipeline loop"; |
| 257 | }); |
| 258 | |
| 259 | return Changed; |
| 260 | } |
| 261 | |
| 262 | ++NumTrytoPipeline; |
| 263 | |
| 264 | Changed = swingModuloScheduler(L); |
| 265 | |
| 266 | return Changed; |
| 267 | } |
| 268 | |
| 269 | void MachinePipeliner::setPragmaPipelineOptions(MachineLoop &L) { |
| 270 | // Reset the pragma for the next loop in iteration. |
| 271 | disabledByPragma = false; |
| 272 | II_setByPragma = 0; |
| 273 | |
| 274 | MachineBasicBlock *LBLK = L.getTopBlock(); |
| 275 | |
| 276 | if (LBLK == nullptr) |
| 277 | return; |
| 278 | |
| 279 | const BasicBlock *BBLK = LBLK->getBasicBlock(); |
| 280 | if (BBLK == nullptr) |
| 281 | return; |
| 282 | |
| 283 | const Instruction *TI = BBLK->getTerminator(); |
| 284 | if (TI == nullptr) |
| 285 | return; |
| 286 | |
| 287 | MDNode *LoopID = TI->getMetadata(LLVMContext::MD_loop); |
| 288 | if (LoopID == nullptr) |
| 289 | return; |
| 290 | |
| 291 | assert(LoopID->getNumOperands() > 0 && "requires atleast one operand")((void)0); |
| 292 | assert(LoopID->getOperand(0) == LoopID && "invalid loop")((void)0); |
| 293 | |
| 294 | for (unsigned i = 1, e = LoopID->getNumOperands(); i < e; ++i) { |
| 295 | MDNode *MD = dyn_cast<MDNode>(LoopID->getOperand(i)); |
| 296 | |
| 297 | if (MD == nullptr) |
| 298 | continue; |
| 299 | |
| 300 | MDString *S = dyn_cast<MDString>(MD->getOperand(0)); |
| 301 | |
| 302 | if (S == nullptr) |
| 303 | continue; |
| 304 | |
| 305 | if (S->getString() == "llvm.loop.pipeline.initiationinterval") { |
| 306 | assert(MD->getNumOperands() == 2 &&((void)0) |
| 307 | "Pipeline initiation interval hint metadata should have two operands.")((void)0); |
| 308 | II_setByPragma = |
| 309 | mdconst::extract<ConstantInt>(MD->getOperand(1))->getZExtValue(); |
| 310 | assert(II_setByPragma >= 1 && "Pipeline initiation interval must be positive.")((void)0); |
| 311 | } else if (S->getString() == "llvm.loop.pipeline.disable") { |
| 312 | disabledByPragma = true; |
| 313 | } |
| 314 | } |
| 315 | } |
| 316 | |
| 317 | /// Return true if the loop can be software pipelined. The algorithm is |
| 318 | /// restricted to loops with a single basic block. Make sure that the |
| 319 | /// branch in the loop can be analyzed. |
| 320 | bool MachinePipeliner::canPipelineLoop(MachineLoop &L) { |
| 321 | if (L.getNumBlocks() != 1) { |
| 322 | ORE->emit([&]() { |
| 323 | return MachineOptimizationRemarkAnalysis(DEBUG_TYPE"pipeliner", "canPipelineLoop", |
| 324 | L.getStartLoc(), L.getHeader()) |
| 325 | << "Not a single basic block: " |
| 326 | << ore::NV("NumBlocks", L.getNumBlocks()); |
| 327 | }); |
| 328 | return false; |
| 329 | } |
| 330 | |
| 331 | if (disabledByPragma) { |
| 332 | ORE->emit([&]() { |
| 333 | return MachineOptimizationRemarkAnalysis(DEBUG_TYPE"pipeliner", "canPipelineLoop", |
| 334 | L.getStartLoc(), L.getHeader()) |
| 335 | << "Disabled by Pragma."; |
| 336 | }); |
| 337 | return false; |
| 338 | } |
| 339 | |
| 340 | // Check if the branch can't be understood because we can't do pipelining |
| 341 | // if that's the case. |
| 342 | LI.TBB = nullptr; |
| 343 | LI.FBB = nullptr; |
| 344 | LI.BrCond.clear(); |
| 345 | if (TII->analyzeBranch(*L.getHeader(), LI.TBB, LI.FBB, LI.BrCond)) { |
| 346 | LLVM_DEBUG(dbgs() << "Unable to analyzeBranch, can NOT pipeline Loop\n")do { } while (false); |
| 347 | NumFailBranch++; |
| 348 | ORE->emit([&]() { |
| 349 | return MachineOptimizationRemarkAnalysis(DEBUG_TYPE"pipeliner", "canPipelineLoop", |
| 350 | L.getStartLoc(), L.getHeader()) |
| 351 | << "The branch can't be understood"; |
| 352 | }); |
| 353 | return false; |
| 354 | } |
| 355 | |
| 356 | LI.LoopInductionVar = nullptr; |
| 357 | LI.LoopCompare = nullptr; |
| 358 | if (!TII->analyzeLoopForPipelining(L.getTopBlock())) { |
| 359 | LLVM_DEBUG(dbgs() << "Unable to analyzeLoop, can NOT pipeline Loop\n")do { } while (false); |
| 360 | NumFailLoop++; |
| 361 | ORE->emit([&]() { |
| 362 | return MachineOptimizationRemarkAnalysis(DEBUG_TYPE"pipeliner", "canPipelineLoop", |
| 363 | L.getStartLoc(), L.getHeader()) |
| 364 | << "The loop structure is not supported"; |
| 365 | }); |
| 366 | return false; |
| 367 | } |
| 368 | |
| 369 | if (!L.getLoopPreheader()) { |
| 370 | LLVM_DEBUG(dbgs() << "Preheader not found, can NOT pipeline Loop\n")do { } while (false); |
| 371 | NumFailPreheader++; |
| 372 | ORE->emit([&]() { |
| 373 | return MachineOptimizationRemarkAnalysis(DEBUG_TYPE"pipeliner", "canPipelineLoop", |
| 374 | L.getStartLoc(), L.getHeader()) |
| 375 | << "No loop preheader found"; |
| 376 | }); |
| 377 | return false; |
| 378 | } |
| 379 | |
| 380 | // Remove any subregisters from inputs to phi nodes. |
| 381 | preprocessPhiNodes(*L.getHeader()); |
| 382 | return true; |
| 383 | } |
| 384 | |
| 385 | void MachinePipeliner::preprocessPhiNodes(MachineBasicBlock &B) { |
| 386 | MachineRegisterInfo &MRI = MF->getRegInfo(); |
| 387 | SlotIndexes &Slots = *getAnalysis<LiveIntervals>().getSlotIndexes(); |
| 388 | |
| 389 | for (MachineInstr &PI : make_range(B.begin(), B.getFirstNonPHI())) { |
| 390 | MachineOperand &DefOp = PI.getOperand(0); |
| 391 | assert(DefOp.getSubReg() == 0)((void)0); |
| 392 | auto *RC = MRI.getRegClass(DefOp.getReg()); |
| 393 | |
| 394 | for (unsigned i = 1, n = PI.getNumOperands(); i != n; i += 2) { |
| 395 | MachineOperand &RegOp = PI.getOperand(i); |
| 396 | if (RegOp.getSubReg() == 0) |
| 397 | continue; |
| 398 | |
| 399 | // If the operand uses a subregister, replace it with a new register |
| 400 | // without subregisters, and generate a copy to the new register. |
| 401 | Register NewReg = MRI.createVirtualRegister(RC); |
| 402 | MachineBasicBlock &PredB = *PI.getOperand(i+1).getMBB(); |
| 403 | MachineBasicBlock::iterator At = PredB.getFirstTerminator(); |
| 404 | const DebugLoc &DL = PredB.findDebugLoc(At); |
| 405 | auto Copy = BuildMI(PredB, At, DL, TII->get(TargetOpcode::COPY), NewReg) |
| 406 | .addReg(RegOp.getReg(), getRegState(RegOp), |
| 407 | RegOp.getSubReg()); |
| 408 | Slots.insertMachineInstrInMaps(*Copy); |
| 409 | RegOp.setReg(NewReg); |
| 410 | RegOp.setSubReg(0); |
| 411 | } |
| 412 | } |
| 413 | } |
| 414 | |
| 415 | /// The SMS algorithm consists of the following main steps: |
| 416 | /// 1. Computation and analysis of the dependence graph. |
| 417 | /// 2. Ordering of the nodes (instructions). |
| 418 | /// 3. Attempt to Schedule the loop. |
| 419 | bool MachinePipeliner::swingModuloScheduler(MachineLoop &L) { |
| 420 | assert(L.getBlocks().size() == 1 && "SMS works on single blocks only.")((void)0); |
| 421 | |
| 422 | SwingSchedulerDAG SMS(*this, L, getAnalysis<LiveIntervals>(), RegClassInfo, |
| 423 | II_setByPragma); |
| 424 | |
| 425 | MachineBasicBlock *MBB = L.getHeader(); |
| 426 | // The kernel should not include any terminator instructions. These |
| 427 | // will be added back later. |
| 428 | SMS.startBlock(MBB); |
| 429 | |
| 430 | // Compute the number of 'real' instructions in the basic block by |
| 431 | // ignoring terminators. |
| 432 | unsigned size = MBB->size(); |
| 433 | for (MachineBasicBlock::iterator I = MBB->getFirstTerminator(), |
| 434 | E = MBB->instr_end(); |
| 435 | I != E; ++I, --size) |
| 436 | ; |
| 437 | |
| 438 | SMS.enterRegion(MBB, MBB->begin(), MBB->getFirstTerminator(), size); |
| 439 | SMS.schedule(); |
| 440 | SMS.exitRegion(); |
| 441 | |
| 442 | SMS.finishBlock(); |
| 443 | return SMS.hasNewSchedule(); |
| 444 | } |
| 445 | |
| 446 | void MachinePipeliner::getAnalysisUsage(AnalysisUsage &AU) const { |
| 447 | AU.addRequired<AAResultsWrapperPass>(); |
| 448 | AU.addPreserved<AAResultsWrapperPass>(); |
| 449 | AU.addRequired<MachineLoopInfo>(); |
| 450 | AU.addRequired<MachineDominatorTree>(); |
| 451 | AU.addRequired<LiveIntervals>(); |
| 452 | AU.addRequired<MachineOptimizationRemarkEmitterPass>(); |
| 453 | MachineFunctionPass::getAnalysisUsage(AU); |
| 454 | } |
| 455 | |
| 456 | void SwingSchedulerDAG::setMII(unsigned ResMII, unsigned RecMII) { |
| 457 | if (II_setByPragma > 0) |
| 458 | MII = II_setByPragma; |
| 459 | else |
| 460 | MII = std::max(ResMII, RecMII); |
| 461 | } |
| 462 | |
| 463 | void SwingSchedulerDAG::setMAX_II() { |
| 464 | if (II_setByPragma > 0) |
| 465 | MAX_II = II_setByPragma; |
| 466 | else |
| 467 | MAX_II = MII + 10; |
| 468 | } |
| 469 | |
| 470 | /// We override the schedule function in ScheduleDAGInstrs to implement the |
| 471 | /// scheduling part of the Swing Modulo Scheduling algorithm. |
| 472 | void SwingSchedulerDAG::schedule() { |
| 473 | AliasAnalysis *AA = &Pass.getAnalysis<AAResultsWrapperPass>().getAAResults(); |
| 474 | buildSchedGraph(AA); |
| 475 | addLoopCarriedDependences(AA); |
| 476 | updatePhiDependences(); |
| 477 | Topo.InitDAGTopologicalSorting(); |
| 478 | changeDependences(); |
| 479 | postprocessDAG(); |
| 480 | LLVM_DEBUG(dump())do { } while (false); |
| 481 | |
| 482 | NodeSetType NodeSets; |
| 483 | findCircuits(NodeSets); |
| 484 | NodeSetType Circuits = NodeSets; |
| 485 | |
| 486 | // Calculate the MII. |
| 487 | unsigned ResMII = calculateResMII(); |
| 488 | unsigned RecMII = calculateRecMII(NodeSets); |
| 489 | |
| 490 | fuseRecs(NodeSets); |
| 491 | |
| 492 | // This flag is used for testing and can cause correctness problems. |
| 493 | if (SwpIgnoreRecMII) |
| 494 | RecMII = 0; |
| 495 | |
| 496 | setMII(ResMII, RecMII); |
| 497 | setMAX_II(); |
| 498 | |
| 499 | LLVM_DEBUG(dbgs() << "MII = " << MII << " MAX_II = " << MAX_IIdo { } while (false) |
| 500 | << " (rec=" << RecMII << ", res=" << ResMII << ")\n")do { } while (false); |
| 501 | |
| 502 | // Can't schedule a loop without a valid MII. |
| 503 | if (MII == 0) { |
| 504 | LLVM_DEBUG(dbgs() << "Invalid Minimal Initiation Interval: 0\n")do { } while (false); |
| 505 | NumFailZeroMII++; |
| 506 | Pass.ORE->emit([&]() { |
| 507 | return MachineOptimizationRemarkAnalysis( |
| 508 | DEBUG_TYPE"pipeliner", "schedule", Loop.getStartLoc(), Loop.getHeader()) |
| 509 | << "Invalid Minimal Initiation Interval: 0"; |
| 510 | }); |
| 511 | return; |
| 512 | } |
| 513 | |
| 514 | // Don't pipeline large loops. |
| 515 | if (SwpMaxMii != -1 && (int)MII > SwpMaxMii) { |
| 516 | LLVM_DEBUG(dbgs() << "MII > " << SwpMaxMiido { } while (false) |
| 517 | << ", we don't pipleline large loops\n")do { } while (false); |
| 518 | NumFailLargeMaxMII++; |
| 519 | Pass.ORE->emit([&]() { |
| 520 | return MachineOptimizationRemarkAnalysis( |
| 521 | DEBUG_TYPE"pipeliner", "schedule", Loop.getStartLoc(), Loop.getHeader()) |
| 522 | << "Minimal Initiation Interval too large: " |
| 523 | << ore::NV("MII", (int)MII) << " > " |
| 524 | << ore::NV("SwpMaxMii", SwpMaxMii) << "." |
| 525 | << "Refer to -pipeliner-max-mii."; |
| 526 | }); |
| 527 | return; |
| 528 | } |
| 529 | |
| 530 | computeNodeFunctions(NodeSets); |
| 531 | |
| 532 | registerPressureFilter(NodeSets); |
| 533 | |
| 534 | colocateNodeSets(NodeSets); |
| 535 | |
| 536 | checkNodeSets(NodeSets); |
| 537 | |
| 538 | LLVM_DEBUG({do { } while (false) |
| 539 | for (auto &I : NodeSets) {do { } while (false) |
| 540 | dbgs() << " Rec NodeSet ";do { } while (false) |
| 541 | I.dump();do { } while (false) |
| 542 | }do { } while (false) |
| 543 | })do { } while (false); |
| 544 | |
| 545 | llvm::stable_sort(NodeSets, std::greater<NodeSet>()); |
| 546 | |
| 547 | groupRemainingNodes(NodeSets); |
| 548 | |
| 549 | removeDuplicateNodes(NodeSets); |
| 550 | |
| 551 | LLVM_DEBUG({do { } while (false) |
| 552 | for (auto &I : NodeSets) {do { } while (false) |
| 553 | dbgs() << " NodeSet ";do { } while (false) |
| 554 | I.dump();do { } while (false) |
| 555 | }do { } while (false) |
| 556 | })do { } while (false); |
| 557 | |
| 558 | computeNodeOrder(NodeSets); |
| 559 | |
| 560 | // check for node order issues |
| 561 | checkValidNodeOrder(Circuits); |
| 562 | |
| 563 | SMSchedule Schedule(Pass.MF); |
| 564 | Scheduled = schedulePipeline(Schedule); |
| 565 | |
| 566 | if (!Scheduled){ |
| 567 | LLVM_DEBUG(dbgs() << "No schedule found, return\n")do { } while (false); |
| 568 | NumFailNoSchedule++; |
| 569 | Pass.ORE->emit([&]() { |
| 570 | return MachineOptimizationRemarkAnalysis( |
| 571 | DEBUG_TYPE"pipeliner", "schedule", Loop.getStartLoc(), Loop.getHeader()) |
| 572 | << "Unable to find schedule"; |
| 573 | }); |
| 574 | return; |
| 575 | } |
| 576 | |
| 577 | unsigned numStages = Schedule.getMaxStageCount(); |
| 578 | // No need to generate pipeline if there are no overlapped iterations. |
| 579 | if (numStages == 0) { |
| 580 | LLVM_DEBUG(dbgs() << "No overlapped iterations, skip.\n")do { } while (false); |
| 581 | NumFailZeroStage++; |
| 582 | Pass.ORE->emit([&]() { |
| 583 | return MachineOptimizationRemarkAnalysis( |
| 584 | DEBUG_TYPE"pipeliner", "schedule", Loop.getStartLoc(), Loop.getHeader()) |
| 585 | << "No need to pipeline - no overlapped iterations in schedule."; |
| 586 | }); |
| 587 | return; |
| 588 | } |
| 589 | // Check that the maximum stage count is less than user-defined limit. |
| 590 | if (SwpMaxStages > -1 && (int)numStages > SwpMaxStages) { |
| 591 | LLVM_DEBUG(dbgs() << "numStages:" << numStages << ">" << SwpMaxStagesdo { } while (false) |
| 592 | << " : too many stages, abort\n")do { } while (false); |
| 593 | NumFailLargeMaxStage++; |
| 594 | Pass.ORE->emit([&]() { |
| 595 | return MachineOptimizationRemarkAnalysis( |
| 596 | DEBUG_TYPE"pipeliner", "schedule", Loop.getStartLoc(), Loop.getHeader()) |
| 597 | << "Too many stages in schedule: " |
| 598 | << ore::NV("numStages", (int)numStages) << " > " |
| 599 | << ore::NV("SwpMaxStages", SwpMaxStages) |
| 600 | << ". Refer to -pipeliner-max-stages."; |
| 601 | }); |
| 602 | return; |
| 603 | } |
| 604 | |
| 605 | Pass.ORE->emit([&]() { |
| 606 | return MachineOptimizationRemark(DEBUG_TYPE"pipeliner", "schedule", Loop.getStartLoc(), |
| 607 | Loop.getHeader()) |
| 608 | << "Pipelined succesfully!"; |
| 609 | }); |
| 610 | |
| 611 | // Generate the schedule as a ModuloSchedule. |
| 612 | DenseMap<MachineInstr *, int> Cycles, Stages; |
| 613 | std::vector<MachineInstr *> OrderedInsts; |
| 614 | for (int Cycle = Schedule.getFirstCycle(); Cycle <= Schedule.getFinalCycle(); |
| 615 | ++Cycle) { |
| 616 | for (SUnit *SU : Schedule.getInstructions(Cycle)) { |
| 617 | OrderedInsts.push_back(SU->getInstr()); |
| 618 | Cycles[SU->getInstr()] = Cycle; |
| 619 | Stages[SU->getInstr()] = Schedule.stageScheduled(SU); |
| 620 | } |
| 621 | } |
| 622 | DenseMap<MachineInstr *, std::pair<unsigned, int64_t>> NewInstrChanges; |
| 623 | for (auto &KV : NewMIs) { |
| 624 | Cycles[KV.first] = Cycles[KV.second]; |
| 625 | Stages[KV.first] = Stages[KV.second]; |
| 626 | NewInstrChanges[KV.first] = InstrChanges[getSUnit(KV.first)]; |
| 627 | } |
| 628 | |
| 629 | ModuloSchedule MS(MF, &Loop, std::move(OrderedInsts), std::move(Cycles), |
| 630 | std::move(Stages)); |
| 631 | if (EmitTestAnnotations) { |
| 632 | assert(NewInstrChanges.empty() &&((void)0) |
| 633 | "Cannot serialize a schedule with InstrChanges!")((void)0); |
| 634 | ModuloScheduleTestAnnotater MSTI(MF, MS); |
| 635 | MSTI.annotate(); |
| 636 | return; |
| 637 | } |
| 638 | // The experimental code generator can't work if there are InstChanges. |
| 639 | if (ExperimentalCodeGen && NewInstrChanges.empty()) { |
| 640 | PeelingModuloScheduleExpander MSE(MF, MS, &LIS); |
| 641 | MSE.expand(); |
| 642 | } else { |
| 643 | ModuloScheduleExpander MSE(MF, MS, LIS, std::move(NewInstrChanges)); |
| 644 | MSE.expand(); |
| 645 | MSE.cleanup(); |
| 646 | } |
| 647 | ++NumPipelined; |
| 648 | } |
| 649 | |
| 650 | /// Clean up after the software pipeliner runs. |
| 651 | void SwingSchedulerDAG::finishBlock() { |
| 652 | for (auto &KV : NewMIs) |
| 653 | MF.DeleteMachineInstr(KV.second); |
| 654 | NewMIs.clear(); |
| 655 | |
| 656 | // Call the superclass. |
| 657 | ScheduleDAGInstrs::finishBlock(); |
| 658 | } |
| 659 | |
| 660 | /// Return the register values for the operands of a Phi instruction. |
| 661 | /// This function assume the instruction is a Phi. |
| 662 | static void getPhiRegs(MachineInstr &Phi, MachineBasicBlock *Loop, |
| 663 | unsigned &InitVal, unsigned &LoopVal) { |
| 664 | assert(Phi.isPHI() && "Expecting a Phi.")((void)0); |
| 665 | |
| 666 | InitVal = 0; |
| 667 | LoopVal = 0; |
| 668 | for (unsigned i = 1, e = Phi.getNumOperands(); i != e; i += 2) |
| 669 | if (Phi.getOperand(i + 1).getMBB() != Loop) |
| 670 | InitVal = Phi.getOperand(i).getReg(); |
| 671 | else |
| 672 | LoopVal = Phi.getOperand(i).getReg(); |
| 673 | |
| 674 | assert(InitVal != 0 && LoopVal != 0 && "Unexpected Phi structure.")((void)0); |
| 675 | } |
| 676 | |
| 677 | /// Return the Phi register value that comes the loop block. |
| 678 | static unsigned getLoopPhiReg(MachineInstr &Phi, MachineBasicBlock *LoopBB) { |
| 679 | for (unsigned i = 1, e = Phi.getNumOperands(); i != e; i += 2) |
| 680 | if (Phi.getOperand(i + 1).getMBB() == LoopBB) |
| 681 | return Phi.getOperand(i).getReg(); |
| 682 | return 0; |
| 683 | } |
| 684 | |
| 685 | /// Return true if SUb can be reached from SUa following the chain edges. |
| 686 | static bool isSuccOrder(SUnit *SUa, SUnit *SUb) { |
| 687 | SmallPtrSet<SUnit *, 8> Visited; |
| 688 | SmallVector<SUnit *, 8> Worklist; |
| 689 | Worklist.push_back(SUa); |
| 690 | while (!Worklist.empty()) { |
| 691 | const SUnit *SU = Worklist.pop_back_val(); |
| 692 | for (auto &SI : SU->Succs) { |
| 693 | SUnit *SuccSU = SI.getSUnit(); |
| 694 | if (SI.getKind() == SDep::Order) { |
| 695 | if (Visited.count(SuccSU)) |
| 696 | continue; |
| 697 | if (SuccSU == SUb) |
| 698 | return true; |
| 699 | Worklist.push_back(SuccSU); |
| 700 | Visited.insert(SuccSU); |
| 701 | } |
| 702 | } |
| 703 | } |
| 704 | return false; |
| 705 | } |
| 706 | |
| 707 | /// Return true if the instruction causes a chain between memory |
| 708 | /// references before and after it. |
| 709 | static bool isDependenceBarrier(MachineInstr &MI, AliasAnalysis *AA) { |
| 710 | return MI.isCall() || MI.mayRaiseFPException() || |
| 711 | MI.hasUnmodeledSideEffects() || |
| 712 | (MI.hasOrderedMemoryRef() && |
| 713 | (!MI.mayLoad() || !MI.isDereferenceableInvariantLoad(AA))); |
| 714 | } |
| 715 | |
| 716 | /// Return the underlying objects for the memory references of an instruction. |
| 717 | /// This function calls the code in ValueTracking, but first checks that the |
| 718 | /// instruction has a memory operand. |
| 719 | static void getUnderlyingObjects(const MachineInstr *MI, |
| 720 | SmallVectorImpl<const Value *> &Objs) { |
| 721 | if (!MI->hasOneMemOperand()) |
| 722 | return; |
| 723 | MachineMemOperand *MM = *MI->memoperands_begin(); |
| 724 | if (!MM->getValue()) |
| 725 | return; |
| 726 | getUnderlyingObjects(MM->getValue(), Objs); |
| 727 | for (const Value *V : Objs) { |
| 728 | if (!isIdentifiedObject(V)) { |
| 729 | Objs.clear(); |
| 730 | return; |
| 731 | } |
| 732 | Objs.push_back(V); |
| 733 | } |
| 734 | } |
| 735 | |
| 736 | /// Add a chain edge between a load and store if the store can be an |
| 737 | /// alias of the load on a subsequent iteration, i.e., a loop carried |
| 738 | /// dependence. This code is very similar to the code in ScheduleDAGInstrs |
| 739 | /// but that code doesn't create loop carried dependences. |
| 740 | void SwingSchedulerDAG::addLoopCarriedDependences(AliasAnalysis *AA) { |
| 741 | MapVector<const Value *, SmallVector<SUnit *, 4>> PendingLoads; |
| 742 | Value *UnknownValue = |
| 743 | UndefValue::get(Type::getVoidTy(MF.getFunction().getContext())); |
| 744 | for (auto &SU : SUnits) { |
| 745 | MachineInstr &MI = *SU.getInstr(); |
| 746 | if (isDependenceBarrier(MI, AA)) |
| 747 | PendingLoads.clear(); |
| 748 | else if (MI.mayLoad()) { |
| 749 | SmallVector<const Value *, 4> Objs; |
| 750 | ::getUnderlyingObjects(&MI, Objs); |
| 751 | if (Objs.empty()) |
| 752 | Objs.push_back(UnknownValue); |
| 753 | for (auto V : Objs) { |
| 754 | SmallVector<SUnit *, 4> &SUs = PendingLoads[V]; |
| 755 | SUs.push_back(&SU); |
| 756 | } |
| 757 | } else if (MI.mayStore()) { |
| 758 | SmallVector<const Value *, 4> Objs; |
| 759 | ::getUnderlyingObjects(&MI, Objs); |
| 760 | if (Objs.empty()) |
| 761 | Objs.push_back(UnknownValue); |
| 762 | for (auto V : Objs) { |
| 763 | MapVector<const Value *, SmallVector<SUnit *, 4>>::iterator I = |
| 764 | PendingLoads.find(V); |
| 765 | if (I == PendingLoads.end()) |
| 766 | continue; |
| 767 | for (auto Load : I->second) { |
| 768 | if (isSuccOrder(Load, &SU)) |
| 769 | continue; |
| 770 | MachineInstr &LdMI = *Load->getInstr(); |
| 771 | // First, perform the cheaper check that compares the base register. |
| 772 | // If they are the same and the load offset is less than the store |
| 773 | // offset, then mark the dependence as loop carried potentially. |
| 774 | const MachineOperand *BaseOp1, *BaseOp2; |
| 775 | int64_t Offset1, Offset2; |
| 776 | bool Offset1IsScalable, Offset2IsScalable; |
| 777 | if (TII->getMemOperandWithOffset(LdMI, BaseOp1, Offset1, |
| 778 | Offset1IsScalable, TRI) && |
| 779 | TII->getMemOperandWithOffset(MI, BaseOp2, Offset2, |
| 780 | Offset2IsScalable, TRI)) { |
| 781 | if (BaseOp1->isIdenticalTo(*BaseOp2) && |
| 782 | Offset1IsScalable == Offset2IsScalable && |
| 783 | (int)Offset1 < (int)Offset2) { |
| 784 | assert(TII->areMemAccessesTriviallyDisjoint(LdMI, MI) &&((void)0) |
| 785 | "What happened to the chain edge?")((void)0); |
| 786 | SDep Dep(Load, SDep::Barrier); |
| 787 | Dep.setLatency(1); |
| 788 | SU.addPred(Dep); |
| 789 | continue; |
| 790 | } |
| 791 | } |
| 792 | // Second, the more expensive check that uses alias analysis on the |
| 793 | // base registers. If they alias, and the load offset is less than |
| 794 | // the store offset, the mark the dependence as loop carried. |
| 795 | if (!AA) { |
| 796 | SDep Dep(Load, SDep::Barrier); |
| 797 | Dep.setLatency(1); |
| 798 | SU.addPred(Dep); |
| 799 | continue; |
| 800 | } |
| 801 | MachineMemOperand *MMO1 = *LdMI.memoperands_begin(); |
| 802 | MachineMemOperand *MMO2 = *MI.memoperands_begin(); |
| 803 | if (!MMO1->getValue() || !MMO2->getValue()) { |
| 804 | SDep Dep(Load, SDep::Barrier); |
| 805 | Dep.setLatency(1); |
| 806 | SU.addPred(Dep); |
| 807 | continue; |
| 808 | } |
| 809 | if (MMO1->getValue() == MMO2->getValue() && |
| 810 | MMO1->getOffset() <= MMO2->getOffset()) { |
| 811 | SDep Dep(Load, SDep::Barrier); |
| 812 | Dep.setLatency(1); |
| 813 | SU.addPred(Dep); |
| 814 | continue; |
| 815 | } |
| 816 | if (!AA->isNoAlias( |
| 817 | MemoryLocation::getAfter(MMO1->getValue(), MMO1->getAAInfo()), |
| 818 | MemoryLocation::getAfter(MMO2->getValue(), |
| 819 | MMO2->getAAInfo()))) { |
| 820 | SDep Dep(Load, SDep::Barrier); |
| 821 | Dep.setLatency(1); |
| 822 | SU.addPred(Dep); |
| 823 | } |
| 824 | } |
| 825 | } |
| 826 | } |
| 827 | } |
| 828 | } |
| 829 | |
| 830 | /// Update the phi dependences to the DAG because ScheduleDAGInstrs no longer |
| 831 | /// processes dependences for PHIs. This function adds true dependences |
| 832 | /// from a PHI to a use, and a loop carried dependence from the use to the |
| 833 | /// PHI. The loop carried dependence is represented as an anti dependence |
| 834 | /// edge. This function also removes chain dependences between unrelated |
| 835 | /// PHIs. |
| 836 | void SwingSchedulerDAG::updatePhiDependences() { |
| 837 | SmallVector<SDep, 4> RemoveDeps; |
| 838 | const TargetSubtargetInfo &ST = MF.getSubtarget<TargetSubtargetInfo>(); |
| 839 | |
| 840 | // Iterate over each DAG node. |
| 841 | for (SUnit &I : SUnits) { |
| 842 | RemoveDeps.clear(); |
| 843 | // Set to true if the instruction has an operand defined by a Phi. |
| 844 | unsigned HasPhiUse = 0; |
| 845 | unsigned HasPhiDef = 0; |
| 846 | MachineInstr *MI = I.getInstr(); |
| 847 | // Iterate over each operand, and we process the definitions. |
| 848 | for (MachineInstr::mop_iterator MOI = MI->operands_begin(), |
| 849 | MOE = MI->operands_end(); |
| 850 | MOI != MOE; ++MOI) { |
| 851 | if (!MOI->isReg()) |
| 852 | continue; |
| 853 | Register Reg = MOI->getReg(); |
| 854 | if (MOI->isDef()) { |
| 855 | // If the register is used by a Phi, then create an anti dependence. |
| 856 | for (MachineRegisterInfo::use_instr_iterator |
| 857 | UI = MRI.use_instr_begin(Reg), |
| 858 | UE = MRI.use_instr_end(); |
| 859 | UI != UE; ++UI) { |
| 860 | MachineInstr *UseMI = &*UI; |
| 861 | SUnit *SU = getSUnit(UseMI); |
| 862 | if (SU != nullptr && UseMI->isPHI()) { |
| 863 | if (!MI->isPHI()) { |
| 864 | SDep Dep(SU, SDep::Anti, Reg); |
| 865 | Dep.setLatency(1); |
| 866 | I.addPred(Dep); |
| 867 | } else { |
| 868 | HasPhiDef = Reg; |
| 869 | // Add a chain edge to a dependent Phi that isn't an existing |
| 870 | // predecessor. |
| 871 | if (SU->NodeNum < I.NodeNum && !I.isPred(SU)) |
| 872 | I.addPred(SDep(SU, SDep::Barrier)); |
| 873 | } |
| 874 | } |
| 875 | } |
| 876 | } else if (MOI->isUse()) { |
| 877 | // If the register is defined by a Phi, then create a true dependence. |
| 878 | MachineInstr *DefMI = MRI.getUniqueVRegDef(Reg); |
| 879 | if (DefMI == nullptr) |
| 880 | continue; |
| 881 | SUnit *SU = getSUnit(DefMI); |
| 882 | if (SU != nullptr && DefMI->isPHI()) { |
| 883 | if (!MI->isPHI()) { |
| 884 | SDep Dep(SU, SDep::Data, Reg); |
| 885 | Dep.setLatency(0); |
| 886 | ST.adjustSchedDependency(SU, 0, &I, MI->getOperandNo(MOI), Dep); |
| 887 | I.addPred(Dep); |
| 888 | } else { |
| 889 | HasPhiUse = Reg; |
| 890 | // Add a chain edge to a dependent Phi that isn't an existing |
| 891 | // predecessor. |
| 892 | if (SU->NodeNum < I.NodeNum && !I.isPred(SU)) |
| 893 | I.addPred(SDep(SU, SDep::Barrier)); |
| 894 | } |
| 895 | } |
| 896 | } |
| 897 | } |
| 898 | // Remove order dependences from an unrelated Phi. |
| 899 | if (!SwpPruneDeps) |
| 900 | continue; |
| 901 | for (auto &PI : I.Preds) { |
| 902 | MachineInstr *PMI = PI.getSUnit()->getInstr(); |
| 903 | if (PMI->isPHI() && PI.getKind() == SDep::Order) { |
| 904 | if (I.getInstr()->isPHI()) { |
| 905 | if (PMI->getOperand(0).getReg() == HasPhiUse) |
| 906 | continue; |
| 907 | if (getLoopPhiReg(*PMI, PMI->getParent()) == HasPhiDef) |
| 908 | continue; |
| 909 | } |
| 910 | RemoveDeps.push_back(PI); |
| 911 | } |
| 912 | } |
| 913 | for (int i = 0, e = RemoveDeps.size(); i != e; ++i) |
| 914 | I.removePred(RemoveDeps[i]); |
| 915 | } |
| 916 | } |
| 917 | |
| 918 | /// Iterate over each DAG node and see if we can change any dependences |
| 919 | /// in order to reduce the recurrence MII. |
| 920 | void SwingSchedulerDAG::changeDependences() { |
| 921 | // See if an instruction can use a value from the previous iteration. |
| 922 | // If so, we update the base and offset of the instruction and change |
| 923 | // the dependences. |
| 924 | for (SUnit &I : SUnits) { |
| 925 | unsigned BasePos = 0, OffsetPos = 0, NewBase = 0; |
| 926 | int64_t NewOffset = 0; |
| 927 | if (!canUseLastOffsetValue(I.getInstr(), BasePos, OffsetPos, NewBase, |
| 928 | NewOffset)) |
| 929 | continue; |
| 930 | |
| 931 | // Get the MI and SUnit for the instruction that defines the original base. |
| 932 | Register OrigBase = I.getInstr()->getOperand(BasePos).getReg(); |
| 933 | MachineInstr *DefMI = MRI.getUniqueVRegDef(OrigBase); |
| 934 | if (!DefMI) |
| 935 | continue; |
| 936 | SUnit *DefSU = getSUnit(DefMI); |
| 937 | if (!DefSU) |
| 938 | continue; |
| 939 | // Get the MI and SUnit for the instruction that defins the new base. |
| 940 | MachineInstr *LastMI = MRI.getUniqueVRegDef(NewBase); |
| 941 | if (!LastMI) |
| 942 | continue; |
| 943 | SUnit *LastSU = getSUnit(LastMI); |
| 944 | if (!LastSU) |
| 945 | continue; |
| 946 | |
| 947 | if (Topo.IsReachable(&I, LastSU)) |
| 948 | continue; |
| 949 | |
| 950 | // Remove the dependence. The value now depends on a prior iteration. |
| 951 | SmallVector<SDep, 4> Deps; |
| 952 | for (const SDep &P : I.Preds) |
| 953 | if (P.getSUnit() == DefSU) |
| 954 | Deps.push_back(P); |
| 955 | for (int i = 0, e = Deps.size(); i != e; i++) { |
| 956 | Topo.RemovePred(&I, Deps[i].getSUnit()); |
| 957 | I.removePred(Deps[i]); |
| 958 | } |
| 959 | // Remove the chain dependence between the instructions. |
| 960 | Deps.clear(); |
| 961 | for (auto &P : LastSU->Preds) |
| 962 | if (P.getSUnit() == &I && P.getKind() == SDep::Order) |
| 963 | Deps.push_back(P); |
| 964 | for (int i = 0, e = Deps.size(); i != e; i++) { |
| 965 | Topo.RemovePred(LastSU, Deps[i].getSUnit()); |
| 966 | LastSU->removePred(Deps[i]); |
| 967 | } |
| 968 | |
| 969 | // Add a dependence between the new instruction and the instruction |
| 970 | // that defines the new base. |
| 971 | SDep Dep(&I, SDep::Anti, NewBase); |
| 972 | Topo.AddPred(LastSU, &I); |
| 973 | LastSU->addPred(Dep); |
| 974 | |
| 975 | // Remember the base and offset information so that we can update the |
| 976 | // instruction during code generation. |
| 977 | InstrChanges[&I] = std::make_pair(NewBase, NewOffset); |
| 978 | } |
| 979 | } |
| 980 | |
| 981 | namespace { |
| 982 | |
| 983 | // FuncUnitSorter - Comparison operator used to sort instructions by |
| 984 | // the number of functional unit choices. |
| 985 | struct FuncUnitSorter { |
| 986 | const InstrItineraryData *InstrItins; |
| 987 | const MCSubtargetInfo *STI; |
| 988 | DenseMap<InstrStage::FuncUnits, unsigned> Resources; |
| 989 | |
| 990 | FuncUnitSorter(const TargetSubtargetInfo &TSI) |
| 991 | : InstrItins(TSI.getInstrItineraryData()), STI(&TSI) {} |
| 992 | |
| 993 | // Compute the number of functional unit alternatives needed |
| 994 | // at each stage, and take the minimum value. We prioritize the |
| 995 | // instructions by the least number of choices first. |
| 996 | unsigned minFuncUnits(const MachineInstr *Inst, |
| 997 | InstrStage::FuncUnits &F) const { |
| 998 | unsigned SchedClass = Inst->getDesc().getSchedClass(); |
| 999 | unsigned min = UINT_MAX(2147483647 *2U +1U); |
| 1000 | if (InstrItins && !InstrItins->isEmpty()) { |
| 1001 | for (const InstrStage &IS : |
| 1002 | make_range(InstrItins->beginStage(SchedClass), |
| 1003 | InstrItins->endStage(SchedClass))) { |
| 1004 | InstrStage::FuncUnits funcUnits = IS.getUnits(); |
| 1005 | unsigned numAlternatives = countPopulation(funcUnits); |
| 1006 | if (numAlternatives < min) { |
| 1007 | min = numAlternatives; |
| 1008 | F = funcUnits; |
| 1009 | } |
| 1010 | } |
| 1011 | return min; |
| 1012 | } |
| 1013 | if (STI && STI->getSchedModel().hasInstrSchedModel()) { |
| 1014 | const MCSchedClassDesc *SCDesc = |
| 1015 | STI->getSchedModel().getSchedClassDesc(SchedClass); |
| 1016 | if (!SCDesc->isValid()) |
| 1017 | // No valid Schedule Class Desc for schedClass, should be |
| 1018 | // Pseudo/PostRAPseudo |
| 1019 | return min; |
| 1020 | |
| 1021 | for (const MCWriteProcResEntry &PRE : |
| 1022 | make_range(STI->getWriteProcResBegin(SCDesc), |
| 1023 | STI->getWriteProcResEnd(SCDesc))) { |
| 1024 | if (!PRE.Cycles) |
| 1025 | continue; |
| 1026 | const MCProcResourceDesc *ProcResource = |
| 1027 | STI->getSchedModel().getProcResource(PRE.ProcResourceIdx); |
| 1028 | unsigned NumUnits = ProcResource->NumUnits; |
| 1029 | if (NumUnits < min) { |
| 1030 | min = NumUnits; |
| 1031 | F = PRE.ProcResourceIdx; |
| 1032 | } |
| 1033 | } |
| 1034 | return min; |
| 1035 | } |
| 1036 | llvm_unreachable("Should have non-empty InstrItins or hasInstrSchedModel!")__builtin_unreachable(); |
| 1037 | } |
| 1038 | |
| 1039 | // Compute the critical resources needed by the instruction. This |
| 1040 | // function records the functional units needed by instructions that |
| 1041 | // must use only one functional unit. We use this as a tie breaker |
| 1042 | // for computing the resource MII. The instrutions that require |
| 1043 | // the same, highly used, functional unit have high priority. |
| 1044 | void calcCriticalResources(MachineInstr &MI) { |
| 1045 | unsigned SchedClass = MI.getDesc().getSchedClass(); |
| 1046 | if (InstrItins && !InstrItins->isEmpty()) { |
| 1047 | for (const InstrStage &IS : |
| 1048 | make_range(InstrItins->beginStage(SchedClass), |
| 1049 | InstrItins->endStage(SchedClass))) { |
| 1050 | InstrStage::FuncUnits FuncUnits = IS.getUnits(); |
| 1051 | if (countPopulation(FuncUnits) == 1) |
| 1052 | Resources[FuncUnits]++; |
| 1053 | } |
| 1054 | return; |
| 1055 | } |
| 1056 | if (STI && STI->getSchedModel().hasInstrSchedModel()) { |
| 1057 | const MCSchedClassDesc *SCDesc = |
| 1058 | STI->getSchedModel().getSchedClassDesc(SchedClass); |
| 1059 | if (!SCDesc->isValid()) |
| 1060 | // No valid Schedule Class Desc for schedClass, should be |
| 1061 | // Pseudo/PostRAPseudo |
| 1062 | return; |
| 1063 | |
| 1064 | for (const MCWriteProcResEntry &PRE : |
| 1065 | make_range(STI->getWriteProcResBegin(SCDesc), |
| 1066 | STI->getWriteProcResEnd(SCDesc))) { |
| 1067 | if (!PRE.Cycles) |
| 1068 | continue; |
| 1069 | Resources[PRE.ProcResourceIdx]++; |
| 1070 | } |
| 1071 | return; |
| 1072 | } |
| 1073 | llvm_unreachable("Should have non-empty InstrItins or hasInstrSchedModel!")__builtin_unreachable(); |
| 1074 | } |
| 1075 | |
| 1076 | /// Return true if IS1 has less priority than IS2. |
| 1077 | bool operator()(const MachineInstr *IS1, const MachineInstr *IS2) const { |
| 1078 | InstrStage::FuncUnits F1 = 0, F2 = 0; |
| 1079 | unsigned MFUs1 = minFuncUnits(IS1, F1); |
| 1080 | unsigned MFUs2 = minFuncUnits(IS2, F2); |
| 1081 | if (MFUs1 == MFUs2) |
| 1082 | return Resources.lookup(F1) < Resources.lookup(F2); |
| 1083 | return MFUs1 > MFUs2; |
| 1084 | } |
| 1085 | }; |
| 1086 | |
| 1087 | } // end anonymous namespace |
| 1088 | |
| 1089 | /// Calculate the resource constrained minimum initiation interval for the |
| 1090 | /// specified loop. We use the DFA to model the resources needed for |
| 1091 | /// each instruction, and we ignore dependences. A different DFA is created |
| 1092 | /// for each cycle that is required. When adding a new instruction, we attempt |
| 1093 | /// to add it to each existing DFA, until a legal space is found. If the |
| 1094 | /// instruction cannot be reserved in an existing DFA, we create a new one. |
| 1095 | unsigned SwingSchedulerDAG::calculateResMII() { |
| 1096 | |
| 1097 | LLVM_DEBUG(dbgs() << "calculateResMII:\n")do { } while (false); |
| 1098 | SmallVector<ResourceManager*, 8> Resources; |
| 1099 | MachineBasicBlock *MBB = Loop.getHeader(); |
| 1100 | Resources.push_back(new ResourceManager(&MF.getSubtarget())); |
| 1101 | |
| 1102 | // Sort the instructions by the number of available choices for scheduling, |
| 1103 | // least to most. Use the number of critical resources as the tie breaker. |
| 1104 | FuncUnitSorter FUS = FuncUnitSorter(MF.getSubtarget()); |
| 1105 | for (MachineBasicBlock::iterator I = MBB->getFirstNonPHI(), |
| 1106 | E = MBB->getFirstTerminator(); |
| 1107 | I != E; ++I) |
| 1108 | FUS.calcCriticalResources(*I); |
| 1109 | PriorityQueue<MachineInstr *, std::vector<MachineInstr *>, FuncUnitSorter> |
| 1110 | FuncUnitOrder(FUS); |
| 1111 | |
| 1112 | for (MachineBasicBlock::iterator I = MBB->getFirstNonPHI(), |
| 1113 | E = MBB->getFirstTerminator(); |
| 1114 | I != E; ++I) |
| 1115 | FuncUnitOrder.push(&*I); |
| 1116 | |
| 1117 | while (!FuncUnitOrder.empty()) { |
| 1118 | MachineInstr *MI = FuncUnitOrder.top(); |
| 1119 | FuncUnitOrder.pop(); |
| 1120 | if (TII->isZeroCost(MI->getOpcode())) |
| 1121 | continue; |
| 1122 | // Attempt to reserve the instruction in an existing DFA. At least one |
| 1123 | // DFA is needed for each cycle. |
| 1124 | unsigned NumCycles = getSUnit(MI)->Latency; |
| 1125 | unsigned ReservedCycles = 0; |
| 1126 | SmallVectorImpl<ResourceManager *>::iterator RI = Resources.begin(); |
| 1127 | SmallVectorImpl<ResourceManager *>::iterator RE = Resources.end(); |
| 1128 | LLVM_DEBUG({do { } while (false) |
| 1129 | dbgs() << "Trying to reserve resource for " << NumCyclesdo { } while (false) |
| 1130 | << " cycles for \n";do { } while (false) |
| 1131 | MI->dump();do { } while (false) |
| 1132 | })do { } while (false); |
| 1133 | for (unsigned C = 0; C < NumCycles; ++C) |
| 1134 | while (RI != RE) { |
| 1135 | if ((*RI)->canReserveResources(*MI)) { |
| 1136 | (*RI)->reserveResources(*MI); |
| 1137 | ++ReservedCycles; |
| 1138 | break; |
| 1139 | } |
| 1140 | RI++; |
| 1141 | } |
| 1142 | LLVM_DEBUG(dbgs() << "ReservedCycles:" << ReservedCyclesdo { } while (false) |
| 1143 | << ", NumCycles:" << NumCycles << "\n")do { } while (false); |
| 1144 | // Add new DFAs, if needed, to reserve resources. |
| 1145 | for (unsigned C = ReservedCycles; C < NumCycles; ++C) { |
| 1146 | LLVM_DEBUG(if (SwpDebugResource) dbgs()do { } while (false) |
| 1147 | << "NewResource created to reserve resources"do { } while (false) |
| 1148 | << "\n")do { } while (false); |
| 1149 | ResourceManager *NewResource = new ResourceManager(&MF.getSubtarget()); |
| 1150 | assert(NewResource->canReserveResources(*MI) && "Reserve error.")((void)0); |
| 1151 | NewResource->reserveResources(*MI); |
| 1152 | Resources.push_back(NewResource); |
| 1153 | } |
| 1154 | } |
| 1155 | int Resmii = Resources.size(); |
| 1156 | LLVM_DEBUG(dbgs() << "Return Res MII:" << Resmii << "\n")do { } while (false); |
| 1157 | // Delete the memory for each of the DFAs that were created earlier. |
| 1158 | for (ResourceManager *RI : Resources) { |
| 1159 | ResourceManager *D = RI; |
| 1160 | delete D; |
| 1161 | } |
| 1162 | Resources.clear(); |
| 1163 | return Resmii; |
| 1164 | } |
| 1165 | |
| 1166 | /// Calculate the recurrence-constrainted minimum initiation interval. |
| 1167 | /// Iterate over each circuit. Compute the delay(c) and distance(c) |
| 1168 | /// for each circuit. The II needs to satisfy the inequality |
| 1169 | /// delay(c) - II*distance(c) <= 0. For each circuit, choose the smallest |
| 1170 | /// II that satisfies the inequality, and the RecMII is the maximum |
| 1171 | /// of those values. |
| 1172 | unsigned SwingSchedulerDAG::calculateRecMII(NodeSetType &NodeSets) { |
| 1173 | unsigned RecMII = 0; |
| 1174 | |
| 1175 | for (NodeSet &Nodes : NodeSets) { |
| 1176 | if (Nodes.empty()) |
| 1177 | continue; |
| 1178 | |
| 1179 | unsigned Delay = Nodes.getLatency(); |
| 1180 | unsigned Distance = 1; |
| 1181 | |
| 1182 | // ii = ceil(delay / distance) |
| 1183 | unsigned CurMII = (Delay + Distance - 1) / Distance; |
| 1184 | Nodes.setRecMII(CurMII); |
| 1185 | if (CurMII > RecMII) |
| 1186 | RecMII = CurMII; |
| 1187 | } |
| 1188 | |
| 1189 | return RecMII; |
| 1190 | } |
| 1191 | |
| 1192 | /// Swap all the anti dependences in the DAG. That means it is no longer a DAG, |
| 1193 | /// but we do this to find the circuits, and then change them back. |
| 1194 | static void swapAntiDependences(std::vector<SUnit> &SUnits) { |
| 1195 | SmallVector<std::pair<SUnit *, SDep>, 8> DepsAdded; |
| 1196 | for (unsigned i = 0, e = SUnits.size(); i != e; ++i) { |
| 1197 | SUnit *SU = &SUnits[i]; |
| 1198 | for (SUnit::pred_iterator IP = SU->Preds.begin(), EP = SU->Preds.end(); |
| 1199 | IP != EP; ++IP) { |
| 1200 | if (IP->getKind() != SDep::Anti) |
| 1201 | continue; |
| 1202 | DepsAdded.push_back(std::make_pair(SU, *IP)); |
| 1203 | } |
| 1204 | } |
| 1205 | for (std::pair<SUnit *, SDep> &P : DepsAdded) { |
| 1206 | // Remove this anti dependency and add one in the reverse direction. |
| 1207 | SUnit *SU = P.first; |
| 1208 | SDep &D = P.second; |
| 1209 | SUnit *TargetSU = D.getSUnit(); |
| 1210 | unsigned Reg = D.getReg(); |
| 1211 | unsigned Lat = D.getLatency(); |
| 1212 | SU->removePred(D); |
| 1213 | SDep Dep(SU, SDep::Anti, Reg); |
| 1214 | Dep.setLatency(Lat); |
| 1215 | TargetSU->addPred(Dep); |
| 1216 | } |
| 1217 | } |
| 1218 | |
| 1219 | /// Create the adjacency structure of the nodes in the graph. |
| 1220 | void SwingSchedulerDAG::Circuits::createAdjacencyStructure( |
| 1221 | SwingSchedulerDAG *DAG) { |
| 1222 | BitVector Added(SUnits.size()); |
| 1223 | DenseMap<int, int> OutputDeps; |
| 1224 | for (int i = 0, e = SUnits.size(); i != e; ++i) { |
| 1225 | Added.reset(); |
| 1226 | // Add any successor to the adjacency matrix and exclude duplicates. |
| 1227 | for (auto &SI : SUnits[i].Succs) { |
| 1228 | // Only create a back-edge on the first and last nodes of a dependence |
| 1229 | // chain. This records any chains and adds them later. |
| 1230 | if (SI.getKind() == SDep::Output) { |
| 1231 | int N = SI.getSUnit()->NodeNum; |
| 1232 | int BackEdge = i; |
| 1233 | auto Dep = OutputDeps.find(BackEdge); |
| 1234 | if (Dep != OutputDeps.end()) { |
| 1235 | BackEdge = Dep->second; |
| 1236 | OutputDeps.erase(Dep); |
| 1237 | } |
| 1238 | OutputDeps[N] = BackEdge; |
| 1239 | } |
| 1240 | // Do not process a boundary node, an artificial node. |
| 1241 | // A back-edge is processed only if it goes to a Phi. |
| 1242 | if (SI.getSUnit()->isBoundaryNode() || SI.isArtificial() || |
| 1243 | (SI.getKind() == SDep::Anti && !SI.getSUnit()->getInstr()->isPHI())) |
| 1244 | continue; |
| 1245 | int N = SI.getSUnit()->NodeNum; |
| 1246 | if (!Added.test(N)) { |
| 1247 | AdjK[i].push_back(N); |
| 1248 | Added.set(N); |
| 1249 | } |
| 1250 | } |
| 1251 | // A chain edge between a store and a load is treated as a back-edge in the |
| 1252 | // adjacency matrix. |
| 1253 | for (auto &PI : SUnits[i].Preds) { |
| 1254 | if (!SUnits[i].getInstr()->mayStore() || |
| 1255 | !DAG->isLoopCarriedDep(&SUnits[i], PI, false)) |
| 1256 | continue; |
| 1257 | if (PI.getKind() == SDep::Order && PI.getSUnit()->getInstr()->mayLoad()) { |
| 1258 | int N = PI.getSUnit()->NodeNum; |
| 1259 | if (!Added.test(N)) { |
| 1260 | AdjK[i].push_back(N); |
| 1261 | Added.set(N); |
| 1262 | } |
| 1263 | } |
| 1264 | } |
| 1265 | } |
| 1266 | // Add back-edges in the adjacency matrix for the output dependences. |
| 1267 | for (auto &OD : OutputDeps) |
| 1268 | if (!Added.test(OD.second)) { |
| 1269 | AdjK[OD.first].push_back(OD.second); |
| 1270 | Added.set(OD.second); |
| 1271 | } |
| 1272 | } |
| 1273 | |
| 1274 | /// Identify an elementary circuit in the dependence graph starting at the |
| 1275 | /// specified node. |
| 1276 | bool SwingSchedulerDAG::Circuits::circuit(int V, int S, NodeSetType &NodeSets, |
| 1277 | bool HasBackedge) { |
| 1278 | SUnit *SV = &SUnits[V]; |
| 1279 | bool F = false; |
| 1280 | Stack.insert(SV); |
| 1281 | Blocked.set(V); |
| 1282 | |
| 1283 | for (auto W : AdjK[V]) { |
| 1284 | if (NumPaths > MaxPaths) |
| 1285 | break; |
| 1286 | if (W < S) |
| 1287 | continue; |
| 1288 | if (W == S) { |
| 1289 | if (!HasBackedge) |
| 1290 | NodeSets.push_back(NodeSet(Stack.begin(), Stack.end())); |
| 1291 | F = true; |
| 1292 | ++NumPaths; |
| 1293 | break; |
| 1294 | } else if (!Blocked.test(W)) { |
| 1295 | if (circuit(W, S, NodeSets, |
| 1296 | Node2Idx->at(W) < Node2Idx->at(V) ? true : HasBackedge)) |
| 1297 | F = true; |
| 1298 | } |
| 1299 | } |
| 1300 | |
| 1301 | if (F) |
| 1302 | unblock(V); |
| 1303 | else { |
| 1304 | for (auto W : AdjK[V]) { |
| 1305 | if (W < S) |
| 1306 | continue; |
| 1307 | if (B[W].count(SV) == 0) |
| 1308 | B[W].insert(SV); |
| 1309 | } |
| 1310 | } |
| 1311 | Stack.pop_back(); |
| 1312 | return F; |
| 1313 | } |
| 1314 | |
| 1315 | /// Unblock a node in the circuit finding algorithm. |
| 1316 | void SwingSchedulerDAG::Circuits::unblock(int U) { |
| 1317 | Blocked.reset(U); |
| 1318 | SmallPtrSet<SUnit *, 4> &BU = B[U]; |
| 1319 | while (!BU.empty()) { |
| 1320 | SmallPtrSet<SUnit *, 4>::iterator SI = BU.begin(); |
| 1321 | assert(SI != BU.end() && "Invalid B set.")((void)0); |
| 1322 | SUnit *W = *SI; |
| 1323 | BU.erase(W); |
| 1324 | if (Blocked.test(W->NodeNum)) |
| 1325 | unblock(W->NodeNum); |
| 1326 | } |
| 1327 | } |
| 1328 | |
| 1329 | /// Identify all the elementary circuits in the dependence graph using |
| 1330 | /// Johnson's circuit algorithm. |
| 1331 | void SwingSchedulerDAG::findCircuits(NodeSetType &NodeSets) { |
| 1332 | // Swap all the anti dependences in the DAG. That means it is no longer a DAG, |
| 1333 | // but we do this to find the circuits, and then change them back. |
| 1334 | swapAntiDependences(SUnits); |
| 1335 | |
| 1336 | Circuits Cir(SUnits, Topo); |
| 1337 | // Create the adjacency structure. |
| 1338 | Cir.createAdjacencyStructure(this); |
| 1339 | for (int i = 0, e = SUnits.size(); i != e; ++i) { |
| 1340 | Cir.reset(); |
| 1341 | Cir.circuit(i, i, NodeSets); |
| 1342 | } |
| 1343 | |
| 1344 | // Change the dependences back so that we've created a DAG again. |
| 1345 | swapAntiDependences(SUnits); |
| 1346 | } |
| 1347 | |
| 1348 | // Create artificial dependencies between the source of COPY/REG_SEQUENCE that |
| 1349 | // is loop-carried to the USE in next iteration. This will help pipeliner avoid |
| 1350 | // additional copies that are needed across iterations. An artificial dependence |
| 1351 | // edge is added from USE to SOURCE of COPY/REG_SEQUENCE. |
| 1352 | |
| 1353 | // PHI-------Anti-Dep-----> COPY/REG_SEQUENCE (loop-carried) |
| 1354 | // SRCOfCopY------True-Dep---> COPY/REG_SEQUENCE |
| 1355 | // PHI-------True-Dep------> USEOfPhi |
| 1356 | |
| 1357 | // The mutation creates |
| 1358 | // USEOfPHI -------Artificial-Dep---> SRCOfCopy |
| 1359 | |
| 1360 | // This overall will ensure, the USEOfPHI is scheduled before SRCOfCopy |
| 1361 | // (since USE is a predecessor), implies, the COPY/ REG_SEQUENCE is scheduled |
| 1362 | // late to avoid additional copies across iterations. The possible scheduling |
| 1363 | // order would be |
| 1364 | // USEOfPHI --- SRCOfCopy--- COPY/REG_SEQUENCE. |
| 1365 | |
| 1366 | void SwingSchedulerDAG::CopyToPhiMutation::apply(ScheduleDAGInstrs *DAG) { |
| 1367 | for (SUnit &SU : DAG->SUnits) { |
| 1368 | // Find the COPY/REG_SEQUENCE instruction. |
| 1369 | if (!SU.getInstr()->isCopy() && !SU.getInstr()->isRegSequence()) |
| 1370 | continue; |
| 1371 | |
| 1372 | // Record the loop carried PHIs. |
| 1373 | SmallVector<SUnit *, 4> PHISUs; |
| 1374 | // Record the SrcSUs that feed the COPY/REG_SEQUENCE instructions. |
| 1375 | SmallVector<SUnit *, 4> SrcSUs; |
| 1376 | |
| 1377 | for (auto &Dep : SU.Preds) { |
| 1378 | SUnit *TmpSU = Dep.getSUnit(); |
| 1379 | MachineInstr *TmpMI = TmpSU->getInstr(); |
| 1380 | SDep::Kind DepKind = Dep.getKind(); |
| 1381 | // Save the loop carried PHI. |
| 1382 | if (DepKind == SDep::Anti && TmpMI->isPHI()) |
| 1383 | PHISUs.push_back(TmpSU); |
| 1384 | // Save the source of COPY/REG_SEQUENCE. |
| 1385 | // If the source has no pre-decessors, we will end up creating cycles. |
| 1386 | else if (DepKind == SDep::Data && !TmpMI->isPHI() && TmpSU->NumPreds > 0) |
| 1387 | SrcSUs.push_back(TmpSU); |
| 1388 | } |
| 1389 | |
| 1390 | if (PHISUs.size() == 0 || SrcSUs.size() == 0) |
| 1391 | continue; |
| 1392 | |
| 1393 | // Find the USEs of PHI. If the use is a PHI or REG_SEQUENCE, push back this |
| 1394 | // SUnit to the container. |
| 1395 | SmallVector<SUnit *, 8> UseSUs; |
| 1396 | // Do not use iterator based loop here as we are updating the container. |
| 1397 | for (size_t Index = 0; Index < PHISUs.size(); ++Index) { |
| 1398 | for (auto &Dep : PHISUs[Index]->Succs) { |
| 1399 | if (Dep.getKind() != SDep::Data) |
| 1400 | continue; |
| 1401 | |
| 1402 | SUnit *TmpSU = Dep.getSUnit(); |
| 1403 | MachineInstr *TmpMI = TmpSU->getInstr(); |
| 1404 | if (TmpMI->isPHI() || TmpMI->isRegSequence()) { |
| 1405 | PHISUs.push_back(TmpSU); |
| 1406 | continue; |
| 1407 | } |
| 1408 | UseSUs.push_back(TmpSU); |
| 1409 | } |
| 1410 | } |
| 1411 | |
| 1412 | if (UseSUs.size() == 0) |
| 1413 | continue; |
| 1414 | |
| 1415 | SwingSchedulerDAG *SDAG = cast<SwingSchedulerDAG>(DAG); |
| 1416 | // Add the artificial dependencies if it does not form a cycle. |
| 1417 | for (auto I : UseSUs) { |
| 1418 | for (auto Src : SrcSUs) { |
| 1419 | if (!SDAG->Topo.IsReachable(I, Src) && Src != I) { |
| 1420 | Src->addPred(SDep(I, SDep::Artificial)); |
| 1421 | SDAG->Topo.AddPred(Src, I); |
| 1422 | } |
| 1423 | } |
| 1424 | } |
| 1425 | } |
| 1426 | } |
| 1427 | |
| 1428 | /// Return true for DAG nodes that we ignore when computing the cost functions. |
| 1429 | /// We ignore the back-edge recurrence in order to avoid unbounded recursion |
| 1430 | /// in the calculation of the ASAP, ALAP, etc functions. |
| 1431 | static bool ignoreDependence(const SDep &D, bool isPred) { |
| 1432 | if (D.isArtificial()) |
| 1433 | return true; |
| 1434 | return D.getKind() == SDep::Anti && isPred; |
| 1435 | } |
| 1436 | |
| 1437 | /// Compute several functions need to order the nodes for scheduling. |
| 1438 | /// ASAP - Earliest time to schedule a node. |
| 1439 | /// ALAP - Latest time to schedule a node. |
| 1440 | /// MOV - Mobility function, difference between ALAP and ASAP. |
| 1441 | /// D - Depth of each node. |
| 1442 | /// H - Height of each node. |
| 1443 | void SwingSchedulerDAG::computeNodeFunctions(NodeSetType &NodeSets) { |
| 1444 | ScheduleInfo.resize(SUnits.size()); |
| 1445 | |
| 1446 | LLVM_DEBUG({do { } while (false) |
| 1447 | for (int I : Topo) {do { } while (false) |
| 1448 | const SUnit &SU = SUnits[I];do { } while (false) |
| 1449 | dumpNode(SU);do { } while (false) |
| 1450 | }do { } while (false) |
| 1451 | })do { } while (false); |
| 1452 | |
| 1453 | int maxASAP = 0; |
| 1454 | // Compute ASAP and ZeroLatencyDepth. |
| 1455 | for (int I : Topo) { |
| 1456 | int asap = 0; |
| 1457 | int zeroLatencyDepth = 0; |
| 1458 | SUnit *SU = &SUnits[I]; |
| 1459 | for (SUnit::const_pred_iterator IP = SU->Preds.begin(), |
| 1460 | EP = SU->Preds.end(); |
| 1461 | IP != EP; ++IP) { |
| 1462 | SUnit *pred = IP->getSUnit(); |
| 1463 | if (IP->getLatency() == 0) |
| 1464 | zeroLatencyDepth = |
| 1465 | std::max(zeroLatencyDepth, getZeroLatencyDepth(pred) + 1); |
| 1466 | if (ignoreDependence(*IP, true)) |
| 1467 | continue; |
| 1468 | asap = std::max(asap, (int)(getASAP(pred) + IP->getLatency() - |
| 1469 | getDistance(pred, SU, *IP) * MII)); |
| 1470 | } |
| 1471 | maxASAP = std::max(maxASAP, asap); |
| 1472 | ScheduleInfo[I].ASAP = asap; |
| 1473 | ScheduleInfo[I].ZeroLatencyDepth = zeroLatencyDepth; |
| 1474 | } |
| 1475 | |
| 1476 | // Compute ALAP, ZeroLatencyHeight, and MOV. |
| 1477 | for (ScheduleDAGTopologicalSort::const_reverse_iterator I = Topo.rbegin(), |
| 1478 | E = Topo.rend(); |
| 1479 | I != E; ++I) { |
| 1480 | int alap = maxASAP; |
| 1481 | int zeroLatencyHeight = 0; |
| 1482 | SUnit *SU = &SUnits[*I]; |
| 1483 | for (SUnit::const_succ_iterator IS = SU->Succs.begin(), |
| 1484 | ES = SU->Succs.end(); |
| 1485 | IS != ES; ++IS) { |
| 1486 | SUnit *succ = IS->getSUnit(); |
| 1487 | if (IS->getLatency() == 0) |
| 1488 | zeroLatencyHeight = |
| 1489 | std::max(zeroLatencyHeight, getZeroLatencyHeight(succ) + 1); |
| 1490 | if (ignoreDependence(*IS, true)) |
| 1491 | continue; |
| 1492 | alap = std::min(alap, (int)(getALAP(succ) - IS->getLatency() + |
| 1493 | getDistance(SU, succ, *IS) * MII)); |
| 1494 | } |
| 1495 | |
| 1496 | ScheduleInfo[*I].ALAP = alap; |
| 1497 | ScheduleInfo[*I].ZeroLatencyHeight = zeroLatencyHeight; |
| 1498 | } |
| 1499 | |
| 1500 | // After computing the node functions, compute the summary for each node set. |
| 1501 | for (NodeSet &I : NodeSets) |
| 1502 | I.computeNodeSetInfo(this); |
| 1503 | |
| 1504 | LLVM_DEBUG({do { } while (false) |
| 1505 | for (unsigned i = 0; i < SUnits.size(); i++) {do { } while (false) |
| 1506 | dbgs() << "\tNode " << i << ":\n";do { } while (false) |
| 1507 | dbgs() << "\t ASAP = " << getASAP(&SUnits[i]) << "\n";do { } while (false) |
| 1508 | dbgs() << "\t ALAP = " << getALAP(&SUnits[i]) << "\n";do { } while (false) |
| 1509 | dbgs() << "\t MOV = " << getMOV(&SUnits[i]) << "\n";do { } while (false) |
| 1510 | dbgs() << "\t D = " << getDepth(&SUnits[i]) << "\n";do { } while (false) |
| 1511 | dbgs() << "\t H = " << getHeight(&SUnits[i]) << "\n";do { } while (false) |
| 1512 | dbgs() << "\t ZLD = " << getZeroLatencyDepth(&SUnits[i]) << "\n";do { } while (false) |
| 1513 | dbgs() << "\t ZLH = " << getZeroLatencyHeight(&SUnits[i]) << "\n";do { } while (false) |
| 1514 | }do { } while (false) |
| 1515 | })do { } while (false); |
| 1516 | } |
| 1517 | |
| 1518 | /// Compute the Pred_L(O) set, as defined in the paper. The set is defined |
| 1519 | /// as the predecessors of the elements of NodeOrder that are not also in |
| 1520 | /// NodeOrder. |
| 1521 | static bool pred_L(SetVector<SUnit *> &NodeOrder, |
| 1522 | SmallSetVector<SUnit *, 8> &Preds, |
| 1523 | const NodeSet *S = nullptr) { |
| 1524 | Preds.clear(); |
| 1525 | for (SetVector<SUnit *>::iterator I = NodeOrder.begin(), E = NodeOrder.end(); |
| 1526 | I != E; ++I) { |
| 1527 | for (const SDep &Pred : (*I)->Preds) { |
| 1528 | if (S && S->count(Pred.getSUnit()) == 0) |
| 1529 | continue; |
| 1530 | if (ignoreDependence(Pred, true)) |
| 1531 | continue; |
| 1532 | if (NodeOrder.count(Pred.getSUnit()) == 0) |
| 1533 | Preds.insert(Pred.getSUnit()); |
| 1534 | } |
| 1535 | // Back-edges are predecessors with an anti-dependence. |
| 1536 | for (const SDep &Succ : (*I)->Succs) { |
| 1537 | if (Succ.getKind() != SDep::Anti) |
| 1538 | continue; |
| 1539 | if (S && S->count(Succ.getSUnit()) == 0) |
| 1540 | continue; |
| 1541 | if (NodeOrder.count(Succ.getSUnit()) == 0) |
| 1542 | Preds.insert(Succ.getSUnit()); |
| 1543 | } |
| 1544 | } |
| 1545 | return !Preds.empty(); |
| 1546 | } |
| 1547 | |
| 1548 | /// Compute the Succ_L(O) set, as defined in the paper. The set is defined |
| 1549 | /// as the successors of the elements of NodeOrder that are not also in |
| 1550 | /// NodeOrder. |
| 1551 | static bool succ_L(SetVector<SUnit *> &NodeOrder, |
| 1552 | SmallSetVector<SUnit *, 8> &Succs, |
| 1553 | const NodeSet *S = nullptr) { |
| 1554 | Succs.clear(); |
| 1555 | for (SetVector<SUnit *>::iterator I = NodeOrder.begin(), E = NodeOrder.end(); |
| 1556 | I != E; ++I) { |
| 1557 | for (SDep &Succ : (*I)->Succs) { |
| 1558 | if (S && S->count(Succ.getSUnit()) == 0) |
| 1559 | continue; |
| 1560 | if (ignoreDependence(Succ, false)) |
| 1561 | continue; |
| 1562 | if (NodeOrder.count(Succ.getSUnit()) == 0) |
| 1563 | Succs.insert(Succ.getSUnit()); |
| 1564 | } |
| 1565 | for (SDep &Pred : (*I)->Preds) { |
| 1566 | if (Pred.getKind() != SDep::Anti) |
| 1567 | continue; |
| 1568 | if (S && S->count(Pred.getSUnit()) == 0) |
| 1569 | continue; |
| 1570 | if (NodeOrder.count(Pred.getSUnit()) == 0) |
| 1571 | Succs.insert(Pred.getSUnit()); |
| 1572 | } |
| 1573 | } |
| 1574 | return !Succs.empty(); |
| 1575 | } |
| 1576 | |
| 1577 | /// Return true if there is a path from the specified node to any of the nodes |
| 1578 | /// in DestNodes. Keep track and return the nodes in any path. |
| 1579 | static bool computePath(SUnit *Cur, SetVector<SUnit *> &Path, |
| 1580 | SetVector<SUnit *> &DestNodes, |
| 1581 | SetVector<SUnit *> &Exclude, |
| 1582 | SmallPtrSet<SUnit *, 8> &Visited) { |
| 1583 | if (Cur->isBoundaryNode()) |
| 1584 | return false; |
| 1585 | if (Exclude.contains(Cur)) |
| 1586 | return false; |
| 1587 | if (DestNodes.contains(Cur)) |
| 1588 | return true; |
| 1589 | if (!Visited.insert(Cur).second) |
| 1590 | return Path.contains(Cur); |
| 1591 | bool FoundPath = false; |
| 1592 | for (auto &SI : Cur->Succs) |
| 1593 | FoundPath |= computePath(SI.getSUnit(), Path, DestNodes, Exclude, Visited); |
| 1594 | for (auto &PI : Cur->Preds) |
| 1595 | if (PI.getKind() == SDep::Anti) |
| 1596 | FoundPath |= |
| 1597 | computePath(PI.getSUnit(), Path, DestNodes, Exclude, Visited); |
| 1598 | if (FoundPath) |
| 1599 | Path.insert(Cur); |
| 1600 | return FoundPath; |
| 1601 | } |
| 1602 | |
| 1603 | /// Compute the live-out registers for the instructions in a node-set. |
| 1604 | /// The live-out registers are those that are defined in the node-set, |
| 1605 | /// but not used. Except for use operands of Phis. |
| 1606 | static void computeLiveOuts(MachineFunction &MF, RegPressureTracker &RPTracker, |
| 1607 | NodeSet &NS) { |
| 1608 | const TargetRegisterInfo *TRI = MF.getSubtarget().getRegisterInfo(); |
| 1609 | MachineRegisterInfo &MRI = MF.getRegInfo(); |
| 1610 | SmallVector<RegisterMaskPair, 8> LiveOutRegs; |
| 1611 | SmallSet<unsigned, 4> Uses; |
| 1612 | for (SUnit *SU : NS) { |
| 1613 | const MachineInstr *MI = SU->getInstr(); |
| 1614 | if (MI->isPHI()) |
| 1615 | continue; |
| 1616 | for (const MachineOperand &MO : MI->operands()) |
| 1617 | if (MO.isReg() && MO.isUse()) { |
| 1618 | Register Reg = MO.getReg(); |
| 1619 | if (Register::isVirtualRegister(Reg)) |
| 1620 | Uses.insert(Reg); |
| 1621 | else if (MRI.isAllocatable(Reg)) |
| 1622 | for (MCRegUnitIterator Units(Reg.asMCReg(), TRI); Units.isValid(); |
| 1623 | ++Units) |
| 1624 | Uses.insert(*Units); |
| 1625 | } |
| 1626 | } |
| 1627 | for (SUnit *SU : NS) |
| 1628 | for (const MachineOperand &MO : SU->getInstr()->operands()) |
| 1629 | if (MO.isReg() && MO.isDef() && !MO.isDead()) { |
| 1630 | Register Reg = MO.getReg(); |
| 1631 | if (Register::isVirtualRegister(Reg)) { |
| 1632 | if (!Uses.count(Reg)) |
| 1633 | LiveOutRegs.push_back(RegisterMaskPair(Reg, |
| 1634 | LaneBitmask::getNone())); |
| 1635 | } else if (MRI.isAllocatable(Reg)) { |
| 1636 | for (MCRegUnitIterator Units(Reg.asMCReg(), TRI); Units.isValid(); |
| 1637 | ++Units) |
| 1638 | if (!Uses.count(*Units)) |
| 1639 | LiveOutRegs.push_back(RegisterMaskPair(*Units, |
| 1640 | LaneBitmask::getNone())); |
| 1641 | } |
| 1642 | } |
| 1643 | RPTracker.addLiveRegs(LiveOutRegs); |
| 1644 | } |
| 1645 | |
| 1646 | /// A heuristic to filter nodes in recurrent node-sets if the register |
| 1647 | /// pressure of a set is too high. |
| 1648 | void SwingSchedulerDAG::registerPressureFilter(NodeSetType &NodeSets) { |
| 1649 | for (auto &NS : NodeSets) { |
| 1650 | // Skip small node-sets since they won't cause register pressure problems. |
| 1651 | if (NS.size() <= 2) |
| 1652 | continue; |
| 1653 | IntervalPressure RecRegPressure; |
| 1654 | RegPressureTracker RecRPTracker(RecRegPressure); |
| 1655 | RecRPTracker.init(&MF, &RegClassInfo, &LIS, BB, BB->end(), false, true); |
| 1656 | computeLiveOuts(MF, RecRPTracker, NS); |
| 1657 | RecRPTracker.closeBottom(); |
| 1658 | |
| 1659 | std::vector<SUnit *> SUnits(NS.begin(), NS.end()); |
| 1660 | llvm::sort(SUnits, [](const SUnit *A, const SUnit *B) { |
| 1661 | return A->NodeNum > B->NodeNum; |
| 1662 | }); |
| 1663 | |
| 1664 | for (auto &SU : SUnits) { |
| 1665 | // Since we're computing the register pressure for a subset of the |
| 1666 | // instructions in a block, we need to set the tracker for each |
| 1667 | // instruction in the node-set. The tracker is set to the instruction |
| 1668 | // just after the one we're interested in. |
| 1669 | MachineBasicBlock::const_iterator CurInstI = SU->getInstr(); |
| 1670 | RecRPTracker.setPos(std::next(CurInstI)); |
| 1671 | |
| 1672 | RegPressureDelta RPDelta; |
| 1673 | ArrayRef<PressureChange> CriticalPSets; |
| 1674 | RecRPTracker.getMaxUpwardPressureDelta(SU->getInstr(), nullptr, RPDelta, |
| 1675 | CriticalPSets, |
| 1676 | RecRegPressure.MaxSetPressure); |
| 1677 | if (RPDelta.Excess.isValid()) { |
| 1678 | LLVM_DEBUG(do { } while (false) |
| 1679 | dbgs() << "Excess register pressure: SU(" << SU->NodeNum << ") "do { } while (false) |
| 1680 | << TRI->getRegPressureSetName(RPDelta.Excess.getPSet())do { } while (false) |
| 1681 | << ":" << RPDelta.Excess.getUnitInc())do { } while (false); |
| 1682 | NS.setExceedPressure(SU); |
| 1683 | break; |
| 1684 | } |
| 1685 | RecRPTracker.recede(); |
| 1686 | } |
| 1687 | } |
| 1688 | } |
| 1689 | |
| 1690 | /// A heuristic to colocate node sets that have the same set of |
| 1691 | /// successors. |
| 1692 | void SwingSchedulerDAG::colocateNodeSets(NodeSetType &NodeSets) { |
| 1693 | unsigned Colocate = 0; |
| 1694 | for (int i = 0, e = NodeSets.size(); i < e; ++i) { |
| 1695 | NodeSet &N1 = NodeSets[i]; |
| 1696 | SmallSetVector<SUnit *, 8> S1; |
| 1697 | if (N1.empty() || !succ_L(N1, S1)) |
| 1698 | continue; |
| 1699 | for (int j = i + 1; j < e; ++j) { |
| 1700 | NodeSet &N2 = NodeSets[j]; |
| 1701 | if (N1.compareRecMII(N2) != 0) |
| 1702 | continue; |
| 1703 | SmallSetVector<SUnit *, 8> S2; |
| 1704 | if (N2.empty() || !succ_L(N2, S2)) |
| 1705 | continue; |
| 1706 | if (llvm::set_is_subset(S1, S2) && S1.size() == S2.size()) { |
| 1707 | N1.setColocate(++Colocate); |
| 1708 | N2.setColocate(Colocate); |
| 1709 | break; |
| 1710 | } |
| 1711 | } |
| 1712 | } |
| 1713 | } |
| 1714 | |
| 1715 | /// Check if the existing node-sets are profitable. If not, then ignore the |
| 1716 | /// recurrent node-sets, and attempt to schedule all nodes together. This is |
| 1717 | /// a heuristic. If the MII is large and all the recurrent node-sets are small, |
| 1718 | /// then it's best to try to schedule all instructions together instead of |
| 1719 | /// starting with the recurrent node-sets. |
| 1720 | void SwingSchedulerDAG::checkNodeSets(NodeSetType &NodeSets) { |
| 1721 | // Look for loops with a large MII. |
| 1722 | if (MII < 17) |
| 1723 | return; |
| 1724 | // Check if the node-set contains only a simple add recurrence. |
| 1725 | for (auto &NS : NodeSets) { |
| 1726 | if (NS.getRecMII() > 2) |
| 1727 | return; |
| 1728 | if (NS.getMaxDepth() > MII) |
| 1729 | return; |
| 1730 | } |
| 1731 | NodeSets.clear(); |
| 1732 | LLVM_DEBUG(dbgs() << "Clear recurrence node-sets\n")do { } while (false); |
| 1733 | } |
| 1734 | |
| 1735 | /// Add the nodes that do not belong to a recurrence set into groups |
| 1736 | /// based upon connected componenets. |
| 1737 | void SwingSchedulerDAG::groupRemainingNodes(NodeSetType &NodeSets) { |
| 1738 | SetVector<SUnit *> NodesAdded; |
| 1739 | SmallPtrSet<SUnit *, 8> Visited; |
| 1740 | // Add the nodes that are on a path between the previous node sets and |
| 1741 | // the current node set. |
| 1742 | for (NodeSet &I : NodeSets) { |
| 1743 | SmallSetVector<SUnit *, 8> N; |
| 1744 | // Add the nodes from the current node set to the previous node set. |
| 1745 | if (succ_L(I, N)) { |
| 1746 | SetVector<SUnit *> Path; |
| 1747 | for (SUnit *NI : N) { |
| 1748 | Visited.clear(); |
| 1749 | computePath(NI, Path, NodesAdded, I, Visited); |
| 1750 | } |
| 1751 | if (!Path.empty()) |
| 1752 | I.insert(Path.begin(), Path.end()); |
| 1753 | } |
| 1754 | // Add the nodes from the previous node set to the current node set. |
| 1755 | N.clear(); |
| 1756 | if (succ_L(NodesAdded, N)) { |
| 1757 | SetVector<SUnit *> Path; |
| 1758 | for (SUnit *NI : N) { |
| 1759 | Visited.clear(); |
| 1760 | computePath(NI, Path, I, NodesAdded, Visited); |
| 1761 | } |
| 1762 | if (!Path.empty()) |
| 1763 | I.insert(Path.begin(), Path.end()); |
| 1764 | } |
| 1765 | NodesAdded.insert(I.begin(), I.end()); |
| 1766 | } |
| 1767 | |
| 1768 | // Create a new node set with the connected nodes of any successor of a node |
| 1769 | // in a recurrent set. |
| 1770 | NodeSet NewSet; |
| 1771 | SmallSetVector<SUnit *, 8> N; |
| 1772 | if (succ_L(NodesAdded, N)) |
| 1773 | for (SUnit *I : N) |
| 1774 | addConnectedNodes(I, NewSet, NodesAdded); |
| 1775 | if (!NewSet.empty()) |
| 1776 | NodeSets.push_back(NewSet); |
| 1777 | |
| 1778 | // Create a new node set with the connected nodes of any predecessor of a node |
| 1779 | // in a recurrent set. |
| 1780 | NewSet.clear(); |
| 1781 | if (pred_L(NodesAdded, N)) |
| 1782 | for (SUnit *I : N) |
| 1783 | addConnectedNodes(I, NewSet, NodesAdded); |
| 1784 | if (!NewSet.empty()) |
| 1785 | NodeSets.push_back(NewSet); |
| 1786 | |
| 1787 | // Create new nodes sets with the connected nodes any remaining node that |
| 1788 | // has no predecessor. |
| 1789 | for (SUnit &SU : SUnits) { |
| 1790 | if (NodesAdded.count(&SU) == 0) { |
| 1791 | NewSet.clear(); |
| 1792 | addConnectedNodes(&SU, NewSet, NodesAdded); |
| 1793 | if (!NewSet.empty()) |
| 1794 | NodeSets.push_back(NewSet); |
| 1795 | } |
| 1796 | } |
| 1797 | } |
| 1798 | |
| 1799 | /// Add the node to the set, and add all of its connected nodes to the set. |
| 1800 | void SwingSchedulerDAG::addConnectedNodes(SUnit *SU, NodeSet &NewSet, |
| 1801 | SetVector<SUnit *> &NodesAdded) { |
| 1802 | NewSet.insert(SU); |
| 1803 | NodesAdded.insert(SU); |
| 1804 | for (auto &SI : SU->Succs) { |
| 1805 | SUnit *Successor = SI.getSUnit(); |
| 1806 | if (!SI.isArtificial() && NodesAdded.count(Successor) == 0) |
| 1807 | addConnectedNodes(Successor, NewSet, NodesAdded); |
| 1808 | } |
| 1809 | for (auto &PI : SU->Preds) { |
| 1810 | SUnit *Predecessor = PI.getSUnit(); |
| 1811 | if (!PI.isArtificial() && NodesAdded.count(Predecessor) == 0) |
| 1812 | addConnectedNodes(Predecessor, NewSet, NodesAdded); |
| 1813 | } |
| 1814 | } |
| 1815 | |
| 1816 | /// Return true if Set1 contains elements in Set2. The elements in common |
| 1817 | /// are returned in a different container. |
| 1818 | static bool isIntersect(SmallSetVector<SUnit *, 8> &Set1, const NodeSet &Set2, |
| 1819 | SmallSetVector<SUnit *, 8> &Result) { |
| 1820 | Result.clear(); |
| 1821 | for (unsigned i = 0, e = Set1.size(); i != e; ++i) { |
| 1822 | SUnit *SU = Set1[i]; |
| 1823 | if (Set2.count(SU) != 0) |
| 1824 | Result.insert(SU); |
| 1825 | } |
| 1826 | return !Result.empty(); |
| 1827 | } |
| 1828 | |
| 1829 | /// Merge the recurrence node sets that have the same initial node. |
| 1830 | void SwingSchedulerDAG::fuseRecs(NodeSetType &NodeSets) { |
| 1831 | for (NodeSetType::iterator I = NodeSets.begin(), E = NodeSets.end(); I != E; |
| 1832 | ++I) { |
| 1833 | NodeSet &NI = *I; |
| 1834 | for (NodeSetType::iterator J = I + 1; J != E;) { |
| 1835 | NodeSet &NJ = *J; |
| 1836 | if (NI.getNode(0)->NodeNum == NJ.getNode(0)->NodeNum) { |
| 1837 | if (NJ.compareRecMII(NI) > 0) |
| 1838 | NI.setRecMII(NJ.getRecMII()); |
| 1839 | for (SUnit *SU : *J) |
| 1840 | I->insert(SU); |
| 1841 | NodeSets.erase(J); |
| 1842 | E = NodeSets.end(); |
| 1843 | } else { |
| 1844 | ++J; |
| 1845 | } |
| 1846 | } |
| 1847 | } |
| 1848 | } |
| 1849 | |
| 1850 | /// Remove nodes that have been scheduled in previous NodeSets. |
| 1851 | void SwingSchedulerDAG::removeDuplicateNodes(NodeSetType &NodeSets) { |
| 1852 | for (NodeSetType::iterator I = NodeSets.begin(), E = NodeSets.end(); I != E; |
| 1853 | ++I) |
| 1854 | for (NodeSetType::iterator J = I + 1; J != E;) { |
| 1855 | J->remove_if([&](SUnit *SUJ) { return I->count(SUJ); }); |
| 1856 | |
| 1857 | if (J->empty()) { |
| 1858 | NodeSets.erase(J); |
| 1859 | E = NodeSets.end(); |
| 1860 | } else { |
| 1861 | ++J; |
| 1862 | } |
| 1863 | } |
| 1864 | } |
| 1865 | |
| 1866 | /// Compute an ordered list of the dependence graph nodes, which |
| 1867 | /// indicates the order that the nodes will be scheduled. This is a |
| 1868 | /// two-level algorithm. First, a partial order is created, which |
| 1869 | /// consists of a list of sets ordered from highest to lowest priority. |
| 1870 | void SwingSchedulerDAG::computeNodeOrder(NodeSetType &NodeSets) { |
| 1871 | SmallSetVector<SUnit *, 8> R; |
| 1872 | NodeOrder.clear(); |
| 1873 | |
| 1874 | for (auto &Nodes : NodeSets) { |
| 1875 | LLVM_DEBUG(dbgs() << "NodeSet size " << Nodes.size() << "\n")do { } while (false); |
| 1876 | OrderKind Order; |
| 1877 | SmallSetVector<SUnit *, 8> N; |
| 1878 | if (pred_L(NodeOrder, N) && llvm::set_is_subset(N, Nodes)) { |
| 1879 | R.insert(N.begin(), N.end()); |
| 1880 | Order = BottomUp; |
| 1881 | LLVM_DEBUG(dbgs() << " Bottom up (preds) ")do { } while (false); |
| 1882 | } else if (succ_L(NodeOrder, N) && llvm::set_is_subset(N, Nodes)) { |
| 1883 | R.insert(N.begin(), N.end()); |
| 1884 | Order = TopDown; |
| 1885 | LLVM_DEBUG(dbgs() << " Top down (succs) ")do { } while (false); |
| 1886 | } else if (isIntersect(N, Nodes, R)) { |
| 1887 | // If some of the successors are in the existing node-set, then use the |
| 1888 | // top-down ordering. |
| 1889 | Order = TopDown; |
| 1890 | LLVM_DEBUG(dbgs() << " Top down (intersect) ")do { } while (false); |
| 1891 | } else if (NodeSets.size() == 1) { |
| 1892 | for (auto &N : Nodes) |
| 1893 | if (N->Succs.size() == 0) |
| 1894 | R.insert(N); |
| 1895 | Order = BottomUp; |
| 1896 | LLVM_DEBUG(dbgs() << " Bottom up (all) ")do { } while (false); |
| 1897 | } else { |
| 1898 | // Find the node with the highest ASAP. |
| 1899 | SUnit *maxASAP = nullptr; |
| 1900 | for (SUnit *SU : Nodes) { |
| 1901 | if (maxASAP == nullptr || getASAP(SU) > getASAP(maxASAP) || |
| 1902 | (getASAP(SU) == getASAP(maxASAP) && SU->NodeNum > maxASAP->NodeNum)) |
| 1903 | maxASAP = SU; |
| 1904 | } |
| 1905 | R.insert(maxASAP); |
| 1906 | Order = BottomUp; |
| 1907 | LLVM_DEBUG(dbgs() << " Bottom up (default) ")do { } while (false); |
| 1908 | } |
| 1909 | |
| 1910 | while (!R.empty()) { |
| 1911 | if (Order == TopDown) { |
| 1912 | // Choose the node with the maximum height. If more than one, choose |
| 1913 | // the node wiTH the maximum ZeroLatencyHeight. If still more than one, |
| 1914 | // choose the node with the lowest MOV. |
| 1915 | while (!R.empty()) { |
| 1916 | SUnit *maxHeight = nullptr; |
| 1917 | for (SUnit *I : R) { |
| 1918 | if (maxHeight == nullptr || getHeight(I) > getHeight(maxHeight)) |
| 1919 | maxHeight = I; |
| 1920 | else if (getHeight(I) == getHeight(maxHeight) && |
| 1921 | getZeroLatencyHeight(I) > getZeroLatencyHeight(maxHeight)) |
| 1922 | maxHeight = I; |
| 1923 | else if (getHeight(I) == getHeight(maxHeight) && |
| 1924 | getZeroLatencyHeight(I) == |
| 1925 | getZeroLatencyHeight(maxHeight) && |
| 1926 | getMOV(I) < getMOV(maxHeight)) |
| 1927 | maxHeight = I; |
| 1928 | } |
| 1929 | NodeOrder.insert(maxHeight); |
| 1930 | LLVM_DEBUG(dbgs() << maxHeight->NodeNum << " ")do { } while (false); |
| 1931 | R.remove(maxHeight); |
| 1932 | for (const auto &I : maxHeight->Succs) { |
| 1933 | if (Nodes.count(I.getSUnit()) == 0) |
| 1934 | continue; |
| 1935 | if (NodeOrder.contains(I.getSUnit())) |
| 1936 | continue; |
| 1937 | if (ignoreDependence(I, false)) |
| 1938 | continue; |
| 1939 | R.insert(I.getSUnit()); |
| 1940 | } |
| 1941 | // Back-edges are predecessors with an anti-dependence. |
| 1942 | for (const auto &I : maxHeight->Preds) { |
| 1943 | if (I.getKind() != SDep::Anti) |
| 1944 | continue; |
| 1945 | if (Nodes.count(I.getSUnit()) == 0) |
| 1946 | continue; |
| 1947 | if (NodeOrder.contains(I.getSUnit())) |
| 1948 | continue; |
| 1949 | R.insert(I.getSUnit()); |
| 1950 | } |
| 1951 | } |
| 1952 | Order = BottomUp; |
| 1953 | LLVM_DEBUG(dbgs() << "\n Switching order to bottom up ")do { } while (false); |
| 1954 | SmallSetVector<SUnit *, 8> N; |
| 1955 | if (pred_L(NodeOrder, N, &Nodes)) |
| 1956 | R.insert(N.begin(), N.end()); |
| 1957 | } else { |
| 1958 | // Choose the node with the maximum depth. If more than one, choose |
| 1959 | // the node with the maximum ZeroLatencyDepth. If still more than one, |
| 1960 | // choose the node with the lowest MOV. |
| 1961 | while (!R.empty()) { |
| 1962 | SUnit *maxDepth = nullptr; |
| 1963 | for (SUnit *I : R) { |
| 1964 | if (maxDepth == nullptr || getDepth(I) > getDepth(maxDepth)) |
| 1965 | maxDepth = I; |
| 1966 | else if (getDepth(I) == getDepth(maxDepth) && |
| 1967 | getZeroLatencyDepth(I) > getZeroLatencyDepth(maxDepth)) |
| 1968 | maxDepth = I; |
| 1969 | else if (getDepth(I) == getDepth(maxDepth) && |
| 1970 | getZeroLatencyDepth(I) == getZeroLatencyDepth(maxDepth) && |
| 1971 | getMOV(I) < getMOV(maxDepth)) |
| 1972 | maxDepth = I; |
| 1973 | } |
| 1974 | NodeOrder.insert(maxDepth); |
| 1975 | LLVM_DEBUG(dbgs() << maxDepth->NodeNum << " ")do { } while (false); |
| 1976 | R.remove(maxDepth); |
| 1977 | if (Nodes.isExceedSU(maxDepth)) { |
| 1978 | Order = TopDown; |
Value stored to 'Order' is never read | |
| 1979 | R.clear(); |
| 1980 | R.insert(Nodes.getNode(0)); |
| 1981 | break; |
| 1982 | } |
| 1983 | for (const auto &I : maxDepth->Preds) { |
| 1984 | if (Nodes.count(I.getSUnit()) == 0) |
| 1985 | continue; |
| 1986 | if (NodeOrder.contains(I.getSUnit())) |
| 1987 | continue; |
| 1988 | R.insert(I.getSUnit()); |
| 1989 | } |
| 1990 | // Back-edges are predecessors with an anti-dependence. |
| 1991 | for (const auto &I : maxDepth->Succs) { |
| 1992 | if (I.getKind() != SDep::Anti) |
| 1993 | continue; |
| 1994 | if (Nodes.count(I.getSUnit()) == 0) |
| 1995 | continue; |
| 1996 | if (NodeOrder.contains(I.getSUnit())) |
| 1997 | continue; |
| 1998 | R.insert(I.getSUnit()); |
| 1999 | } |
| 2000 | } |
| 2001 | Order = TopDown; |
| 2002 | LLVM_DEBUG(dbgs() << "\n Switching order to top down ")do { } while (false); |
| 2003 | SmallSetVector<SUnit *, 8> N; |
| 2004 | if (succ_L(NodeOrder, N, &Nodes)) |
| 2005 | R.insert(N.begin(), N.end()); |
| 2006 | } |
| 2007 | } |
| 2008 | LLVM_DEBUG(dbgs() << "\nDone with Nodeset\n")do { } while (false); |
| 2009 | } |
| 2010 | |
| 2011 | LLVM_DEBUG({do { } while (false) |
| 2012 | dbgs() << "Node order: ";do { } while (false) |
| 2013 | for (SUnit *I : NodeOrder)do { } while (false) |
| 2014 | dbgs() << " " << I->NodeNum << " ";do { } while (false) |
| 2015 | dbgs() << "\n";do { } while (false) |
| 2016 | })do { } while (false); |
| 2017 | } |
| 2018 | |
| 2019 | /// Process the nodes in the computed order and create the pipelined schedule |
| 2020 | /// of the instructions, if possible. Return true if a schedule is found. |
| 2021 | bool SwingSchedulerDAG::schedulePipeline(SMSchedule &Schedule) { |
| 2022 | |
| 2023 | if (NodeOrder.empty()){ |
| 2024 | LLVM_DEBUG(dbgs() << "NodeOrder is empty! abort scheduling\n" )do { } while (false); |
| 2025 | return false; |
| 2026 | } |
| 2027 | |
| 2028 | bool scheduleFound = false; |
| 2029 | // Keep increasing II until a valid schedule is found. |
| 2030 | for (unsigned II = MII; II <= MAX_II && !scheduleFound; ++II) { |
| 2031 | Schedule.reset(); |
| 2032 | Schedule.setInitiationInterval(II); |
| 2033 | LLVM_DEBUG(dbgs() << "Try to schedule with " << II << "\n")do { } while (false); |
| 2034 | |
| 2035 | SetVector<SUnit *>::iterator NI = NodeOrder.begin(); |
| 2036 | SetVector<SUnit *>::iterator NE = NodeOrder.end(); |
| 2037 | do { |
| 2038 | SUnit *SU = *NI; |
| 2039 | |
| 2040 | // Compute the schedule time for the instruction, which is based |
| 2041 | // upon the scheduled time for any predecessors/successors. |
| 2042 | int EarlyStart = INT_MIN(-2147483647 -1); |
| 2043 | int LateStart = INT_MAX2147483647; |
| 2044 | // These values are set when the size of the schedule window is limited |
| 2045 | // due to chain dependences. |
| 2046 | int SchedEnd = INT_MAX2147483647; |
| 2047 | int SchedStart = INT_MIN(-2147483647 -1); |
| 2048 | Schedule.computeStart(SU, &EarlyStart, &LateStart, &SchedEnd, &SchedStart, |
| 2049 | II, this); |
| 2050 | LLVM_DEBUG({do { } while (false) |
| 2051 | dbgs() << "\n";do { } while (false) |
| 2052 | dbgs() << "Inst (" << SU->NodeNum << ") ";do { } while (false) |
| 2053 | SU->getInstr()->dump();do { } while (false) |
| 2054 | dbgs() << "\n";do { } while (false) |
| 2055 | })do { } while (false); |
| 2056 | LLVM_DEBUG({do { } while (false) |
| 2057 | dbgs() << format("\tes: %8x ls: %8x me: %8x ms: %8x\n", EarlyStart,do { } while (false) |
| 2058 | LateStart, SchedEnd, SchedStart);do { } while (false) |
| 2059 | })do { } while (false); |
| 2060 | |
| 2061 | if (EarlyStart > LateStart || SchedEnd < EarlyStart || |
| 2062 | SchedStart > LateStart) |
| 2063 | scheduleFound = false; |
| 2064 | else if (EarlyStart != INT_MIN(-2147483647 -1) && LateStart == INT_MAX2147483647) { |
| 2065 | SchedEnd = std::min(SchedEnd, EarlyStart + (int)II - 1); |
| 2066 | scheduleFound = Schedule.insert(SU, EarlyStart, SchedEnd, II); |
| 2067 | } else if (EarlyStart == INT_MIN(-2147483647 -1) && LateStart != INT_MAX2147483647) { |
| 2068 | SchedStart = std::max(SchedStart, LateStart - (int)II + 1); |
| 2069 | scheduleFound = Schedule.insert(SU, LateStart, SchedStart, II); |
| 2070 | } else if (EarlyStart != INT_MIN(-2147483647 -1) && LateStart != INT_MAX2147483647) { |
| 2071 | SchedEnd = |
| 2072 | std::min(SchedEnd, std::min(LateStart, EarlyStart + (int)II - 1)); |
| 2073 | // When scheduling a Phi it is better to start at the late cycle and go |
| 2074 | // backwards. The default order may insert the Phi too far away from |
| 2075 | // its first dependence. |
| 2076 | if (SU->getInstr()->isPHI()) |
| 2077 | scheduleFound = Schedule.insert(SU, SchedEnd, EarlyStart, II); |
| 2078 | else |
| 2079 | scheduleFound = Schedule.insert(SU, EarlyStart, SchedEnd, II); |
| 2080 | } else { |
| 2081 | int FirstCycle = Schedule.getFirstCycle(); |
| 2082 | scheduleFound = Schedule.insert(SU, FirstCycle + getASAP(SU), |
| 2083 | FirstCycle + getASAP(SU) + II - 1, II); |
| 2084 | } |
| 2085 | // Even if we find a schedule, make sure the schedule doesn't exceed the |
| 2086 | // allowable number of stages. We keep trying if this happens. |
| 2087 | if (scheduleFound) |
| 2088 | if (SwpMaxStages > -1 && |
| 2089 | Schedule.getMaxStageCount() > (unsigned)SwpMaxStages) |
| 2090 | scheduleFound = false; |
| 2091 | |
| 2092 | LLVM_DEBUG({do { } while (false) |
| 2093 | if (!scheduleFound)do { } while (false) |
| 2094 | dbgs() << "\tCan't schedule\n";do { } while (false) |
| 2095 | })do { } while (false); |
| 2096 | } while (++NI != NE && scheduleFound); |
| 2097 | |
| 2098 | // If a schedule is found, check if it is a valid schedule too. |
| 2099 | if (scheduleFound) |
| 2100 | scheduleFound = Schedule.isValidSchedule(this); |
| 2101 | } |
| 2102 | |
| 2103 | LLVM_DEBUG(dbgs() << "Schedule Found? " << scheduleFounddo { } while (false) |
| 2104 | << " (II=" << Schedule.getInitiationInterval()do { } while (false) |
| 2105 | << ")\n")do { } while (false); |
| 2106 | |
| 2107 | if (scheduleFound) { |
| 2108 | Schedule.finalizeSchedule(this); |
| 2109 | Pass.ORE->emit([&]() { |
| 2110 | return MachineOptimizationRemarkAnalysis( |
| 2111 | DEBUG_TYPE"pipeliner", "schedule", Loop.getStartLoc(), Loop.getHeader()) |
| 2112 | << "Schedule found with Initiation Interval: " |
| 2113 | << ore::NV("II", Schedule.getInitiationInterval()) |
| 2114 | << ", MaxStageCount: " |
| 2115 | << ore::NV("MaxStageCount", Schedule.getMaxStageCount()); |
| 2116 | }); |
| 2117 | } else |
| 2118 | Schedule.reset(); |
| 2119 | |
| 2120 | return scheduleFound && Schedule.getMaxStageCount() > 0; |
| 2121 | } |
| 2122 | |
| 2123 | /// Return true if we can compute the amount the instruction changes |
| 2124 | /// during each iteration. Set Delta to the amount of the change. |
| 2125 | bool SwingSchedulerDAG::computeDelta(MachineInstr &MI, unsigned &Delta) { |
| 2126 | const TargetRegisterInfo *TRI = MF.getSubtarget().getRegisterInfo(); |
| 2127 | const MachineOperand *BaseOp; |
| 2128 | int64_t Offset; |
| 2129 | bool OffsetIsScalable; |
| 2130 | if (!TII->getMemOperandWithOffset(MI, BaseOp, Offset, OffsetIsScalable, TRI)) |
| 2131 | return false; |
| 2132 | |
| 2133 | // FIXME: This algorithm assumes instructions have fixed-size offsets. |
| 2134 | if (OffsetIsScalable) |
| 2135 | return false; |
| 2136 | |
| 2137 | if (!BaseOp->isReg()) |
| 2138 | return false; |
| 2139 | |
| 2140 | Register BaseReg = BaseOp->getReg(); |
| 2141 | |
| 2142 | MachineRegisterInfo &MRI = MF.getRegInfo(); |
| 2143 | // Check if there is a Phi. If so, get the definition in the loop. |
| 2144 | MachineInstr *BaseDef = MRI.getVRegDef(BaseReg); |
| 2145 | if (BaseDef && BaseDef->isPHI()) { |
| 2146 | BaseReg = getLoopPhiReg(*BaseDef, MI.getParent()); |
| 2147 | BaseDef = MRI.getVRegDef(BaseReg); |
| 2148 | } |
| 2149 | if (!BaseDef) |
| 2150 | return false; |
| 2151 | |
| 2152 | int D = 0; |
| 2153 | if (!TII->getIncrementValue(*BaseDef, D) && D >= 0) |
| 2154 | return false; |
| 2155 | |
| 2156 | Delta = D; |
| 2157 | return true; |
| 2158 | } |
| 2159 | |
| 2160 | /// Check if we can change the instruction to use an offset value from the |
| 2161 | /// previous iteration. If so, return true and set the base and offset values |
| 2162 | /// so that we can rewrite the load, if necessary. |
| 2163 | /// v1 = Phi(v0, v3) |
| 2164 | /// v2 = load v1, 0 |
| 2165 | /// v3 = post_store v1, 4, x |
| 2166 | /// This function enables the load to be rewritten as v2 = load v3, 4. |
| 2167 | bool SwingSchedulerDAG::canUseLastOffsetValue(MachineInstr *MI, |
| 2168 | unsigned &BasePos, |
| 2169 | unsigned &OffsetPos, |
| 2170 | unsigned &NewBase, |
| 2171 | int64_t &Offset) { |
| 2172 | // Get the load instruction. |
| 2173 | if (TII->isPostIncrement(*MI)) |
| 2174 | return false; |
| 2175 | unsigned BasePosLd, OffsetPosLd; |
| 2176 | if (!TII->getBaseAndOffsetPosition(*MI, BasePosLd, OffsetPosLd)) |
| 2177 | return false; |
| 2178 | Register BaseReg = MI->getOperand(BasePosLd).getReg(); |
| 2179 | |
| 2180 | // Look for the Phi instruction. |
| 2181 | MachineRegisterInfo &MRI = MI->getMF()->getRegInfo(); |
| 2182 | MachineInstr *Phi = MRI.getVRegDef(BaseReg); |
| 2183 | if (!Phi || !Phi->isPHI()) |
| 2184 | return false; |
| 2185 | // Get the register defined in the loop block. |
| 2186 | unsigned PrevReg = getLoopPhiReg(*Phi, MI->getParent()); |
| 2187 | if (!PrevReg) |
| 2188 | return false; |
| 2189 | |
| 2190 | // Check for the post-increment load/store instruction. |
| 2191 | MachineInstr *PrevDef = MRI.getVRegDef(PrevReg); |
| 2192 | if (!PrevDef || PrevDef == MI) |
| 2193 | return false; |
| 2194 | |
| 2195 | if (!TII->isPostIncrement(*PrevDef)) |
| 2196 | return false; |
| 2197 | |
| 2198 | unsigned BasePos1 = 0, OffsetPos1 = 0; |
| 2199 | if (!TII->getBaseAndOffsetPosition(*PrevDef, BasePos1, OffsetPos1)) |
| 2200 | return false; |
| 2201 | |
| 2202 | // Make sure that the instructions do not access the same memory location in |
| 2203 | // the next iteration. |
| 2204 | int64_t LoadOffset = MI->getOperand(OffsetPosLd).getImm(); |
| 2205 | int64_t StoreOffset = PrevDef->getOperand(OffsetPos1).getImm(); |
| 2206 | MachineInstr *NewMI = MF.CloneMachineInstr(MI); |
| 2207 | NewMI->getOperand(OffsetPosLd).setImm(LoadOffset + StoreOffset); |
| 2208 | bool Disjoint = TII->areMemAccessesTriviallyDisjoint(*NewMI, *PrevDef); |
| 2209 | MF.DeleteMachineInstr(NewMI); |
| 2210 | if (!Disjoint) |
| 2211 | return false; |
| 2212 | |
| 2213 | // Set the return value once we determine that we return true. |
| 2214 | BasePos = BasePosLd; |
| 2215 | OffsetPos = OffsetPosLd; |
| 2216 | NewBase = PrevReg; |
| 2217 | Offset = StoreOffset; |
| 2218 | return true; |
| 2219 | } |
| 2220 | |
| 2221 | /// Apply changes to the instruction if needed. The changes are need |
| 2222 | /// to improve the scheduling and depend up on the final schedule. |
| 2223 | void SwingSchedulerDAG::applyInstrChange(MachineInstr *MI, |
| 2224 | SMSchedule &Schedule) { |
| 2225 | SUnit *SU = getSUnit(MI); |
| 2226 | DenseMap<SUnit *, std::pair<unsigned, int64_t>>::iterator It = |
| 2227 | InstrChanges.find(SU); |
| 2228 | if (It != InstrChanges.end()) { |
| 2229 | std::pair<unsigned, int64_t> RegAndOffset = It->second; |
| 2230 | unsigned BasePos, OffsetPos; |
| 2231 | if (!TII->getBaseAndOffsetPosition(*MI, BasePos, OffsetPos)) |
| 2232 | return; |
| 2233 | Register BaseReg = MI->getOperand(BasePos).getReg(); |
| 2234 | MachineInstr *LoopDef = findDefInLoop(BaseReg); |
| 2235 | int DefStageNum = Schedule.stageScheduled(getSUnit(LoopDef)); |
| 2236 | int DefCycleNum = Schedule.cycleScheduled(getSUnit(LoopDef)); |
| 2237 | int BaseStageNum = Schedule.stageScheduled(SU); |
| 2238 | int BaseCycleNum = Schedule.cycleScheduled(SU); |
| 2239 | if (BaseStageNum < DefStageNum) { |
| 2240 | MachineInstr *NewMI = MF.CloneMachineInstr(MI); |
| 2241 | int OffsetDiff = DefStageNum - BaseStageNum; |
| 2242 | if (DefCycleNum < BaseCycleNum) { |
| 2243 | NewMI->getOperand(BasePos).setReg(RegAndOffset.first); |
| 2244 | if (OffsetDiff > 0) |
| 2245 | --OffsetDiff; |
| 2246 | } |
| 2247 | int64_t NewOffset = |
| 2248 | MI->getOperand(OffsetPos).getImm() + RegAndOffset.second * OffsetDiff; |
| 2249 | NewMI->getOperand(OffsetPos).setImm(NewOffset); |
| 2250 | SU->setInstr(NewMI); |
| 2251 | MISUnitMap[NewMI] = SU; |
| 2252 | NewMIs[MI] = NewMI; |
| 2253 | } |
| 2254 | } |
| 2255 | } |
| 2256 | |
| 2257 | /// Return the instruction in the loop that defines the register. |
| 2258 | /// If the definition is a Phi, then follow the Phi operand to |
| 2259 | /// the instruction in the loop. |
| 2260 | MachineInstr *SwingSchedulerDAG::findDefInLoop(Register Reg) { |
| 2261 | SmallPtrSet<MachineInstr *, 8> Visited; |
| 2262 | MachineInstr *Def = MRI.getVRegDef(Reg); |
| 2263 | while (Def->isPHI()) { |
| 2264 | if (!Visited.insert(Def).second) |
| 2265 | break; |
| 2266 | for (unsigned i = 1, e = Def->getNumOperands(); i < e; i += 2) |
| 2267 | if (Def->getOperand(i + 1).getMBB() == BB) { |
| 2268 | Def = MRI.getVRegDef(Def->getOperand(i).getReg()); |
| 2269 | break; |
| 2270 | } |
| 2271 | } |
| 2272 | return Def; |
| 2273 | } |
| 2274 | |
| 2275 | /// Return true for an order or output dependence that is loop carried |
| 2276 | /// potentially. A dependence is loop carried if the destination defines a valu |
| 2277 | /// that may be used or defined by the source in a subsequent iteration. |
| 2278 | bool SwingSchedulerDAG::isLoopCarriedDep(SUnit *Source, const SDep &Dep, |
| 2279 | bool isSucc) { |
| 2280 | if ((Dep.getKind() != SDep::Order && Dep.getKind() != SDep::Output) || |
| 2281 | Dep.isArtificial()) |
| 2282 | return false; |
| 2283 | |
| 2284 | if (!SwpPruneLoopCarried) |
| 2285 | return true; |
| 2286 | |
| 2287 | if (Dep.getKind() == SDep::Output) |
| 2288 | return true; |
| 2289 | |
| 2290 | MachineInstr *SI = Source->getInstr(); |
| 2291 | MachineInstr *DI = Dep.getSUnit()->getInstr(); |
| 2292 | if (!isSucc) |
| 2293 | std::swap(SI, DI); |
| 2294 | assert(SI != nullptr && DI != nullptr && "Expecting SUnit with an MI.")((void)0); |
| 2295 | |
| 2296 | // Assume ordered loads and stores may have a loop carried dependence. |
| 2297 | if (SI->hasUnmodeledSideEffects() || DI->hasUnmodeledSideEffects() || |
| 2298 | SI->mayRaiseFPException() || DI->mayRaiseFPException() || |
| 2299 | SI->hasOrderedMemoryRef() || DI->hasOrderedMemoryRef()) |
| 2300 | return true; |
| 2301 | |
| 2302 | // Only chain dependences between a load and store can be loop carried. |
| 2303 | if (!DI->mayStore() || !SI->mayLoad()) |
| 2304 | return false; |
| 2305 | |
| 2306 | unsigned DeltaS, DeltaD; |
| 2307 | if (!computeDelta(*SI, DeltaS) || !computeDelta(*DI, DeltaD)) |
| 2308 | return true; |
| 2309 | |
| 2310 | const MachineOperand *BaseOpS, *BaseOpD; |
| 2311 | int64_t OffsetS, OffsetD; |
| 2312 | bool OffsetSIsScalable, OffsetDIsScalable; |
| 2313 | const TargetRegisterInfo *TRI = MF.getSubtarget().getRegisterInfo(); |
| 2314 | if (!TII->getMemOperandWithOffset(*SI, BaseOpS, OffsetS, OffsetSIsScalable, |
| 2315 | TRI) || |
| 2316 | !TII->getMemOperandWithOffset(*DI, BaseOpD, OffsetD, OffsetDIsScalable, |
| 2317 | TRI)) |
| 2318 | return true; |
| 2319 | |
| 2320 | assert(!OffsetSIsScalable && !OffsetDIsScalable &&((void)0) |
| 2321 | "Expected offsets to be byte offsets")((void)0); |
| 2322 | |
| 2323 | if (!BaseOpS->isIdenticalTo(*BaseOpD)) |
| 2324 | return true; |
| 2325 | |
| 2326 | // Check that the base register is incremented by a constant value for each |
| 2327 | // iteration. |
| 2328 | MachineInstr *Def = MRI.getVRegDef(BaseOpS->getReg()); |
| 2329 | if (!Def || !Def->isPHI()) |
| 2330 | return true; |
| 2331 | unsigned InitVal = 0; |
| 2332 | unsigned LoopVal = 0; |
| 2333 | getPhiRegs(*Def, BB, InitVal, LoopVal); |
| 2334 | MachineInstr *LoopDef = MRI.getVRegDef(LoopVal); |
| 2335 | int D = 0; |
| 2336 | if (!LoopDef || !TII->getIncrementValue(*LoopDef, D)) |
| 2337 | return true; |
| 2338 | |
| 2339 | uint64_t AccessSizeS = (*SI->memoperands_begin())->getSize(); |
| 2340 | uint64_t AccessSizeD = (*DI->memoperands_begin())->getSize(); |
| 2341 | |
| 2342 | // This is the main test, which checks the offset values and the loop |
| 2343 | // increment value to determine if the accesses may be loop carried. |
| 2344 | if (AccessSizeS == MemoryLocation::UnknownSize || |
| 2345 | AccessSizeD == MemoryLocation::UnknownSize) |
| 2346 | return true; |
| 2347 | |
| 2348 | if (DeltaS != DeltaD || DeltaS < AccessSizeS || DeltaD < AccessSizeD) |
| 2349 | return true; |
| 2350 | |
| 2351 | return (OffsetS + (int64_t)AccessSizeS < OffsetD + (int64_t)AccessSizeD); |
| 2352 | } |
| 2353 | |
| 2354 | void SwingSchedulerDAG::postprocessDAG() { |
| 2355 | for (auto &M : Mutations) |
| 2356 | M->apply(this); |
| 2357 | } |
| 2358 | |
| 2359 | /// Try to schedule the node at the specified StartCycle and continue |
| 2360 | /// until the node is schedule or the EndCycle is reached. This function |
| 2361 | /// returns true if the node is scheduled. This routine may search either |
| 2362 | /// forward or backward for a place to insert the instruction based upon |
| 2363 | /// the relative values of StartCycle and EndCycle. |
| 2364 | bool SMSchedule::insert(SUnit *SU, int StartCycle, int EndCycle, int II) { |
| 2365 | bool forward = true; |
| 2366 | LLVM_DEBUG({do { } while (false) |
| 2367 | dbgs() << "Trying to insert node between " << StartCycle << " and "do { } while (false) |
| 2368 | << EndCycle << " II: " << II << "\n";do { } while (false) |
| 2369 | })do { } while (false); |
| 2370 | if (StartCycle > EndCycle) |
| 2371 | forward = false; |
| 2372 | |
| 2373 | // The terminating condition depends on the direction. |
| 2374 | int termCycle = forward ? EndCycle + 1 : EndCycle - 1; |
| 2375 | for (int curCycle = StartCycle; curCycle != termCycle; |
| 2376 | forward ? ++curCycle : --curCycle) { |
| 2377 | |
| 2378 | // Add the already scheduled instructions at the specified cycle to the |
| 2379 | // DFA. |
| 2380 | ProcItinResources.clearResources(); |
| 2381 | for (int checkCycle = FirstCycle + ((curCycle - FirstCycle) % II); |
| 2382 | checkCycle <= LastCycle; checkCycle += II) { |
| 2383 | std::deque<SUnit *> &cycleInstrs = ScheduledInstrs[checkCycle]; |
| 2384 | |
| 2385 | for (SUnit *CI : cycleInstrs) { |
| 2386 | if (ST.getInstrInfo()->isZeroCost(CI->getInstr()->getOpcode())) |
| 2387 | continue; |
| 2388 | assert(ProcItinResources.canReserveResources(*CI->getInstr()) &&((void)0) |
| 2389 | "These instructions have already been scheduled.")((void)0); |
| 2390 | ProcItinResources.reserveResources(*CI->getInstr()); |
| 2391 | } |
| 2392 | } |
| 2393 | if (ST.getInstrInfo()->isZeroCost(SU->getInstr()->getOpcode()) || |
| 2394 | ProcItinResources.canReserveResources(*SU->getInstr())) { |
| 2395 | LLVM_DEBUG({do { } while (false) |
| 2396 | dbgs() << "\tinsert at cycle " << curCycle << " ";do { } while (false) |
| 2397 | SU->getInstr()->dump();do { } while (false) |
| 2398 | })do { } while (false); |
| 2399 | |
| 2400 | ScheduledInstrs[curCycle].push_back(SU); |
| 2401 | InstrToCycle.insert(std::make_pair(SU, curCycle)); |
| 2402 | if (curCycle > LastCycle) |
| 2403 | LastCycle = curCycle; |
| 2404 | if (curCycle < FirstCycle) |
| 2405 | FirstCycle = curCycle; |
| 2406 | return true; |
| 2407 | } |
| 2408 | LLVM_DEBUG({do { } while (false) |
| 2409 | dbgs() << "\tfailed to insert at cycle " << curCycle << " ";do { } while (false) |
| 2410 | SU->getInstr()->dump();do { } while (false) |
| 2411 | })do { } while (false); |
| 2412 | } |
| 2413 | return false; |
| 2414 | } |
| 2415 | |
| 2416 | // Return the cycle of the earliest scheduled instruction in the chain. |
| 2417 | int SMSchedule::earliestCycleInChain(const SDep &Dep) { |
| 2418 | SmallPtrSet<SUnit *, 8> Visited; |
| 2419 | SmallVector<SDep, 8> Worklist; |
| 2420 | Worklist.push_back(Dep); |
| 2421 | int EarlyCycle = INT_MAX2147483647; |
| 2422 | while (!Worklist.empty()) { |
| 2423 | const SDep &Cur = Worklist.pop_back_val(); |
| 2424 | SUnit *PrevSU = Cur.getSUnit(); |
| 2425 | if (Visited.count(PrevSU)) |
| 2426 | continue; |
| 2427 | std::map<SUnit *, int>::const_iterator it = InstrToCycle.find(PrevSU); |
| 2428 | if (it == InstrToCycle.end()) |
| 2429 | continue; |
| 2430 | EarlyCycle = std::min(EarlyCycle, it->second); |
| 2431 | for (const auto &PI : PrevSU->Preds) |
| 2432 | if (PI.getKind() == SDep::Order || PI.getKind() == SDep::Output) |
| 2433 | Worklist.push_back(PI); |
| 2434 | Visited.insert(PrevSU); |
| 2435 | } |
| 2436 | return EarlyCycle; |
| 2437 | } |
| 2438 | |
| 2439 | // Return the cycle of the latest scheduled instruction in the chain. |
| 2440 | int SMSchedule::latestCycleInChain(const SDep &Dep) { |
| 2441 | SmallPtrSet<SUnit *, 8> Visited; |
| 2442 | SmallVector<SDep, 8> Worklist; |
| 2443 | Worklist.push_back(Dep); |
| 2444 | int LateCycle = INT_MIN(-2147483647 -1); |
| 2445 | while (!Worklist.empty()) { |
| 2446 | const SDep &Cur = Worklist.pop_back_val(); |
| 2447 | SUnit *SuccSU = Cur.getSUnit(); |
| 2448 | if (Visited.count(SuccSU)) |
| 2449 | continue; |
| 2450 | std::map<SUnit *, int>::const_iterator it = InstrToCycle.find(SuccSU); |
| 2451 | if (it == InstrToCycle.end()) |
| 2452 | continue; |
| 2453 | LateCycle = std::max(LateCycle, it->second); |
| 2454 | for (const auto &SI : SuccSU->Succs) |
| 2455 | if (SI.getKind() == SDep::Order || SI.getKind() == SDep::Output) |
| 2456 | Worklist.push_back(SI); |
| 2457 | Visited.insert(SuccSU); |
| 2458 | } |
| 2459 | return LateCycle; |
| 2460 | } |
| 2461 | |
| 2462 | /// If an instruction has a use that spans multiple iterations, then |
| 2463 | /// return true. These instructions are characterized by having a back-ege |
| 2464 | /// to a Phi, which contains a reference to another Phi. |
| 2465 | static SUnit *multipleIterations(SUnit *SU, SwingSchedulerDAG *DAG) { |
| 2466 | for (auto &P : SU->Preds) |
| 2467 | if (DAG->isBackedge(SU, P) && P.getSUnit()->getInstr()->isPHI()) |
| 2468 | for (auto &S : P.getSUnit()->Succs) |
| 2469 | if (S.getKind() == SDep::Data && S.getSUnit()->getInstr()->isPHI()) |
| 2470 | return P.getSUnit(); |
| 2471 | return nullptr; |
| 2472 | } |
| 2473 | |
| 2474 | /// Compute the scheduling start slot for the instruction. The start slot |
| 2475 | /// depends on any predecessor or successor nodes scheduled already. |
| 2476 | void SMSchedule::computeStart(SUnit *SU, int *MaxEarlyStart, int *MinLateStart, |
| 2477 | int *MinEnd, int *MaxStart, int II, |
| 2478 | SwingSchedulerDAG *DAG) { |
| 2479 | // Iterate over each instruction that has been scheduled already. The start |
| 2480 | // slot computation depends on whether the previously scheduled instruction |
| 2481 | // is a predecessor or successor of the specified instruction. |
| 2482 | for (int cycle = getFirstCycle(); cycle <= LastCycle; ++cycle) { |
| 2483 | |
| 2484 | // Iterate over each instruction in the current cycle. |
| 2485 | for (SUnit *I : getInstructions(cycle)) { |
| 2486 | // Because we're processing a DAG for the dependences, we recognize |
| 2487 | // the back-edge in recurrences by anti dependences. |
| 2488 | for (unsigned i = 0, e = (unsigned)SU->Preds.size(); i != e; ++i) { |
| 2489 | const SDep &Dep = SU->Preds[i]; |
| 2490 | if (Dep.getSUnit() == I) { |
| 2491 | if (!DAG->isBackedge(SU, Dep)) { |
| 2492 | int EarlyStart = cycle + Dep.getLatency() - |
| 2493 | DAG->getDistance(Dep.getSUnit(), SU, Dep) * II; |
| 2494 | *MaxEarlyStart = std::max(*MaxEarlyStart, EarlyStart); |
| 2495 | if (DAG->isLoopCarriedDep(SU, Dep, false)) { |
| 2496 | int End = earliestCycleInChain(Dep) + (II - 1); |
| 2497 | *MinEnd = std::min(*MinEnd, End); |
| 2498 | } |
| 2499 | } else { |
| 2500 | int LateStart = cycle - Dep.getLatency() + |
| 2501 | DAG->getDistance(SU, Dep.getSUnit(), Dep) * II; |
| 2502 | *MinLateStart = std::min(*MinLateStart, LateStart); |
| 2503 | } |
| 2504 | } |
| 2505 | // For instruction that requires multiple iterations, make sure that |
| 2506 | // the dependent instruction is not scheduled past the definition. |
| 2507 | SUnit *BE = multipleIterations(I, DAG); |
| 2508 | if (BE && Dep.getSUnit() == BE && !SU->getInstr()->isPHI() && |
| 2509 | !SU->isPred(I)) |
| 2510 | *MinLateStart = std::min(*MinLateStart, cycle); |
| 2511 | } |
| 2512 | for (unsigned i = 0, e = (unsigned)SU->Succs.size(); i != e; ++i) { |
| 2513 | if (SU->Succs[i].getSUnit() == I) { |
| 2514 | const SDep &Dep = SU->Succs[i]; |
| 2515 | if (!DAG->isBackedge(SU, Dep)) { |
| 2516 | int LateStart = cycle - Dep.getLatency() + |
| 2517 | DAG->getDistance(SU, Dep.getSUnit(), Dep) * II; |
| 2518 | *MinLateStart = std::min(*MinLateStart, LateStart); |
| 2519 | if (DAG->isLoopCarriedDep(SU, Dep)) { |
| 2520 | int Start = latestCycleInChain(Dep) + 1 - II; |
| 2521 | *MaxStart = std::max(*MaxStart, Start); |
| 2522 | } |
| 2523 | } else { |
| 2524 | int EarlyStart = cycle + Dep.getLatency() - |
| 2525 | DAG->getDistance(Dep.getSUnit(), SU, Dep) * II; |
| 2526 | *MaxEarlyStart = std::max(*MaxEarlyStart, EarlyStart); |
| 2527 | } |
| 2528 | } |
| 2529 | } |
| 2530 | } |
| 2531 | } |
| 2532 | } |
| 2533 | |
| 2534 | /// Order the instructions within a cycle so that the definitions occur |
| 2535 | /// before the uses. Returns true if the instruction is added to the start |
| 2536 | /// of the list, or false if added to the end. |
| 2537 | void SMSchedule::orderDependence(SwingSchedulerDAG *SSD, SUnit *SU, |
| 2538 | std::deque<SUnit *> &Insts) { |
| 2539 | MachineInstr *MI = SU->getInstr(); |
| 2540 | bool OrderBeforeUse = false; |
| 2541 | bool OrderAfterDef = false; |
| 2542 | bool OrderBeforeDef = false; |
| 2543 | unsigned MoveDef = 0; |
| 2544 | unsigned MoveUse = 0; |
| 2545 | int StageInst1 = stageScheduled(SU); |
| 2546 | |
| 2547 | unsigned Pos = 0; |
| 2548 | for (std::deque<SUnit *>::iterator I = Insts.begin(), E = Insts.end(); I != E; |
| 2549 | ++I, ++Pos) { |
| 2550 | for (unsigned i = 0, e = MI->getNumOperands(); i < e; ++i) { |
| 2551 | MachineOperand &MO = MI->getOperand(i); |
| 2552 | if (!MO.isReg() || !Register::isVirtualRegister(MO.getReg())) |
| 2553 | continue; |
| 2554 | |
| 2555 | Register Reg = MO.getReg(); |
| 2556 | unsigned BasePos, OffsetPos; |
| 2557 | if (ST.getInstrInfo()->getBaseAndOffsetPosition(*MI, BasePos, OffsetPos)) |
| 2558 | if (MI->getOperand(BasePos).getReg() == Reg) |
| 2559 | if (unsigned NewReg = SSD->getInstrBaseReg(SU)) |
| 2560 | Reg = NewReg; |
| 2561 | bool Reads, Writes; |
| 2562 | std::tie(Reads, Writes) = |
| 2563 | (*I)->getInstr()->readsWritesVirtualRegister(Reg); |
| 2564 | if (MO.isDef() && Reads && stageScheduled(*I) <= StageInst1) { |
| 2565 | OrderBeforeUse = true; |
| 2566 | if (MoveUse == 0) |
| 2567 | MoveUse = Pos; |
| 2568 | } else if (MO.isDef() && Reads && stageScheduled(*I) > StageInst1) { |
| 2569 | // Add the instruction after the scheduled instruction. |
| 2570 | OrderAfterDef = true; |
| 2571 | MoveDef = Pos; |
| 2572 | } else if (MO.isUse() && Writes && stageScheduled(*I) == StageInst1) { |
| 2573 | if (cycleScheduled(*I) == cycleScheduled(SU) && !(*I)->isSucc(SU)) { |
| 2574 | OrderBeforeUse = true; |
| 2575 | if (MoveUse == 0) |
| 2576 | MoveUse = Pos; |
| 2577 | } else { |
| 2578 | OrderAfterDef = true; |
| 2579 | MoveDef = Pos; |
| 2580 | } |
| 2581 | } else if (MO.isUse() && Writes && stageScheduled(*I) > StageInst1) { |
| 2582 | OrderBeforeUse = true; |
| 2583 | if (MoveUse == 0) |
| 2584 | MoveUse = Pos; |
| 2585 | if (MoveUse != 0) { |
| 2586 | OrderAfterDef = true; |
| 2587 | MoveDef = Pos - 1; |
| 2588 | } |
| 2589 | } else if (MO.isUse() && Writes && stageScheduled(*I) < StageInst1) { |
| 2590 | // Add the instruction before the scheduled instruction. |
| 2591 | OrderBeforeUse = true; |
| 2592 | if (MoveUse == 0) |
| 2593 | MoveUse = Pos; |
| 2594 | } else if (MO.isUse() && stageScheduled(*I) == StageInst1 && |
| 2595 | isLoopCarriedDefOfUse(SSD, (*I)->getInstr(), MO)) { |
| 2596 | if (MoveUse == 0) { |
| 2597 | OrderBeforeDef = true; |
| 2598 | MoveUse = Pos; |
| 2599 | } |
| 2600 | } |
| 2601 | } |
| 2602 | // Check for order dependences between instructions. Make sure the source |
| 2603 | // is ordered before the destination. |
| 2604 | for (auto &S : SU->Succs) { |
| 2605 | if (S.getSUnit() != *I) |
| 2606 | continue; |
| 2607 | if (S.getKind() == SDep::Order && stageScheduled(*I) == StageInst1) { |
| 2608 | OrderBeforeUse = true; |
| 2609 | if (Pos < MoveUse) |
| 2610 | MoveUse = Pos; |
| 2611 | } |
| 2612 | // We did not handle HW dependences in previous for loop, |
| 2613 | // and we normally set Latency = 0 for Anti deps, |
| 2614 | // so may have nodes in same cycle with Anti denpendent on HW regs. |
| 2615 | else if (S.getKind() == SDep::Anti && stageScheduled(*I) == StageInst1) { |
| 2616 | OrderBeforeUse = true; |
| 2617 | if ((MoveUse == 0) || (Pos < MoveUse)) |
| 2618 | MoveUse = Pos; |
| 2619 | } |
| 2620 | } |
| 2621 | for (auto &P : SU->Preds) { |
| 2622 | if (P.getSUnit() != *I) |
| 2623 | continue; |
| 2624 | if (P.getKind() == SDep::Order && stageScheduled(*I) == StageInst1) { |
| 2625 | OrderAfterDef = true; |
| 2626 | MoveDef = Pos; |
| 2627 | } |
| 2628 | } |
| 2629 | } |
| 2630 | |
| 2631 | // A circular dependence. |
| 2632 | if (OrderAfterDef && OrderBeforeUse && MoveUse == MoveDef) |
| 2633 | OrderBeforeUse = false; |
| 2634 | |
| 2635 | // OrderAfterDef takes precedences over OrderBeforeDef. The latter is due |
| 2636 | // to a loop-carried dependence. |
| 2637 | if (OrderBeforeDef) |
| 2638 | OrderBeforeUse = !OrderAfterDef || (MoveUse > MoveDef); |
| 2639 | |
| 2640 | // The uncommon case when the instruction order needs to be updated because |
| 2641 | // there is both a use and def. |
| 2642 | if (OrderBeforeUse && OrderAfterDef) { |
| 2643 | SUnit *UseSU = Insts.at(MoveUse); |
| 2644 | SUnit *DefSU = Insts.at(MoveDef); |
| 2645 | if (MoveUse > MoveDef) { |
| 2646 | Insts.erase(Insts.begin() + MoveUse); |
| 2647 | Insts.erase(Insts.begin() + MoveDef); |
| 2648 | } else { |
| 2649 | Insts.erase(Insts.begin() + MoveDef); |
| 2650 | Insts.erase(Insts.begin() + MoveUse); |
| 2651 | } |
| 2652 | orderDependence(SSD, UseSU, Insts); |
| 2653 | orderDependence(SSD, SU, Insts); |
| 2654 | orderDependence(SSD, DefSU, Insts); |
| 2655 | return; |
| 2656 | } |
| 2657 | // Put the new instruction first if there is a use in the list. Otherwise, |
| 2658 | // put it at the end of the list. |
| 2659 | if (OrderBeforeUse) |
| 2660 | Insts.push_front(SU); |
| 2661 | else |
| 2662 | Insts.push_back(SU); |
| 2663 | } |
| 2664 | |
| 2665 | /// Return true if the scheduled Phi has a loop carried operand. |
| 2666 | bool SMSchedule::isLoopCarried(SwingSchedulerDAG *SSD, MachineInstr &Phi) { |
| 2667 | if (!Phi.isPHI()) |
| 2668 | return false; |
| 2669 | assert(Phi.isPHI() && "Expecting a Phi.")((void)0); |
| 2670 | SUnit *DefSU = SSD->getSUnit(&Phi); |
| 2671 | unsigned DefCycle = cycleScheduled(DefSU); |
| 2672 | int DefStage = stageScheduled(DefSU); |
| 2673 | |
| 2674 | unsigned InitVal = 0; |
| 2675 | unsigned LoopVal = 0; |
| 2676 | getPhiRegs(Phi, Phi.getParent(), InitVal, LoopVal); |
| 2677 | SUnit *UseSU = SSD->getSUnit(MRI.getVRegDef(LoopVal)); |
| 2678 | if (!UseSU) |
| 2679 | return true; |
| 2680 | if (UseSU->getInstr()->isPHI()) |
| 2681 | return true; |
| 2682 | unsigned LoopCycle = cycleScheduled(UseSU); |
| 2683 | int LoopStage = stageScheduled(UseSU); |
| 2684 | return (LoopCycle > DefCycle) || (LoopStage <= DefStage); |
| 2685 | } |
| 2686 | |
| 2687 | /// Return true if the instruction is a definition that is loop carried |
| 2688 | /// and defines the use on the next iteration. |
| 2689 | /// v1 = phi(v2, v3) |
| 2690 | /// (Def) v3 = op v1 |
| 2691 | /// (MO) = v1 |
| 2692 | /// If MO appears before Def, then then v1 and v3 may get assigned to the same |
| 2693 | /// register. |
| 2694 | bool SMSchedule::isLoopCarriedDefOfUse(SwingSchedulerDAG *SSD, |
| 2695 | MachineInstr *Def, MachineOperand &MO) { |
| 2696 | if (!MO.isReg()) |
| 2697 | return false; |
| 2698 | if (Def->isPHI()) |
| 2699 | return false; |
| 2700 | MachineInstr *Phi = MRI.getVRegDef(MO.getReg()); |
| 2701 | if (!Phi || !Phi->isPHI() || Phi->getParent() != Def->getParent()) |
| 2702 | return false; |
| 2703 | if (!isLoopCarried(SSD, *Phi)) |
| 2704 | return false; |
| 2705 | unsigned LoopReg = getLoopPhiReg(*Phi, Phi->getParent()); |
| 2706 | for (unsigned i = 0, e = Def->getNumOperands(); i != e; ++i) { |
| 2707 | MachineOperand &DMO = Def->getOperand(i); |
| 2708 | if (!DMO.isReg() || !DMO.isDef()) |
| 2709 | continue; |
| 2710 | if (DMO.getReg() == LoopReg) |
| 2711 | return true; |
| 2712 | } |
| 2713 | return false; |
| 2714 | } |
| 2715 | |
| 2716 | // Check if the generated schedule is valid. This function checks if |
| 2717 | // an instruction that uses a physical register is scheduled in a |
| 2718 | // different stage than the definition. The pipeliner does not handle |
| 2719 | // physical register values that may cross a basic block boundary. |
| 2720 | bool SMSchedule::isValidSchedule(SwingSchedulerDAG *SSD) { |
| 2721 | for (SUnit &SU : SSD->SUnits) { |
| 2722 | if (!SU.hasPhysRegDefs) |
| 2723 | continue; |
| 2724 | int StageDef = stageScheduled(&SU); |
| 2725 | assert(StageDef != -1 && "Instruction should have been scheduled.")((void)0); |
| 2726 | for (auto &SI : SU.Succs) |
| 2727 | if (SI.isAssignedRegDep()) |
| 2728 | if (Register::isPhysicalRegister(SI.getReg())) |
| 2729 | if (stageScheduled(SI.getSUnit()) != StageDef) |
| 2730 | return false; |
| 2731 | } |
| 2732 | return true; |
| 2733 | } |
| 2734 | |
| 2735 | /// A property of the node order in swing-modulo-scheduling is |
| 2736 | /// that for nodes outside circuits the following holds: |
| 2737 | /// none of them is scheduled after both a successor and a |
| 2738 | /// predecessor. |
| 2739 | /// The method below checks whether the property is met. |
| 2740 | /// If not, debug information is printed and statistics information updated. |
| 2741 | /// Note that we do not use an assert statement. |
| 2742 | /// The reason is that although an invalid node oder may prevent |
| 2743 | /// the pipeliner from finding a pipelined schedule for arbitrary II, |
| 2744 | /// it does not lead to the generation of incorrect code. |
| 2745 | void SwingSchedulerDAG::checkValidNodeOrder(const NodeSetType &Circuits) const { |
| 2746 | |
| 2747 | // a sorted vector that maps each SUnit to its index in the NodeOrder |
| 2748 | typedef std::pair<SUnit *, unsigned> UnitIndex; |
| 2749 | std::vector<UnitIndex> Indices(NodeOrder.size(), std::make_pair(nullptr, 0)); |
| 2750 | |
| 2751 | for (unsigned i = 0, s = NodeOrder.size(); i < s; ++i) |
| 2752 | Indices.push_back(std::make_pair(NodeOrder[i], i)); |
| 2753 | |
| 2754 | auto CompareKey = [](UnitIndex i1, UnitIndex i2) { |
| 2755 | return std::get<0>(i1) < std::get<0>(i2); |
| 2756 | }; |
| 2757 | |
| 2758 | // sort, so that we can perform a binary search |
| 2759 | llvm::sort(Indices, CompareKey); |
| 2760 | |
| 2761 | bool Valid = true; |
| 2762 | (void)Valid; |
| 2763 | // for each SUnit in the NodeOrder, check whether |
| 2764 | // it appears after both a successor and a predecessor |
| 2765 | // of the SUnit. If this is the case, and the SUnit |
| 2766 | // is not part of circuit, then the NodeOrder is not |
| 2767 | // valid. |
| 2768 | for (unsigned i = 0, s = NodeOrder.size(); i < s; ++i) { |
| 2769 | SUnit *SU = NodeOrder[i]; |
| 2770 | unsigned Index = i; |
| 2771 | |
| 2772 | bool PredBefore = false; |
| 2773 | bool SuccBefore = false; |
| 2774 | |
| 2775 | SUnit *Succ; |
| 2776 | SUnit *Pred; |
| 2777 | (void)Succ; |
| 2778 | (void)Pred; |
| 2779 | |
| 2780 | for (SDep &PredEdge : SU->Preds) { |
| 2781 | SUnit *PredSU = PredEdge.getSUnit(); |
| 2782 | unsigned PredIndex = std::get<1>( |
| 2783 | *llvm::lower_bound(Indices, std::make_pair(PredSU, 0), CompareKey)); |
| 2784 | if (!PredSU->getInstr()->isPHI() && PredIndex < Index) { |
| 2785 | PredBefore = true; |
| 2786 | Pred = PredSU; |
| 2787 | break; |
| 2788 | } |
| 2789 | } |
| 2790 | |
| 2791 | for (SDep &SuccEdge : SU->Succs) { |
| 2792 | SUnit *SuccSU = SuccEdge.getSUnit(); |
| 2793 | // Do not process a boundary node, it was not included in NodeOrder, |
| 2794 | // hence not in Indices either, call to std::lower_bound() below will |
| 2795 | // return Indices.end(). |
| 2796 | if (SuccSU->isBoundaryNode()) |
| 2797 | continue; |
| 2798 | unsigned SuccIndex = std::get<1>( |
| 2799 | *llvm::lower_bound(Indices, std::make_pair(SuccSU, 0), CompareKey)); |
| 2800 | if (!SuccSU->getInstr()->isPHI() && SuccIndex < Index) { |
| 2801 | SuccBefore = true; |
| 2802 | Succ = SuccSU; |
| 2803 | break; |
| 2804 | } |
| 2805 | } |
| 2806 | |
| 2807 | if (PredBefore && SuccBefore && !SU->getInstr()->isPHI()) { |
| 2808 | // instructions in circuits are allowed to be scheduled |
| 2809 | // after both a successor and predecessor. |
| 2810 | bool InCircuit = llvm::any_of( |
| 2811 | Circuits, [SU](const NodeSet &Circuit) { return Circuit.count(SU); }); |
| 2812 | if (InCircuit) |
| 2813 | LLVM_DEBUG(dbgs() << "In a circuit, predecessor ";)do { } while (false); |
| 2814 | else { |
| 2815 | Valid = false; |
| 2816 | NumNodeOrderIssues++; |
| 2817 | LLVM_DEBUG(dbgs() << "Predecessor ";)do { } while (false); |
| 2818 | } |
| 2819 | LLVM_DEBUG(dbgs() << Pred->NodeNum << " and successor " << Succ->NodeNumdo { } while (false) |
| 2820 | << " are scheduled before node " << SU->NodeNumdo { } while (false) |
| 2821 | << "\n";)do { } while (false); |
| 2822 | } |
| 2823 | } |
| 2824 | |
| 2825 | LLVM_DEBUG({do { } while (false) |
| 2826 | if (!Valid)do { } while (false) |
| 2827 | dbgs() << "Invalid node order found!\n";do { } while (false) |
| 2828 | })do { } while (false); |
| 2829 | } |
| 2830 | |
| 2831 | /// Attempt to fix the degenerate cases when the instruction serialization |
| 2832 | /// causes the register lifetimes to overlap. For example, |
| 2833 | /// p' = store_pi(p, b) |
| 2834 | /// = load p, offset |
| 2835 | /// In this case p and p' overlap, which means that two registers are needed. |
| 2836 | /// Instead, this function changes the load to use p' and updates the offset. |
| 2837 | void SwingSchedulerDAG::fixupRegisterOverlaps(std::deque<SUnit *> &Instrs) { |
| 2838 | unsigned OverlapReg = 0; |
| 2839 | unsigned NewBaseReg = 0; |
| 2840 | for (SUnit *SU : Instrs) { |
| 2841 | MachineInstr *MI = SU->getInstr(); |
| 2842 | for (unsigned i = 0, e = MI->getNumOperands(); i < e; ++i) { |
| 2843 | const MachineOperand &MO = MI->getOperand(i); |
| 2844 | // Look for an instruction that uses p. The instruction occurs in the |
| 2845 | // same cycle but occurs later in the serialized order. |
| 2846 | if (MO.isReg() && MO.isUse() && MO.getReg() == OverlapReg) { |
| 2847 | // Check that the instruction appears in the InstrChanges structure, |
| 2848 | // which contains instructions that can have the offset updated. |
| 2849 | DenseMap<SUnit *, std::pair<unsigned, int64_t>>::iterator It = |
| 2850 | InstrChanges.find(SU); |
| 2851 | if (It != InstrChanges.end()) { |
| 2852 | unsigned BasePos, OffsetPos; |
| 2853 | // Update the base register and adjust the offset. |
| 2854 | if (TII->getBaseAndOffsetPosition(*MI, BasePos, OffsetPos)) { |
| 2855 | MachineInstr *NewMI = MF.CloneMachineInstr(MI); |
| 2856 | NewMI->getOperand(BasePos).setReg(NewBaseReg); |
| 2857 | int64_t NewOffset = |
| 2858 | MI->getOperand(OffsetPos).getImm() - It->second.second; |
| 2859 | NewMI->getOperand(OffsetPos).setImm(NewOffset); |
| 2860 | SU->setInstr(NewMI); |
| 2861 | MISUnitMap[NewMI] = SU; |
| 2862 | NewMIs[MI] = NewMI; |
| 2863 | } |
| 2864 | } |
| 2865 | OverlapReg = 0; |
| 2866 | NewBaseReg = 0; |
| 2867 | break; |
| 2868 | } |
| 2869 | // Look for an instruction of the form p' = op(p), which uses and defines |
| 2870 | // two virtual registers that get allocated to the same physical register. |
| 2871 | unsigned TiedUseIdx = 0; |
| 2872 | if (MI->isRegTiedToUseOperand(i, &TiedUseIdx)) { |
| 2873 | // OverlapReg is p in the example above. |
| 2874 | OverlapReg = MI->getOperand(TiedUseIdx).getReg(); |
| 2875 | // NewBaseReg is p' in the example above. |
| 2876 | NewBaseReg = MI->getOperand(i).getReg(); |
| 2877 | break; |
| 2878 | } |
| 2879 | } |
| 2880 | } |
| 2881 | } |
| 2882 | |
| 2883 | /// After the schedule has been formed, call this function to combine |
| 2884 | /// the instructions from the different stages/cycles. That is, this |
| 2885 | /// function creates a schedule that represents a single iteration. |
| 2886 | void SMSchedule::finalizeSchedule(SwingSchedulerDAG *SSD) { |
| 2887 | // Move all instructions to the first stage from later stages. |
| 2888 | for (int cycle = getFirstCycle(); cycle <= getFinalCycle(); ++cycle) { |
| 2889 | for (int stage = 1, lastStage = getMaxStageCount(); stage <= lastStage; |
| 2890 | ++stage) { |
| 2891 | std::deque<SUnit *> &cycleInstrs = |
| 2892 | ScheduledInstrs[cycle + (stage * InitiationInterval)]; |
| 2893 | for (std::deque<SUnit *>::reverse_iterator I = cycleInstrs.rbegin(), |
| 2894 | E = cycleInstrs.rend(); |
| 2895 | I != E; ++I) |
| 2896 | ScheduledInstrs[cycle].push_front(*I); |
| 2897 | } |
| 2898 | } |
| 2899 | |
| 2900 | // Erase all the elements in the later stages. Only one iteration should |
| 2901 | // remain in the scheduled list, and it contains all the instructions. |
| 2902 | for (int cycle = getFinalCycle() + 1; cycle <= LastCycle; ++cycle) |
| 2903 | ScheduledInstrs.erase(cycle); |
| 2904 | |
| 2905 | // Change the registers in instruction as specified in the InstrChanges |
| 2906 | // map. We need to use the new registers to create the correct order. |
| 2907 | for (int i = 0, e = SSD->SUnits.size(); i != e; ++i) { |
| 2908 | SUnit *SU = &SSD->SUnits[i]; |
| 2909 | SSD->applyInstrChange(SU->getInstr(), *this); |
| 2910 | } |
| 2911 | |
| 2912 | // Reorder the instructions in each cycle to fix and improve the |
| 2913 | // generated code. |
| 2914 | for (int Cycle = getFirstCycle(), E = getFinalCycle(); Cycle <= E; ++Cycle) { |
| 2915 | std::deque<SUnit *> &cycleInstrs = ScheduledInstrs[Cycle]; |
| 2916 | std::deque<SUnit *> newOrderPhi; |
| 2917 | for (SUnit *SU : cycleInstrs) { |
| 2918 | if (SU->getInstr()->isPHI()) |
| 2919 | newOrderPhi.push_back(SU); |
| 2920 | } |
| 2921 | std::deque<SUnit *> newOrderI; |
| 2922 | for (SUnit *SU : cycleInstrs) { |
| 2923 | if (!SU->getInstr()->isPHI()) |
| 2924 | orderDependence(SSD, SU, newOrderI); |
| 2925 | } |
| 2926 | // Replace the old order with the new order. |
| 2927 | cycleInstrs.swap(newOrderPhi); |
| 2928 | llvm::append_range(cycleInstrs, newOrderI); |
| 2929 | SSD->fixupRegisterOverlaps(cycleInstrs); |
| 2930 | } |
| 2931 | |
| 2932 | LLVM_DEBUG(dump();)do { } while (false); |
| 2933 | } |
| 2934 | |
| 2935 | void NodeSet::print(raw_ostream &os) const { |
| 2936 | os << "Num nodes " << size() << " rec " << RecMII << " mov " << MaxMOV |
| 2937 | << " depth " << MaxDepth << " col " << Colocate << "\n"; |
| 2938 | for (const auto &I : Nodes) |
| 2939 | os << " SU(" << I->NodeNum << ") " << *(I->getInstr()); |
| 2940 | os << "\n"; |
| 2941 | } |
| 2942 | |
| 2943 | #if !defined(NDEBUG1) || defined(LLVM_ENABLE_DUMP) |
| 2944 | /// Print the schedule information to the given output. |
| 2945 | void SMSchedule::print(raw_ostream &os) const { |
| 2946 | // Iterate over each cycle. |
| 2947 | for (int cycle = getFirstCycle(); cycle <= getFinalCycle(); ++cycle) { |
| 2948 | // Iterate over each instruction in the cycle. |
| 2949 | const_sched_iterator cycleInstrs = ScheduledInstrs.find(cycle); |
| 2950 | for (SUnit *CI : cycleInstrs->second) { |
| 2951 | os << "cycle " << cycle << " (" << stageScheduled(CI) << ") "; |
| 2952 | os << "(" << CI->NodeNum << ") "; |
| 2953 | CI->getInstr()->print(os); |
| 2954 | os << "\n"; |
| 2955 | } |
| 2956 | } |
| 2957 | } |
| 2958 | |
| 2959 | /// Utility function used for debugging to print the schedule. |
| 2960 | LLVM_DUMP_METHOD__attribute__((noinline)) void SMSchedule::dump() const { print(dbgs()); } |
| 2961 | LLVM_DUMP_METHOD__attribute__((noinline)) void NodeSet::dump() const { print(dbgs()); } |
| 2962 | |
| 2963 | #endif |
| 2964 | |
| 2965 | void ResourceManager::initProcResourceVectors( |
| 2966 | const MCSchedModel &SM, SmallVectorImpl<uint64_t> &Masks) { |
| 2967 | unsigned ProcResourceID = 0; |
| 2968 | |
| 2969 | // We currently limit the resource kinds to 64 and below so that we can use |
| 2970 | // uint64_t for Masks |
| 2971 | assert(SM.getNumProcResourceKinds() < 64 &&((void)0) |
| 2972 | "Too many kinds of resources, unsupported")((void)0); |
| 2973 | // Create a unique bitmask for every processor resource unit. |
| 2974 | // Skip resource at index 0, since it always references 'InvalidUnit'. |
| 2975 | Masks.resize(SM.getNumProcResourceKinds()); |
| 2976 | for (unsigned I = 1, E = SM.getNumProcResourceKinds(); I < E; ++I) { |
| 2977 | const MCProcResourceDesc &Desc = *SM.getProcResource(I); |
| 2978 | if (Desc.SubUnitsIdxBegin) |
| 2979 | continue; |
| 2980 | Masks[I] = 1ULL << ProcResourceID; |
| 2981 | ProcResourceID++; |
| 2982 | } |
| 2983 | // Create a unique bitmask for every processor resource group. |
| 2984 | for (unsigned I = 1, E = SM.getNumProcResourceKinds(); I < E; ++I) { |
| 2985 | const MCProcResourceDesc &Desc = *SM.getProcResource(I); |
| 2986 | if (!Desc.SubUnitsIdxBegin) |
| 2987 | continue; |
| 2988 | Masks[I] = 1ULL << ProcResourceID; |
| 2989 | for (unsigned U = 0; U < Desc.NumUnits; ++U) |
| 2990 | Masks[I] |= Masks[Desc.SubUnitsIdxBegin[U]]; |
| 2991 | ProcResourceID++; |
| 2992 | } |
| 2993 | LLVM_DEBUG({do { } while (false) |
| 2994 | if (SwpShowResMask) {do { } while (false) |
| 2995 | dbgs() << "ProcResourceDesc:\n";do { } while (false) |
| 2996 | for (unsigned I = 1, E = SM.getNumProcResourceKinds(); I < E; ++I) {do { } while (false) |
| 2997 | const MCProcResourceDesc *ProcResource = SM.getProcResource(I);do { } while (false) |
| 2998 | dbgs() << format(" %16s(%2d): Mask: 0x%08x, NumUnits:%2d\n",do { } while (false) |
| 2999 | ProcResource->Name, I, Masks[I],do { } while (false) |
| 3000 | ProcResource->NumUnits);do { } while (false) |
| 3001 | }do { } while (false) |
| 3002 | dbgs() << " -----------------\n";do { } while (false) |
| 3003 | }do { } while (false) |
| 3004 | })do { } while (false); |
| 3005 | } |
| 3006 | |
| 3007 | bool ResourceManager::canReserveResources(const MCInstrDesc *MID) const { |
| 3008 | |
| 3009 | LLVM_DEBUG({do { } while (false) |
| 3010 | if (SwpDebugResource)do { } while (false) |
| 3011 | dbgs() << "canReserveResources:\n";do { } while (false) |
| 3012 | })do { } while (false); |
| 3013 | if (UseDFA) |
| 3014 | return DFAResources->canReserveResources(MID); |
| 3015 | |
| 3016 | unsigned InsnClass = MID->getSchedClass(); |
| 3017 | const MCSchedClassDesc *SCDesc = SM.getSchedClassDesc(InsnClass); |
| 3018 | if (!SCDesc->isValid()) { |
| 3019 | LLVM_DEBUG({do { } while (false) |
| 3020 | dbgs() << "No valid Schedule Class Desc for schedClass!\n";do { } while (false) |
| 3021 | dbgs() << "isPseduo:" << MID->isPseudo() << "\n";do { } while (false) |
| 3022 | })do { } while (false); |
| 3023 | return true; |
| 3024 | } |
| 3025 | |
| 3026 | const MCWriteProcResEntry *I = STI->getWriteProcResBegin(SCDesc); |
| 3027 | const MCWriteProcResEntry *E = STI->getWriteProcResEnd(SCDesc); |
| 3028 | for (; I != E; ++I) { |
| 3029 | if (!I->Cycles) |
| 3030 | continue; |
| 3031 | const MCProcResourceDesc *ProcResource = |
| 3032 | SM.getProcResource(I->ProcResourceIdx); |
| 3033 | unsigned NumUnits = ProcResource->NumUnits; |
| 3034 | LLVM_DEBUG({do { } while (false) |
| 3035 | if (SwpDebugResource)do { } while (false) |
| 3036 | dbgs() << format(" %16s(%2d): Count: %2d, NumUnits:%2d, Cycles:%2d\n",do { } while (false) |
| 3037 | ProcResource->Name, I->ProcResourceIdx,do { } while (false) |
| 3038 | ProcResourceCount[I->ProcResourceIdx], NumUnits,do { } while (false) |
| 3039 | I->Cycles);do { } while (false) |
| 3040 | })do { } while (false); |
| 3041 | if (ProcResourceCount[I->ProcResourceIdx] >= NumUnits) |
| 3042 | return false; |
| 3043 | } |
| 3044 | LLVM_DEBUG(if (SwpDebugResource) dbgs() << "return true\n\n";)do { } while (false); |
| 3045 | return true; |
| 3046 | } |
| 3047 | |
| 3048 | void ResourceManager::reserveResources(const MCInstrDesc *MID) { |
| 3049 | LLVM_DEBUG({do { } while (false) |
| 3050 | if (SwpDebugResource)do { } while (false) |
| 3051 | dbgs() << "reserveResources:\n";do { } while (false) |
| 3052 | })do { } while (false); |
| 3053 | if (UseDFA) |
| 3054 | return DFAResources->reserveResources(MID); |
| 3055 | |
| 3056 | unsigned InsnClass = MID->getSchedClass(); |
| 3057 | const MCSchedClassDesc *SCDesc = SM.getSchedClassDesc(InsnClass); |
| 3058 | if (!SCDesc->isValid()) { |
| 3059 | LLVM_DEBUG({do { } while (false) |
| 3060 | dbgs() << "No valid Schedule Class Desc for schedClass!\n";do { } while (false) |
| 3061 | dbgs() << "isPseduo:" << MID->isPseudo() << "\n";do { } while (false) |
| 3062 | })do { } while (false); |
| 3063 | return; |
| 3064 | } |
| 3065 | for (const MCWriteProcResEntry &PRE : |
| 3066 | make_range(STI->getWriteProcResBegin(SCDesc), |
| 3067 | STI->getWriteProcResEnd(SCDesc))) { |
| 3068 | if (!PRE.Cycles) |
| 3069 | continue; |
| 3070 | ++ProcResourceCount[PRE.ProcResourceIdx]; |
| 3071 | LLVM_DEBUG({do { } while (false) |
| 3072 | if (SwpDebugResource) {do { } while (false) |
| 3073 | const MCProcResourceDesc *ProcResource =do { } while (false) |
| 3074 | SM.getProcResource(PRE.ProcResourceIdx);do { } while (false) |
| 3075 | dbgs() << format(" %16s(%2d): Count: %2d, NumUnits:%2d, Cycles:%2d\n",do { } while (false) |
| 3076 | ProcResource->Name, PRE.ProcResourceIdx,do { } while (false) |
| 3077 | ProcResourceCount[PRE.ProcResourceIdx],do { } while (false) |
| 3078 | ProcResource->NumUnits, PRE.Cycles);do { } while (false) |
| 3079 | }do { } while (false) |
| 3080 | })do { } while (false); |
| 3081 | } |
| 3082 | LLVM_DEBUG({do { } while (false) |
| 3083 | if (SwpDebugResource)do { } while (false) |
| 3084 | dbgs() << "reserveResources: done!\n\n";do { } while (false) |
| 3085 | })do { } while (false); |
| 3086 | } |
| 3087 | |
| 3088 | bool ResourceManager::canReserveResources(const MachineInstr &MI) const { |
| 3089 | return canReserveResources(&MI.getDesc()); |
| 3090 | } |
| 3091 | |
| 3092 | void ResourceManager::reserveResources(const MachineInstr &MI) { |
| 3093 | return reserveResources(&MI.getDesc()); |
| 3094 | } |
| 3095 | |
| 3096 | void ResourceManager::clearResources() { |
| 3097 | if (UseDFA) |
| 3098 | return DFAResources->clearResources(); |
| 3099 | std::fill(ProcResourceCount.begin(), ProcResourceCount.end(), 0); |
| 3100 | } |