1 //===-- SelectionDAGISel.cpp - Implement the SelectionDAGISel class -------===//
3 // The LLVM Compiler Infrastructure
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 // This implements the SelectionDAGISel class.
12 //===----------------------------------------------------------------------===//
14 #include "llvm/CodeGen/SelectionDAG.h"
15 #include "ScheduleDAGSDNodes.h"
16 #include "SelectionDAGBuilder.h"
17 #include "llvm/ADT/PostOrderIterator.h"
18 #include "llvm/ADT/Statistic.h"
19 #include "llvm/Analysis/AliasAnalysis.h"
20 #include "llvm/Analysis/BranchProbabilityInfo.h"
21 #include "llvm/Analysis/CFG.h"
22 #include "llvm/Analysis/EHPersonalities.h"
23 #include "llvm/Analysis/TargetLibraryInfo.h"
24 #include "llvm/CodeGen/FastISel.h"
25 #include "llvm/CodeGen/FunctionLoweringInfo.h"
26 #include "llvm/CodeGen/GCMetadata.h"
27 #include "llvm/CodeGen/GCStrategy.h"
28 #include "llvm/CodeGen/MachineFrameInfo.h"
29 #include "llvm/CodeGen/MachineFunction.h"
30 #include "llvm/CodeGen/MachineInstrBuilder.h"
31 #include "llvm/CodeGen/MachineModuleInfo.h"
32 #include "llvm/CodeGen/MachineRegisterInfo.h"
33 #include "llvm/CodeGen/ScheduleHazardRecognizer.h"
34 #include "llvm/CodeGen/SchedulerRegistry.h"
35 #include "llvm/CodeGen/SelectionDAGISel.h"
36 #include "llvm/CodeGen/StackProtector.h"
37 #include "llvm/CodeGen/WinEHFuncInfo.h"
38 #include "llvm/IR/Constants.h"
39 #include "llvm/IR/DebugInfo.h"
40 #include "llvm/IR/Function.h"
41 #include "llvm/IR/InlineAsm.h"
42 #include "llvm/IR/Instructions.h"
43 #include "llvm/IR/IntrinsicInst.h"
44 #include "llvm/IR/Intrinsics.h"
45 #include "llvm/IR/LLVMContext.h"
46 #include "llvm/IR/Module.h"
47 #include "llvm/MC/MCAsmInfo.h"
48 #include "llvm/Support/Compiler.h"
49 #include "llvm/Support/Debug.h"
50 #include "llvm/Support/ErrorHandling.h"
51 #include "llvm/Support/Timer.h"
52 #include "llvm/Support/raw_ostream.h"
53 #include "llvm/Target/TargetInstrInfo.h"
54 #include "llvm/Target/TargetIntrinsicInfo.h"
55 #include "llvm/Target/TargetLowering.h"
56 #include "llvm/Target/TargetMachine.h"
57 #include "llvm/Target/TargetOptions.h"
58 #include "llvm/Target/TargetRegisterInfo.h"
59 #include "llvm/Target/TargetSubtargetInfo.h"
60 #include "llvm/Transforms/Utils/BasicBlockUtils.h"
65 #define DEBUG_TYPE "isel"
67 STATISTIC(NumFastIselFailures, "Number of instructions fast isel failed on");
68 STATISTIC(NumFastIselSuccess, "Number of instructions fast isel selected");
69 STATISTIC(NumFastIselBlocks, "Number of blocks selected entirely by fast isel");
70 STATISTIC(NumDAGBlocks, "Number of blocks selected using DAG");
71 STATISTIC(NumDAGIselRetries,"Number of times dag isel has to try another path");
72 STATISTIC(NumEntryBlocks, "Number of entry blocks encountered");
73 STATISTIC(NumFastIselFailLowerArguments,
74 "Number of entry blocks where fast isel failed to lower arguments");
78 EnableFastISelVerbose2("fast-isel-verbose2", cl::Hidden,
79 cl::desc("Enable extra verbose messages in the \"fast\" "
80 "instruction selector"));
83 STATISTIC(NumFastIselFailRet,"Fast isel fails on Ret");
84 STATISTIC(NumFastIselFailBr,"Fast isel fails on Br");
85 STATISTIC(NumFastIselFailSwitch,"Fast isel fails on Switch");
86 STATISTIC(NumFastIselFailIndirectBr,"Fast isel fails on IndirectBr");
87 STATISTIC(NumFastIselFailInvoke,"Fast isel fails on Invoke");
88 STATISTIC(NumFastIselFailResume,"Fast isel fails on Resume");
89 STATISTIC(NumFastIselFailUnreachable,"Fast isel fails on Unreachable");
91 // Standard binary operators...
92 STATISTIC(NumFastIselFailAdd,"Fast isel fails on Add");
93 STATISTIC(NumFastIselFailFAdd,"Fast isel fails on FAdd");
94 STATISTIC(NumFastIselFailSub,"Fast isel fails on Sub");
95 STATISTIC(NumFastIselFailFSub,"Fast isel fails on FSub");
96 STATISTIC(NumFastIselFailMul,"Fast isel fails on Mul");
97 STATISTIC(NumFastIselFailFMul,"Fast isel fails on FMul");
98 STATISTIC(NumFastIselFailUDiv,"Fast isel fails on UDiv");
99 STATISTIC(NumFastIselFailSDiv,"Fast isel fails on SDiv");
100 STATISTIC(NumFastIselFailFDiv,"Fast isel fails on FDiv");
101 STATISTIC(NumFastIselFailURem,"Fast isel fails on URem");
102 STATISTIC(NumFastIselFailSRem,"Fast isel fails on SRem");
103 STATISTIC(NumFastIselFailFRem,"Fast isel fails on FRem");
105 // Logical operators...
106 STATISTIC(NumFastIselFailAnd,"Fast isel fails on And");
107 STATISTIC(NumFastIselFailOr,"Fast isel fails on Or");
108 STATISTIC(NumFastIselFailXor,"Fast isel fails on Xor");
110 // Memory instructions...
111 STATISTIC(NumFastIselFailAlloca,"Fast isel fails on Alloca");
112 STATISTIC(NumFastIselFailLoad,"Fast isel fails on Load");
113 STATISTIC(NumFastIselFailStore,"Fast isel fails on Store");
114 STATISTIC(NumFastIselFailAtomicCmpXchg,"Fast isel fails on AtomicCmpXchg");
115 STATISTIC(NumFastIselFailAtomicRMW,"Fast isel fails on AtomicRWM");
116 STATISTIC(NumFastIselFailFence,"Fast isel fails on Frence");
117 STATISTIC(NumFastIselFailGetElementPtr,"Fast isel fails on GetElementPtr");
119 // Convert instructions...
120 STATISTIC(NumFastIselFailTrunc,"Fast isel fails on Trunc");
121 STATISTIC(NumFastIselFailZExt,"Fast isel fails on ZExt");
122 STATISTIC(NumFastIselFailSExt,"Fast isel fails on SExt");
123 STATISTIC(NumFastIselFailFPTrunc,"Fast isel fails on FPTrunc");
124 STATISTIC(NumFastIselFailFPExt,"Fast isel fails on FPExt");
125 STATISTIC(NumFastIselFailFPToUI,"Fast isel fails on FPToUI");
126 STATISTIC(NumFastIselFailFPToSI,"Fast isel fails on FPToSI");
127 STATISTIC(NumFastIselFailUIToFP,"Fast isel fails on UIToFP");
128 STATISTIC(NumFastIselFailSIToFP,"Fast isel fails on SIToFP");
129 STATISTIC(NumFastIselFailIntToPtr,"Fast isel fails on IntToPtr");
130 STATISTIC(NumFastIselFailPtrToInt,"Fast isel fails on PtrToInt");
131 STATISTIC(NumFastIselFailBitCast,"Fast isel fails on BitCast");
133 // Other instructions...
134 STATISTIC(NumFastIselFailICmp,"Fast isel fails on ICmp");
135 STATISTIC(NumFastIselFailFCmp,"Fast isel fails on FCmp");
136 STATISTIC(NumFastIselFailPHI,"Fast isel fails on PHI");
137 STATISTIC(NumFastIselFailSelect,"Fast isel fails on Select");
138 STATISTIC(NumFastIselFailCall,"Fast isel fails on Call");
139 STATISTIC(NumFastIselFailShl,"Fast isel fails on Shl");
140 STATISTIC(NumFastIselFailLShr,"Fast isel fails on LShr");
141 STATISTIC(NumFastIselFailAShr,"Fast isel fails on AShr");
142 STATISTIC(NumFastIselFailVAArg,"Fast isel fails on VAArg");
143 STATISTIC(NumFastIselFailExtractElement,"Fast isel fails on ExtractElement");
144 STATISTIC(NumFastIselFailInsertElement,"Fast isel fails on InsertElement");
145 STATISTIC(NumFastIselFailShuffleVector,"Fast isel fails on ShuffleVector");
146 STATISTIC(NumFastIselFailExtractValue,"Fast isel fails on ExtractValue");
147 STATISTIC(NumFastIselFailInsertValue,"Fast isel fails on InsertValue");
148 STATISTIC(NumFastIselFailLandingPad,"Fast isel fails on LandingPad");
150 // Intrinsic instructions...
151 STATISTIC(NumFastIselFailIntrinsicCall, "Fast isel fails on Intrinsic call");
152 STATISTIC(NumFastIselFailSAddWithOverflow,
153 "Fast isel fails on sadd.with.overflow");
154 STATISTIC(NumFastIselFailUAddWithOverflow,
155 "Fast isel fails on uadd.with.overflow");
156 STATISTIC(NumFastIselFailSSubWithOverflow,
157 "Fast isel fails on ssub.with.overflow");
158 STATISTIC(NumFastIselFailUSubWithOverflow,
159 "Fast isel fails on usub.with.overflow");
160 STATISTIC(NumFastIselFailSMulWithOverflow,
161 "Fast isel fails on smul.with.overflow");
162 STATISTIC(NumFastIselFailUMulWithOverflow,
163 "Fast isel fails on umul.with.overflow");
164 STATISTIC(NumFastIselFailFrameaddress, "Fast isel fails on Frameaddress");
165 STATISTIC(NumFastIselFailSqrt, "Fast isel fails on sqrt call");
166 STATISTIC(NumFastIselFailStackMap, "Fast isel fails on StackMap call");
167 STATISTIC(NumFastIselFailPatchPoint, "Fast isel fails on PatchPoint call");
171 EnableFastISelVerbose("fast-isel-verbose", cl::Hidden,
172 cl::desc("Enable verbose messages in the \"fast\" "
173 "instruction selector"));
174 static cl::opt<int> EnableFastISelAbort(
175 "fast-isel-abort", cl::Hidden,
176 cl::desc("Enable abort calls when \"fast\" instruction selection "
177 "fails to lower an instruction: 0 disable the abort, 1 will "
178 "abort but for args, calls and terminators, 2 will also "
179 "abort for argument lowering, and 3 will never fallback "
180 "to SelectionDAG."));
184 cl::desc("use Machine Branch Probability Info"),
185 cl::init(true), cl::Hidden);
188 static cl::opt<std::string>
189 FilterDAGBasicBlockName("filter-view-dags", cl::Hidden,
190 cl::desc("Only display the basic block whose name "
191 "matches this for all view-*-dags options"));
193 ViewDAGCombine1("view-dag-combine1-dags", cl::Hidden,
194 cl::desc("Pop up a window to show dags before the first "
195 "dag combine pass"));
197 ViewLegalizeTypesDAGs("view-legalize-types-dags", cl::Hidden,
198 cl::desc("Pop up a window to show dags before legalize types"));
200 ViewLegalizeDAGs("view-legalize-dags", cl::Hidden,
201 cl::desc("Pop up a window to show dags before legalize"));
203 ViewDAGCombine2("view-dag-combine2-dags", cl::Hidden,
204 cl::desc("Pop up a window to show dags before the second "
205 "dag combine pass"));
207 ViewDAGCombineLT("view-dag-combine-lt-dags", cl::Hidden,
208 cl::desc("Pop up a window to show dags before the post legalize types"
209 " dag combine pass"));
211 ViewISelDAGs("view-isel-dags", cl::Hidden,
212 cl::desc("Pop up a window to show isel dags as they are selected"));
214 ViewSchedDAGs("view-sched-dags", cl::Hidden,
215 cl::desc("Pop up a window to show sched dags as they are processed"));
217 ViewSUnitDAGs("view-sunit-dags", cl::Hidden,
218 cl::desc("Pop up a window to show SUnit dags after they are processed"));
220 static const bool ViewDAGCombine1 = false,
221 ViewLegalizeTypesDAGs = false, ViewLegalizeDAGs = false,
222 ViewDAGCombine2 = false,
223 ViewDAGCombineLT = false,
224 ViewISelDAGs = false, ViewSchedDAGs = false,
225 ViewSUnitDAGs = false;
228 //===---------------------------------------------------------------------===//
230 /// RegisterScheduler class - Track the registration of instruction schedulers.
232 //===---------------------------------------------------------------------===//
233 MachinePassRegistry RegisterScheduler::Registry;
235 //===---------------------------------------------------------------------===//
237 /// ISHeuristic command line option for instruction schedulers.
239 //===---------------------------------------------------------------------===//
240 static cl::opt<RegisterScheduler::FunctionPassCtor, false,
241 RegisterPassParser<RegisterScheduler> >
242 ISHeuristic("pre-RA-sched",
243 cl::init(&createDefaultScheduler), cl::Hidden,
244 cl::desc("Instruction schedulers available (before register"
247 static RegisterScheduler
248 defaultListDAGScheduler("default", "Best scheduler for the target",
249 createDefaultScheduler);
252 //===--------------------------------------------------------------------===//
253 /// \brief This class is used by SelectionDAGISel to temporarily override
254 /// the optimization level on a per-function basis.
255 class OptLevelChanger {
256 SelectionDAGISel &IS;
257 CodeGenOpt::Level SavedOptLevel;
261 OptLevelChanger(SelectionDAGISel &ISel,
262 CodeGenOpt::Level NewOptLevel) : IS(ISel) {
263 SavedOptLevel = IS.OptLevel;
264 if (NewOptLevel == SavedOptLevel)
266 IS.OptLevel = NewOptLevel;
267 IS.TM.setOptLevel(NewOptLevel);
268 DEBUG(dbgs() << "\nChanging optimization level for Function "
269 << IS.MF->getFunction()->getName() << "\n");
270 DEBUG(dbgs() << "\tBefore: -O" << SavedOptLevel
271 << " ; After: -O" << NewOptLevel << "\n");
272 SavedFastISel = IS.TM.Options.EnableFastISel;
273 if (NewOptLevel == CodeGenOpt::None) {
274 IS.TM.setFastISel(IS.TM.getO0WantsFastISel());
275 DEBUG(dbgs() << "\tFastISel is "
276 << (IS.TM.Options.EnableFastISel ? "enabled" : "disabled")
282 if (IS.OptLevel == SavedOptLevel)
284 DEBUG(dbgs() << "\nRestoring optimization level for Function "
285 << IS.MF->getFunction()->getName() << "\n");
286 DEBUG(dbgs() << "\tBefore: -O" << IS.OptLevel
287 << " ; After: -O" << SavedOptLevel << "\n");
288 IS.OptLevel = SavedOptLevel;
289 IS.TM.setOptLevel(SavedOptLevel);
290 IS.TM.setFastISel(SavedFastISel);
294 //===--------------------------------------------------------------------===//
295 /// createDefaultScheduler - This creates an instruction scheduler appropriate
297 ScheduleDAGSDNodes* createDefaultScheduler(SelectionDAGISel *IS,
298 CodeGenOpt::Level OptLevel) {
299 const TargetLowering *TLI = IS->TLI;
300 const TargetSubtargetInfo &ST = IS->MF->getSubtarget();
302 // Try first to see if the Target has its own way of selecting a scheduler
303 if (auto *SchedulerCtor = ST.getDAGScheduler(OptLevel)) {
304 return SchedulerCtor(IS, OptLevel);
307 if (OptLevel == CodeGenOpt::None ||
308 (ST.enableMachineScheduler() && ST.enableMachineSchedDefaultSched()) ||
309 TLI->getSchedulingPreference() == Sched::Source)
310 return createSourceListDAGScheduler(IS, OptLevel);
311 if (TLI->getSchedulingPreference() == Sched::RegPressure)
312 return createBURRListDAGScheduler(IS, OptLevel);
313 if (TLI->getSchedulingPreference() == Sched::Hybrid)
314 return createHybridListDAGScheduler(IS, OptLevel);
315 if (TLI->getSchedulingPreference() == Sched::VLIW)
316 return createVLIWDAGScheduler(IS, OptLevel);
317 assert(TLI->getSchedulingPreference() == Sched::ILP &&
318 "Unknown sched type!");
319 return createILPListDAGScheduler(IS, OptLevel);
321 } // end namespace llvm
323 // EmitInstrWithCustomInserter - This method should be implemented by targets
324 // that mark instructions with the 'usesCustomInserter' flag. These
325 // instructions are special in various ways, which require special support to
326 // insert. The specified MachineInstr is created but not inserted into any
327 // basic blocks, and this method is called to expand it into a sequence of
328 // instructions, potentially also creating new basic blocks and control flow.
329 // When new basic blocks are inserted and the edges from MBB to its successors
330 // are modified, the method should insert pairs of <OldSucc, NewSucc> into the
333 TargetLowering::EmitInstrWithCustomInserter(MachineInstr &MI,
334 MachineBasicBlock *MBB) const {
336 dbgs() << "If a target marks an instruction with "
337 "'usesCustomInserter', it must implement "
338 "TargetLowering::EmitInstrWithCustomInserter!";
340 llvm_unreachable(nullptr);
343 void TargetLowering::AdjustInstrPostInstrSelection(MachineInstr &MI,
344 SDNode *Node) const {
345 assert(!MI.hasPostISelHook() &&
346 "If a target marks an instruction with 'hasPostISelHook', "
347 "it must implement TargetLowering::AdjustInstrPostInstrSelection!");
350 //===----------------------------------------------------------------------===//
351 // SelectionDAGISel code
352 //===----------------------------------------------------------------------===//
354 SelectionDAGISel::SelectionDAGISel(TargetMachine &tm,
355 CodeGenOpt::Level OL) :
356 MachineFunctionPass(ID), TM(tm),
357 FuncInfo(new FunctionLoweringInfo()),
358 CurDAG(new SelectionDAG(tm, OL)),
359 SDB(new SelectionDAGBuilder(*CurDAG, *FuncInfo, OL)),
363 initializeGCModuleInfoPass(*PassRegistry::getPassRegistry());
364 initializeBranchProbabilityInfoWrapperPassPass(
365 *PassRegistry::getPassRegistry());
366 initializeAAResultsWrapperPassPass(*PassRegistry::getPassRegistry());
367 initializeTargetLibraryInfoWrapperPassPass(
368 *PassRegistry::getPassRegistry());
371 SelectionDAGISel::~SelectionDAGISel() {
377 void SelectionDAGISel::getAnalysisUsage(AnalysisUsage &AU) const {
378 AU.addRequired<AAResultsWrapperPass>();
379 AU.addRequired<GCModuleInfo>();
380 AU.addRequired<StackProtector>();
381 AU.addPreserved<StackProtector>();
382 AU.addPreserved<GCModuleInfo>();
383 AU.addRequired<TargetLibraryInfoWrapperPass>();
384 if (UseMBPI && OptLevel != CodeGenOpt::None)
385 AU.addRequired<BranchProbabilityInfoWrapperPass>();
386 MachineFunctionPass::getAnalysisUsage(AU);
389 /// SplitCriticalSideEffectEdges - Look for critical edges with a PHI value that
390 /// may trap on it. In this case we have to split the edge so that the path
391 /// through the predecessor block that doesn't go to the phi block doesn't
392 /// execute the possibly trapping instruction.
394 /// This is required for correctness, so it must be done at -O0.
396 static void SplitCriticalSideEffectEdges(Function &Fn) {
397 // Loop for blocks with phi nodes.
398 for (BasicBlock &BB : Fn) {
399 PHINode *PN = dyn_cast<PHINode>(BB.begin());
403 // For each block with a PHI node, check to see if any of the input values
404 // are potentially trapping constant expressions. Constant expressions are
405 // the only potentially trapping value that can occur as the argument to a
407 for (BasicBlock::iterator I = BB.begin(); (PN = dyn_cast<PHINode>(I)); ++I)
408 for (unsigned i = 0, e = PN->getNumIncomingValues(); i != e; ++i) {
409 ConstantExpr *CE = dyn_cast<ConstantExpr>(PN->getIncomingValue(i));
410 if (!CE || !CE->canTrap()) continue;
412 // The only case we have to worry about is when the edge is critical.
413 // Since this block has a PHI Node, we assume it has multiple input
414 // edges: check to see if the pred has multiple successors.
415 BasicBlock *Pred = PN->getIncomingBlock(i);
416 if (Pred->getTerminator()->getNumSuccessors() == 1)
419 // Okay, we have to split this edge.
421 Pred->getTerminator(), GetSuccessorNumber(Pred, &BB),
422 CriticalEdgeSplittingOptions().setMergeIdenticalEdges());
428 bool SelectionDAGISel::runOnMachineFunction(MachineFunction &mf) {
429 // If we already selected that function, we do not need to run SDISel.
430 if (mf.getProperties().hasProperty(
431 MachineFunctionProperties::Property::Selected))
433 // Do some sanity-checking on the command-line options.
434 assert((!EnableFastISelVerbose || TM.Options.EnableFastISel) &&
435 "-fast-isel-verbose requires -fast-isel");
436 assert((!EnableFastISelAbort || TM.Options.EnableFastISel) &&
437 "-fast-isel-abort > 0 requires -fast-isel");
439 const Function &Fn = *mf.getFunction();
442 // Reset the target options before resetting the optimization
444 // FIXME: This is a horrible hack and should be processed via
445 // codegen looking at the optimization level explicitly when
446 // it wants to look at it.
447 TM.resetTargetOptions(Fn);
448 // Reset OptLevel to None for optnone functions.
449 CodeGenOpt::Level NewOptLevel = OptLevel;
450 if (OptLevel != CodeGenOpt::None && skipFunction(Fn))
451 NewOptLevel = CodeGenOpt::None;
452 OptLevelChanger OLC(*this, NewOptLevel);
454 TII = MF->getSubtarget().getInstrInfo();
455 TLI = MF->getSubtarget().getTargetLowering();
456 RegInfo = &MF->getRegInfo();
457 AA = &getAnalysis<AAResultsWrapperPass>().getAAResults();
458 LibInfo = &getAnalysis<TargetLibraryInfoWrapperPass>().getTLI();
459 GFI = Fn.hasGC() ? &getAnalysis<GCModuleInfo>().getFunctionInfo(Fn) : nullptr;
461 DEBUG(dbgs() << "\n\n\n=== " << Fn.getName() << "\n");
463 SplitCriticalSideEffectEdges(const_cast<Function &>(Fn));
466 FuncInfo->set(Fn, *MF, CurDAG);
468 if (UseMBPI && OptLevel != CodeGenOpt::None)
469 FuncInfo->BPI = &getAnalysis<BranchProbabilityInfoWrapperPass>().getBPI();
471 FuncInfo->BPI = nullptr;
473 SDB->init(GFI, *AA, LibInfo);
475 MF->setHasInlineAsm(false);
477 FuncInfo->SplitCSR = false;
479 // We split CSR if the target supports it for the given function
480 // and the function has only return exits.
481 if (OptLevel != CodeGenOpt::None && TLI->supportSplitCSR(MF)) {
482 FuncInfo->SplitCSR = true;
484 // Collect all the return blocks.
485 for (const BasicBlock &BB : Fn) {
486 if (!succ_empty(&BB))
489 const TerminatorInst *Term = BB.getTerminator();
490 if (isa<UnreachableInst>(Term) || isa<ReturnInst>(Term))
493 // Bail out if the exit block is not Return nor Unreachable.
494 FuncInfo->SplitCSR = false;
499 MachineBasicBlock *EntryMBB = &MF->front();
500 if (FuncInfo->SplitCSR)
501 // This performs initialization so lowering for SplitCSR will be correct.
502 TLI->initializeSplitCSR(EntryMBB);
504 SelectAllBasicBlocks(Fn);
506 // If the first basic block in the function has live ins that need to be
507 // copied into vregs, emit the copies into the top of the block before
508 // emitting the code for the block.
509 const TargetRegisterInfo &TRI = *MF->getSubtarget().getRegisterInfo();
510 RegInfo->EmitLiveInCopies(EntryMBB, TRI, *TII);
512 // Insert copies in the entry block and the return blocks.
513 if (FuncInfo->SplitCSR) {
514 SmallVector<MachineBasicBlock*, 4> Returns;
515 // Collect all the return blocks.
516 for (MachineBasicBlock &MBB : mf) {
517 if (!MBB.succ_empty())
520 MachineBasicBlock::iterator Term = MBB.getFirstTerminator();
521 if (Term != MBB.end() && Term->isReturn()) {
522 Returns.push_back(&MBB);
526 TLI->insertCopiesSplitCSR(EntryMBB, Returns);
529 DenseMap<unsigned, unsigned> LiveInMap;
530 if (!FuncInfo->ArgDbgValues.empty())
531 for (MachineRegisterInfo::livein_iterator LI = RegInfo->livein_begin(),
532 E = RegInfo->livein_end(); LI != E; ++LI)
534 LiveInMap.insert(std::make_pair(LI->first, LI->second));
536 // Insert DBG_VALUE instructions for function arguments to the entry block.
537 for (unsigned i = 0, e = FuncInfo->ArgDbgValues.size(); i != e; ++i) {
538 MachineInstr *MI = FuncInfo->ArgDbgValues[e-i-1];
539 bool hasFI = MI->getOperand(0).isFI();
541 hasFI ? TRI.getFrameRegister(*MF) : MI->getOperand(0).getReg();
542 if (TargetRegisterInfo::isPhysicalRegister(Reg))
543 EntryMBB->insert(EntryMBB->begin(), MI);
545 MachineInstr *Def = RegInfo->getVRegDef(Reg);
547 MachineBasicBlock::iterator InsertPos = Def;
548 // FIXME: VR def may not be in entry block.
549 Def->getParent()->insert(std::next(InsertPos), MI);
551 DEBUG(dbgs() << "Dropping debug info for dead vreg"
552 << TargetRegisterInfo::virtReg2Index(Reg) << "\n");
555 // If Reg is live-in then update debug info to track its copy in a vreg.
556 DenseMap<unsigned, unsigned>::iterator LDI = LiveInMap.find(Reg);
557 if (LDI != LiveInMap.end()) {
558 assert(!hasFI && "There's no handling of frame pointer updating here yet "
560 MachineInstr *Def = RegInfo->getVRegDef(LDI->second);
561 MachineBasicBlock::iterator InsertPos = Def;
562 const MDNode *Variable = MI->getDebugVariable();
563 const MDNode *Expr = MI->getDebugExpression();
564 DebugLoc DL = MI->getDebugLoc();
565 bool IsIndirect = MI->isIndirectDebugValue();
566 unsigned Offset = IsIndirect ? MI->getOperand(1).getImm() : 0;
567 assert(cast<DILocalVariable>(Variable)->isValidLocationForIntrinsic(DL) &&
568 "Expected inlined-at fields to agree");
569 // Def is never a terminator here, so it is ok to increment InsertPos.
570 BuildMI(*EntryMBB, ++InsertPos, DL, TII->get(TargetOpcode::DBG_VALUE),
571 IsIndirect, LDI->second, Offset, Variable, Expr);
573 // If this vreg is directly copied into an exported register then
574 // that COPY instructions also need DBG_VALUE, if it is the only
575 // user of LDI->second.
576 MachineInstr *CopyUseMI = nullptr;
577 for (MachineRegisterInfo::use_instr_iterator
578 UI = RegInfo->use_instr_begin(LDI->second),
579 E = RegInfo->use_instr_end(); UI != E; ) {
580 MachineInstr *UseMI = &*(UI++);
581 if (UseMI->isDebugValue()) continue;
582 if (UseMI->isCopy() && !CopyUseMI && UseMI->getParent() == EntryMBB) {
583 CopyUseMI = UseMI; continue;
585 // Otherwise this is another use or second copy use.
586 CopyUseMI = nullptr; break;
589 // Use MI's debug location, which describes where Variable was
590 // declared, rather than whatever is attached to CopyUseMI.
591 MachineInstr *NewMI =
592 BuildMI(*MF, DL, TII->get(TargetOpcode::DBG_VALUE), IsIndirect,
593 CopyUseMI->getOperand(0).getReg(), Offset, Variable, Expr);
594 MachineBasicBlock::iterator Pos = CopyUseMI;
595 EntryMBB->insertAfter(Pos, NewMI);
600 // Determine if there are any calls in this machine function.
601 MachineFrameInfo &MFI = MF->getFrameInfo();
602 for (const auto &MBB : *MF) {
603 if (MFI.hasCalls() && MF->hasInlineAsm())
606 for (const auto &MI : MBB) {
607 const MCInstrDesc &MCID = TII->get(MI.getOpcode());
608 if ((MCID.isCall() && !MCID.isReturn()) ||
609 MI.isStackAligningInlineAsm()) {
610 MFI.setHasCalls(true);
612 if (MI.isInlineAsm()) {
613 MF->setHasInlineAsm(true);
618 // Determine if there is a call to setjmp in the machine function.
619 MF->setExposesReturnsTwice(Fn.callsFunctionThatReturnsTwice());
621 // Replace forward-declared registers with the registers containing
622 // the desired value.
623 MachineRegisterInfo &MRI = MF->getRegInfo();
624 for (DenseMap<unsigned, unsigned>::iterator
625 I = FuncInfo->RegFixups.begin(), E = FuncInfo->RegFixups.end();
627 unsigned From = I->first;
628 unsigned To = I->second;
629 // If To is also scheduled to be replaced, find what its ultimate
632 DenseMap<unsigned, unsigned>::iterator J = FuncInfo->RegFixups.find(To);
636 // Make sure the new register has a sufficiently constrained register class.
637 if (TargetRegisterInfo::isVirtualRegister(From) &&
638 TargetRegisterInfo::isVirtualRegister(To))
639 MRI.constrainRegClass(To, MRI.getRegClass(From));
643 // Replacing one register with another won't touch the kill flags.
644 // We need to conservatively clear the kill flags as a kill on the old
645 // register might dominate existing uses of the new register.
646 if (!MRI.use_empty(To))
647 MRI.clearKillFlags(From);
648 MRI.replaceRegWith(From, To);
651 if (TLI->hasCopyImplyingStackAdjustment(MF))
652 MFI.setHasCopyImplyingStackAdjustment(true);
654 // Freeze the set of reserved registers now that MachineFrameInfo has been
655 // set up. All the information required by getReservedRegs() should be
657 MRI.freezeReservedRegs(*MF);
659 // Release function-specific state. SDB and CurDAG are already cleared
663 DEBUG(dbgs() << "*** MachineFunction at end of ISel ***\n");
664 DEBUG(MF->print(dbgs()));
669 void SelectionDAGISel::SelectBasicBlock(BasicBlock::const_iterator Begin,
670 BasicBlock::const_iterator End,
672 // Lower the instructions. If a call is emitted as a tail call, cease emitting
673 // nodes for this block.
674 for (BasicBlock::const_iterator I = Begin; I != End && !SDB->HasTailCall; ++I)
677 // Make sure the root of the DAG is up-to-date.
678 CurDAG->setRoot(SDB->getControlRoot());
679 HadTailCall = SDB->HasTailCall;
682 // Final step, emit the lowered DAG as machine code.
686 void SelectionDAGISel::ComputeLiveOutVRegInfo() {
687 SmallPtrSet<SDNode*, 16> VisitedNodes;
688 SmallVector<SDNode*, 128> Worklist;
690 Worklist.push_back(CurDAG->getRoot().getNode());
696 SDNode *N = Worklist.pop_back_val();
698 // If we've already seen this node, ignore it.
699 if (!VisitedNodes.insert(N).second)
702 // Otherwise, add all chain operands to the worklist.
703 for (const SDValue &Op : N->op_values())
704 if (Op.getValueType() == MVT::Other)
705 Worklist.push_back(Op.getNode());
707 // If this is a CopyToReg with a vreg dest, process it.
708 if (N->getOpcode() != ISD::CopyToReg)
711 unsigned DestReg = cast<RegisterSDNode>(N->getOperand(1))->getReg();
712 if (!TargetRegisterInfo::isVirtualRegister(DestReg))
715 // Ignore non-scalar or non-integer values.
716 SDValue Src = N->getOperand(2);
717 EVT SrcVT = Src.getValueType();
718 if (!SrcVT.isInteger() || SrcVT.isVector())
721 unsigned NumSignBits = CurDAG->ComputeNumSignBits(Src);
722 CurDAG->computeKnownBits(Src, KnownZero, KnownOne);
723 FuncInfo->AddLiveOutRegInfo(DestReg, NumSignBits, KnownZero, KnownOne);
724 } while (!Worklist.empty());
727 void SelectionDAGISel::CodeGenAndEmitDAG() {
728 StringRef GroupName = "sdag";
729 StringRef GroupDescription = "Instruction Selection and Scheduling";
730 std::string BlockName;
731 int BlockNumber = -1;
733 bool MatchFilterBB = false; (void)MatchFilterBB;
735 MatchFilterBB = (FilterDAGBasicBlockName.empty() ||
736 FilterDAGBasicBlockName ==
737 FuncInfo->MBB->getBasicBlock()->getName().str());
740 if (ViewDAGCombine1 || ViewLegalizeTypesDAGs || ViewLegalizeDAGs ||
741 ViewDAGCombine2 || ViewDAGCombineLT || ViewISelDAGs || ViewSchedDAGs ||
745 BlockNumber = FuncInfo->MBB->getNumber();
747 (MF->getName() + ":" + FuncInfo->MBB->getBasicBlock()->getName()).str();
749 DEBUG(dbgs() << "Initial selection DAG: BB#" << BlockNumber
750 << " '" << BlockName << "'\n"; CurDAG->dump());
752 if (ViewDAGCombine1 && MatchFilterBB)
753 CurDAG->viewGraph("dag-combine1 input for " + BlockName);
755 // Run the DAG combiner in pre-legalize mode.
757 NamedRegionTimer T("combine1", "DAG Combining 1", GroupName,
758 GroupDescription, TimePassesIsEnabled);
759 CurDAG->Combine(BeforeLegalizeTypes, *AA, OptLevel);
762 DEBUG(dbgs() << "Optimized lowered selection DAG: BB#" << BlockNumber
763 << " '" << BlockName << "'\n"; CurDAG->dump());
765 // Second step, hack on the DAG until it only uses operations and types that
766 // the target supports.
767 if (ViewLegalizeTypesDAGs && MatchFilterBB)
768 CurDAG->viewGraph("legalize-types input for " + BlockName);
772 NamedRegionTimer T("legalize_types", "Type Legalization", GroupName,
773 GroupDescription, TimePassesIsEnabled);
774 Changed = CurDAG->LegalizeTypes();
777 DEBUG(dbgs() << "Type-legalized selection DAG: BB#" << BlockNumber
778 << " '" << BlockName << "'\n"; CurDAG->dump());
780 CurDAG->NewNodesMustHaveLegalTypes = true;
783 if (ViewDAGCombineLT && MatchFilterBB)
784 CurDAG->viewGraph("dag-combine-lt input for " + BlockName);
786 // Run the DAG combiner in post-type-legalize mode.
788 NamedRegionTimer T("combine_lt", "DAG Combining after legalize types",
789 GroupName, GroupDescription, TimePassesIsEnabled);
790 CurDAG->Combine(AfterLegalizeTypes, *AA, OptLevel);
793 DEBUG(dbgs() << "Optimized type-legalized selection DAG: BB#" << BlockNumber
794 << " '" << BlockName << "'\n"; CurDAG->dump());
799 NamedRegionTimer T("legalize_vec", "Vector Legalization", GroupName,
800 GroupDescription, TimePassesIsEnabled);
801 Changed = CurDAG->LegalizeVectors();
806 NamedRegionTimer T("legalize_types2", "Type Legalization 2", GroupName,
807 GroupDescription, TimePassesIsEnabled);
808 CurDAG->LegalizeTypes();
811 if (ViewDAGCombineLT && MatchFilterBB)
812 CurDAG->viewGraph("dag-combine-lv input for " + BlockName);
814 // Run the DAG combiner in post-type-legalize mode.
816 NamedRegionTimer T("combine_lv", "DAG Combining after legalize vectors",
817 GroupName, GroupDescription, TimePassesIsEnabled);
818 CurDAG->Combine(AfterLegalizeVectorOps, *AA, OptLevel);
821 DEBUG(dbgs() << "Optimized vector-legalized selection DAG: BB#"
822 << BlockNumber << " '" << BlockName << "'\n"; CurDAG->dump());
825 if (ViewLegalizeDAGs && MatchFilterBB)
826 CurDAG->viewGraph("legalize input for " + BlockName);
829 NamedRegionTimer T("legalize", "DAG Legalization", GroupName,
830 GroupDescription, TimePassesIsEnabled);
834 DEBUG(dbgs() << "Legalized selection DAG: BB#" << BlockNumber
835 << " '" << BlockName << "'\n"; CurDAG->dump());
837 if (ViewDAGCombine2 && MatchFilterBB)
838 CurDAG->viewGraph("dag-combine2 input for " + BlockName);
840 // Run the DAG combiner in post-legalize mode.
842 NamedRegionTimer T("combine2", "DAG Combining 2", GroupName,
843 GroupDescription, TimePassesIsEnabled);
844 CurDAG->Combine(AfterLegalizeDAG, *AA, OptLevel);
847 DEBUG(dbgs() << "Optimized legalized selection DAG: BB#" << BlockNumber
848 << " '" << BlockName << "'\n"; CurDAG->dump());
850 if (OptLevel != CodeGenOpt::None)
851 ComputeLiveOutVRegInfo();
853 if (ViewISelDAGs && MatchFilterBB)
854 CurDAG->viewGraph("isel input for " + BlockName);
856 // Third, instruction select all of the operations to machine code, adding the
857 // code to the MachineBasicBlock.
859 NamedRegionTimer T("isel", "Instruction Selection", GroupName,
860 GroupDescription, TimePassesIsEnabled);
861 DoInstructionSelection();
864 DEBUG(dbgs() << "Selected selection DAG: BB#" << BlockNumber
865 << " '" << BlockName << "'\n"; CurDAG->dump());
867 if (ViewSchedDAGs && MatchFilterBB)
868 CurDAG->viewGraph("scheduler input for " + BlockName);
870 // Schedule machine code.
871 ScheduleDAGSDNodes *Scheduler = CreateScheduler();
873 NamedRegionTimer T("sched", "Instruction Scheduling", GroupName,
874 GroupDescription, TimePassesIsEnabled);
875 Scheduler->Run(CurDAG, FuncInfo->MBB);
878 if (ViewSUnitDAGs && MatchFilterBB)
879 Scheduler->viewGraph();
881 // Emit machine code to BB. This can change 'BB' to the last block being
883 MachineBasicBlock *FirstMBB = FuncInfo->MBB, *LastMBB;
885 NamedRegionTimer T("emit", "Instruction Creation", GroupName,
886 GroupDescription, TimePassesIsEnabled);
888 // FuncInfo->InsertPt is passed by reference and set to the end of the
889 // scheduled instructions.
890 LastMBB = FuncInfo->MBB = Scheduler->EmitSchedule(FuncInfo->InsertPt);
893 // If the block was split, make sure we update any references that are used to
894 // update PHI nodes later on.
895 if (FirstMBB != LastMBB)
896 SDB->UpdateSplitBlock(FirstMBB, LastMBB);
898 // Free the scheduler state.
900 NamedRegionTimer T("cleanup", "Instruction Scheduling Cleanup", GroupName,
901 GroupDescription, TimePassesIsEnabled);
905 // Free the SelectionDAG state, now that we're finished with it.
910 /// ISelUpdater - helper class to handle updates of the instruction selection
912 class ISelUpdater : public SelectionDAG::DAGUpdateListener {
913 SelectionDAG::allnodes_iterator &ISelPosition;
915 ISelUpdater(SelectionDAG &DAG, SelectionDAG::allnodes_iterator &isp)
916 : SelectionDAG::DAGUpdateListener(DAG), ISelPosition(isp) {}
918 /// NodeDeleted - Handle nodes deleted from the graph. If the node being
919 /// deleted is the current ISelPosition node, update ISelPosition.
921 void NodeDeleted(SDNode *N, SDNode *E) override {
922 if (ISelPosition == SelectionDAG::allnodes_iterator(N))
926 } // end anonymous namespace
928 void SelectionDAGISel::DoInstructionSelection() {
929 DEBUG(dbgs() << "===== Instruction selection begins: BB#"
930 << FuncInfo->MBB->getNumber()
931 << " '" << FuncInfo->MBB->getName() << "'\n");
935 // Select target instructions for the DAG.
937 // Number all nodes with a topological order and set DAGSize.
938 DAGSize = CurDAG->AssignTopologicalOrder();
940 // Create a dummy node (which is not added to allnodes), that adds
941 // a reference to the root node, preventing it from being deleted,
942 // and tracking any changes of the root.
943 HandleSDNode Dummy(CurDAG->getRoot());
944 SelectionDAG::allnodes_iterator ISelPosition (CurDAG->getRoot().getNode());
947 // Make sure that ISelPosition gets properly updated when nodes are deleted
948 // in calls made from this function.
949 ISelUpdater ISU(*CurDAG, ISelPosition);
951 // The AllNodes list is now topological-sorted. Visit the
952 // nodes by starting at the end of the list (the root of the
953 // graph) and preceding back toward the beginning (the entry
955 while (ISelPosition != CurDAG->allnodes_begin()) {
956 SDNode *Node = &*--ISelPosition;
957 // Skip dead nodes. DAGCombiner is expected to eliminate all dead nodes,
958 // but there are currently some corner cases that it misses. Also, this
959 // makes it theoretically possible to disable the DAGCombiner.
960 if (Node->use_empty())
966 CurDAG->setRoot(Dummy.getValue());
969 DEBUG(dbgs() << "===== Instruction selection ends:\n");
971 PostprocessISelDAG();
974 static bool hasExceptionPointerOrCodeUser(const CatchPadInst *CPI) {
975 for (const User *U : CPI->users()) {
976 if (const IntrinsicInst *EHPtrCall = dyn_cast<IntrinsicInst>(U)) {
977 Intrinsic::ID IID = EHPtrCall->getIntrinsicID();
978 if (IID == Intrinsic::eh_exceptionpointer ||
979 IID == Intrinsic::eh_exceptioncode)
986 /// PrepareEHLandingPad - Emit an EH_LABEL, set up live-in registers, and
987 /// do other setup for EH landing-pad blocks.
988 bool SelectionDAGISel::PrepareEHLandingPad() {
989 MachineBasicBlock *MBB = FuncInfo->MBB;
990 const Constant *PersonalityFn = FuncInfo->Fn->getPersonalityFn();
991 const BasicBlock *LLVMBB = MBB->getBasicBlock();
992 const TargetRegisterClass *PtrRC =
993 TLI->getRegClassFor(TLI->getPointerTy(CurDAG->getDataLayout()));
995 // Catchpads have one live-in register, which typically holds the exception
997 if (const auto *CPI = dyn_cast<CatchPadInst>(LLVMBB->getFirstNonPHI())) {
998 if (hasExceptionPointerOrCodeUser(CPI)) {
999 // Get or create the virtual register to hold the pointer or code. Mark
1000 // the live in physreg and copy into the vreg.
1001 MCPhysReg EHPhysReg = TLI->getExceptionPointerRegister(PersonalityFn);
1002 assert(EHPhysReg && "target lacks exception pointer register");
1003 MBB->addLiveIn(EHPhysReg);
1004 unsigned VReg = FuncInfo->getCatchPadExceptionPointerVReg(CPI, PtrRC);
1005 BuildMI(*MBB, FuncInfo->InsertPt, SDB->getCurDebugLoc(),
1006 TII->get(TargetOpcode::COPY), VReg)
1007 .addReg(EHPhysReg, RegState::Kill);
1012 if (!LLVMBB->isLandingPad())
1015 // Add a label to mark the beginning of the landing pad. Deletion of the
1016 // landing pad can thus be detected via the MachineModuleInfo.
1017 MCSymbol *Label = MF->addLandingPad(MBB);
1019 // Assign the call site to the landing pad's begin label.
1020 MF->setCallSiteLandingPad(Label, SDB->LPadToCallSiteMap[MBB]);
1022 const MCInstrDesc &II = TII->get(TargetOpcode::EH_LABEL);
1023 BuildMI(*MBB, FuncInfo->InsertPt, SDB->getCurDebugLoc(), II)
1026 // Mark exception register as live in.
1027 if (unsigned Reg = TLI->getExceptionPointerRegister(PersonalityFn))
1028 FuncInfo->ExceptionPointerVirtReg = MBB->addLiveIn(Reg, PtrRC);
1030 // Mark exception selector register as live in.
1031 if (unsigned Reg = TLI->getExceptionSelectorRegister(PersonalityFn))
1032 FuncInfo->ExceptionSelectorVirtReg = MBB->addLiveIn(Reg, PtrRC);
1037 /// isFoldedOrDeadInstruction - Return true if the specified instruction is
1038 /// side-effect free and is either dead or folded into a generated instruction.
1039 /// Return false if it needs to be emitted.
1040 static bool isFoldedOrDeadInstruction(const Instruction *I,
1041 FunctionLoweringInfo *FuncInfo) {
1042 return !I->mayWriteToMemory() && // Side-effecting instructions aren't folded.
1043 !isa<TerminatorInst>(I) && // Terminators aren't folded.
1044 !isa<DbgInfoIntrinsic>(I) && // Debug instructions aren't folded.
1045 !I->isEHPad() && // EH pad instructions aren't folded.
1046 !FuncInfo->isExportedInst(I); // Exported instrs must be computed.
1050 // Collect per Instruction statistics for fast-isel misses. Only those
1051 // instructions that cause the bail are accounted for. It does not account for
1052 // instructions higher in the block. Thus, summing the per instructions stats
1053 // will not add up to what is reported by NumFastIselFailures.
1054 static void collectFailStats(const Instruction *I) {
1055 switch (I->getOpcode()) {
1056 default: assert (0 && "<Invalid operator> ");
1059 case Instruction::Ret: NumFastIselFailRet++; return;
1060 case Instruction::Br: NumFastIselFailBr++; return;
1061 case Instruction::Switch: NumFastIselFailSwitch++; return;
1062 case Instruction::IndirectBr: NumFastIselFailIndirectBr++; return;
1063 case Instruction::Invoke: NumFastIselFailInvoke++; return;
1064 case Instruction::Resume: NumFastIselFailResume++; return;
1065 case Instruction::Unreachable: NumFastIselFailUnreachable++; return;
1067 // Standard binary operators...
1068 case Instruction::Add: NumFastIselFailAdd++; return;
1069 case Instruction::FAdd: NumFastIselFailFAdd++; return;
1070 case Instruction::Sub: NumFastIselFailSub++; return;
1071 case Instruction::FSub: NumFastIselFailFSub++; return;
1072 case Instruction::Mul: NumFastIselFailMul++; return;
1073 case Instruction::FMul: NumFastIselFailFMul++; return;
1074 case Instruction::UDiv: NumFastIselFailUDiv++; return;
1075 case Instruction::SDiv: NumFastIselFailSDiv++; return;
1076 case Instruction::FDiv: NumFastIselFailFDiv++; return;
1077 case Instruction::URem: NumFastIselFailURem++; return;
1078 case Instruction::SRem: NumFastIselFailSRem++; return;
1079 case Instruction::FRem: NumFastIselFailFRem++; return;
1081 // Logical operators...
1082 case Instruction::And: NumFastIselFailAnd++; return;
1083 case Instruction::Or: NumFastIselFailOr++; return;
1084 case Instruction::Xor: NumFastIselFailXor++; return;
1086 // Memory instructions...
1087 case Instruction::Alloca: NumFastIselFailAlloca++; return;
1088 case Instruction::Load: NumFastIselFailLoad++; return;
1089 case Instruction::Store: NumFastIselFailStore++; return;
1090 case Instruction::AtomicCmpXchg: NumFastIselFailAtomicCmpXchg++; return;
1091 case Instruction::AtomicRMW: NumFastIselFailAtomicRMW++; return;
1092 case Instruction::Fence: NumFastIselFailFence++; return;
1093 case Instruction::GetElementPtr: NumFastIselFailGetElementPtr++; return;
1095 // Convert instructions...
1096 case Instruction::Trunc: NumFastIselFailTrunc++; return;
1097 case Instruction::ZExt: NumFastIselFailZExt++; return;
1098 case Instruction::SExt: NumFastIselFailSExt++; return;
1099 case Instruction::FPTrunc: NumFastIselFailFPTrunc++; return;
1100 case Instruction::FPExt: NumFastIselFailFPExt++; return;
1101 case Instruction::FPToUI: NumFastIselFailFPToUI++; return;
1102 case Instruction::FPToSI: NumFastIselFailFPToSI++; return;
1103 case Instruction::UIToFP: NumFastIselFailUIToFP++; return;
1104 case Instruction::SIToFP: NumFastIselFailSIToFP++; return;
1105 case Instruction::IntToPtr: NumFastIselFailIntToPtr++; return;
1106 case Instruction::PtrToInt: NumFastIselFailPtrToInt++; return;
1107 case Instruction::BitCast: NumFastIselFailBitCast++; return;
1109 // Other instructions...
1110 case Instruction::ICmp: NumFastIselFailICmp++; return;
1111 case Instruction::FCmp: NumFastIselFailFCmp++; return;
1112 case Instruction::PHI: NumFastIselFailPHI++; return;
1113 case Instruction::Select: NumFastIselFailSelect++; return;
1114 case Instruction::Call: {
1115 if (auto const *Intrinsic = dyn_cast<IntrinsicInst>(I)) {
1116 switch (Intrinsic->getIntrinsicID()) {
1118 NumFastIselFailIntrinsicCall++; return;
1119 case Intrinsic::sadd_with_overflow:
1120 NumFastIselFailSAddWithOverflow++; return;
1121 case Intrinsic::uadd_with_overflow:
1122 NumFastIselFailUAddWithOverflow++; return;
1123 case Intrinsic::ssub_with_overflow:
1124 NumFastIselFailSSubWithOverflow++; return;
1125 case Intrinsic::usub_with_overflow:
1126 NumFastIselFailUSubWithOverflow++; return;
1127 case Intrinsic::smul_with_overflow:
1128 NumFastIselFailSMulWithOverflow++; return;
1129 case Intrinsic::umul_with_overflow:
1130 NumFastIselFailUMulWithOverflow++; return;
1131 case Intrinsic::frameaddress:
1132 NumFastIselFailFrameaddress++; return;
1133 case Intrinsic::sqrt:
1134 NumFastIselFailSqrt++; return;
1135 case Intrinsic::experimental_stackmap:
1136 NumFastIselFailStackMap++; return;
1137 case Intrinsic::experimental_patchpoint_void: // fall-through
1138 case Intrinsic::experimental_patchpoint_i64:
1139 NumFastIselFailPatchPoint++; return;
1142 NumFastIselFailCall++;
1145 case Instruction::Shl: NumFastIselFailShl++; return;
1146 case Instruction::LShr: NumFastIselFailLShr++; return;
1147 case Instruction::AShr: NumFastIselFailAShr++; return;
1148 case Instruction::VAArg: NumFastIselFailVAArg++; return;
1149 case Instruction::ExtractElement: NumFastIselFailExtractElement++; return;
1150 case Instruction::InsertElement: NumFastIselFailInsertElement++; return;
1151 case Instruction::ShuffleVector: NumFastIselFailShuffleVector++; return;
1152 case Instruction::ExtractValue: NumFastIselFailExtractValue++; return;
1153 case Instruction::InsertValue: NumFastIselFailInsertValue++; return;
1154 case Instruction::LandingPad: NumFastIselFailLandingPad++; return;
1159 /// Set up SwiftErrorVals by going through the function. If the function has
1160 /// swifterror argument, it will be the first entry.
1161 static void setupSwiftErrorVals(const Function &Fn, const TargetLowering *TLI,
1162 FunctionLoweringInfo *FuncInfo) {
1163 if (!TLI->supportSwiftError())
1166 FuncInfo->SwiftErrorVals.clear();
1167 FuncInfo->SwiftErrorVRegDefMap.clear();
1168 FuncInfo->SwiftErrorVRegUpwardsUse.clear();
1169 FuncInfo->SwiftErrorArg = nullptr;
1171 // Check if function has a swifterror argument.
1172 bool HaveSeenSwiftErrorArg = false;
1173 for (Function::const_arg_iterator AI = Fn.arg_begin(), AE = Fn.arg_end();
1175 if (AI->hasSwiftErrorAttr()) {
1176 assert(!HaveSeenSwiftErrorArg &&
1177 "Must have only one swifterror parameter");
1178 (void)HaveSeenSwiftErrorArg; // silence warning.
1179 HaveSeenSwiftErrorArg = true;
1180 FuncInfo->SwiftErrorArg = &*AI;
1181 FuncInfo->SwiftErrorVals.push_back(&*AI);
1184 for (const auto &LLVMBB : Fn)
1185 for (const auto &Inst : LLVMBB) {
1186 if (const AllocaInst *Alloca = dyn_cast<AllocaInst>(&Inst))
1187 if (Alloca->isSwiftError())
1188 FuncInfo->SwiftErrorVals.push_back(Alloca);
1192 static void createSwiftErrorEntriesInEntryBlock(FunctionLoweringInfo *FuncInfo,
1193 const TargetLowering *TLI,
1194 const TargetInstrInfo *TII,
1195 const BasicBlock *LLVMBB,
1196 SelectionDAGBuilder *SDB) {
1197 if (!TLI->supportSwiftError())
1200 // We only need to do this when we have swifterror parameter or swifterror
1202 if (FuncInfo->SwiftErrorVals.empty())
1205 if (pred_begin(LLVMBB) == pred_end(LLVMBB)) {
1206 auto &DL = FuncInfo->MF->getDataLayout();
1207 auto const *RC = TLI->getRegClassFor(TLI->getPointerTy(DL));
1208 for (const auto *SwiftErrorVal : FuncInfo->SwiftErrorVals) {
1209 // We will always generate a copy from the argument. It is always used at
1210 // least by the 'return' of the swifterror.
1211 if (FuncInfo->SwiftErrorArg && FuncInfo->SwiftErrorArg == SwiftErrorVal)
1213 unsigned VReg = FuncInfo->MF->getRegInfo().createVirtualRegister(RC);
1214 // Assign Undef to Vreg. We construct MI directly to make sure it works
1216 BuildMI(*FuncInfo->MBB, FuncInfo->MBB->getFirstNonPHI(),
1217 SDB->getCurDebugLoc(), TII->get(TargetOpcode::IMPLICIT_DEF),
1219 FuncInfo->setCurrentSwiftErrorVReg(FuncInfo->MBB, SwiftErrorVal, VReg);
1224 /// Propagate swifterror values through the machine function CFG.
1225 static void propagateSwiftErrorVRegs(FunctionLoweringInfo *FuncInfo) {
1226 auto *TLI = FuncInfo->TLI;
1227 if (!TLI->supportSwiftError())
1230 // We only need to do this when we have swifterror parameter or swifterror
1232 if (FuncInfo->SwiftErrorVals.empty())
1235 // For each machine basic block in reverse post order.
1236 ReversePostOrderTraversal<MachineFunction *> RPOT(FuncInfo->MF);
1237 for (ReversePostOrderTraversal<MachineFunction *>::rpo_iterator
1241 MachineBasicBlock *MBB = *It;
1243 // For each swifterror value in the function.
1244 for(const auto *SwiftErrorVal : FuncInfo->SwiftErrorVals) {
1245 auto Key = std::make_pair(MBB, SwiftErrorVal);
1246 auto UUseIt = FuncInfo->SwiftErrorVRegUpwardsUse.find(Key);
1247 auto VRegDefIt = FuncInfo->SwiftErrorVRegDefMap.find(Key);
1248 bool UpwardsUse = UUseIt != FuncInfo->SwiftErrorVRegUpwardsUse.end();
1249 unsigned UUseVReg = UpwardsUse ? UUseIt->second : 0;
1250 bool DownwardDef = VRegDefIt != FuncInfo->SwiftErrorVRegDefMap.end();
1251 assert(!(UpwardsUse && !DownwardDef) &&
1252 "We can't have an upwards use but no downwards def");
1254 // If there is no upwards exposed use and an entry for the swifterror in
1255 // the def map for this value we don't need to do anything: We already
1256 // have a downward def for this basic block.
1257 if (!UpwardsUse && DownwardDef)
1260 // Otherwise we either have an upwards exposed use vreg that we need to
1261 // materialize or need to forward the downward def from predecessors.
1263 // Check whether we have a single vreg def from all predecessors.
1264 // Otherwise we need a phi.
1265 SmallVector<std::pair<MachineBasicBlock *, unsigned>, 4> VRegs;
1266 SmallSet<const MachineBasicBlock*, 8> Visited;
1267 for (auto *Pred : MBB->predecessors()) {
1268 if (!Visited.insert(Pred).second)
1270 VRegs.push_back(std::make_pair(
1271 Pred, FuncInfo->getOrCreateSwiftErrorVReg(Pred, SwiftErrorVal)));
1274 // We have a self-edge.
1275 // If there was no upwards use in this basic block there is now one: the
1276 // phi needs to use it self.
1279 UUseIt = FuncInfo->SwiftErrorVRegUpwardsUse.find(Key);
1280 assert(UUseIt != FuncInfo->SwiftErrorVRegUpwardsUse.end());
1281 UUseVReg = UUseIt->second;
1285 // We need a phi node if we have more than one predecessor with different
1288 VRegs.size() >= 1 &&
1290 VRegs.begin(), VRegs.end(),
1291 [&](const std::pair<const MachineBasicBlock *, unsigned> &V)
1292 -> bool { return V.second != VRegs[0].second; }) !=
1295 // If there is no upwards exposed used and we don't need a phi just
1296 // forward the swifterror vreg from the predecessor(s).
1297 if (!UpwardsUse && !needPHI) {
1298 assert(!VRegs.empty() &&
1299 "No predecessors? The entry block should bail out earlier");
1300 // Just forward the swifterror vreg from the predecessor(s).
1301 FuncInfo->setCurrentSwiftErrorVReg(MBB, SwiftErrorVal, VRegs[0].second);
1305 auto DLoc = isa<Instruction>(SwiftErrorVal)
1306 ? dyn_cast<Instruction>(SwiftErrorVal)->getDebugLoc()
1308 const auto *TII = FuncInfo->MF->getSubtarget().getInstrInfo();
1310 // If we don't need a phi create a copy to the upward exposed vreg.
1313 unsigned DestReg = UUseVReg;
1314 BuildMI(*MBB, MBB->getFirstNonPHI(), DLoc, TII->get(TargetOpcode::COPY),
1316 .addReg(VRegs[0].second);
1320 // We need a phi: if there is an upwards exposed use we already have a
1321 // destination virtual register number otherwise we generate a new one.
1322 auto &DL = FuncInfo->MF->getDataLayout();
1323 auto const *RC = TLI->getRegClassFor(TLI->getPointerTy(DL));
1325 UpwardsUse ? UUseVReg
1326 : FuncInfo->MF->getRegInfo().createVirtualRegister(RC);
1327 MachineInstrBuilder SwiftErrorPHI =
1328 BuildMI(*MBB, MBB->getFirstNonPHI(), DLoc,
1329 TII->get(TargetOpcode::PHI), PHIVReg);
1330 for (auto BBRegPair : VRegs) {
1331 SwiftErrorPHI.addReg(BBRegPair.second).addMBB(BBRegPair.first);
1334 // We did not have a definition in this block before: store the phi's vreg
1335 // as this block downward exposed def.
1337 FuncInfo->setCurrentSwiftErrorVReg(MBB, SwiftErrorVal, PHIVReg);
1342 void SelectionDAGISel::SelectAllBasicBlocks(const Function &Fn) {
1343 // Initialize the Fast-ISel state, if needed.
1344 FastISel *FastIS = nullptr;
1345 if (TM.Options.EnableFastISel)
1346 FastIS = TLI->createFastISel(*FuncInfo, LibInfo);
1348 setupSwiftErrorVals(Fn, TLI, FuncInfo);
1350 // Iterate over all basic blocks in the function.
1351 ReversePostOrderTraversal<const Function*> RPOT(&Fn);
1352 for (ReversePostOrderTraversal<const Function*>::rpo_iterator
1353 I = RPOT.begin(), E = RPOT.end(); I != E; ++I) {
1354 const BasicBlock *LLVMBB = *I;
1356 if (OptLevel != CodeGenOpt::None) {
1357 bool AllPredsVisited = true;
1358 for (const_pred_iterator PI = pred_begin(LLVMBB), PE = pred_end(LLVMBB);
1360 if (!FuncInfo->VisitedBBs.count(*PI)) {
1361 AllPredsVisited = false;
1366 if (AllPredsVisited) {
1367 for (BasicBlock::const_iterator I = LLVMBB->begin();
1368 const PHINode *PN = dyn_cast<PHINode>(I); ++I)
1369 FuncInfo->ComputePHILiveOutRegInfo(PN);
1371 for (BasicBlock::const_iterator I = LLVMBB->begin();
1372 const PHINode *PN = dyn_cast<PHINode>(I); ++I)
1373 FuncInfo->InvalidatePHILiveOutRegInfo(PN);
1376 FuncInfo->VisitedBBs.insert(LLVMBB);
1379 BasicBlock::const_iterator const Begin =
1380 LLVMBB->getFirstNonPHI()->getIterator();
1381 BasicBlock::const_iterator const End = LLVMBB->end();
1382 BasicBlock::const_iterator BI = End;
1384 FuncInfo->MBB = FuncInfo->MBBMap[LLVMBB];
1386 continue; // Some blocks like catchpads have no code or MBB.
1387 FuncInfo->InsertPt = FuncInfo->MBB->getFirstNonPHI();
1388 createSwiftErrorEntriesInEntryBlock(FuncInfo, TLI, TII, LLVMBB, SDB);
1390 // Setup an EH landing-pad block.
1391 FuncInfo->ExceptionPointerVirtReg = 0;
1392 FuncInfo->ExceptionSelectorVirtReg = 0;
1393 if (LLVMBB->isEHPad())
1394 if (!PrepareEHLandingPad())
1397 // Before doing SelectionDAG ISel, see if FastISel has been requested.
1399 FastIS->startNewBlock();
1401 // Emit code for any incoming arguments. This must happen before
1402 // beginning FastISel on the entry block.
1403 if (LLVMBB == &Fn.getEntryBlock()) {
1406 // Lower any arguments needed in this block if this is the entry block.
1407 if (!FastIS->lowerArguments()) {
1408 // Fast isel failed to lower these arguments
1409 ++NumFastIselFailLowerArguments;
1410 if (EnableFastISelAbort > 1)
1411 report_fatal_error("FastISel didn't lower all arguments");
1413 // Use SelectionDAG argument lowering
1415 CurDAG->setRoot(SDB->getControlRoot());
1417 CodeGenAndEmitDAG();
1420 // If we inserted any instructions at the beginning, make a note of
1421 // where they are, so we can be sure to emit subsequent instructions
1423 if (FuncInfo->InsertPt != FuncInfo->MBB->begin())
1424 FastIS->setLastLocalValue(&*std::prev(FuncInfo->InsertPt));
1426 FastIS->setLastLocalValue(nullptr);
1429 unsigned NumFastIselRemaining = std::distance(Begin, End);
1430 // Do FastISel on as many instructions as possible.
1431 for (; BI != Begin; --BI) {
1432 const Instruction *Inst = &*std::prev(BI);
1434 // If we no longer require this instruction, skip it.
1435 if (isFoldedOrDeadInstruction(Inst, FuncInfo)) {
1436 --NumFastIselRemaining;
1440 // Bottom-up: reset the insert pos at the top, after any local-value
1442 FastIS->recomputeInsertPt();
1444 // Try to select the instruction with FastISel.
1445 if (FastIS->selectInstruction(Inst)) {
1446 --NumFastIselRemaining;
1447 ++NumFastIselSuccess;
1448 // If fast isel succeeded, skip over all the folded instructions, and
1449 // then see if there is a load right before the selected instructions.
1450 // Try to fold the load if so.
1451 const Instruction *BeforeInst = Inst;
1452 while (BeforeInst != &*Begin) {
1453 BeforeInst = &*std::prev(BasicBlock::const_iterator(BeforeInst));
1454 if (!isFoldedOrDeadInstruction(BeforeInst, FuncInfo))
1457 if (BeforeInst != Inst && isa<LoadInst>(BeforeInst) &&
1458 BeforeInst->hasOneUse() &&
1459 FastIS->tryToFoldLoad(cast<LoadInst>(BeforeInst), Inst)) {
1460 // If we succeeded, don't re-select the load.
1461 BI = std::next(BasicBlock::const_iterator(BeforeInst));
1462 --NumFastIselRemaining;
1463 ++NumFastIselSuccess;
1469 if (EnableFastISelVerbose2)
1470 collectFailStats(Inst);
1473 // Then handle certain instructions as single-LLVM-Instruction blocks.
1474 if (isa<CallInst>(Inst)) {
1476 if (EnableFastISelVerbose || EnableFastISelAbort) {
1477 dbgs() << "FastISel missed call: ";
1480 if (EnableFastISelAbort > 2)
1481 // FastISel selector couldn't handle something and bailed.
1482 // For the purpose of debugging, just abort.
1483 report_fatal_error("FastISel didn't select the entire block");
1485 if (!Inst->getType()->isVoidTy() && !Inst->getType()->isTokenTy() &&
1486 !Inst->use_empty()) {
1487 unsigned &R = FuncInfo->ValueMap[Inst];
1489 R = FuncInfo->CreateRegs(Inst->getType());
1492 bool HadTailCall = false;
1493 MachineBasicBlock::iterator SavedInsertPt = FuncInfo->InsertPt;
1494 SelectBasicBlock(Inst->getIterator(), BI, HadTailCall);
1496 // If the call was emitted as a tail call, we're done with the block.
1497 // We also need to delete any previously emitted instructions.
1499 FastIS->removeDeadCode(SavedInsertPt, FuncInfo->MBB->end());
1504 // Recompute NumFastIselRemaining as Selection DAG instruction
1505 // selection may have handled the call, input args, etc.
1506 unsigned RemainingNow = std::distance(Begin, BI);
1507 NumFastIselFailures += NumFastIselRemaining - RemainingNow;
1508 NumFastIselRemaining = RemainingNow;
1512 bool ShouldAbort = EnableFastISelAbort;
1513 if (EnableFastISelVerbose || EnableFastISelAbort) {
1514 if (isa<TerminatorInst>(Inst)) {
1515 // Use a different message for terminator misses.
1516 dbgs() << "FastISel missed terminator: ";
1517 // Don't abort unless for terminator unless the level is really high
1518 ShouldAbort = (EnableFastISelAbort > 2);
1520 dbgs() << "FastISel miss: ";
1525 // FastISel selector couldn't handle something and bailed.
1526 // For the purpose of debugging, just abort.
1527 report_fatal_error("FastISel didn't select the entire block");
1529 NumFastIselFailures += NumFastIselRemaining;
1533 FastIS->recomputeInsertPt();
1535 // Lower any arguments needed in this block if this is the entry block.
1536 if (LLVMBB == &Fn.getEntryBlock()) {
1541 if (getAnalysis<StackProtector>().shouldEmitSDCheck(*LLVMBB)) {
1542 bool FunctionBasedInstrumentation =
1543 TLI->getSSPStackGuardCheck(*Fn.getParent());
1544 SDB->SPDescriptor.initialize(LLVMBB, FuncInfo->MBBMap[LLVMBB],
1545 FunctionBasedInstrumentation);
1551 ++NumFastIselBlocks;
1554 // Run SelectionDAG instruction selection on the remainder of the block
1555 // not handled by FastISel. If FastISel is not run, this is the entire
1558 SelectBasicBlock(Begin, BI, HadTailCall);
1562 FuncInfo->PHINodesToUpdate.clear();
1565 propagateSwiftErrorVRegs(FuncInfo);
1568 SDB->clearDanglingDebugInfo();
1569 SDB->SPDescriptor.resetPerFunctionState();
1572 /// Given that the input MI is before a partial terminator sequence TSeq, return
1573 /// true if M + TSeq also a partial terminator sequence.
1575 /// A Terminator sequence is a sequence of MachineInstrs which at this point in
1576 /// lowering copy vregs into physical registers, which are then passed into
1577 /// terminator instructors so we can satisfy ABI constraints. A partial
1578 /// terminator sequence is an improper subset of a terminator sequence (i.e. it
1579 /// may be the whole terminator sequence).
1580 static bool MIIsInTerminatorSequence(const MachineInstr &MI) {
1581 // If we do not have a copy or an implicit def, we return true if and only if
1582 // MI is a debug value.
1583 if (!MI.isCopy() && !MI.isImplicitDef())
1584 // Sometimes DBG_VALUE MI sneak in between the copies from the vregs to the
1585 // physical registers if there is debug info associated with the terminator
1586 // of our mbb. We want to include said debug info in our terminator
1587 // sequence, so we return true in that case.
1588 return MI.isDebugValue();
1590 // We have left the terminator sequence if we are not doing one of the
1593 // 1. Copying a vreg into a physical register.
1594 // 2. Copying a vreg into a vreg.
1595 // 3. Defining a register via an implicit def.
1597 // OPI should always be a register definition...
1598 MachineInstr::const_mop_iterator OPI = MI.operands_begin();
1599 if (!OPI->isReg() || !OPI->isDef())
1602 // Defining any register via an implicit def is always ok.
1603 if (MI.isImplicitDef())
1606 // Grab the copy source...
1607 MachineInstr::const_mop_iterator OPI2 = OPI;
1609 assert(OPI2 != MI.operands_end()
1610 && "Should have a copy implying we should have 2 arguments.");
1612 // Make sure that the copy dest is not a vreg when the copy source is a
1613 // physical register.
1614 if (!OPI2->isReg() ||
1615 (!TargetRegisterInfo::isPhysicalRegister(OPI->getReg()) &&
1616 TargetRegisterInfo::isPhysicalRegister(OPI2->getReg())))
1622 /// Find the split point at which to splice the end of BB into its success stack
1623 /// protector check machine basic block.
1625 /// On many platforms, due to ABI constraints, terminators, even before register
1626 /// allocation, use physical registers. This creates an issue for us since
1627 /// physical registers at this point can not travel across basic
1628 /// blocks. Luckily, selectiondag always moves physical registers into vregs
1629 /// when they enter functions and moves them through a sequence of copies back
1630 /// into the physical registers right before the terminator creating a
1631 /// ``Terminator Sequence''. This function is searching for the beginning of the
1632 /// terminator sequence so that we can ensure that we splice off not just the
1633 /// terminator, but additionally the copies that move the vregs into the
1634 /// physical registers.
1635 static MachineBasicBlock::iterator
1636 FindSplitPointForStackProtector(MachineBasicBlock *BB) {
1637 MachineBasicBlock::iterator SplitPoint = BB->getFirstTerminator();
1639 if (SplitPoint == BB->begin())
1642 MachineBasicBlock::iterator Start = BB->begin();
1643 MachineBasicBlock::iterator Previous = SplitPoint;
1646 while (MIIsInTerminatorSequence(*Previous)) {
1647 SplitPoint = Previous;
1648 if (Previous == Start)
1657 SelectionDAGISel::FinishBasicBlock() {
1658 DEBUG(dbgs() << "Total amount of phi nodes to update: "
1659 << FuncInfo->PHINodesToUpdate.size() << "\n";
1660 for (unsigned i = 0, e = FuncInfo->PHINodesToUpdate.size(); i != e; ++i)
1661 dbgs() << "Node " << i << " : ("
1662 << FuncInfo->PHINodesToUpdate[i].first
1663 << ", " << FuncInfo->PHINodesToUpdate[i].second << ")\n");
1665 // Next, now that we know what the last MBB the LLVM BB expanded is, update
1666 // PHI nodes in successors.
1667 for (unsigned i = 0, e = FuncInfo->PHINodesToUpdate.size(); i != e; ++i) {
1668 MachineInstrBuilder PHI(*MF, FuncInfo->PHINodesToUpdate[i].first);
1669 assert(PHI->isPHI() &&
1670 "This is not a machine PHI node that we are updating!");
1671 if (!FuncInfo->MBB->isSuccessor(PHI->getParent()))
1673 PHI.addReg(FuncInfo->PHINodesToUpdate[i].second).addMBB(FuncInfo->MBB);
1676 // Handle stack protector.
1677 if (SDB->SPDescriptor.shouldEmitFunctionBasedCheckStackProtector()) {
1678 // The target provides a guard check function. There is no need to
1679 // generate error handling code or to split current basic block.
1680 MachineBasicBlock *ParentMBB = SDB->SPDescriptor.getParentMBB();
1682 // Add load and check to the basicblock.
1683 FuncInfo->MBB = ParentMBB;
1684 FuncInfo->InsertPt =
1685 FindSplitPointForStackProtector(ParentMBB);
1686 SDB->visitSPDescriptorParent(SDB->SPDescriptor, ParentMBB);
1687 CurDAG->setRoot(SDB->getRoot());
1689 CodeGenAndEmitDAG();
1691 // Clear the Per-BB State.
1692 SDB->SPDescriptor.resetPerBBState();
1693 } else if (SDB->SPDescriptor.shouldEmitStackProtector()) {
1694 MachineBasicBlock *ParentMBB = SDB->SPDescriptor.getParentMBB();
1695 MachineBasicBlock *SuccessMBB = SDB->SPDescriptor.getSuccessMBB();
1697 // Find the split point to split the parent mbb. At the same time copy all
1698 // physical registers used in the tail of parent mbb into virtual registers
1699 // before the split point and back into physical registers after the split
1700 // point. This prevents us needing to deal with Live-ins and many other
1701 // register allocation issues caused by us splitting the parent mbb. The
1702 // register allocator will clean up said virtual copies later on.
1703 MachineBasicBlock::iterator SplitPoint =
1704 FindSplitPointForStackProtector(ParentMBB);
1706 // Splice the terminator of ParentMBB into SuccessMBB.
1707 SuccessMBB->splice(SuccessMBB->end(), ParentMBB,
1711 // Add compare/jump on neq/jump to the parent BB.
1712 FuncInfo->MBB = ParentMBB;
1713 FuncInfo->InsertPt = ParentMBB->end();
1714 SDB->visitSPDescriptorParent(SDB->SPDescriptor, ParentMBB);
1715 CurDAG->setRoot(SDB->getRoot());
1717 CodeGenAndEmitDAG();
1719 // CodeGen Failure MBB if we have not codegened it yet.
1720 MachineBasicBlock *FailureMBB = SDB->SPDescriptor.getFailureMBB();
1721 if (FailureMBB->empty()) {
1722 FuncInfo->MBB = FailureMBB;
1723 FuncInfo->InsertPt = FailureMBB->end();
1724 SDB->visitSPDescriptorFailure(SDB->SPDescriptor);
1725 CurDAG->setRoot(SDB->getRoot());
1727 CodeGenAndEmitDAG();
1730 // Clear the Per-BB State.
1731 SDB->SPDescriptor.resetPerBBState();
1734 // Lower each BitTestBlock.
1735 for (auto &BTB : SDB->BitTestCases) {
1736 // Lower header first, if it wasn't already lowered
1738 // Set the current basic block to the mbb we wish to insert the code into
1739 FuncInfo->MBB = BTB.Parent;
1740 FuncInfo->InsertPt = FuncInfo->MBB->end();
1742 SDB->visitBitTestHeader(BTB, FuncInfo->MBB);
1743 CurDAG->setRoot(SDB->getRoot());
1745 CodeGenAndEmitDAG();
1748 BranchProbability UnhandledProb = BTB.Prob;
1749 for (unsigned j = 0, ej = BTB.Cases.size(); j != ej; ++j) {
1750 UnhandledProb -= BTB.Cases[j].ExtraProb;
1751 // Set the current basic block to the mbb we wish to insert the code into
1752 FuncInfo->MBB = BTB.Cases[j].ThisBB;
1753 FuncInfo->InsertPt = FuncInfo->MBB->end();
1756 // If all cases cover a contiguous range, it is not necessary to jump to
1757 // the default block after the last bit test fails. This is because the
1758 // range check during bit test header creation has guaranteed that every
1759 // case here doesn't go outside the range. In this case, there is no need
1760 // to perform the last bit test, as it will always be true. Instead, make
1761 // the second-to-last bit-test fall through to the target of the last bit
1762 // test, and delete the last bit test.
1764 MachineBasicBlock *NextMBB;
1765 if (BTB.ContiguousRange && j + 2 == ej) {
1766 // Second-to-last bit-test with contiguous range: fall through to the
1767 // target of the final bit test.
1768 NextMBB = BTB.Cases[j + 1].TargetBB;
1769 } else if (j + 1 == ej) {
1770 // For the last bit test, fall through to Default.
1771 NextMBB = BTB.Default;
1773 // Otherwise, fall through to the next bit test.
1774 NextMBB = BTB.Cases[j + 1].ThisBB;
1777 SDB->visitBitTestCase(BTB, NextMBB, UnhandledProb, BTB.Reg, BTB.Cases[j],
1780 CurDAG->setRoot(SDB->getRoot());
1782 CodeGenAndEmitDAG();
1784 if (BTB.ContiguousRange && j + 2 == ej) {
1785 // Since we're not going to use the final bit test, remove it.
1786 BTB.Cases.pop_back();
1792 for (unsigned pi = 0, pe = FuncInfo->PHINodesToUpdate.size();
1794 MachineInstrBuilder PHI(*MF, FuncInfo->PHINodesToUpdate[pi].first);
1795 MachineBasicBlock *PHIBB = PHI->getParent();
1796 assert(PHI->isPHI() &&
1797 "This is not a machine PHI node that we are updating!");
1798 // This is "default" BB. We have two jumps to it. From "header" BB and
1799 // from last "case" BB, unless the latter was skipped.
1800 if (PHIBB == BTB.Default) {
1801 PHI.addReg(FuncInfo->PHINodesToUpdate[pi].second).addMBB(BTB.Parent);
1802 if (!BTB.ContiguousRange) {
1803 PHI.addReg(FuncInfo->PHINodesToUpdate[pi].second)
1804 .addMBB(BTB.Cases.back().ThisBB);
1807 // One of "cases" BB.
1808 for (unsigned j = 0, ej = BTB.Cases.size();
1810 MachineBasicBlock* cBB = BTB.Cases[j].ThisBB;
1811 if (cBB->isSuccessor(PHIBB))
1812 PHI.addReg(FuncInfo->PHINodesToUpdate[pi].second).addMBB(cBB);
1816 SDB->BitTestCases.clear();
1818 // If the JumpTable record is filled in, then we need to emit a jump table.
1819 // Updating the PHI nodes is tricky in this case, since we need to determine
1820 // whether the PHI is a successor of the range check MBB or the jump table MBB
1821 for (unsigned i = 0, e = SDB->JTCases.size(); i != e; ++i) {
1822 // Lower header first, if it wasn't already lowered
1823 if (!SDB->JTCases[i].first.Emitted) {
1824 // Set the current basic block to the mbb we wish to insert the code into
1825 FuncInfo->MBB = SDB->JTCases[i].first.HeaderBB;
1826 FuncInfo->InsertPt = FuncInfo->MBB->end();
1828 SDB->visitJumpTableHeader(SDB->JTCases[i].second, SDB->JTCases[i].first,
1830 CurDAG->setRoot(SDB->getRoot());
1832 CodeGenAndEmitDAG();
1835 // Set the current basic block to the mbb we wish to insert the code into
1836 FuncInfo->MBB = SDB->JTCases[i].second.MBB;
1837 FuncInfo->InsertPt = FuncInfo->MBB->end();
1839 SDB->visitJumpTable(SDB->JTCases[i].second);
1840 CurDAG->setRoot(SDB->getRoot());
1842 CodeGenAndEmitDAG();
1845 for (unsigned pi = 0, pe = FuncInfo->PHINodesToUpdate.size();
1847 MachineInstrBuilder PHI(*MF, FuncInfo->PHINodesToUpdate[pi].first);
1848 MachineBasicBlock *PHIBB = PHI->getParent();
1849 assert(PHI->isPHI() &&
1850 "This is not a machine PHI node that we are updating!");
1851 // "default" BB. We can go there only from header BB.
1852 if (PHIBB == SDB->JTCases[i].second.Default)
1853 PHI.addReg(FuncInfo->PHINodesToUpdate[pi].second)
1854 .addMBB(SDB->JTCases[i].first.HeaderBB);
1855 // JT BB. Just iterate over successors here
1856 if (FuncInfo->MBB->isSuccessor(PHIBB))
1857 PHI.addReg(FuncInfo->PHINodesToUpdate[pi].second).addMBB(FuncInfo->MBB);
1860 SDB->JTCases.clear();
1862 // If we generated any switch lowering information, build and codegen any
1863 // additional DAGs necessary.
1864 for (unsigned i = 0, e = SDB->SwitchCases.size(); i != e; ++i) {
1865 // Set the current basic block to the mbb we wish to insert the code into
1866 FuncInfo->MBB = SDB->SwitchCases[i].ThisBB;
1867 FuncInfo->InsertPt = FuncInfo->MBB->end();
1869 // Determine the unique successors.
1870 SmallVector<MachineBasicBlock *, 2> Succs;
1871 Succs.push_back(SDB->SwitchCases[i].TrueBB);
1872 if (SDB->SwitchCases[i].TrueBB != SDB->SwitchCases[i].FalseBB)
1873 Succs.push_back(SDB->SwitchCases[i].FalseBB);
1875 // Emit the code. Note that this could result in FuncInfo->MBB being split.
1876 SDB->visitSwitchCase(SDB->SwitchCases[i], FuncInfo->MBB);
1877 CurDAG->setRoot(SDB->getRoot());
1879 CodeGenAndEmitDAG();
1881 // Remember the last block, now that any splitting is done, for use in
1882 // populating PHI nodes in successors.
1883 MachineBasicBlock *ThisBB = FuncInfo->MBB;
1885 // Handle any PHI nodes in successors of this chunk, as if we were coming
1886 // from the original BB before switch expansion. Note that PHI nodes can
1887 // occur multiple times in PHINodesToUpdate. We have to be very careful to
1888 // handle them the right number of times.
1889 for (unsigned i = 0, e = Succs.size(); i != e; ++i) {
1890 FuncInfo->MBB = Succs[i];
1891 FuncInfo->InsertPt = FuncInfo->MBB->end();
1892 // FuncInfo->MBB may have been removed from the CFG if a branch was
1894 if (ThisBB->isSuccessor(FuncInfo->MBB)) {
1895 for (MachineBasicBlock::iterator
1896 MBBI = FuncInfo->MBB->begin(), MBBE = FuncInfo->MBB->end();
1897 MBBI != MBBE && MBBI->isPHI(); ++MBBI) {
1898 MachineInstrBuilder PHI(*MF, MBBI);
1899 // This value for this PHI node is recorded in PHINodesToUpdate.
1900 for (unsigned pn = 0; ; ++pn) {
1901 assert(pn != FuncInfo->PHINodesToUpdate.size() &&
1902 "Didn't find PHI entry!");
1903 if (FuncInfo->PHINodesToUpdate[pn].first == PHI) {
1904 PHI.addReg(FuncInfo->PHINodesToUpdate[pn].second).addMBB(ThisBB);
1912 SDB->SwitchCases.clear();
1915 /// Create the scheduler. If a specific scheduler was specified
1916 /// via the SchedulerRegistry, use it, otherwise select the
1917 /// one preferred by the target.
1919 ScheduleDAGSDNodes *SelectionDAGISel::CreateScheduler() {
1920 return ISHeuristic(this, OptLevel);
1923 //===----------------------------------------------------------------------===//
1924 // Helper functions used by the generated instruction selector.
1925 //===----------------------------------------------------------------------===//
1926 // Calls to these methods are generated by tblgen.
1928 /// CheckAndMask - The isel is trying to match something like (and X, 255). If
1929 /// the dag combiner simplified the 255, we still want to match. RHS is the
1930 /// actual value in the DAG on the RHS of an AND, and DesiredMaskS is the value
1931 /// specified in the .td file (e.g. 255).
1932 bool SelectionDAGISel::CheckAndMask(SDValue LHS, ConstantSDNode *RHS,
1933 int64_t DesiredMaskS) const {
1934 const APInt &ActualMask = RHS->getAPIntValue();
1935 const APInt &DesiredMask = APInt(LHS.getValueSizeInBits(), DesiredMaskS);
1937 // If the actual mask exactly matches, success!
1938 if (ActualMask == DesiredMask)
1941 // If the actual AND mask is allowing unallowed bits, this doesn't match.
1942 if (ActualMask.intersects(~DesiredMask))
1945 // Otherwise, the DAG Combiner may have proven that the value coming in is
1946 // either already zero or is not demanded. Check for known zero input bits.
1947 APInt NeededMask = DesiredMask & ~ActualMask;
1948 if (CurDAG->MaskedValueIsZero(LHS, NeededMask))
1951 // TODO: check to see if missing bits are just not demanded.
1953 // Otherwise, this pattern doesn't match.
1957 /// CheckOrMask - The isel is trying to match something like (or X, 255). If
1958 /// the dag combiner simplified the 255, we still want to match. RHS is the
1959 /// actual value in the DAG on the RHS of an OR, and DesiredMaskS is the value
1960 /// specified in the .td file (e.g. 255).
1961 bool SelectionDAGISel::CheckOrMask(SDValue LHS, ConstantSDNode *RHS,
1962 int64_t DesiredMaskS) const {
1963 const APInt &ActualMask = RHS->getAPIntValue();
1964 const APInt &DesiredMask = APInt(LHS.getValueSizeInBits(), DesiredMaskS);
1966 // If the actual mask exactly matches, success!
1967 if (ActualMask == DesiredMask)
1970 // If the actual AND mask is allowing unallowed bits, this doesn't match.
1971 if (ActualMask.intersects(~DesiredMask))
1974 // Otherwise, the DAG Combiner may have proven that the value coming in is
1975 // either already zero or is not demanded. Check for known zero input bits.
1976 APInt NeededMask = DesiredMask & ~ActualMask;
1978 APInt KnownZero, KnownOne;
1979 CurDAG->computeKnownBits(LHS, KnownZero, KnownOne);
1981 // If all the missing bits in the or are already known to be set, match!
1982 if ((NeededMask & KnownOne) == NeededMask)
1985 // TODO: check to see if missing bits are just not demanded.
1987 // Otherwise, this pattern doesn't match.
1991 /// SelectInlineAsmMemoryOperands - Calls to this are automatically generated
1992 /// by tblgen. Others should not call it.
1993 void SelectionDAGISel::SelectInlineAsmMemoryOperands(std::vector<SDValue> &Ops,
1995 std::vector<SDValue> InOps;
1996 std::swap(InOps, Ops);
1998 Ops.push_back(InOps[InlineAsm::Op_InputChain]); // 0
1999 Ops.push_back(InOps[InlineAsm::Op_AsmString]); // 1
2000 Ops.push_back(InOps[InlineAsm::Op_MDNode]); // 2, !srcloc
2001 Ops.push_back(InOps[InlineAsm::Op_ExtraInfo]); // 3 (SideEffect, AlignStack)
2003 unsigned i = InlineAsm::Op_FirstOperand, e = InOps.size();
2004 if (InOps[e-1].getValueType() == MVT::Glue)
2005 --e; // Don't process a glue operand if it is here.
2008 unsigned Flags = cast<ConstantSDNode>(InOps[i])->getZExtValue();
2009 if (!InlineAsm::isMemKind(Flags)) {
2010 // Just skip over this operand, copying the operands verbatim.
2011 Ops.insert(Ops.end(), InOps.begin()+i,
2012 InOps.begin()+i+InlineAsm::getNumOperandRegisters(Flags) + 1);
2013 i += InlineAsm::getNumOperandRegisters(Flags) + 1;
2015 assert(InlineAsm::getNumOperandRegisters(Flags) == 1 &&
2016 "Memory operand with multiple values?");
2018 unsigned TiedToOperand;
2019 if (InlineAsm::isUseOperandTiedToDef(Flags, TiedToOperand)) {
2020 // We need the constraint ID from the operand this is tied to.
2021 unsigned CurOp = InlineAsm::Op_FirstOperand;
2022 Flags = cast<ConstantSDNode>(InOps[CurOp])->getZExtValue();
2023 for (; TiedToOperand; --TiedToOperand) {
2024 CurOp += InlineAsm::getNumOperandRegisters(Flags)+1;
2025 Flags = cast<ConstantSDNode>(InOps[CurOp])->getZExtValue();
2029 // Otherwise, this is a memory operand. Ask the target to select it.
2030 std::vector<SDValue> SelOps;
2031 unsigned ConstraintID = InlineAsm::getMemoryConstraintID(Flags);
2032 if (SelectInlineAsmMemoryOperand(InOps[i+1], ConstraintID, SelOps))
2033 report_fatal_error("Could not match memory address. Inline asm"
2036 // Add this to the output node.
2038 InlineAsm::getFlagWord(InlineAsm::Kind_Mem, SelOps.size());
2039 NewFlags = InlineAsm::getFlagWordForMem(NewFlags, ConstraintID);
2040 Ops.push_back(CurDAG->getTargetConstant(NewFlags, DL, MVT::i32));
2041 Ops.insert(Ops.end(), SelOps.begin(), SelOps.end());
2046 // Add the glue input back if present.
2047 if (e != InOps.size())
2048 Ops.push_back(InOps.back());
2051 /// findGlueUse - Return use of MVT::Glue value produced by the specified
2054 static SDNode *findGlueUse(SDNode *N) {
2055 unsigned FlagResNo = N->getNumValues()-1;
2056 for (SDNode::use_iterator I = N->use_begin(), E = N->use_end(); I != E; ++I) {
2057 SDUse &Use = I.getUse();
2058 if (Use.getResNo() == FlagResNo)
2059 return Use.getUser();
2064 /// findNonImmUse - Return true if "Use" is a non-immediate use of "Def".
2065 /// This function recursively traverses up the operand chain, ignoring
2067 static bool findNonImmUse(SDNode *Use, SDNode* Def, SDNode *ImmedUse,
2068 SDNode *Root, SmallPtrSetImpl<SDNode*> &Visited,
2069 bool IgnoreChains) {
2070 // The NodeID's are given uniques ID's where a node ID is guaranteed to be
2071 // greater than all of its (recursive) operands. If we scan to a point where
2072 // 'use' is smaller than the node we're scanning for, then we know we will
2075 // The Use may be -1 (unassigned) if it is a newly allocated node. This can
2076 // happen because we scan down to newly selected nodes in the case of glue
2078 if ((Use->getNodeId() < Def->getNodeId() && Use->getNodeId() != -1))
2081 // Don't revisit nodes if we already scanned it and didn't fail, we know we
2082 // won't fail if we scan it again.
2083 if (!Visited.insert(Use).second)
2086 for (const SDValue &Op : Use->op_values()) {
2087 // Ignore chain uses, they are validated by HandleMergeInputChains.
2088 if (Op.getValueType() == MVT::Other && IgnoreChains)
2091 SDNode *N = Op.getNode();
2093 if (Use == ImmedUse || Use == Root)
2094 continue; // We are not looking for immediate use.
2099 // Traverse up the operand chain.
2100 if (findNonImmUse(N, Def, ImmedUse, Root, Visited, IgnoreChains))
2106 /// IsProfitableToFold - Returns true if it's profitable to fold the specific
2107 /// operand node N of U during instruction selection that starts at Root.
2108 bool SelectionDAGISel::IsProfitableToFold(SDValue N, SDNode *U,
2109 SDNode *Root) const {
2110 if (OptLevel == CodeGenOpt::None) return false;
2111 return N.hasOneUse();
2114 /// IsLegalToFold - Returns true if the specific operand node N of
2115 /// U can be folded during instruction selection that starts at Root.
2116 bool SelectionDAGISel::IsLegalToFold(SDValue N, SDNode *U, SDNode *Root,
2117 CodeGenOpt::Level OptLevel,
2118 bool IgnoreChains) {
2119 if (OptLevel == CodeGenOpt::None) return false;
2121 // If Root use can somehow reach N through a path that that doesn't contain
2122 // U then folding N would create a cycle. e.g. In the following
2123 // diagram, Root can reach N through X. If N is folded into into Root, then
2124 // X is both a predecessor and a successor of U.
2135 // * indicates nodes to be folded together.
2137 // If Root produces glue, then it gets (even more) interesting. Since it
2138 // will be "glued" together with its glue use in the scheduler, we need to
2139 // check if it might reach N.
2158 // If GU (glue use) indirectly reaches N (the load), and Root folds N
2159 // (call it Fold), then X is a predecessor of GU and a successor of
2160 // Fold. But since Fold and GU are glued together, this will create
2161 // a cycle in the scheduling graph.
2163 // If the node has glue, walk down the graph to the "lowest" node in the
2165 EVT VT = Root->getValueType(Root->getNumValues()-1);
2166 while (VT == MVT::Glue) {
2167 SDNode *GU = findGlueUse(Root);
2171 VT = Root->getValueType(Root->getNumValues()-1);
2173 // If our query node has a glue result with a use, we've walked up it. If
2174 // the user (which has already been selected) has a chain or indirectly uses
2175 // the chain, our WalkChainUsers predicate will not consider it. Because of
2176 // this, we cannot ignore chains in this predicate.
2177 IgnoreChains = false;
2181 SmallPtrSet<SDNode*, 16> Visited;
2182 return !findNonImmUse(Root, N.getNode(), U, Root, Visited, IgnoreChains);
2185 void SelectionDAGISel::Select_INLINEASM(SDNode *N) {
2188 std::vector<SDValue> Ops(N->op_begin(), N->op_end());
2189 SelectInlineAsmMemoryOperands(Ops, DL);
2191 const EVT VTs[] = {MVT::Other, MVT::Glue};
2192 SDValue New = CurDAG->getNode(ISD::INLINEASM, DL, VTs, Ops);
2194 ReplaceUses(N, New.getNode());
2195 CurDAG->RemoveDeadNode(N);
2198 void SelectionDAGISel::Select_READ_REGISTER(SDNode *Op) {
2200 MDNodeSDNode *MD = dyn_cast<MDNodeSDNode>(Op->getOperand(1));
2201 const MDString *RegStr = dyn_cast<MDString>(MD->getMD()->getOperand(0));
2203 TLI->getRegisterByName(RegStr->getString().data(), Op->getValueType(0),
2205 SDValue New = CurDAG->getCopyFromReg(
2206 Op->getOperand(0), dl, Reg, Op->getValueType(0));
2208 ReplaceUses(Op, New.getNode());
2209 CurDAG->RemoveDeadNode(Op);
2212 void SelectionDAGISel::Select_WRITE_REGISTER(SDNode *Op) {
2214 MDNodeSDNode *MD = dyn_cast<MDNodeSDNode>(Op->getOperand(1));
2215 const MDString *RegStr = dyn_cast<MDString>(MD->getMD()->getOperand(0));
2216 unsigned Reg = TLI->getRegisterByName(RegStr->getString().data(),
2217 Op->getOperand(2).getValueType(),
2219 SDValue New = CurDAG->getCopyToReg(
2220 Op->getOperand(0), dl, Reg, Op->getOperand(2));
2222 ReplaceUses(Op, New.getNode());
2223 CurDAG->RemoveDeadNode(Op);
2226 void SelectionDAGISel::Select_UNDEF(SDNode *N) {
2227 CurDAG->SelectNodeTo(N, TargetOpcode::IMPLICIT_DEF, N->getValueType(0));
2230 /// GetVBR - decode a vbr encoding whose top bit is set.
2231 LLVM_ATTRIBUTE_ALWAYS_INLINE static inline uint64_t
2232 GetVBR(uint64_t Val, const unsigned char *MatcherTable, unsigned &Idx) {
2233 assert(Val >= 128 && "Not a VBR");
2234 Val &= 127; // Remove first vbr bit.
2239 NextBits = MatcherTable[Idx++];
2240 Val |= (NextBits&127) << Shift;
2242 } while (NextBits & 128);
2247 /// When a match is complete, this method updates uses of interior chain results
2248 /// to use the new results.
2249 void SelectionDAGISel::UpdateChains(
2250 SDNode *NodeToMatch, SDValue InputChain,
2251 SmallVectorImpl<SDNode *> &ChainNodesMatched, bool isMorphNodeTo) {
2252 SmallVector<SDNode*, 4> NowDeadNodes;
2254 // Now that all the normal results are replaced, we replace the chain and
2255 // glue results if present.
2256 if (!ChainNodesMatched.empty()) {
2257 assert(InputChain.getNode() &&
2258 "Matched input chains but didn't produce a chain");
2259 // Loop over all of the nodes we matched that produced a chain result.
2260 // Replace all the chain results with the final chain we ended up with.
2261 for (unsigned i = 0, e = ChainNodesMatched.size(); i != e; ++i) {
2262 SDNode *ChainNode = ChainNodesMatched[i];
2263 // If ChainNode is null, it's because we replaced it on a previous
2264 // iteration and we cleared it out of the map. Just skip it.
2268 assert(ChainNode->getOpcode() != ISD::DELETED_NODE &&
2269 "Deleted node left in chain");
2271 // Don't replace the results of the root node if we're doing a
2273 if (ChainNode == NodeToMatch && isMorphNodeTo)
2276 SDValue ChainVal = SDValue(ChainNode, ChainNode->getNumValues()-1);
2277 if (ChainVal.getValueType() == MVT::Glue)
2278 ChainVal = ChainVal.getValue(ChainVal->getNumValues()-2);
2279 assert(ChainVal.getValueType() == MVT::Other && "Not a chain?");
2280 SelectionDAG::DAGNodeDeletedListener NDL(
2281 *CurDAG, [&](SDNode *N, SDNode *E) {
2282 std::replace(ChainNodesMatched.begin(), ChainNodesMatched.end(), N,
2283 static_cast<SDNode *>(nullptr));
2285 CurDAG->ReplaceAllUsesOfValueWith(ChainVal, InputChain);
2287 // If the node became dead and we haven't already seen it, delete it.
2288 if (ChainNode != NodeToMatch && ChainNode->use_empty() &&
2289 !std::count(NowDeadNodes.begin(), NowDeadNodes.end(), ChainNode))
2290 NowDeadNodes.push_back(ChainNode);
2294 if (!NowDeadNodes.empty())
2295 CurDAG->RemoveDeadNodes(NowDeadNodes);
2297 DEBUG(dbgs() << "ISEL: Match complete!\n");
2303 CR_LeadsToInteriorNode
2306 /// WalkChainUsers - Walk down the users of the specified chained node that is
2307 /// part of the pattern we're matching, looking at all of the users we find.
2308 /// This determines whether something is an interior node, whether we have a
2309 /// non-pattern node in between two pattern nodes (which prevent folding because
2310 /// it would induce a cycle) and whether we have a TokenFactor node sandwiched
2311 /// between pattern nodes (in which case the TF becomes part of the pattern).
2313 /// The walk we do here is guaranteed to be small because we quickly get down to
2314 /// already selected nodes "below" us.
2316 WalkChainUsers(const SDNode *ChainedNode,
2317 SmallVectorImpl<SDNode *> &ChainedNodesInPattern,
2318 DenseMap<const SDNode *, ChainResult> &TokenFactorResult,
2319 SmallVectorImpl<SDNode *> &InteriorChainedNodes) {
2320 ChainResult Result = CR_Simple;
2322 for (SDNode::use_iterator UI = ChainedNode->use_begin(),
2323 E = ChainedNode->use_end(); UI != E; ++UI) {
2324 // Make sure the use is of the chain, not some other value we produce.
2325 if (UI.getUse().getValueType() != MVT::Other) continue;
2329 if (User->getOpcode() == ISD::HANDLENODE) // Root of the graph.
2332 // If we see an already-selected machine node, then we've gone beyond the
2333 // pattern that we're selecting down into the already selected chunk of the
2335 unsigned UserOpcode = User->getOpcode();
2336 if (User->isMachineOpcode() ||
2337 UserOpcode == ISD::CopyToReg ||
2338 UserOpcode == ISD::CopyFromReg ||
2339 UserOpcode == ISD::INLINEASM ||
2340 UserOpcode == ISD::EH_LABEL ||
2341 UserOpcode == ISD::LIFETIME_START ||
2342 UserOpcode == ISD::LIFETIME_END) {
2343 // If their node ID got reset to -1 then they've already been selected.
2344 // Treat them like a MachineOpcode.
2345 if (User->getNodeId() == -1)
2349 // If we have a TokenFactor, we handle it specially.
2350 if (User->getOpcode() != ISD::TokenFactor) {
2351 // If the node isn't a token factor and isn't part of our pattern, then it
2352 // must be a random chained node in between two nodes we're selecting.
2353 // This happens when we have something like:
2358 // Because we structurally match the load/store as a read/modify/write,
2359 // but the call is chained between them. We cannot fold in this case
2360 // because it would induce a cycle in the graph.
2361 if (!std::count(ChainedNodesInPattern.begin(),
2362 ChainedNodesInPattern.end(), User))
2363 return CR_InducesCycle;
2365 // Otherwise we found a node that is part of our pattern. For example in:
2369 // This would happen when we're scanning down from the load and see the
2370 // store as a user. Record that there is a use of ChainedNode that is
2371 // part of the pattern and keep scanning uses.
2372 Result = CR_LeadsToInteriorNode;
2373 InteriorChainedNodes.push_back(User);
2377 // If we found a TokenFactor, there are two cases to consider: first if the
2378 // TokenFactor is just hanging "below" the pattern we're matching (i.e. no
2379 // uses of the TF are in our pattern) we just want to ignore it. Second,
2380 // the TokenFactor can be sandwiched in between two chained nodes, like so:
2386 // | \ DAG's like cheese
2389 // [TokenFactor] [Op]
2396 // In this case, the TokenFactor becomes part of our match and we rewrite it
2397 // as a new TokenFactor.
2399 // To distinguish these two cases, do a recursive walk down the uses.
2400 auto MemoizeResult = TokenFactorResult.find(User);
2401 bool Visited = MemoizeResult != TokenFactorResult.end();
2402 // Recursively walk chain users only if the result is not memoized.
2404 auto Res = WalkChainUsers(User, ChainedNodesInPattern, TokenFactorResult,
2405 InteriorChainedNodes);
2406 MemoizeResult = TokenFactorResult.insert(std::make_pair(User, Res)).first;
2408 switch (MemoizeResult->second) {
2410 // If the uses of the TokenFactor are just already-selected nodes, ignore
2411 // it, it is "below" our pattern.
2413 case CR_InducesCycle:
2414 // If the uses of the TokenFactor lead to nodes that are not part of our
2415 // pattern that are not selected, folding would turn this into a cycle,
2417 return CR_InducesCycle;
2418 case CR_LeadsToInteriorNode:
2419 break; // Otherwise, keep processing.
2422 // Okay, we know we're in the interesting interior case. The TokenFactor
2423 // is now going to be considered part of the pattern so that we rewrite its
2424 // uses (it may have uses that are not part of the pattern) with the
2425 // ultimate chain result of the generated code. We will also add its chain
2426 // inputs as inputs to the ultimate TokenFactor we create.
2427 Result = CR_LeadsToInteriorNode;
2429 ChainedNodesInPattern.push_back(User);
2430 InteriorChainedNodes.push_back(User);
2437 /// HandleMergeInputChains - This implements the OPC_EmitMergeInputChains
2438 /// operation for when the pattern matched at least one node with a chains. The
2439 /// input vector contains a list of all of the chained nodes that we match. We
2440 /// must determine if this is a valid thing to cover (i.e. matching it won't
2441 /// induce cycles in the DAG) and if so, creating a TokenFactor node. that will
2442 /// be used as the input node chain for the generated nodes.
2444 HandleMergeInputChains(SmallVectorImpl<SDNode*> &ChainNodesMatched,
2445 SelectionDAG *CurDAG) {
2446 // Used for memoization. Without it WalkChainUsers could take exponential
2448 DenseMap<const SDNode *, ChainResult> TokenFactorResult;
2449 // Walk all of the chained nodes we've matched, recursively scanning down the
2450 // users of the chain result. This adds any TokenFactor nodes that are caught
2451 // in between chained nodes to the chained and interior nodes list.
2452 SmallVector<SDNode*, 3> InteriorChainedNodes;
2453 for (unsigned i = 0, e = ChainNodesMatched.size(); i != e; ++i) {
2454 if (WalkChainUsers(ChainNodesMatched[i], ChainNodesMatched,
2456 InteriorChainedNodes) == CR_InducesCycle)
2457 return SDValue(); // Would induce a cycle.
2460 // Okay, we have walked all the matched nodes and collected TokenFactor nodes
2461 // that we are interested in. Form our input TokenFactor node.
2462 SmallVector<SDValue, 3> InputChains;
2463 for (unsigned i = 0, e = ChainNodesMatched.size(); i != e; ++i) {
2464 // Add the input chain of this node to the InputChains list (which will be
2465 // the operands of the generated TokenFactor) if it's not an interior node.
2466 SDNode *N = ChainNodesMatched[i];
2467 if (N->getOpcode() != ISD::TokenFactor) {
2468 if (std::count(InteriorChainedNodes.begin(),InteriorChainedNodes.end(),N))
2471 // Otherwise, add the input chain.
2472 SDValue InChain = ChainNodesMatched[i]->getOperand(0);
2473 assert(InChain.getValueType() == MVT::Other && "Not a chain");
2474 InputChains.push_back(InChain);
2478 // If we have a token factor, we want to add all inputs of the token factor
2479 // that are not part of the pattern we're matching.
2480 for (const SDValue &Op : N->op_values()) {
2481 if (!std::count(ChainNodesMatched.begin(), ChainNodesMatched.end(),
2483 InputChains.push_back(Op);
2487 if (InputChains.size() == 1)
2488 return InputChains[0];
2489 return CurDAG->getNode(ISD::TokenFactor, SDLoc(ChainNodesMatched[0]),
2490 MVT::Other, InputChains);
2493 /// MorphNode - Handle morphing a node in place for the selector.
2494 SDNode *SelectionDAGISel::
2495 MorphNode(SDNode *Node, unsigned TargetOpc, SDVTList VTList,
2496 ArrayRef<SDValue> Ops, unsigned EmitNodeInfo) {
2497 // It is possible we're using MorphNodeTo to replace a node with no
2498 // normal results with one that has a normal result (or we could be
2499 // adding a chain) and the input could have glue and chains as well.
2500 // In this case we need to shift the operands down.
2501 // FIXME: This is a horrible hack and broken in obscure cases, no worse
2502 // than the old isel though.
2503 int OldGlueResultNo = -1, OldChainResultNo = -1;
2505 unsigned NTMNumResults = Node->getNumValues();
2506 if (Node->getValueType(NTMNumResults-1) == MVT::Glue) {
2507 OldGlueResultNo = NTMNumResults-1;
2508 if (NTMNumResults != 1 &&
2509 Node->getValueType(NTMNumResults-2) == MVT::Other)
2510 OldChainResultNo = NTMNumResults-2;
2511 } else if (Node->getValueType(NTMNumResults-1) == MVT::Other)
2512 OldChainResultNo = NTMNumResults-1;
2514 // Call the underlying SelectionDAG routine to do the transmogrification. Note
2515 // that this deletes operands of the old node that become dead.
2516 SDNode *Res = CurDAG->MorphNodeTo(Node, ~TargetOpc, VTList, Ops);
2518 // MorphNodeTo can operate in two ways: if an existing node with the
2519 // specified operands exists, it can just return it. Otherwise, it
2520 // updates the node in place to have the requested operands.
2522 // If we updated the node in place, reset the node ID. To the isel,
2523 // this should be just like a newly allocated machine node.
2527 unsigned ResNumResults = Res->getNumValues();
2528 // Move the glue if needed.
2529 if ((EmitNodeInfo & OPFL_GlueOutput) && OldGlueResultNo != -1 &&
2530 (unsigned)OldGlueResultNo != ResNumResults-1)
2531 CurDAG->ReplaceAllUsesOfValueWith(SDValue(Node, OldGlueResultNo),
2532 SDValue(Res, ResNumResults-1));
2534 if ((EmitNodeInfo & OPFL_GlueOutput) != 0)
2537 // Move the chain reference if needed.
2538 if ((EmitNodeInfo & OPFL_Chain) && OldChainResultNo != -1 &&
2539 (unsigned)OldChainResultNo != ResNumResults-1)
2540 CurDAG->ReplaceAllUsesOfValueWith(SDValue(Node, OldChainResultNo),
2541 SDValue(Res, ResNumResults-1));
2543 // Otherwise, no replacement happened because the node already exists. Replace
2544 // Uses of the old node with the new one.
2546 CurDAG->ReplaceAllUsesWith(Node, Res);
2547 CurDAG->RemoveDeadNode(Node);
2553 /// CheckSame - Implements OP_CheckSame.
2554 LLVM_ATTRIBUTE_ALWAYS_INLINE static inline bool
2555 CheckSame(const unsigned char *MatcherTable, unsigned &MatcherIndex,
2557 const SmallVectorImpl<std::pair<SDValue, SDNode*> > &RecordedNodes) {
2558 // Accept if it is exactly the same as a previously recorded node.
2559 unsigned RecNo = MatcherTable[MatcherIndex++];
2560 assert(RecNo < RecordedNodes.size() && "Invalid CheckSame");
2561 return N == RecordedNodes[RecNo].first;
2564 /// CheckChildSame - Implements OP_CheckChildXSame.
2565 LLVM_ATTRIBUTE_ALWAYS_INLINE static inline bool
2566 CheckChildSame(const unsigned char *MatcherTable, unsigned &MatcherIndex,
2568 const SmallVectorImpl<std::pair<SDValue, SDNode*> > &RecordedNodes,
2570 if (ChildNo >= N.getNumOperands())
2571 return false; // Match fails if out of range child #.
2572 return ::CheckSame(MatcherTable, MatcherIndex, N.getOperand(ChildNo),
2576 /// CheckPatternPredicate - Implements OP_CheckPatternPredicate.
2577 LLVM_ATTRIBUTE_ALWAYS_INLINE static inline bool
2578 CheckPatternPredicate(const unsigned char *MatcherTable, unsigned &MatcherIndex,
2579 const SelectionDAGISel &SDISel) {
2580 return SDISel.CheckPatternPredicate(MatcherTable[MatcherIndex++]);
2583 /// CheckNodePredicate - Implements OP_CheckNodePredicate.
2584 LLVM_ATTRIBUTE_ALWAYS_INLINE static inline bool
2585 CheckNodePredicate(const unsigned char *MatcherTable, unsigned &MatcherIndex,
2586 const SelectionDAGISel &SDISel, SDNode *N) {
2587 return SDISel.CheckNodePredicate(N, MatcherTable[MatcherIndex++]);
2590 LLVM_ATTRIBUTE_ALWAYS_INLINE static inline bool
2591 CheckOpcode(const unsigned char *MatcherTable, unsigned &MatcherIndex,
2593 uint16_t Opc = MatcherTable[MatcherIndex++];
2594 Opc |= (unsigned short)MatcherTable[MatcherIndex++] << 8;
2595 return N->getOpcode() == Opc;
2598 LLVM_ATTRIBUTE_ALWAYS_INLINE static inline bool
2599 CheckType(const unsigned char *MatcherTable, unsigned &MatcherIndex, SDValue N,
2600 const TargetLowering *TLI, const DataLayout &DL) {
2601 MVT::SimpleValueType VT = (MVT::SimpleValueType)MatcherTable[MatcherIndex++];
2602 if (N.getValueType() == VT) return true;
2604 // Handle the case when VT is iPTR.
2605 return VT == MVT::iPTR && N.getValueType() == TLI->getPointerTy(DL);
2608 LLVM_ATTRIBUTE_ALWAYS_INLINE static inline bool
2609 CheckChildType(const unsigned char *MatcherTable, unsigned &MatcherIndex,
2610 SDValue N, const TargetLowering *TLI, const DataLayout &DL,
2612 if (ChildNo >= N.getNumOperands())
2613 return false; // Match fails if out of range child #.
2614 return ::CheckType(MatcherTable, MatcherIndex, N.getOperand(ChildNo), TLI,
2618 LLVM_ATTRIBUTE_ALWAYS_INLINE static inline bool
2619 CheckCondCode(const unsigned char *MatcherTable, unsigned &MatcherIndex,
2621 return cast<CondCodeSDNode>(N)->get() ==
2622 (ISD::CondCode)MatcherTable[MatcherIndex++];
2625 LLVM_ATTRIBUTE_ALWAYS_INLINE static inline bool
2626 CheckValueType(const unsigned char *MatcherTable, unsigned &MatcherIndex,
2627 SDValue N, const TargetLowering *TLI, const DataLayout &DL) {
2628 MVT::SimpleValueType VT = (MVT::SimpleValueType)MatcherTable[MatcherIndex++];
2629 if (cast<VTSDNode>(N)->getVT() == VT)
2632 // Handle the case when VT is iPTR.
2633 return VT == MVT::iPTR && cast<VTSDNode>(N)->getVT() == TLI->getPointerTy(DL);
2636 LLVM_ATTRIBUTE_ALWAYS_INLINE static inline bool
2637 CheckInteger(const unsigned char *MatcherTable, unsigned &MatcherIndex,
2639 int64_t Val = MatcherTable[MatcherIndex++];
2641 Val = GetVBR(Val, MatcherTable, MatcherIndex);
2643 ConstantSDNode *C = dyn_cast<ConstantSDNode>(N);
2644 return C && C->getSExtValue() == Val;
2647 LLVM_ATTRIBUTE_ALWAYS_INLINE static inline bool
2648 CheckChildInteger(const unsigned char *MatcherTable, unsigned &MatcherIndex,
2649 SDValue N, unsigned ChildNo) {
2650 if (ChildNo >= N.getNumOperands())
2651 return false; // Match fails if out of range child #.
2652 return ::CheckInteger(MatcherTable, MatcherIndex, N.getOperand(ChildNo));
2655 LLVM_ATTRIBUTE_ALWAYS_INLINE static inline bool
2656 CheckAndImm(const unsigned char *MatcherTable, unsigned &MatcherIndex,
2657 SDValue N, const SelectionDAGISel &SDISel) {
2658 int64_t Val = MatcherTable[MatcherIndex++];
2660 Val = GetVBR(Val, MatcherTable, MatcherIndex);
2662 if (N->getOpcode() != ISD::AND) return false;
2664 ConstantSDNode *C = dyn_cast<ConstantSDNode>(N->getOperand(1));
2665 return C && SDISel.CheckAndMask(N.getOperand(0), C, Val);
2668 LLVM_ATTRIBUTE_ALWAYS_INLINE static inline bool
2669 CheckOrImm(const unsigned char *MatcherTable, unsigned &MatcherIndex,
2670 SDValue N, const SelectionDAGISel &SDISel) {
2671 int64_t Val = MatcherTable[MatcherIndex++];
2673 Val = GetVBR(Val, MatcherTable, MatcherIndex);
2675 if (N->getOpcode() != ISD::OR) return false;
2677 ConstantSDNode *C = dyn_cast<ConstantSDNode>(N->getOperand(1));
2678 return C && SDISel.CheckOrMask(N.getOperand(0), C, Val);
2681 /// IsPredicateKnownToFail - If we know how and can do so without pushing a
2682 /// scope, evaluate the current node. If the current predicate is known to
2683 /// fail, set Result=true and return anything. If the current predicate is
2684 /// known to pass, set Result=false and return the MatcherIndex to continue
2685 /// with. If the current predicate is unknown, set Result=false and return the
2686 /// MatcherIndex to continue with.
2687 static unsigned IsPredicateKnownToFail(const unsigned char *Table,
2688 unsigned Index, SDValue N,
2690 const SelectionDAGISel &SDISel,
2691 SmallVectorImpl<std::pair<SDValue, SDNode*> > &RecordedNodes) {
2692 switch (Table[Index++]) {
2695 return Index-1; // Could not evaluate this predicate.
2696 case SelectionDAGISel::OPC_CheckSame:
2697 Result = !::CheckSame(Table, Index, N, RecordedNodes);
2699 case SelectionDAGISel::OPC_CheckChild0Same:
2700 case SelectionDAGISel::OPC_CheckChild1Same:
2701 case SelectionDAGISel::OPC_CheckChild2Same:
2702 case SelectionDAGISel::OPC_CheckChild3Same:
2703 Result = !::CheckChildSame(Table, Index, N, RecordedNodes,
2704 Table[Index-1] - SelectionDAGISel::OPC_CheckChild0Same);
2706 case SelectionDAGISel::OPC_CheckPatternPredicate:
2707 Result = !::CheckPatternPredicate(Table, Index, SDISel);
2709 case SelectionDAGISel::OPC_CheckPredicate:
2710 Result = !::CheckNodePredicate(Table, Index, SDISel, N.getNode());
2712 case SelectionDAGISel::OPC_CheckOpcode:
2713 Result = !::CheckOpcode(Table, Index, N.getNode());
2715 case SelectionDAGISel::OPC_CheckType:
2716 Result = !::CheckType(Table, Index, N, SDISel.TLI,
2717 SDISel.CurDAG->getDataLayout());
2719 case SelectionDAGISel::OPC_CheckChild0Type:
2720 case SelectionDAGISel::OPC_CheckChild1Type:
2721 case SelectionDAGISel::OPC_CheckChild2Type:
2722 case SelectionDAGISel::OPC_CheckChild3Type:
2723 case SelectionDAGISel::OPC_CheckChild4Type:
2724 case SelectionDAGISel::OPC_CheckChild5Type:
2725 case SelectionDAGISel::OPC_CheckChild6Type:
2726 case SelectionDAGISel::OPC_CheckChild7Type:
2727 Result = !::CheckChildType(
2728 Table, Index, N, SDISel.TLI, SDISel.CurDAG->getDataLayout(),
2729 Table[Index - 1] - SelectionDAGISel::OPC_CheckChild0Type);
2731 case SelectionDAGISel::OPC_CheckCondCode:
2732 Result = !::CheckCondCode(Table, Index, N);
2734 case SelectionDAGISel::OPC_CheckValueType:
2735 Result = !::CheckValueType(Table, Index, N, SDISel.TLI,
2736 SDISel.CurDAG->getDataLayout());
2738 case SelectionDAGISel::OPC_CheckInteger:
2739 Result = !::CheckInteger(Table, Index, N);
2741 case SelectionDAGISel::OPC_CheckChild0Integer:
2742 case SelectionDAGISel::OPC_CheckChild1Integer:
2743 case SelectionDAGISel::OPC_CheckChild2Integer:
2744 case SelectionDAGISel::OPC_CheckChild3Integer:
2745 case SelectionDAGISel::OPC_CheckChild4Integer:
2746 Result = !::CheckChildInteger(Table, Index, N,
2747 Table[Index-1] - SelectionDAGISel::OPC_CheckChild0Integer);
2749 case SelectionDAGISel::OPC_CheckAndImm:
2750 Result = !::CheckAndImm(Table, Index, N, SDISel);
2752 case SelectionDAGISel::OPC_CheckOrImm:
2753 Result = !::CheckOrImm(Table, Index, N, SDISel);
2760 /// FailIndex - If this match fails, this is the index to continue with.
2763 /// NodeStack - The node stack when the scope was formed.
2764 SmallVector<SDValue, 4> NodeStack;
2766 /// NumRecordedNodes - The number of recorded nodes when the scope was formed.
2767 unsigned NumRecordedNodes;
2769 /// NumMatchedMemRefs - The number of matched memref entries.
2770 unsigned NumMatchedMemRefs;
2772 /// InputChain/InputGlue - The current chain/glue
2773 SDValue InputChain, InputGlue;
2775 /// HasChainNodesMatched - True if the ChainNodesMatched list is non-empty.
2776 bool HasChainNodesMatched;
2779 /// \\brief A DAG update listener to keep the matching state
2780 /// (i.e. RecordedNodes and MatchScope) uptodate if the target is allowed to
2781 /// change the DAG while matching. X86 addressing mode matcher is an example
2783 class MatchStateUpdater : public SelectionDAG::DAGUpdateListener
2785 SDNode **NodeToMatch;
2786 SmallVectorImpl<std::pair<SDValue, SDNode *>> &RecordedNodes;
2787 SmallVectorImpl<MatchScope> &MatchScopes;
2789 MatchStateUpdater(SelectionDAG &DAG, SDNode **NodeToMatch,
2790 SmallVectorImpl<std::pair<SDValue, SDNode *>> &RN,
2791 SmallVectorImpl<MatchScope> &MS)
2792 : SelectionDAG::DAGUpdateListener(DAG), NodeToMatch(NodeToMatch),
2793 RecordedNodes(RN), MatchScopes(MS) {}
2795 void NodeDeleted(SDNode *N, SDNode *E) override {
2796 // Some early-returns here to avoid the search if we deleted the node or
2797 // if the update comes from MorphNodeTo (MorphNodeTo is the last thing we
2798 // do, so it's unnecessary to update matching state at that point).
2799 // Neither of these can occur currently because we only install this
2800 // update listener during matching a complex patterns.
2801 if (!E || E->isMachineOpcode())
2803 // Check if NodeToMatch was updated.
2804 if (N == *NodeToMatch)
2806 // Performing linear search here does not matter because we almost never
2807 // run this code. You'd have to have a CSE during complex pattern
2809 for (auto &I : RecordedNodes)
2810 if (I.first.getNode() == N)
2813 for (auto &I : MatchScopes)
2814 for (auto &J : I.NodeStack)
2815 if (J.getNode() == N)
2819 } // end anonymous namespace
2821 void SelectionDAGISel::SelectCodeCommon(SDNode *NodeToMatch,
2822 const unsigned char *MatcherTable,
2823 unsigned TableSize) {
2824 // FIXME: Should these even be selected? Handle these cases in the caller?
2825 switch (NodeToMatch->getOpcode()) {
2828 case ISD::EntryToken: // These nodes remain the same.
2829 case ISD::BasicBlock:
2831 case ISD::RegisterMask:
2832 case ISD::HANDLENODE:
2833 case ISD::MDNODE_SDNODE:
2834 case ISD::TargetConstant:
2835 case ISD::TargetConstantFP:
2836 case ISD::TargetConstantPool:
2837 case ISD::TargetFrameIndex:
2838 case ISD::TargetExternalSymbol:
2840 case ISD::TargetBlockAddress:
2841 case ISD::TargetJumpTable:
2842 case ISD::TargetGlobalTLSAddress:
2843 case ISD::TargetGlobalAddress:
2844 case ISD::TokenFactor:
2845 case ISD::CopyFromReg:
2846 case ISD::CopyToReg:
2848 case ISD::LIFETIME_START:
2849 case ISD::LIFETIME_END:
2850 NodeToMatch->setNodeId(-1); // Mark selected.
2852 case ISD::AssertSext:
2853 case ISD::AssertZext:
2854 CurDAG->ReplaceAllUsesOfValueWith(SDValue(NodeToMatch, 0),
2855 NodeToMatch->getOperand(0));
2856 CurDAG->RemoveDeadNode(NodeToMatch);
2858 case ISD::INLINEASM:
2859 Select_INLINEASM(NodeToMatch);
2861 case ISD::READ_REGISTER:
2862 Select_READ_REGISTER(NodeToMatch);
2864 case ISD::WRITE_REGISTER:
2865 Select_WRITE_REGISTER(NodeToMatch);
2868 Select_UNDEF(NodeToMatch);
2872 assert(!NodeToMatch->isMachineOpcode() && "Node already selected!");
2874 // Set up the node stack with NodeToMatch as the only node on the stack.
2875 SmallVector<SDValue, 8> NodeStack;
2876 SDValue N = SDValue(NodeToMatch, 0);
2877 NodeStack.push_back(N);
2879 // MatchScopes - Scopes used when matching, if a match failure happens, this
2880 // indicates where to continue checking.
2881 SmallVector<MatchScope, 8> MatchScopes;
2883 // RecordedNodes - This is the set of nodes that have been recorded by the
2884 // state machine. The second value is the parent of the node, or null if the
2885 // root is recorded.
2886 SmallVector<std::pair<SDValue, SDNode*>, 8> RecordedNodes;
2888 // MatchedMemRefs - This is the set of MemRef's we've seen in the input
2890 SmallVector<MachineMemOperand*, 2> MatchedMemRefs;
2892 // These are the current input chain and glue for use when generating nodes.
2893 // Various Emit operations change these. For example, emitting a copytoreg
2894 // uses and updates these.
2895 SDValue InputChain, InputGlue;
2897 // ChainNodesMatched - If a pattern matches nodes that have input/output
2898 // chains, the OPC_EmitMergeInputChains operation is emitted which indicates
2899 // which ones they are. The result is captured into this list so that we can
2900 // update the chain results when the pattern is complete.
2901 SmallVector<SDNode*, 3> ChainNodesMatched;
2903 DEBUG(dbgs() << "ISEL: Starting pattern match on root node: ";
2904 NodeToMatch->dump(CurDAG);
2907 // Determine where to start the interpreter. Normally we start at opcode #0,
2908 // but if the state machine starts with an OPC_SwitchOpcode, then we
2909 // accelerate the first lookup (which is guaranteed to be hot) with the
2910 // OpcodeOffset table.
2911 unsigned MatcherIndex = 0;
2913 if (!OpcodeOffset.empty()) {
2914 // Already computed the OpcodeOffset table, just index into it.
2915 if (N.getOpcode() < OpcodeOffset.size())
2916 MatcherIndex = OpcodeOffset[N.getOpcode()];
2917 DEBUG(dbgs() << " Initial Opcode index to " << MatcherIndex << "\n");
2919 } else if (MatcherTable[0] == OPC_SwitchOpcode) {
2920 // Otherwise, the table isn't computed, but the state machine does start
2921 // with an OPC_SwitchOpcode instruction. Populate the table now, since this
2922 // is the first time we're selecting an instruction.
2925 // Get the size of this case.
2926 unsigned CaseSize = MatcherTable[Idx++];
2928 CaseSize = GetVBR(CaseSize, MatcherTable, Idx);
2929 if (CaseSize == 0) break;
2931 // Get the opcode, add the index to the table.
2932 uint16_t Opc = MatcherTable[Idx++];
2933 Opc |= (unsigned short)MatcherTable[Idx++] << 8;
2934 if (Opc >= OpcodeOffset.size())
2935 OpcodeOffset.resize((Opc+1)*2);
2936 OpcodeOffset[Opc] = Idx;
2940 // Okay, do the lookup for the first opcode.
2941 if (N.getOpcode() < OpcodeOffset.size())
2942 MatcherIndex = OpcodeOffset[N.getOpcode()];
2946 assert(MatcherIndex < TableSize && "Invalid index");
2948 unsigned CurrentOpcodeIndex = MatcherIndex;
2950 BuiltinOpcodes Opcode = (BuiltinOpcodes)MatcherTable[MatcherIndex++];
2953 // Okay, the semantics of this operation are that we should push a scope
2954 // then evaluate the first child. However, pushing a scope only to have
2955 // the first check fail (which then pops it) is inefficient. If we can
2956 // determine immediately that the first check (or first several) will
2957 // immediately fail, don't even bother pushing a scope for them.
2961 unsigned NumToSkip = MatcherTable[MatcherIndex++];
2962 if (NumToSkip & 128)
2963 NumToSkip = GetVBR(NumToSkip, MatcherTable, MatcherIndex);
2964 // Found the end of the scope with no match.
2965 if (NumToSkip == 0) {
2970 FailIndex = MatcherIndex+NumToSkip;
2972 unsigned MatcherIndexOfPredicate = MatcherIndex;
2973 (void)MatcherIndexOfPredicate; // silence warning.
2975 // If we can't evaluate this predicate without pushing a scope (e.g. if
2976 // it is a 'MoveParent') or if the predicate succeeds on this node, we
2977 // push the scope and evaluate the full predicate chain.
2979 MatcherIndex = IsPredicateKnownToFail(MatcherTable, MatcherIndex, N,
2980 Result, *this, RecordedNodes);
2984 DEBUG(dbgs() << " Skipped scope entry (due to false predicate) at "
2985 << "index " << MatcherIndexOfPredicate
2986 << ", continuing at " << FailIndex << "\n");
2987 ++NumDAGIselRetries;
2989 // Otherwise, we know that this case of the Scope is guaranteed to fail,
2990 // move to the next case.
2991 MatcherIndex = FailIndex;
2994 // If the whole scope failed to match, bail.
2995 if (FailIndex == 0) break;
2997 // Push a MatchScope which indicates where to go if the first child fails
2999 MatchScope NewEntry;
3000 NewEntry.FailIndex = FailIndex;
3001 NewEntry.NodeStack.append(NodeStack.begin(), NodeStack.end());
3002 NewEntry.NumRecordedNodes = RecordedNodes.size();
3003 NewEntry.NumMatchedMemRefs = MatchedMemRefs.size();
3004 NewEntry.InputChain = InputChain;
3005 NewEntry.InputGlue = InputGlue;
3006 NewEntry.HasChainNodesMatched = !ChainNodesMatched.empty();
3007 MatchScopes.push_back(NewEntry);
3010 case OPC_RecordNode: {
3011 // Remember this node, it may end up being an operand in the pattern.
3012 SDNode *Parent = nullptr;
3013 if (NodeStack.size() > 1)
3014 Parent = NodeStack[NodeStack.size()-2].getNode();
3015 RecordedNodes.push_back(std::make_pair(N, Parent));
3019 case OPC_RecordChild0: case OPC_RecordChild1:
3020 case OPC_RecordChild2: case OPC_RecordChild3:
3021 case OPC_RecordChild4: case OPC_RecordChild5:
3022 case OPC_RecordChild6: case OPC_RecordChild7: {
3023 unsigned ChildNo = Opcode-OPC_RecordChild0;
3024 if (ChildNo >= N.getNumOperands())
3025 break; // Match fails if out of range child #.
3027 RecordedNodes.push_back(std::make_pair(N->getOperand(ChildNo),
3031 case OPC_RecordMemRef:
3032 MatchedMemRefs.push_back(cast<MemSDNode>(N)->getMemOperand());
3035 case OPC_CaptureGlueInput:
3036 // If the current node has an input glue, capture it in InputGlue.
3037 if (N->getNumOperands() != 0 &&
3038 N->getOperand(N->getNumOperands()-1).getValueType() == MVT::Glue)
3039 InputGlue = N->getOperand(N->getNumOperands()-1);
3042 case OPC_MoveChild: {
3043 unsigned ChildNo = MatcherTable[MatcherIndex++];
3044 if (ChildNo >= N.getNumOperands())
3045 break; // Match fails if out of range child #.
3046 N = N.getOperand(ChildNo);
3047 NodeStack.push_back(N);
3051 case OPC_MoveChild0: case OPC_MoveChild1:
3052 case OPC_MoveChild2: case OPC_MoveChild3:
3053 case OPC_MoveChild4: case OPC_MoveChild5:
3054 case OPC_MoveChild6: case OPC_MoveChild7: {
3055 unsigned ChildNo = Opcode-OPC_MoveChild0;
3056 if (ChildNo >= N.getNumOperands())
3057 break; // Match fails if out of range child #.
3058 N = N.getOperand(ChildNo);
3059 NodeStack.push_back(N);
3063 case OPC_MoveParent:
3064 // Pop the current node off the NodeStack.
3065 NodeStack.pop_back();
3066 assert(!NodeStack.empty() && "Node stack imbalance!");
3067 N = NodeStack.back();
3071 if (!::CheckSame(MatcherTable, MatcherIndex, N, RecordedNodes)) break;
3074 case OPC_CheckChild0Same: case OPC_CheckChild1Same:
3075 case OPC_CheckChild2Same: case OPC_CheckChild3Same:
3076 if (!::CheckChildSame(MatcherTable, MatcherIndex, N, RecordedNodes,
3077 Opcode-OPC_CheckChild0Same))
3081 case OPC_CheckPatternPredicate:
3082 if (!::CheckPatternPredicate(MatcherTable, MatcherIndex, *this)) break;
3084 case OPC_CheckPredicate:
3085 if (!::CheckNodePredicate(MatcherTable, MatcherIndex, *this,
3089 case OPC_CheckComplexPat: {
3090 unsigned CPNum = MatcherTable[MatcherIndex++];
3091 unsigned RecNo = MatcherTable[MatcherIndex++];
3092 assert(RecNo < RecordedNodes.size() && "Invalid CheckComplexPat");
3094 // If target can modify DAG during matching, keep the matching state
3096 std::unique_ptr<MatchStateUpdater> MSU;
3097 if (ComplexPatternFuncMutatesDAG())
3098 MSU.reset(new MatchStateUpdater(*CurDAG, &NodeToMatch, RecordedNodes,
3101 if (!CheckComplexPattern(NodeToMatch, RecordedNodes[RecNo].second,
3102 RecordedNodes[RecNo].first, CPNum,
3107 case OPC_CheckOpcode:
3108 if (!::CheckOpcode(MatcherTable, MatcherIndex, N.getNode())) break;
3112 if (!::CheckType(MatcherTable, MatcherIndex, N, TLI,
3113 CurDAG->getDataLayout()))
3117 case OPC_SwitchOpcode: {
3118 unsigned CurNodeOpcode = N.getOpcode();
3119 unsigned SwitchStart = MatcherIndex-1; (void)SwitchStart;
3122 // Get the size of this case.
3123 CaseSize = MatcherTable[MatcherIndex++];
3125 CaseSize = GetVBR(CaseSize, MatcherTable, MatcherIndex);
3126 if (CaseSize == 0) break;
3128 uint16_t Opc = MatcherTable[MatcherIndex++];
3129 Opc |= (unsigned short)MatcherTable[MatcherIndex++] << 8;
3131 // If the opcode matches, then we will execute this case.
3132 if (CurNodeOpcode == Opc)
3135 // Otherwise, skip over this case.
3136 MatcherIndex += CaseSize;
3139 // If no cases matched, bail out.
3140 if (CaseSize == 0) break;
3142 // Otherwise, execute the case we found.
3143 DEBUG(dbgs() << " OpcodeSwitch from " << SwitchStart
3144 << " to " << MatcherIndex << "\n");
3148 case OPC_SwitchType: {
3149 MVT CurNodeVT = N.getSimpleValueType();
3150 unsigned SwitchStart = MatcherIndex-1; (void)SwitchStart;
3153 // Get the size of this case.
3154 CaseSize = MatcherTable[MatcherIndex++];
3156 CaseSize = GetVBR(CaseSize, MatcherTable, MatcherIndex);
3157 if (CaseSize == 0) break;
3159 MVT CaseVT = (MVT::SimpleValueType)MatcherTable[MatcherIndex++];
3160 if (CaseVT == MVT::iPTR)
3161 CaseVT = TLI->getPointerTy(CurDAG->getDataLayout());
3163 // If the VT matches, then we will execute this case.
3164 if (CurNodeVT == CaseVT)
3167 // Otherwise, skip over this case.
3168 MatcherIndex += CaseSize;
3171 // If no cases matched, bail out.
3172 if (CaseSize == 0) break;
3174 // Otherwise, execute the case we found.
3175 DEBUG(dbgs() << " TypeSwitch[" << EVT(CurNodeVT).getEVTString()
3176 << "] from " << SwitchStart << " to " << MatcherIndex<<'\n');
3179 case OPC_CheckChild0Type: case OPC_CheckChild1Type:
3180 case OPC_CheckChild2Type: case OPC_CheckChild3Type:
3181 case OPC_CheckChild4Type: case OPC_CheckChild5Type:
3182 case OPC_CheckChild6Type: case OPC_CheckChild7Type:
3183 if (!::CheckChildType(MatcherTable, MatcherIndex, N, TLI,
3184 CurDAG->getDataLayout(),
3185 Opcode - OPC_CheckChild0Type))
3188 case OPC_CheckCondCode:
3189 if (!::CheckCondCode(MatcherTable, MatcherIndex, N)) break;
3191 case OPC_CheckValueType:
3192 if (!::CheckValueType(MatcherTable, MatcherIndex, N, TLI,
3193 CurDAG->getDataLayout()))
3196 case OPC_CheckInteger:
3197 if (!::CheckInteger(MatcherTable, MatcherIndex, N)) break;
3199 case OPC_CheckChild0Integer: case OPC_CheckChild1Integer:
3200 case OPC_CheckChild2Integer: case OPC_CheckChild3Integer:
3201 case OPC_CheckChild4Integer:
3202 if (!::CheckChildInteger(MatcherTable, MatcherIndex, N,
3203 Opcode-OPC_CheckChild0Integer)) break;
3205 case OPC_CheckAndImm:
3206 if (!::CheckAndImm(MatcherTable, MatcherIndex, N, *this)) break;
3208 case OPC_CheckOrImm:
3209 if (!::CheckOrImm(MatcherTable, MatcherIndex, N, *this)) break;
3212 case OPC_CheckFoldableChainNode: {
3213 assert(NodeStack.size() != 1 && "No parent node");
3214 // Verify that all intermediate nodes between the root and this one have
3216 bool HasMultipleUses = false;
3217 for (unsigned i = 1, e = NodeStack.size()-1; i != e; ++i)
3218 if (!NodeStack[i].hasOneUse()) {
3219 HasMultipleUses = true;
3222 if (HasMultipleUses) break;
3224 // Check to see that the target thinks this is profitable to fold and that
3225 // we can fold it without inducing cycles in the graph.
3226 if (!IsProfitableToFold(N, NodeStack[NodeStack.size()-2].getNode(),
3228 !IsLegalToFold(N, NodeStack[NodeStack.size()-2].getNode(),
3229 NodeToMatch, OptLevel,
3230 true/*We validate our own chains*/))
3235 case OPC_EmitInteger: {
3236 MVT::SimpleValueType VT =
3237 (MVT::SimpleValueType)MatcherTable[MatcherIndex++];
3238 int64_t Val = MatcherTable[MatcherIndex++];
3240 Val = GetVBR(Val, MatcherTable, MatcherIndex);
3241 RecordedNodes.push_back(std::pair<SDValue, SDNode*>(
3242 CurDAG->getTargetConstant(Val, SDLoc(NodeToMatch),
3246 case OPC_EmitRegister: {
3247 MVT::SimpleValueType VT =
3248 (MVT::SimpleValueType)MatcherTable[MatcherIndex++];
3249 unsigned RegNo = MatcherTable[MatcherIndex++];
3250 RecordedNodes.push_back(std::pair<SDValue, SDNode*>(
3251 CurDAG->getRegister(RegNo, VT), nullptr));
3254 case OPC_EmitRegister2: {
3255 // For targets w/ more than 256 register names, the register enum
3256 // values are stored in two bytes in the matcher table (just like
3258 MVT::SimpleValueType VT =
3259 (MVT::SimpleValueType)MatcherTable[MatcherIndex++];
3260 unsigned RegNo = MatcherTable[MatcherIndex++];
3261 RegNo |= MatcherTable[MatcherIndex++] << 8;
3262 RecordedNodes.push_back(std::pair<SDValue, SDNode*>(
3263 CurDAG->getRegister(RegNo, VT), nullptr));
3267 case OPC_EmitConvertToTarget: {
3268 // Convert from IMM/FPIMM to target version.
3269 unsigned RecNo = MatcherTable[MatcherIndex++];
3270 assert(RecNo < RecordedNodes.size() && "Invalid EmitConvertToTarget");
3271 SDValue Imm = RecordedNodes[RecNo].first;
3273 if (Imm->getOpcode() == ISD::Constant) {
3274 const ConstantInt *Val=cast<ConstantSDNode>(Imm)->getConstantIntValue();
3275 Imm = CurDAG->getTargetConstant(*Val, SDLoc(NodeToMatch),
3276 Imm.getValueType());
3277 } else if (Imm->getOpcode() == ISD::ConstantFP) {
3278 const ConstantFP *Val=cast<ConstantFPSDNode>(Imm)->getConstantFPValue();
3279 Imm = CurDAG->getTargetConstantFP(*Val, SDLoc(NodeToMatch),
3280 Imm.getValueType());
3283 RecordedNodes.push_back(std::make_pair(Imm, RecordedNodes[RecNo].second));
3287 case OPC_EmitMergeInputChains1_0: // OPC_EmitMergeInputChains, 1, 0
3288 case OPC_EmitMergeInputChains1_1: // OPC_EmitMergeInputChains, 1, 1
3289 case OPC_EmitMergeInputChains1_2: { // OPC_EmitMergeInputChains, 1, 2
3290 // These are space-optimized forms of OPC_EmitMergeInputChains.
3291 assert(!InputChain.getNode() &&
3292 "EmitMergeInputChains should be the first chain producing node");
3293 assert(ChainNodesMatched.empty() &&
3294 "Should only have one EmitMergeInputChains per match");
3296 // Read all of the chained nodes.
3297 unsigned RecNo = Opcode - OPC_EmitMergeInputChains1_0;
3298 assert(RecNo < RecordedNodes.size() && "Invalid EmitMergeInputChains");
3299 ChainNodesMatched.push_back(RecordedNodes[RecNo].first.getNode());
3301 // FIXME: What if other value results of the node have uses not matched
3303 if (ChainNodesMatched.back() != NodeToMatch &&
3304 !RecordedNodes[RecNo].first.hasOneUse()) {
3305 ChainNodesMatched.clear();
3309 // Merge the input chains if they are not intra-pattern references.
3310 InputChain = HandleMergeInputChains(ChainNodesMatched, CurDAG);
3312 if (!InputChain.getNode())
3313 break; // Failed to merge.
3317 case OPC_EmitMergeInputChains: {
3318 assert(!InputChain.getNode() &&
3319 "EmitMergeInputChains should be the first chain producing node");
3320 // This node gets a list of nodes we matched in the input that have
3321 // chains. We want to token factor all of the input chains to these nodes
3322 // together. However, if any of the input chains is actually one of the
3323 // nodes matched in this pattern, then we have an intra-match reference.
3324 // Ignore these because the newly token factored chain should not refer to
3326 unsigned NumChains = MatcherTable[MatcherIndex++];
3327 assert(NumChains != 0 && "Can't TF zero chains");
3329 assert(ChainNodesMatched.empty() &&
3330 "Should only have one EmitMergeInputChains per match");
3332 // Read all of the chained nodes.
3333 for (unsigned i = 0; i != NumChains; ++i) {
3334 unsigned RecNo = MatcherTable[MatcherIndex++];
3335 assert(RecNo < RecordedNodes.size() && "Invalid EmitMergeInputChains");
3336 ChainNodesMatched.push_back(RecordedNodes[RecNo].first.getNode());
3338 // FIXME: What if other value results of the node have uses not matched
3340 if (ChainNodesMatched.back() != NodeToMatch &&
3341 !RecordedNodes[RecNo].first.hasOneUse()) {
3342 ChainNodesMatched.clear();
3347 // If the inner loop broke out, the match fails.
3348 if (ChainNodesMatched.empty())
3351 // Merge the input chains if they are not intra-pattern references.
3352 InputChain = HandleMergeInputChains(ChainNodesMatched, CurDAG);
3354 if (!InputChain.getNode())
3355 break; // Failed to merge.
3360 case OPC_EmitCopyToReg: {
3361 unsigned RecNo = MatcherTable[MatcherIndex++];
3362 assert(RecNo < RecordedNodes.size() && "Invalid EmitCopyToReg");
3363 unsigned DestPhysReg = MatcherTable[MatcherIndex++];
3365 if (!InputChain.getNode())
3366 InputChain = CurDAG->getEntryNode();
3368 InputChain = CurDAG->getCopyToReg(InputChain, SDLoc(NodeToMatch),
3369 DestPhysReg, RecordedNodes[RecNo].first,
3372 InputGlue = InputChain.getValue(1);
3376 case OPC_EmitNodeXForm: {
3377 unsigned XFormNo = MatcherTable[MatcherIndex++];
3378 unsigned RecNo = MatcherTable[MatcherIndex++];
3379 assert(RecNo < RecordedNodes.size() && "Invalid EmitNodeXForm");
3380 SDValue Res = RunSDNodeXForm(RecordedNodes[RecNo].first, XFormNo);
3381 RecordedNodes.push_back(std::pair<SDValue,SDNode*>(Res, nullptr));
3385 case OPC_EmitNode: case OPC_MorphNodeTo:
3386 case OPC_EmitNode0: case OPC_EmitNode1: case OPC_EmitNode2:
3387 case OPC_MorphNodeTo0: case OPC_MorphNodeTo1: case OPC_MorphNodeTo2: {
3388 uint16_t TargetOpc = MatcherTable[MatcherIndex++];
3389 TargetOpc |= (unsigned short)MatcherTable[MatcherIndex++] << 8;
3390 unsigned EmitNodeInfo = MatcherTable[MatcherIndex++];
3391 // Get the result VT list.
3393 // If this is one of the compressed forms, get the number of VTs based
3394 // on the Opcode. Otherwise read the next byte from the table.
3395 if (Opcode >= OPC_MorphNodeTo0 && Opcode <= OPC_MorphNodeTo2)
3396 NumVTs = Opcode - OPC_MorphNodeTo0;
3397 else if (Opcode >= OPC_EmitNode0 && Opcode <= OPC_EmitNode2)
3398 NumVTs = Opcode - OPC_EmitNode0;
3400 NumVTs = MatcherTable[MatcherIndex++];
3401 SmallVector<EVT, 4> VTs;
3402 for (unsigned i = 0; i != NumVTs; ++i) {
3403 MVT::SimpleValueType VT =
3404 (MVT::SimpleValueType)MatcherTable[MatcherIndex++];
3405 if (VT == MVT::iPTR)
3406 VT = TLI->getPointerTy(CurDAG->getDataLayout()).SimpleTy;
3410 if (EmitNodeInfo & OPFL_Chain)
3411 VTs.push_back(MVT::Other);
3412 if (EmitNodeInfo & OPFL_GlueOutput)
3413 VTs.push_back(MVT::Glue);
3415 // This is hot code, so optimize the two most common cases of 1 and 2
3418 if (VTs.size() == 1)
3419 VTList = CurDAG->getVTList(VTs[0]);
3420 else if (VTs.size() == 2)
3421 VTList = CurDAG->getVTList(VTs[0], VTs[1]);
3423 VTList = CurDAG->getVTList(VTs);
3425 // Get the operand list.
3426 unsigned NumOps = MatcherTable[MatcherIndex++];
3427 SmallVector<SDValue, 8> Ops;
3428 for (unsigned i = 0; i != NumOps; ++i) {
3429 unsigned RecNo = MatcherTable[MatcherIndex++];
3431 RecNo = GetVBR(RecNo, MatcherTable, MatcherIndex);
3433 assert(RecNo < RecordedNodes.size() && "Invalid EmitNode");
3434 Ops.push_back(RecordedNodes[RecNo].first);
3437 // If there are variadic operands to add, handle them now.
3438 if (EmitNodeInfo & OPFL_VariadicInfo) {
3439 // Determine the start index to copy from.
3440 unsigned FirstOpToCopy = getNumFixedFromVariadicInfo(EmitNodeInfo);
3441 FirstOpToCopy += (EmitNodeInfo & OPFL_Chain) ? 1 : 0;
3442 assert(NodeToMatch->getNumOperands() >= FirstOpToCopy &&
3443 "Invalid variadic node");
3444 // Copy all of the variadic operands, not including a potential glue
3446 for (unsigned i = FirstOpToCopy, e = NodeToMatch->getNumOperands();
3448 SDValue V = NodeToMatch->getOperand(i);
3449 if (V.getValueType() == MVT::Glue) break;
3454 // If this has chain/glue inputs, add them.
3455 if (EmitNodeInfo & OPFL_Chain)
3456 Ops.push_back(InputChain);
3457 if ((EmitNodeInfo & OPFL_GlueInput) && InputGlue.getNode() != nullptr)
3458 Ops.push_back(InputGlue);
3461 SDNode *Res = nullptr;
3462 bool IsMorphNodeTo = Opcode == OPC_MorphNodeTo ||
3463 (Opcode >= OPC_MorphNodeTo0 && Opcode <= OPC_MorphNodeTo2);
3464 if (!IsMorphNodeTo) {
3465 // If this is a normal EmitNode command, just create the new node and
3466 // add the results to the RecordedNodes list.
3467 Res = CurDAG->getMachineNode(TargetOpc, SDLoc(NodeToMatch),
3470 // Add all the non-glue/non-chain results to the RecordedNodes list.
3471 for (unsigned i = 0, e = VTs.size(); i != e; ++i) {
3472 if (VTs[i] == MVT::Other || VTs[i] == MVT::Glue) break;
3473 RecordedNodes.push_back(std::pair<SDValue,SDNode*>(SDValue(Res, i),
3478 assert(NodeToMatch->getOpcode() != ISD::DELETED_NODE &&
3479 "NodeToMatch was removed partway through selection");
3480 SelectionDAG::DAGNodeDeletedListener NDL(*CurDAG, [&](SDNode *N,
3482 auto &Chain = ChainNodesMatched;
3483 assert((!E || !is_contained(Chain, N)) &&
3484 "Chain node replaced during MorphNode");
3485 Chain.erase(std::remove(Chain.begin(), Chain.end(), N), Chain.end());
3487 Res = MorphNode(NodeToMatch, TargetOpc, VTList, Ops, EmitNodeInfo);
3490 // If the node had chain/glue results, update our notion of the current
3492 if (EmitNodeInfo & OPFL_GlueOutput) {
3493 InputGlue = SDValue(Res, VTs.size()-1);
3494 if (EmitNodeInfo & OPFL_Chain)
3495 InputChain = SDValue(Res, VTs.size()-2);
3496 } else if (EmitNodeInfo & OPFL_Chain)
3497 InputChain = SDValue(Res, VTs.size()-1);
3499 // If the OPFL_MemRefs glue is set on this node, slap all of the
3500 // accumulated memrefs onto it.
3502 // FIXME: This is vastly incorrect for patterns with multiple outputs
3503 // instructions that access memory and for ComplexPatterns that match
3505 if (EmitNodeInfo & OPFL_MemRefs) {
3506 // Only attach load or store memory operands if the generated
3507 // instruction may load or store.
3508 const MCInstrDesc &MCID = TII->get(TargetOpc);
3509 bool mayLoad = MCID.mayLoad();
3510 bool mayStore = MCID.mayStore();
3512 unsigned NumMemRefs = 0;
3513 for (SmallVectorImpl<MachineMemOperand *>::const_iterator I =
3514 MatchedMemRefs.begin(), E = MatchedMemRefs.end(); I != E; ++I) {
3515 if ((*I)->isLoad()) {
3518 } else if ((*I)->isStore()) {
3526 MachineSDNode::mmo_iterator MemRefs =
3527 MF->allocateMemRefsArray(NumMemRefs);
3529 MachineSDNode::mmo_iterator MemRefsPos = MemRefs;
3530 for (SmallVectorImpl<MachineMemOperand *>::const_iterator I =
3531 MatchedMemRefs.begin(), E = MatchedMemRefs.end(); I != E; ++I) {
3532 if ((*I)->isLoad()) {
3535 } else if ((*I)->isStore()) {
3543 cast<MachineSDNode>(Res)
3544 ->setMemRefs(MemRefs, MemRefs + NumMemRefs);
3548 << (IsMorphNodeTo ? "Morphed" : "Created")
3549 << " node: "; Res->dump(CurDAG); dbgs() << "\n");
3551 // If this was a MorphNodeTo then we're completely done!
3552 if (IsMorphNodeTo) {
3553 // Update chain uses.
3554 UpdateChains(Res, InputChain, ChainNodesMatched, true);
3560 case OPC_CompleteMatch: {
3561 // The match has been completed, and any new nodes (if any) have been
3562 // created. Patch up references to the matched dag to use the newly
3564 unsigned NumResults = MatcherTable[MatcherIndex++];
3566 for (unsigned i = 0; i != NumResults; ++i) {
3567 unsigned ResSlot = MatcherTable[MatcherIndex++];
3569 ResSlot = GetVBR(ResSlot, MatcherTable, MatcherIndex);
3571 assert(ResSlot < RecordedNodes.size() && "Invalid CompleteMatch");
3572 SDValue Res = RecordedNodes[ResSlot].first;
3574 assert(i < NodeToMatch->getNumValues() &&
3575 NodeToMatch->getValueType(i) != MVT::Other &&
3576 NodeToMatch->getValueType(i) != MVT::Glue &&
3577 "Invalid number of results to complete!");
3578 assert((NodeToMatch->getValueType(i) == Res.getValueType() ||
3579 NodeToMatch->getValueType(i) == MVT::iPTR ||
3580 Res.getValueType() == MVT::iPTR ||
3581 NodeToMatch->getValueType(i).getSizeInBits() ==
3582 Res.getValueSizeInBits()) &&
3583 "invalid replacement");
3584 CurDAG->ReplaceAllUsesOfValueWith(SDValue(NodeToMatch, i), Res);
3587 // Update chain uses.
3588 UpdateChains(NodeToMatch, InputChain, ChainNodesMatched, false);
3590 // If the root node defines glue, we need to update it to the glue result.
3591 // TODO: This never happens in our tests and I think it can be removed /
3592 // replaced with an assert, but if we do it this the way the change is
3594 if (NodeToMatch->getValueType(NodeToMatch->getNumValues() - 1) ==
3596 InputGlue.getNode())
3597 CurDAG->ReplaceAllUsesOfValueWith(
3598 SDValue(NodeToMatch, NodeToMatch->getNumValues() - 1), InputGlue);
3600 assert(NodeToMatch->use_empty() &&
3601 "Didn't replace all uses of the node?");
3602 CurDAG->RemoveDeadNode(NodeToMatch);
3608 // If the code reached this point, then the match failed. See if there is
3609 // another child to try in the current 'Scope', otherwise pop it until we
3610 // find a case to check.
3611 DEBUG(dbgs() << " Match failed at index " << CurrentOpcodeIndex << "\n");
3612 ++NumDAGIselRetries;
3614 if (MatchScopes.empty()) {
3615 CannotYetSelect(NodeToMatch);
3619 // Restore the interpreter state back to the point where the scope was
3621 MatchScope &LastScope = MatchScopes.back();
3622 RecordedNodes.resize(LastScope.NumRecordedNodes);
3624 NodeStack.append(LastScope.NodeStack.begin(), LastScope.NodeStack.end());
3625 N = NodeStack.back();
3627 if (LastScope.NumMatchedMemRefs != MatchedMemRefs.size())
3628 MatchedMemRefs.resize(LastScope.NumMatchedMemRefs);
3629 MatcherIndex = LastScope.FailIndex;
3631 DEBUG(dbgs() << " Continuing at " << MatcherIndex << "\n");
3633 InputChain = LastScope.InputChain;
3634 InputGlue = LastScope.InputGlue;
3635 if (!LastScope.HasChainNodesMatched)
3636 ChainNodesMatched.clear();
3638 // Check to see what the offset is at the new MatcherIndex. If it is zero
3639 // we have reached the end of this scope, otherwise we have another child
3640 // in the current scope to try.
3641 unsigned NumToSkip = MatcherTable[MatcherIndex++];
3642 if (NumToSkip & 128)
3643 NumToSkip = GetVBR(NumToSkip, MatcherTable, MatcherIndex);
3645 // If we have another child in this scope to match, update FailIndex and
3647 if (NumToSkip != 0) {
3648 LastScope.FailIndex = MatcherIndex+NumToSkip;
3652 // End of this scope, pop it and try the next child in the containing
3654 MatchScopes.pop_back();
3659 void SelectionDAGISel::CannotYetSelect(SDNode *N) {
3661 raw_string_ostream Msg(msg);
3662 Msg << "Cannot select: ";
3664 if (N->getOpcode() != ISD::INTRINSIC_W_CHAIN &&
3665 N->getOpcode() != ISD::INTRINSIC_WO_CHAIN &&
3666 N->getOpcode() != ISD::INTRINSIC_VOID) {
3667 N->printrFull(Msg, CurDAG);
3668 Msg << "\nIn function: " << MF->getName();
3670 bool HasInputChain = N->getOperand(0).getValueType() == MVT::Other;
3672 cast<ConstantSDNode>(N->getOperand(HasInputChain))->getZExtValue();
3673 if (iid < Intrinsic::num_intrinsics)
3674 Msg << "intrinsic %" << Intrinsic::getName((Intrinsic::ID)iid, None);
3675 else if (const TargetIntrinsicInfo *TII = TM.getIntrinsicInfo())
3676 Msg << "target intrinsic %" << TII->getName(iid);
3678 Msg << "unknown intrinsic #" << iid;
3680 report_fatal_error(Msg.str());
3683 char SelectionDAGISel::ID = 0;