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 #define DEBUG_TYPE "isel"
15 #include "ScheduleDAGSDNodes.h"
16 #include "SelectionDAGBuilder.h"
17 #include "llvm/CodeGen/FunctionLoweringInfo.h"
18 #include "llvm/CodeGen/SelectionDAGISel.h"
19 #include "llvm/Analysis/AliasAnalysis.h"
20 #include "llvm/Analysis/DebugInfo.h"
21 #include "llvm/Constants.h"
22 #include "llvm/Function.h"
23 #include "llvm/InlineAsm.h"
24 #include "llvm/Instructions.h"
25 #include "llvm/Intrinsics.h"
26 #include "llvm/IntrinsicInst.h"
27 #include "llvm/LLVMContext.h"
28 #include "llvm/Module.h"
29 #include "llvm/CodeGen/FastISel.h"
30 #include "llvm/CodeGen/GCStrategy.h"
31 #include "llvm/CodeGen/GCMetadata.h"
32 #include "llvm/CodeGen/MachineFrameInfo.h"
33 #include "llvm/CodeGen/MachineFunction.h"
34 #include "llvm/CodeGen/MachineInstrBuilder.h"
35 #include "llvm/CodeGen/MachineModuleInfo.h"
36 #include "llvm/CodeGen/MachineRegisterInfo.h"
37 #include "llvm/CodeGen/ScheduleHazardRecognizer.h"
38 #include "llvm/CodeGen/SchedulerRegistry.h"
39 #include "llvm/CodeGen/SelectionDAG.h"
40 #include "llvm/Target/TargetRegisterInfo.h"
41 #include "llvm/Target/TargetIntrinsicInfo.h"
42 #include "llvm/Target/TargetInstrInfo.h"
43 #include "llvm/Target/TargetLowering.h"
44 #include "llvm/Target/TargetMachine.h"
45 #include "llvm/Target/TargetOptions.h"
46 #include "llvm/Transforms/Utils/BasicBlockUtils.h"
47 #include "llvm/Support/Compiler.h"
48 #include "llvm/Support/Debug.h"
49 #include "llvm/Support/ErrorHandling.h"
50 #include "llvm/Support/Timer.h"
51 #include "llvm/Support/raw_ostream.h"
52 #include "llvm/ADT/PostOrderIterator.h"
53 #include "llvm/ADT/Statistic.h"
57 STATISTIC(NumFastIselFailures, "Number of instructions fast isel failed on");
58 STATISTIC(NumFastIselSuccess, "Number of instructions fast isel selected");
59 STATISTIC(NumFastIselBlocks, "Number of blocks selected entirely by fast isel");
60 STATISTIC(NumDAGBlocks, "Number of blocks selected using DAG");
61 STATISTIC(NumDAGIselRetries,"Number of times dag isel has to try another path");
64 STATISTIC(NumBBWithOutOfOrderLineInfo,
65 "Number of blocks with out of order line number info");
66 STATISTIC(NumMBBWithOutOfOrderLineInfo,
67 "Number of machine blocks with out of order line number info");
71 EnableFastISelVerbose("fast-isel-verbose", cl::Hidden,
72 cl::desc("Enable verbose messages in the \"fast\" "
73 "instruction selector"));
75 EnableFastISelAbort("fast-isel-abort", cl::Hidden,
76 cl::desc("Enable abort calls when \"fast\" instruction fails"));
80 ViewDAGCombine1("view-dag-combine1-dags", cl::Hidden,
81 cl::desc("Pop up a window to show dags before the first "
84 ViewLegalizeTypesDAGs("view-legalize-types-dags", cl::Hidden,
85 cl::desc("Pop up a window to show dags before legalize types"));
87 ViewLegalizeDAGs("view-legalize-dags", cl::Hidden,
88 cl::desc("Pop up a window to show dags before legalize"));
90 ViewDAGCombine2("view-dag-combine2-dags", cl::Hidden,
91 cl::desc("Pop up a window to show dags before the second "
94 ViewDAGCombineLT("view-dag-combine-lt-dags", cl::Hidden,
95 cl::desc("Pop up a window to show dags before the post legalize types"
96 " dag combine pass"));
98 ViewISelDAGs("view-isel-dags", cl::Hidden,
99 cl::desc("Pop up a window to show isel dags as they are selected"));
101 ViewSchedDAGs("view-sched-dags", cl::Hidden,
102 cl::desc("Pop up a window to show sched dags as they are processed"));
104 ViewSUnitDAGs("view-sunit-dags", cl::Hidden,
105 cl::desc("Pop up a window to show SUnit dags after they are processed"));
107 static const bool ViewDAGCombine1 = false,
108 ViewLegalizeTypesDAGs = false, ViewLegalizeDAGs = false,
109 ViewDAGCombine2 = false,
110 ViewDAGCombineLT = false,
111 ViewISelDAGs = false, ViewSchedDAGs = false,
112 ViewSUnitDAGs = false;
115 //===---------------------------------------------------------------------===//
117 /// RegisterScheduler class - Track the registration of instruction schedulers.
119 //===---------------------------------------------------------------------===//
120 MachinePassRegistry RegisterScheduler::Registry;
122 //===---------------------------------------------------------------------===//
124 /// ISHeuristic command line option for instruction schedulers.
126 //===---------------------------------------------------------------------===//
127 static cl::opt<RegisterScheduler::FunctionPassCtor, false,
128 RegisterPassParser<RegisterScheduler> >
129 ISHeuristic("pre-RA-sched",
130 cl::init(&createDefaultScheduler),
131 cl::desc("Instruction schedulers available (before register"
134 static RegisterScheduler
135 defaultListDAGScheduler("default", "Best scheduler for the target",
136 createDefaultScheduler);
139 //===--------------------------------------------------------------------===//
140 /// createDefaultScheduler - This creates an instruction scheduler appropriate
142 ScheduleDAGSDNodes* createDefaultScheduler(SelectionDAGISel *IS,
143 CodeGenOpt::Level OptLevel) {
144 const TargetLowering &TLI = IS->getTargetLowering();
146 if (OptLevel == CodeGenOpt::None)
147 return createSourceListDAGScheduler(IS, OptLevel);
148 if (TLI.getSchedulingPreference() == Sched::Latency)
149 return createTDListDAGScheduler(IS, OptLevel);
150 if (TLI.getSchedulingPreference() == Sched::RegPressure)
151 return createBURRListDAGScheduler(IS, OptLevel);
152 if (TLI.getSchedulingPreference() == Sched::Hybrid)
153 return createHybridListDAGScheduler(IS, OptLevel);
154 assert(TLI.getSchedulingPreference() == Sched::ILP &&
155 "Unknown sched type!");
156 return createILPListDAGScheduler(IS, OptLevel);
160 // EmitInstrWithCustomInserter - This method should be implemented by targets
161 // that mark instructions with the 'usesCustomInserter' flag. These
162 // instructions are special in various ways, which require special support to
163 // insert. The specified MachineInstr is created but not inserted into any
164 // basic blocks, and this method is called to expand it into a sequence of
165 // instructions, potentially also creating new basic blocks and control flow.
166 // When new basic blocks are inserted and the edges from MBB to its successors
167 // are modified, the method should insert pairs of <OldSucc, NewSucc> into the
170 TargetLowering::EmitInstrWithCustomInserter(MachineInstr *MI,
171 MachineBasicBlock *MBB) const {
173 dbgs() << "If a target marks an instruction with "
174 "'usesCustomInserter', it must implement "
175 "TargetLowering::EmitInstrWithCustomInserter!";
181 //===----------------------------------------------------------------------===//
182 // SelectionDAGISel code
183 //===----------------------------------------------------------------------===//
185 SelectionDAGISel::SelectionDAGISel(const TargetMachine &tm,
186 CodeGenOpt::Level OL) :
187 MachineFunctionPass(ID), TM(tm), TLI(*tm.getTargetLowering()),
188 FuncInfo(new FunctionLoweringInfo(TLI)),
189 CurDAG(new SelectionDAG(tm)),
190 SDB(new SelectionDAGBuilder(*CurDAG, *FuncInfo, OL)),
194 initializeGCModuleInfoPass(*PassRegistry::getPassRegistry());
195 initializeAliasAnalysisAnalysisGroup(*PassRegistry::getPassRegistry());
198 SelectionDAGISel::~SelectionDAGISel() {
204 void SelectionDAGISel::getAnalysisUsage(AnalysisUsage &AU) const {
205 AU.addRequired<AliasAnalysis>();
206 AU.addPreserved<AliasAnalysis>();
207 AU.addRequired<GCModuleInfo>();
208 AU.addPreserved<GCModuleInfo>();
209 MachineFunctionPass::getAnalysisUsage(AU);
212 /// SplitCriticalSideEffectEdges - Look for critical edges with a PHI value that
213 /// may trap on it. In this case we have to split the edge so that the path
214 /// through the predecessor block that doesn't go to the phi block doesn't
215 /// execute the possibly trapping instruction.
217 /// This is required for correctness, so it must be done at -O0.
219 static void SplitCriticalSideEffectEdges(Function &Fn, Pass *SDISel) {
220 // Loop for blocks with phi nodes.
221 for (Function::iterator BB = Fn.begin(), E = Fn.end(); BB != E; ++BB) {
222 PHINode *PN = dyn_cast<PHINode>(BB->begin());
223 if (PN == 0) continue;
226 // For each block with a PHI node, check to see if any of the input values
227 // are potentially trapping constant expressions. Constant expressions are
228 // the only potentially trapping value that can occur as the argument to a
230 for (BasicBlock::iterator I = BB->begin(); (PN = dyn_cast<PHINode>(I)); ++I)
231 for (unsigned i = 0, e = PN->getNumIncomingValues(); i != e; ++i) {
232 ConstantExpr *CE = dyn_cast<ConstantExpr>(PN->getIncomingValue(i));
233 if (CE == 0 || !CE->canTrap()) continue;
235 // The only case we have to worry about is when the edge is critical.
236 // Since this block has a PHI Node, we assume it has multiple input
237 // edges: check to see if the pred has multiple successors.
238 BasicBlock *Pred = PN->getIncomingBlock(i);
239 if (Pred->getTerminator()->getNumSuccessors() == 1)
242 // Okay, we have to split this edge.
243 SplitCriticalEdge(Pred->getTerminator(),
244 GetSuccessorNumber(Pred, BB), SDISel, true);
250 bool SelectionDAGISel::runOnMachineFunction(MachineFunction &mf) {
251 // Do some sanity-checking on the command-line options.
252 assert((!EnableFastISelVerbose || EnableFastISel) &&
253 "-fast-isel-verbose requires -fast-isel");
254 assert((!EnableFastISelAbort || EnableFastISel) &&
255 "-fast-isel-abort requires -fast-isel");
257 const Function &Fn = *mf.getFunction();
258 const TargetInstrInfo &TII = *TM.getInstrInfo();
259 const TargetRegisterInfo &TRI = *TM.getRegisterInfo();
262 RegInfo = &MF->getRegInfo();
263 AA = &getAnalysis<AliasAnalysis>();
264 GFI = Fn.hasGC() ? &getAnalysis<GCModuleInfo>().getFunctionInfo(Fn) : 0;
266 DEBUG(dbgs() << "\n\n\n=== " << Fn.getName() << "\n");
268 SplitCriticalSideEffectEdges(const_cast<Function&>(Fn), this);
271 FuncInfo->set(Fn, *MF);
274 SelectAllBasicBlocks(Fn);
276 // If the first basic block in the function has live ins that need to be
277 // copied into vregs, emit the copies into the top of the block before
278 // emitting the code for the block.
279 MachineBasicBlock *EntryMBB = MF->begin();
280 RegInfo->EmitLiveInCopies(EntryMBB, TRI, TII);
282 DenseMap<unsigned, unsigned> LiveInMap;
283 if (!FuncInfo->ArgDbgValues.empty())
284 for (MachineRegisterInfo::livein_iterator LI = RegInfo->livein_begin(),
285 E = RegInfo->livein_end(); LI != E; ++LI)
287 LiveInMap.insert(std::make_pair(LI->first, LI->second));
289 // Insert DBG_VALUE instructions for function arguments to the entry block.
290 for (unsigned i = 0, e = FuncInfo->ArgDbgValues.size(); i != e; ++i) {
291 MachineInstr *MI = FuncInfo->ArgDbgValues[e-i-1];
292 unsigned Reg = MI->getOperand(0).getReg();
293 if (TargetRegisterInfo::isPhysicalRegister(Reg))
294 EntryMBB->insert(EntryMBB->begin(), MI);
296 MachineInstr *Def = RegInfo->getVRegDef(Reg);
297 MachineBasicBlock::iterator InsertPos = Def;
298 // FIXME: VR def may not be in entry block.
299 Def->getParent()->insert(llvm::next(InsertPos), MI);
302 // If Reg is live-in then update debug info to track its copy in a vreg.
303 DenseMap<unsigned, unsigned>::iterator LDI = LiveInMap.find(Reg);
304 if (LDI != LiveInMap.end()) {
305 MachineInstr *Def = RegInfo->getVRegDef(LDI->second);
306 MachineBasicBlock::iterator InsertPos = Def;
307 const MDNode *Variable =
308 MI->getOperand(MI->getNumOperands()-1).getMetadata();
309 unsigned Offset = MI->getOperand(1).getImm();
310 // Def is never a terminator here, so it is ok to increment InsertPos.
311 BuildMI(*EntryMBB, ++InsertPos, MI->getDebugLoc(),
312 TII.get(TargetOpcode::DBG_VALUE))
313 .addReg(LDI->second, RegState::Debug)
314 .addImm(Offset).addMetadata(Variable);
316 // If this vreg is directly copied into an exported register then
317 // that COPY instructions also need DBG_VALUE, if it is the only
318 // user of LDI->second.
319 MachineInstr *CopyUseMI = NULL;
320 for (MachineRegisterInfo::use_iterator
321 UI = RegInfo->use_begin(LDI->second);
322 MachineInstr *UseMI = UI.skipInstruction();) {
323 if (UseMI->isDebugValue()) continue;
324 if (UseMI->isCopy() && !CopyUseMI && UseMI->getParent() == EntryMBB) {
325 CopyUseMI = UseMI; continue;
327 // Otherwise this is another use or second copy use.
328 CopyUseMI = NULL; break;
331 MachineInstr *NewMI =
332 BuildMI(*MF, CopyUseMI->getDebugLoc(),
333 TII.get(TargetOpcode::DBG_VALUE))
334 .addReg(CopyUseMI->getOperand(0).getReg(), RegState::Debug)
335 .addImm(Offset).addMetadata(Variable);
336 EntryMBB->insertAfter(CopyUseMI, NewMI);
341 // Determine if there are any calls in this machine function.
342 MachineFrameInfo *MFI = MF->getFrameInfo();
343 if (!MFI->hasCalls()) {
344 for (MachineFunction::const_iterator
345 I = MF->begin(), E = MF->end(); I != E; ++I) {
346 const MachineBasicBlock *MBB = I;
347 for (MachineBasicBlock::const_iterator
348 II = MBB->begin(), IE = MBB->end(); II != IE; ++II) {
349 const TargetInstrDesc &TID = TM.getInstrInfo()->get(II->getOpcode());
351 if ((TID.isCall() && !TID.isReturn()) ||
352 II->isStackAligningInlineAsm()) {
353 MFI->setHasCalls(true);
361 // Determine if there is a call to setjmp in the machine function.
362 MF->setCallsSetJmp(Fn.callsFunctionThatReturnsTwice());
364 // Replace forward-declared registers with the registers containing
365 // the desired value.
366 MachineRegisterInfo &MRI = MF->getRegInfo();
367 for (DenseMap<unsigned, unsigned>::iterator
368 I = FuncInfo->RegFixups.begin(), E = FuncInfo->RegFixups.end();
370 unsigned From = I->first;
371 unsigned To = I->second;
372 // If To is also scheduled to be replaced, find what its ultimate
375 DenseMap<unsigned, unsigned>::iterator J =
376 FuncInfo->RegFixups.find(To);
381 MRI.replaceRegWith(From, To);
384 // Release function-specific state. SDB and CurDAG are already cleared
391 void SelectionDAGISel::SelectBasicBlock(BasicBlock::const_iterator Begin,
392 BasicBlock::const_iterator End,
394 // Lower all of the non-terminator instructions. If a call is emitted
395 // as a tail call, cease emitting nodes for this block. Terminators
396 // are handled below.
397 for (BasicBlock::const_iterator I = Begin; I != End && !SDB->HasTailCall; ++I)
400 // Make sure the root of the DAG is up-to-date.
401 CurDAG->setRoot(SDB->getControlRoot());
402 HadTailCall = SDB->HasTailCall;
405 // Final step, emit the lowered DAG as machine code.
409 void SelectionDAGISel::ComputeLiveOutVRegInfo() {
410 SmallPtrSet<SDNode*, 128> VisitedNodes;
411 SmallVector<SDNode*, 128> Worklist;
413 Worklist.push_back(CurDAG->getRoot().getNode());
420 SDNode *N = Worklist.pop_back_val();
422 // If we've already seen this node, ignore it.
423 if (!VisitedNodes.insert(N))
426 // Otherwise, add all chain operands to the worklist.
427 for (unsigned i = 0, e = N->getNumOperands(); i != e; ++i)
428 if (N->getOperand(i).getValueType() == MVT::Other)
429 Worklist.push_back(N->getOperand(i).getNode());
431 // If this is a CopyToReg with a vreg dest, process it.
432 if (N->getOpcode() != ISD::CopyToReg)
435 unsigned DestReg = cast<RegisterSDNode>(N->getOperand(1))->getReg();
436 if (!TargetRegisterInfo::isVirtualRegister(DestReg))
439 // Ignore non-scalar or non-integer values.
440 SDValue Src = N->getOperand(2);
441 EVT SrcVT = Src.getValueType();
442 if (!SrcVT.isInteger() || SrcVT.isVector())
445 unsigned NumSignBits = CurDAG->ComputeNumSignBits(Src);
446 Mask = APInt::getAllOnesValue(SrcVT.getSizeInBits());
447 CurDAG->ComputeMaskedBits(Src, Mask, KnownZero, KnownOne);
448 FuncInfo->AddLiveOutRegInfo(DestReg, NumSignBits, KnownZero, KnownOne);
449 } while (!Worklist.empty());
452 void SelectionDAGISel::CodeGenAndEmitDAG() {
453 std::string GroupName;
454 if (TimePassesIsEnabled)
455 GroupName = "Instruction Selection and Scheduling";
456 std::string BlockName;
457 int BlockNumber = -1;
459 if (ViewDAGCombine1 || ViewLegalizeTypesDAGs || ViewLegalizeDAGs ||
460 ViewDAGCombine2 || ViewDAGCombineLT || ViewISelDAGs || ViewSchedDAGs ||
464 BlockNumber = FuncInfo->MBB->getNumber();
465 BlockName = MF->getFunction()->getNameStr() + ":" +
466 FuncInfo->MBB->getBasicBlock()->getNameStr();
468 DEBUG(dbgs() << "Initial selection DAG: BB#" << BlockNumber
469 << " '" << BlockName << "'\n"; CurDAG->dump());
471 if (ViewDAGCombine1) CurDAG->viewGraph("dag-combine1 input for " + BlockName);
473 // Run the DAG combiner in pre-legalize mode.
475 NamedRegionTimer T("DAG Combining 1", GroupName, TimePassesIsEnabled);
476 CurDAG->Combine(Unrestricted, *AA, OptLevel);
479 DEBUG(dbgs() << "Optimized lowered selection DAG: BB#" << BlockNumber
480 << " '" << BlockName << "'\n"; CurDAG->dump());
482 // Second step, hack on the DAG until it only uses operations and types that
483 // the target supports.
484 if (ViewLegalizeTypesDAGs) CurDAG->viewGraph("legalize-types input for " +
489 NamedRegionTimer T("Type Legalization", GroupName, TimePassesIsEnabled);
490 Changed = CurDAG->LegalizeTypes();
493 DEBUG(dbgs() << "Type-legalized selection DAG: BB#" << BlockNumber
494 << " '" << BlockName << "'\n"; CurDAG->dump());
497 if (ViewDAGCombineLT)
498 CurDAG->viewGraph("dag-combine-lt input for " + BlockName);
500 // Run the DAG combiner in post-type-legalize mode.
502 NamedRegionTimer T("DAG Combining after legalize types", GroupName,
503 TimePassesIsEnabled);
504 CurDAG->Combine(NoIllegalTypes, *AA, OptLevel);
507 DEBUG(dbgs() << "Optimized type-legalized selection DAG: BB#" << BlockNumber
508 << " '" << BlockName << "'\n"; CurDAG->dump());
512 NamedRegionTimer T("Vector Legalization", GroupName, TimePassesIsEnabled);
513 Changed = CurDAG->LegalizeVectors();
518 NamedRegionTimer T("Type Legalization 2", GroupName, TimePassesIsEnabled);
519 CurDAG->LegalizeTypes();
522 if (ViewDAGCombineLT)
523 CurDAG->viewGraph("dag-combine-lv input for " + BlockName);
525 // Run the DAG combiner in post-type-legalize mode.
527 NamedRegionTimer T("DAG Combining after legalize vectors", GroupName,
528 TimePassesIsEnabled);
529 CurDAG->Combine(NoIllegalOperations, *AA, OptLevel);
532 DEBUG(dbgs() << "Optimized vector-legalized selection DAG: BB#"
533 << BlockNumber << " '" << BlockName << "'\n"; CurDAG->dump());
536 if (ViewLegalizeDAGs) CurDAG->viewGraph("legalize input for " + BlockName);
539 NamedRegionTimer T("DAG Legalization", GroupName, TimePassesIsEnabled);
543 DEBUG(dbgs() << "Legalized selection DAG: BB#" << BlockNumber
544 << " '" << BlockName << "'\n"; CurDAG->dump());
546 if (ViewDAGCombine2) CurDAG->viewGraph("dag-combine2 input for " + BlockName);
548 // Run the DAG combiner in post-legalize mode.
550 NamedRegionTimer T("DAG Combining 2", GroupName, TimePassesIsEnabled);
551 CurDAG->Combine(NoIllegalOperations, *AA, OptLevel);
554 DEBUG(dbgs() << "Optimized legalized selection DAG: BB#" << BlockNumber
555 << " '" << BlockName << "'\n"; CurDAG->dump());
557 if (OptLevel != CodeGenOpt::None)
558 ComputeLiveOutVRegInfo();
560 if (ViewISelDAGs) CurDAG->viewGraph("isel input for " + BlockName);
562 // Third, instruction select all of the operations to machine code, adding the
563 // code to the MachineBasicBlock.
565 NamedRegionTimer T("Instruction Selection", GroupName, TimePassesIsEnabled);
566 DoInstructionSelection();
569 DEBUG(dbgs() << "Selected selection DAG: BB#" << BlockNumber
570 << " '" << BlockName << "'\n"; CurDAG->dump());
572 if (ViewSchedDAGs) CurDAG->viewGraph("scheduler input for " + BlockName);
574 // Schedule machine code.
575 ScheduleDAGSDNodes *Scheduler = CreateScheduler();
577 NamedRegionTimer T("Instruction Scheduling", GroupName,
578 TimePassesIsEnabled);
579 Scheduler->Run(CurDAG, FuncInfo->MBB, FuncInfo->InsertPt);
582 if (ViewSUnitDAGs) Scheduler->viewGraph();
584 // Emit machine code to BB. This can change 'BB' to the last block being
586 MachineBasicBlock *FirstMBB = FuncInfo->MBB, *LastMBB;
588 NamedRegionTimer T("Instruction Creation", GroupName, TimePassesIsEnabled);
590 LastMBB = FuncInfo->MBB = Scheduler->EmitSchedule();
591 FuncInfo->InsertPt = Scheduler->InsertPos;
594 // If the block was split, make sure we update any references that are used to
595 // update PHI nodes later on.
596 if (FirstMBB != LastMBB)
597 SDB->UpdateSplitBlock(FirstMBB, LastMBB);
599 // Free the scheduler state.
601 NamedRegionTimer T("Instruction Scheduling Cleanup", GroupName,
602 TimePassesIsEnabled);
606 // Free the SelectionDAG state, now that we're finished with it.
610 void SelectionDAGISel::DoInstructionSelection() {
611 DEBUG(errs() << "===== Instruction selection begins: BB#"
612 << FuncInfo->MBB->getNumber()
613 << " '" << FuncInfo->MBB->getName() << "'\n");
617 // Select target instructions for the DAG.
619 // Number all nodes with a topological order and set DAGSize.
620 DAGSize = CurDAG->AssignTopologicalOrder();
622 // Create a dummy node (which is not added to allnodes), that adds
623 // a reference to the root node, preventing it from being deleted,
624 // and tracking any changes of the root.
625 HandleSDNode Dummy(CurDAG->getRoot());
626 ISelPosition = SelectionDAG::allnodes_iterator(CurDAG->getRoot().getNode());
629 // The AllNodes list is now topological-sorted. Visit the
630 // nodes by starting at the end of the list (the root of the
631 // graph) and preceding back toward the beginning (the entry
633 while (ISelPosition != CurDAG->allnodes_begin()) {
634 SDNode *Node = --ISelPosition;
635 // Skip dead nodes. DAGCombiner is expected to eliminate all dead nodes,
636 // but there are currently some corner cases that it misses. Also, this
637 // makes it theoretically possible to disable the DAGCombiner.
638 if (Node->use_empty())
641 SDNode *ResNode = Select(Node);
643 // FIXME: This is pretty gross. 'Select' should be changed to not return
644 // anything at all and this code should be nuked with a tactical strike.
646 // If node should not be replaced, continue with the next one.
647 if (ResNode == Node || Node->getOpcode() == ISD::DELETED_NODE)
651 ReplaceUses(Node, ResNode);
653 // If after the replacement this node is not used any more,
654 // remove this dead node.
655 if (Node->use_empty()) { // Don't delete EntryToken, etc.
656 ISelUpdater ISU(ISelPosition);
657 CurDAG->RemoveDeadNode(Node, &ISU);
661 CurDAG->setRoot(Dummy.getValue());
664 DEBUG(errs() << "===== Instruction selection ends:\n");
666 PostprocessISelDAG();
669 /// PrepareEHLandingPad - Emit an EH_LABEL, set up live-in registers, and
670 /// do other setup for EH landing-pad blocks.
671 void SelectionDAGISel::PrepareEHLandingPad() {
672 // Add a label to mark the beginning of the landing pad. Deletion of the
673 // landing pad can thus be detected via the MachineModuleInfo.
674 MCSymbol *Label = MF->getMMI().addLandingPad(FuncInfo->MBB);
676 const TargetInstrDesc &II = TM.getInstrInfo()->get(TargetOpcode::EH_LABEL);
677 BuildMI(*FuncInfo->MBB, FuncInfo->InsertPt, SDB->getCurDebugLoc(), II)
680 // Mark exception register as live in.
681 unsigned Reg = TLI.getExceptionAddressRegister();
682 if (Reg) FuncInfo->MBB->addLiveIn(Reg);
684 // Mark exception selector register as live in.
685 Reg = TLI.getExceptionSelectorRegister();
686 if (Reg) FuncInfo->MBB->addLiveIn(Reg);
688 // FIXME: Hack around an exception handling flaw (PR1508): the personality
689 // function and list of typeids logically belong to the invoke (or, if you
690 // like, the basic block containing the invoke), and need to be associated
691 // with it in the dwarf exception handling tables. Currently however the
692 // information is provided by an intrinsic (eh.selector) that can be moved
693 // to unexpected places by the optimizers: if the unwind edge is critical,
694 // then breaking it can result in the intrinsics being in the successor of
695 // the landing pad, not the landing pad itself. This results
696 // in exceptions not being caught because no typeids are associated with
697 // the invoke. This may not be the only way things can go wrong, but it
698 // is the only way we try to work around for the moment.
699 const BasicBlock *LLVMBB = FuncInfo->MBB->getBasicBlock();
700 const BranchInst *Br = dyn_cast<BranchInst>(LLVMBB->getTerminator());
702 if (Br && Br->isUnconditional()) { // Critical edge?
703 BasicBlock::const_iterator I, E;
704 for (I = LLVMBB->begin(), E = --LLVMBB->end(); I != E; ++I)
705 if (isa<EHSelectorInst>(I))
709 // No catch info found - try to extract some from the successor.
710 CopyCatchInfo(Br->getSuccessor(0), LLVMBB, &MF->getMMI(), *FuncInfo);
716 /// TryToFoldFastISelLoad - We're checking to see if we can fold the specified
717 /// load into the specified FoldInst. Note that we could have a sequence where
718 /// multiple LLVM IR instructions are folded into the same machineinstr. For
719 /// example we could have:
720 /// A: x = load i32 *P
721 /// B: y = icmp A, 42
724 /// In this scenario, LI is "A", and FoldInst is "C". We know about "B" (and
725 /// any other folded instructions) because it is between A and C.
727 /// If we succeed in folding the load into the operation, return true.
729 bool SelectionDAGISel::TryToFoldFastISelLoad(const LoadInst *LI,
730 const Instruction *FoldInst,
732 // We know that the load has a single use, but don't know what it is. If it
733 // isn't one of the folded instructions, then we can't succeed here. Handle
734 // this by scanning the single-use users of the load until we get to FoldInst.
735 unsigned MaxUsers = 6; // Don't scan down huge single-use chains of instrs.
737 const Instruction *TheUser = LI->use_back();
738 while (TheUser != FoldInst && // Scan up until we find FoldInst.
739 // Stay in the right block.
740 TheUser->getParent() == FoldInst->getParent() &&
741 --MaxUsers) { // Don't scan too far.
742 // If there are multiple or no uses of this instruction, then bail out.
743 if (!TheUser->hasOneUse())
746 TheUser = TheUser->use_back();
749 // Don't try to fold volatile loads. Target has to deal with alignment
751 if (LI->isVolatile()) return false;
753 // Figure out which vreg this is going into. If there is no assigned vreg yet
754 // then there actually was no reference to it. Perhaps the load is referenced
755 // by a dead instruction.
756 unsigned LoadReg = FastIS->getRegForValue(LI);
760 // Check to see what the uses of this vreg are. If it has no uses, or more
761 // than one use (at the machine instr level) then we can't fold it.
762 MachineRegisterInfo::reg_iterator RI = RegInfo->reg_begin(LoadReg);
763 if (RI == RegInfo->reg_end())
766 // See if there is exactly one use of the vreg. If there are multiple uses,
767 // then the instruction got lowered to multiple machine instructions or the
768 // use of the loaded value ended up being multiple operands of the result, in
769 // either case, we can't fold this.
770 MachineRegisterInfo::reg_iterator PostRI = RI; ++PostRI;
771 if (PostRI != RegInfo->reg_end())
774 assert(RI.getOperand().isUse() &&
775 "The only use of the vreg must be a use, we haven't emitted the def!");
777 MachineInstr *User = &*RI;
779 // Set the insertion point properly. Folding the load can cause generation of
780 // other random instructions (like sign extends) for addressing modes, make
781 // sure they get inserted in a logical place before the new instruction.
782 FuncInfo->InsertPt = User;
783 FuncInfo->MBB = User->getParent();
785 // Ask the target to try folding the load.
786 return FastIS->TryToFoldLoad(User, RI.getOperandNo(), LI);
790 /// CheckLineNumbers - Check if basic block instructions follow source order
792 static void CheckLineNumbers(const BasicBlock *BB) {
795 for (BasicBlock::const_iterator BI = BB->begin(),
796 BE = BB->end(); BI != BE; ++BI) {
797 const DebugLoc DL = BI->getDebugLoc();
798 if (DL.isUnknown()) continue;
799 unsigned L = DL.getLine();
800 unsigned C = DL.getCol();
801 if (L < Line || (L == Line && C < Col)) {
802 ++NumBBWithOutOfOrderLineInfo;
810 /// CheckLineNumbers - Check if machine basic block instructions follow source
812 static void CheckLineNumbers(const MachineBasicBlock *MBB) {
815 for (MachineBasicBlock::const_iterator MBI = MBB->begin(),
816 MBE = MBB->end(); MBI != MBE; ++MBI) {
817 const DebugLoc DL = MBI->getDebugLoc();
818 if (DL.isUnknown()) continue;
819 unsigned L = DL.getLine();
820 unsigned C = DL.getCol();
821 if (L < Line || (L == Line && C < Col)) {
822 ++NumMBBWithOutOfOrderLineInfo;
831 /// isFoldedOrDeadInstruction - Return true if the specified instruction is
832 /// side-effect free and is either dead or folded into a generated instruction.
833 /// Return false if it needs to be emitted.
834 static bool isFoldedOrDeadInstruction(const Instruction *I,
835 FunctionLoweringInfo *FuncInfo) {
836 return !I->mayWriteToMemory() && // Side-effecting instructions aren't folded.
837 !isa<TerminatorInst>(I) && // Terminators aren't folded.
838 !isa<DbgInfoIntrinsic>(I) && // Debug instructions aren't folded.
839 !FuncInfo->isExportedInst(I); // Exported instrs must be computed.
842 void SelectionDAGISel::SelectAllBasicBlocks(const Function &Fn) {
843 // Initialize the Fast-ISel state, if needed.
844 FastISel *FastIS = 0;
846 FastIS = TLI.createFastISel(*FuncInfo);
848 // Iterate over all basic blocks in the function.
849 ReversePostOrderTraversal<const Function*> RPOT(&Fn);
850 for (ReversePostOrderTraversal<const Function*>::rpo_iterator
851 I = RPOT.begin(), E = RPOT.end(); I != E; ++I) {
852 const BasicBlock *LLVMBB = *I;
854 CheckLineNumbers(LLVMBB);
857 if (OptLevel != CodeGenOpt::None) {
858 bool AllPredsVisited = true;
859 for (const_pred_iterator PI = pred_begin(LLVMBB), PE = pred_end(LLVMBB);
861 if (!FuncInfo->VisitedBBs.count(*PI)) {
862 AllPredsVisited = false;
867 if (AllPredsVisited) {
868 for (BasicBlock::const_iterator I = LLVMBB->begin();
869 isa<PHINode>(I); ++I)
870 FuncInfo->ComputePHILiveOutRegInfo(cast<PHINode>(I));
872 for (BasicBlock::const_iterator I = LLVMBB->begin();
873 isa<PHINode>(I); ++I)
874 FuncInfo->InvalidatePHILiveOutRegInfo(cast<PHINode>(I));
877 FuncInfo->VisitedBBs.insert(LLVMBB);
880 FuncInfo->MBB = FuncInfo->MBBMap[LLVMBB];
881 FuncInfo->InsertPt = FuncInfo->MBB->getFirstNonPHI();
883 BasicBlock::const_iterator const Begin = LLVMBB->getFirstNonPHI();
884 BasicBlock::const_iterator const End = LLVMBB->end();
885 BasicBlock::const_iterator BI = End;
887 FuncInfo->InsertPt = FuncInfo->MBB->getFirstNonPHI();
889 // Setup an EH landing-pad block.
890 if (FuncInfo->MBB->isLandingPad())
891 PrepareEHLandingPad();
893 // Lower any arguments needed in this block if this is the entry block.
894 if (LLVMBB == &Fn.getEntryBlock())
895 LowerArguments(LLVMBB);
897 // Before doing SelectionDAG ISel, see if FastISel has been requested.
899 FastIS->startNewBlock();
901 // Emit code for any incoming arguments. This must happen before
902 // beginning FastISel on the entry block.
903 if (LLVMBB == &Fn.getEntryBlock()) {
904 CurDAG->setRoot(SDB->getControlRoot());
908 // If we inserted any instructions at the beginning, make a note of
909 // where they are, so we can be sure to emit subsequent instructions
911 if (FuncInfo->InsertPt != FuncInfo->MBB->begin())
912 FastIS->setLastLocalValue(llvm::prior(FuncInfo->InsertPt));
914 FastIS->setLastLocalValue(0);
917 // Do FastISel on as many instructions as possible.
918 for (; BI != Begin; --BI) {
919 const Instruction *Inst = llvm::prior(BI);
921 // If we no longer require this instruction, skip it.
922 if (isFoldedOrDeadInstruction(Inst, FuncInfo))
925 // Bottom-up: reset the insert pos at the top, after any local-value
927 FastIS->recomputeInsertPt();
929 // Try to select the instruction with FastISel.
930 if (FastIS->SelectInstruction(Inst)) {
931 ++NumFastIselSuccess;
932 // If fast isel succeeded, skip over all the folded instructions, and
933 // then see if there is a load right before the selected instructions.
934 // Try to fold the load if so.
935 const Instruction *BeforeInst = Inst;
936 while (BeforeInst != Begin) {
937 BeforeInst = llvm::prior(BasicBlock::const_iterator(BeforeInst));
938 if (!isFoldedOrDeadInstruction(BeforeInst, FuncInfo))
941 if (BeforeInst != Inst && isa<LoadInst>(BeforeInst) &&
942 BeforeInst->hasOneUse() &&
943 TryToFoldFastISelLoad(cast<LoadInst>(BeforeInst), Inst, FastIS))
944 // If we succeeded, don't re-select the load.
945 BI = llvm::next(BasicBlock::const_iterator(BeforeInst));
949 // Then handle certain instructions as single-LLVM-Instruction blocks.
950 if (isa<CallInst>(Inst)) {
951 ++NumFastIselFailures;
952 if (EnableFastISelVerbose || EnableFastISelAbort) {
953 dbgs() << "FastISel missed call: ";
957 if (!Inst->getType()->isVoidTy() && !Inst->use_empty()) {
958 unsigned &R = FuncInfo->ValueMap[Inst];
960 R = FuncInfo->CreateRegs(Inst->getType());
963 bool HadTailCall = false;
964 SelectBasicBlock(Inst, BI, HadTailCall);
966 // If the call was emitted as a tail call, we're done with the block.
975 if (isa<TerminatorInst>(Inst) && !isa<BranchInst>(Inst)) {
976 // Don't abort, and use a different message for terminator misses.
977 ++NumFastIselFailures;
978 if (EnableFastISelVerbose || EnableFastISelAbort) {
979 dbgs() << "FastISel missed terminator: ";
983 ++NumFastIselFailures;
984 if (EnableFastISelVerbose || EnableFastISelAbort) {
985 dbgs() << "FastISel miss: ";
988 if (EnableFastISelAbort)
989 // The "fast" selector couldn't handle something and bailed.
990 // For the purpose of debugging, just abort.
991 llvm_unreachable("FastISel didn't select the entire block");
996 FastIS->recomputeInsertPt();
1002 ++NumFastIselBlocks;
1005 // Run SelectionDAG instruction selection on the remainder of the block
1006 // not handled by FastISel. If FastISel is not run, this is the entire
1009 SelectBasicBlock(Begin, BI, HadTailCall);
1013 FuncInfo->PHINodesToUpdate.clear();
1018 for (MachineFunction::const_iterator MBI = MF->begin(), MBE = MF->end();
1020 CheckLineNumbers(MBI);
1025 SelectionDAGISel::FinishBasicBlock() {
1027 DEBUG(dbgs() << "Total amount of phi nodes to update: "
1028 << FuncInfo->PHINodesToUpdate.size() << "\n";
1029 for (unsigned i = 0, e = FuncInfo->PHINodesToUpdate.size(); i != e; ++i)
1030 dbgs() << "Node " << i << " : ("
1031 << FuncInfo->PHINodesToUpdate[i].first
1032 << ", " << FuncInfo->PHINodesToUpdate[i].second << ")\n");
1034 // Next, now that we know what the last MBB the LLVM BB expanded is, update
1035 // PHI nodes in successors.
1036 if (SDB->SwitchCases.empty() &&
1037 SDB->JTCases.empty() &&
1038 SDB->BitTestCases.empty()) {
1039 for (unsigned i = 0, e = FuncInfo->PHINodesToUpdate.size(); i != e; ++i) {
1040 MachineInstr *PHI = FuncInfo->PHINodesToUpdate[i].first;
1041 assert(PHI->isPHI() &&
1042 "This is not a machine PHI node that we are updating!");
1043 if (!FuncInfo->MBB->isSuccessor(PHI->getParent()))
1046 MachineOperand::CreateReg(FuncInfo->PHINodesToUpdate[i].second, false));
1047 PHI->addOperand(MachineOperand::CreateMBB(FuncInfo->MBB));
1052 for (unsigned i = 0, e = SDB->BitTestCases.size(); i != e; ++i) {
1053 // Lower header first, if it wasn't already lowered
1054 if (!SDB->BitTestCases[i].Emitted) {
1055 // Set the current basic block to the mbb we wish to insert the code into
1056 FuncInfo->MBB = SDB->BitTestCases[i].Parent;
1057 FuncInfo->InsertPt = FuncInfo->MBB->end();
1059 SDB->visitBitTestHeader(SDB->BitTestCases[i], FuncInfo->MBB);
1060 CurDAG->setRoot(SDB->getRoot());
1062 CodeGenAndEmitDAG();
1065 for (unsigned j = 0, ej = SDB->BitTestCases[i].Cases.size(); j != ej; ++j) {
1066 // Set the current basic block to the mbb we wish to insert the code into
1067 FuncInfo->MBB = SDB->BitTestCases[i].Cases[j].ThisBB;
1068 FuncInfo->InsertPt = FuncInfo->MBB->end();
1071 SDB->visitBitTestCase(SDB->BitTestCases[i],
1072 SDB->BitTestCases[i].Cases[j+1].ThisBB,
1073 SDB->BitTestCases[i].Reg,
1074 SDB->BitTestCases[i].Cases[j],
1077 SDB->visitBitTestCase(SDB->BitTestCases[i],
1078 SDB->BitTestCases[i].Default,
1079 SDB->BitTestCases[i].Reg,
1080 SDB->BitTestCases[i].Cases[j],
1084 CurDAG->setRoot(SDB->getRoot());
1086 CodeGenAndEmitDAG();
1090 for (unsigned pi = 0, pe = FuncInfo->PHINodesToUpdate.size();
1092 MachineInstr *PHI = FuncInfo->PHINodesToUpdate[pi].first;
1093 MachineBasicBlock *PHIBB = PHI->getParent();
1094 assert(PHI->isPHI() &&
1095 "This is not a machine PHI node that we are updating!");
1096 // This is "default" BB. We have two jumps to it. From "header" BB and
1097 // from last "case" BB.
1098 if (PHIBB == SDB->BitTestCases[i].Default) {
1099 PHI->addOperand(MachineOperand::
1100 CreateReg(FuncInfo->PHINodesToUpdate[pi].second,
1102 PHI->addOperand(MachineOperand::CreateMBB(SDB->BitTestCases[i].Parent));
1103 PHI->addOperand(MachineOperand::
1104 CreateReg(FuncInfo->PHINodesToUpdate[pi].second,
1106 PHI->addOperand(MachineOperand::CreateMBB(SDB->BitTestCases[i].Cases.
1109 // One of "cases" BB.
1110 for (unsigned j = 0, ej = SDB->BitTestCases[i].Cases.size();
1112 MachineBasicBlock* cBB = SDB->BitTestCases[i].Cases[j].ThisBB;
1113 if (cBB->isSuccessor(PHIBB)) {
1114 PHI->addOperand(MachineOperand::
1115 CreateReg(FuncInfo->PHINodesToUpdate[pi].second,
1117 PHI->addOperand(MachineOperand::CreateMBB(cBB));
1122 SDB->BitTestCases.clear();
1124 // If the JumpTable record is filled in, then we need to emit a jump table.
1125 // Updating the PHI nodes is tricky in this case, since we need to determine
1126 // whether the PHI is a successor of the range check MBB or the jump table MBB
1127 for (unsigned i = 0, e = SDB->JTCases.size(); i != e; ++i) {
1128 // Lower header first, if it wasn't already lowered
1129 if (!SDB->JTCases[i].first.Emitted) {
1130 // Set the current basic block to the mbb we wish to insert the code into
1131 FuncInfo->MBB = SDB->JTCases[i].first.HeaderBB;
1132 FuncInfo->InsertPt = FuncInfo->MBB->end();
1134 SDB->visitJumpTableHeader(SDB->JTCases[i].second, SDB->JTCases[i].first,
1136 CurDAG->setRoot(SDB->getRoot());
1138 CodeGenAndEmitDAG();
1141 // Set the current basic block to the mbb we wish to insert the code into
1142 FuncInfo->MBB = SDB->JTCases[i].second.MBB;
1143 FuncInfo->InsertPt = FuncInfo->MBB->end();
1145 SDB->visitJumpTable(SDB->JTCases[i].second);
1146 CurDAG->setRoot(SDB->getRoot());
1148 CodeGenAndEmitDAG();
1151 for (unsigned pi = 0, pe = FuncInfo->PHINodesToUpdate.size();
1153 MachineInstr *PHI = FuncInfo->PHINodesToUpdate[pi].first;
1154 MachineBasicBlock *PHIBB = PHI->getParent();
1155 assert(PHI->isPHI() &&
1156 "This is not a machine PHI node that we are updating!");
1157 // "default" BB. We can go there only from header BB.
1158 if (PHIBB == SDB->JTCases[i].second.Default) {
1160 (MachineOperand::CreateReg(FuncInfo->PHINodesToUpdate[pi].second,
1163 (MachineOperand::CreateMBB(SDB->JTCases[i].first.HeaderBB));
1165 // JT BB. Just iterate over successors here
1166 if (FuncInfo->MBB->isSuccessor(PHIBB)) {
1168 (MachineOperand::CreateReg(FuncInfo->PHINodesToUpdate[pi].second,
1170 PHI->addOperand(MachineOperand::CreateMBB(FuncInfo->MBB));
1174 SDB->JTCases.clear();
1176 // If the switch block involved a branch to one of the actual successors, we
1177 // need to update PHI nodes in that block.
1178 for (unsigned i = 0, e = FuncInfo->PHINodesToUpdate.size(); i != e; ++i) {
1179 MachineInstr *PHI = FuncInfo->PHINodesToUpdate[i].first;
1180 assert(PHI->isPHI() &&
1181 "This is not a machine PHI node that we are updating!");
1182 if (FuncInfo->MBB->isSuccessor(PHI->getParent())) {
1184 MachineOperand::CreateReg(FuncInfo->PHINodesToUpdate[i].second, false));
1185 PHI->addOperand(MachineOperand::CreateMBB(FuncInfo->MBB));
1189 // If we generated any switch lowering information, build and codegen any
1190 // additional DAGs necessary.
1191 for (unsigned i = 0, e = SDB->SwitchCases.size(); i != e; ++i) {
1192 // Set the current basic block to the mbb we wish to insert the code into
1193 FuncInfo->MBB = SDB->SwitchCases[i].ThisBB;
1194 FuncInfo->InsertPt = FuncInfo->MBB->end();
1196 // Determine the unique successors.
1197 SmallVector<MachineBasicBlock *, 2> Succs;
1198 Succs.push_back(SDB->SwitchCases[i].TrueBB);
1199 if (SDB->SwitchCases[i].TrueBB != SDB->SwitchCases[i].FalseBB)
1200 Succs.push_back(SDB->SwitchCases[i].FalseBB);
1202 // Emit the code. Note that this could result in FuncInfo->MBB being split.
1203 SDB->visitSwitchCase(SDB->SwitchCases[i], FuncInfo->MBB);
1204 CurDAG->setRoot(SDB->getRoot());
1206 CodeGenAndEmitDAG();
1208 // Remember the last block, now that any splitting is done, for use in
1209 // populating PHI nodes in successors.
1210 MachineBasicBlock *ThisBB = FuncInfo->MBB;
1212 // Handle any PHI nodes in successors of this chunk, as if we were coming
1213 // from the original BB before switch expansion. Note that PHI nodes can
1214 // occur multiple times in PHINodesToUpdate. We have to be very careful to
1215 // handle them the right number of times.
1216 for (unsigned i = 0, e = Succs.size(); i != e; ++i) {
1217 FuncInfo->MBB = Succs[i];
1218 FuncInfo->InsertPt = FuncInfo->MBB->end();
1219 // FuncInfo->MBB may have been removed from the CFG if a branch was
1221 if (ThisBB->isSuccessor(FuncInfo->MBB)) {
1222 for (MachineBasicBlock::iterator Phi = FuncInfo->MBB->begin();
1223 Phi != FuncInfo->MBB->end() && Phi->isPHI();
1225 // This value for this PHI node is recorded in PHINodesToUpdate.
1226 for (unsigned pn = 0; ; ++pn) {
1227 assert(pn != FuncInfo->PHINodesToUpdate.size() &&
1228 "Didn't find PHI entry!");
1229 if (FuncInfo->PHINodesToUpdate[pn].first == Phi) {
1230 Phi->addOperand(MachineOperand::
1231 CreateReg(FuncInfo->PHINodesToUpdate[pn].second,
1233 Phi->addOperand(MachineOperand::CreateMBB(ThisBB));
1241 SDB->SwitchCases.clear();
1245 /// Create the scheduler. If a specific scheduler was specified
1246 /// via the SchedulerRegistry, use it, otherwise select the
1247 /// one preferred by the target.
1249 ScheduleDAGSDNodes *SelectionDAGISel::CreateScheduler() {
1250 RegisterScheduler::FunctionPassCtor Ctor = RegisterScheduler::getDefault();
1254 RegisterScheduler::setDefault(Ctor);
1257 return Ctor(this, OptLevel);
1260 //===----------------------------------------------------------------------===//
1261 // Helper functions used by the generated instruction selector.
1262 //===----------------------------------------------------------------------===//
1263 // Calls to these methods are generated by tblgen.
1265 /// CheckAndMask - The isel is trying to match something like (and X, 255). If
1266 /// the dag combiner simplified the 255, we still want to match. RHS is the
1267 /// actual value in the DAG on the RHS of an AND, and DesiredMaskS is the value
1268 /// specified in the .td file (e.g. 255).
1269 bool SelectionDAGISel::CheckAndMask(SDValue LHS, ConstantSDNode *RHS,
1270 int64_t DesiredMaskS) const {
1271 const APInt &ActualMask = RHS->getAPIntValue();
1272 const APInt &DesiredMask = APInt(LHS.getValueSizeInBits(), DesiredMaskS);
1274 // If the actual mask exactly matches, success!
1275 if (ActualMask == DesiredMask)
1278 // If the actual AND mask is allowing unallowed bits, this doesn't match.
1279 if (ActualMask.intersects(~DesiredMask))
1282 // Otherwise, the DAG Combiner may have proven that the value coming in is
1283 // either already zero or is not demanded. Check for known zero input bits.
1284 APInt NeededMask = DesiredMask & ~ActualMask;
1285 if (CurDAG->MaskedValueIsZero(LHS, NeededMask))
1288 // TODO: check to see if missing bits are just not demanded.
1290 // Otherwise, this pattern doesn't match.
1294 /// CheckOrMask - The isel is trying to match something like (or X, 255). If
1295 /// the dag combiner simplified the 255, we still want to match. RHS is the
1296 /// actual value in the DAG on the RHS of an OR, and DesiredMaskS is the value
1297 /// specified in the .td file (e.g. 255).
1298 bool SelectionDAGISel::CheckOrMask(SDValue LHS, ConstantSDNode *RHS,
1299 int64_t DesiredMaskS) const {
1300 const APInt &ActualMask = RHS->getAPIntValue();
1301 const APInt &DesiredMask = APInt(LHS.getValueSizeInBits(), DesiredMaskS);
1303 // If the actual mask exactly matches, success!
1304 if (ActualMask == DesiredMask)
1307 // If the actual AND mask is allowing unallowed bits, this doesn't match.
1308 if (ActualMask.intersects(~DesiredMask))
1311 // Otherwise, the DAG Combiner may have proven that the value coming in is
1312 // either already zero or is not demanded. Check for known zero input bits.
1313 APInt NeededMask = DesiredMask & ~ActualMask;
1315 APInt KnownZero, KnownOne;
1316 CurDAG->ComputeMaskedBits(LHS, NeededMask, KnownZero, KnownOne);
1318 // If all the missing bits in the or are already known to be set, match!
1319 if ((NeededMask & KnownOne) == NeededMask)
1322 // TODO: check to see if missing bits are just not demanded.
1324 // Otherwise, this pattern doesn't match.
1329 /// SelectInlineAsmMemoryOperands - Calls to this are automatically generated
1330 /// by tblgen. Others should not call it.
1331 void SelectionDAGISel::
1332 SelectInlineAsmMemoryOperands(std::vector<SDValue> &Ops) {
1333 std::vector<SDValue> InOps;
1334 std::swap(InOps, Ops);
1336 Ops.push_back(InOps[InlineAsm::Op_InputChain]); // 0
1337 Ops.push_back(InOps[InlineAsm::Op_AsmString]); // 1
1338 Ops.push_back(InOps[InlineAsm::Op_MDNode]); // 2, !srcloc
1339 Ops.push_back(InOps[InlineAsm::Op_ExtraInfo]); // 3 (SideEffect, AlignStack)
1341 unsigned i = InlineAsm::Op_FirstOperand, e = InOps.size();
1342 if (InOps[e-1].getValueType() == MVT::Glue)
1343 --e; // Don't process a glue operand if it is here.
1346 unsigned Flags = cast<ConstantSDNode>(InOps[i])->getZExtValue();
1347 if (!InlineAsm::isMemKind(Flags)) {
1348 // Just skip over this operand, copying the operands verbatim.
1349 Ops.insert(Ops.end(), InOps.begin()+i,
1350 InOps.begin()+i+InlineAsm::getNumOperandRegisters(Flags) + 1);
1351 i += InlineAsm::getNumOperandRegisters(Flags) + 1;
1353 assert(InlineAsm::getNumOperandRegisters(Flags) == 1 &&
1354 "Memory operand with multiple values?");
1355 // Otherwise, this is a memory operand. Ask the target to select it.
1356 std::vector<SDValue> SelOps;
1357 if (SelectInlineAsmMemoryOperand(InOps[i+1], 'm', SelOps))
1358 report_fatal_error("Could not match memory address. Inline asm"
1361 // Add this to the output node.
1363 InlineAsm::getFlagWord(InlineAsm::Kind_Mem, SelOps.size());
1364 Ops.push_back(CurDAG->getTargetConstant(NewFlags, MVT::i32));
1365 Ops.insert(Ops.end(), SelOps.begin(), SelOps.end());
1370 // Add the glue input back if present.
1371 if (e != InOps.size())
1372 Ops.push_back(InOps.back());
1375 /// findGlueUse - Return use of MVT::Glue value produced by the specified
1378 static SDNode *findGlueUse(SDNode *N) {
1379 unsigned FlagResNo = N->getNumValues()-1;
1380 for (SDNode::use_iterator I = N->use_begin(), E = N->use_end(); I != E; ++I) {
1381 SDUse &Use = I.getUse();
1382 if (Use.getResNo() == FlagResNo)
1383 return Use.getUser();
1388 /// findNonImmUse - Return true if "Use" is a non-immediate use of "Def".
1389 /// This function recursively traverses up the operand chain, ignoring
1391 static bool findNonImmUse(SDNode *Use, SDNode* Def, SDNode *ImmedUse,
1392 SDNode *Root, SmallPtrSet<SDNode*, 16> &Visited,
1393 bool IgnoreChains) {
1394 // The NodeID's are given uniques ID's where a node ID is guaranteed to be
1395 // greater than all of its (recursive) operands. If we scan to a point where
1396 // 'use' is smaller than the node we're scanning for, then we know we will
1399 // The Use may be -1 (unassigned) if it is a newly allocated node. This can
1400 // happen because we scan down to newly selected nodes in the case of glue
1402 if ((Use->getNodeId() < Def->getNodeId() && Use->getNodeId() != -1))
1405 // Don't revisit nodes if we already scanned it and didn't fail, we know we
1406 // won't fail if we scan it again.
1407 if (!Visited.insert(Use))
1410 for (unsigned i = 0, e = Use->getNumOperands(); i != e; ++i) {
1411 // Ignore chain uses, they are validated by HandleMergeInputChains.
1412 if (Use->getOperand(i).getValueType() == MVT::Other && IgnoreChains)
1415 SDNode *N = Use->getOperand(i).getNode();
1417 if (Use == ImmedUse || Use == Root)
1418 continue; // We are not looking for immediate use.
1423 // Traverse up the operand chain.
1424 if (findNonImmUse(N, Def, ImmedUse, Root, Visited, IgnoreChains))
1430 /// IsProfitableToFold - Returns true if it's profitable to fold the specific
1431 /// operand node N of U during instruction selection that starts at Root.
1432 bool SelectionDAGISel::IsProfitableToFold(SDValue N, SDNode *U,
1433 SDNode *Root) const {
1434 if (OptLevel == CodeGenOpt::None) return false;
1435 return N.hasOneUse();
1438 /// IsLegalToFold - Returns true if the specific operand node N of
1439 /// U can be folded during instruction selection that starts at Root.
1440 bool SelectionDAGISel::IsLegalToFold(SDValue N, SDNode *U, SDNode *Root,
1441 CodeGenOpt::Level OptLevel,
1442 bool IgnoreChains) {
1443 if (OptLevel == CodeGenOpt::None) return false;
1445 // If Root use can somehow reach N through a path that that doesn't contain
1446 // U then folding N would create a cycle. e.g. In the following
1447 // diagram, Root can reach N through X. If N is folded into into Root, then
1448 // X is both a predecessor and a successor of U.
1459 // * indicates nodes to be folded together.
1461 // If Root produces glue, then it gets (even more) interesting. Since it
1462 // will be "glued" together with its glue use in the scheduler, we need to
1463 // check if it might reach N.
1482 // If GU (glue use) indirectly reaches N (the load), and Root folds N
1483 // (call it Fold), then X is a predecessor of GU and a successor of
1484 // Fold. But since Fold and GU are glued together, this will create
1485 // a cycle in the scheduling graph.
1487 // If the node has glue, walk down the graph to the "lowest" node in the
1489 EVT VT = Root->getValueType(Root->getNumValues()-1);
1490 while (VT == MVT::Glue) {
1491 SDNode *GU = findGlueUse(Root);
1495 VT = Root->getValueType(Root->getNumValues()-1);
1497 // If our query node has a glue result with a use, we've walked up it. If
1498 // the user (which has already been selected) has a chain or indirectly uses
1499 // the chain, our WalkChainUsers predicate will not consider it. Because of
1500 // this, we cannot ignore chains in this predicate.
1501 IgnoreChains = false;
1505 SmallPtrSet<SDNode*, 16> Visited;
1506 return !findNonImmUse(Root, N.getNode(), U, Root, Visited, IgnoreChains);
1509 SDNode *SelectionDAGISel::Select_INLINEASM(SDNode *N) {
1510 std::vector<SDValue> Ops(N->op_begin(), N->op_end());
1511 SelectInlineAsmMemoryOperands(Ops);
1513 std::vector<EVT> VTs;
1514 VTs.push_back(MVT::Other);
1515 VTs.push_back(MVT::Glue);
1516 SDValue New = CurDAG->getNode(ISD::INLINEASM, N->getDebugLoc(),
1517 VTs, &Ops[0], Ops.size());
1519 return New.getNode();
1522 SDNode *SelectionDAGISel::Select_UNDEF(SDNode *N) {
1523 return CurDAG->SelectNodeTo(N, TargetOpcode::IMPLICIT_DEF,N->getValueType(0));
1526 /// GetVBR - decode a vbr encoding whose top bit is set.
1527 LLVM_ATTRIBUTE_ALWAYS_INLINE static uint64_t
1528 GetVBR(uint64_t Val, const unsigned char *MatcherTable, unsigned &Idx) {
1529 assert(Val >= 128 && "Not a VBR");
1530 Val &= 127; // Remove first vbr bit.
1535 NextBits = MatcherTable[Idx++];
1536 Val |= (NextBits&127) << Shift;
1538 } while (NextBits & 128);
1544 /// UpdateChainsAndGlue - When a match is complete, this method updates uses of
1545 /// interior glue and chain results to use the new glue and chain results.
1546 void SelectionDAGISel::
1547 UpdateChainsAndGlue(SDNode *NodeToMatch, SDValue InputChain,
1548 const SmallVectorImpl<SDNode*> &ChainNodesMatched,
1550 const SmallVectorImpl<SDNode*> &GlueResultNodesMatched,
1551 bool isMorphNodeTo) {
1552 SmallVector<SDNode*, 4> NowDeadNodes;
1554 ISelUpdater ISU(ISelPosition);
1556 // Now that all the normal results are replaced, we replace the chain and
1557 // glue results if present.
1558 if (!ChainNodesMatched.empty()) {
1559 assert(InputChain.getNode() != 0 &&
1560 "Matched input chains but didn't produce a chain");
1561 // Loop over all of the nodes we matched that produced a chain result.
1562 // Replace all the chain results with the final chain we ended up with.
1563 for (unsigned i = 0, e = ChainNodesMatched.size(); i != e; ++i) {
1564 SDNode *ChainNode = ChainNodesMatched[i];
1566 // If this node was already deleted, don't look at it.
1567 if (ChainNode->getOpcode() == ISD::DELETED_NODE)
1570 // Don't replace the results of the root node if we're doing a
1572 if (ChainNode == NodeToMatch && isMorphNodeTo)
1575 SDValue ChainVal = SDValue(ChainNode, ChainNode->getNumValues()-1);
1576 if (ChainVal.getValueType() == MVT::Glue)
1577 ChainVal = ChainVal.getValue(ChainVal->getNumValues()-2);
1578 assert(ChainVal.getValueType() == MVT::Other && "Not a chain?");
1579 CurDAG->ReplaceAllUsesOfValueWith(ChainVal, InputChain, &ISU);
1581 // If the node became dead and we haven't already seen it, delete it.
1582 if (ChainNode->use_empty() &&
1583 !std::count(NowDeadNodes.begin(), NowDeadNodes.end(), ChainNode))
1584 NowDeadNodes.push_back(ChainNode);
1588 // If the result produces glue, update any glue results in the matched
1589 // pattern with the glue result.
1590 if (InputGlue.getNode() != 0) {
1591 // Handle any interior nodes explicitly marked.
1592 for (unsigned i = 0, e = GlueResultNodesMatched.size(); i != e; ++i) {
1593 SDNode *FRN = GlueResultNodesMatched[i];
1595 // If this node was already deleted, don't look at it.
1596 if (FRN->getOpcode() == ISD::DELETED_NODE)
1599 assert(FRN->getValueType(FRN->getNumValues()-1) == MVT::Glue &&
1600 "Doesn't have a glue result");
1601 CurDAG->ReplaceAllUsesOfValueWith(SDValue(FRN, FRN->getNumValues()-1),
1604 // If the node became dead and we haven't already seen it, delete it.
1605 if (FRN->use_empty() &&
1606 !std::count(NowDeadNodes.begin(), NowDeadNodes.end(), FRN))
1607 NowDeadNodes.push_back(FRN);
1611 if (!NowDeadNodes.empty())
1612 CurDAG->RemoveDeadNodes(NowDeadNodes, &ISU);
1614 DEBUG(errs() << "ISEL: Match complete!\n");
1620 CR_LeadsToInteriorNode
1623 /// WalkChainUsers - Walk down the users of the specified chained node that is
1624 /// part of the pattern we're matching, looking at all of the users we find.
1625 /// This determines whether something is an interior node, whether we have a
1626 /// non-pattern node in between two pattern nodes (which prevent folding because
1627 /// it would induce a cycle) and whether we have a TokenFactor node sandwiched
1628 /// between pattern nodes (in which case the TF becomes part of the pattern).
1630 /// The walk we do here is guaranteed to be small because we quickly get down to
1631 /// already selected nodes "below" us.
1633 WalkChainUsers(SDNode *ChainedNode,
1634 SmallVectorImpl<SDNode*> &ChainedNodesInPattern,
1635 SmallVectorImpl<SDNode*> &InteriorChainedNodes) {
1636 ChainResult Result = CR_Simple;
1638 for (SDNode::use_iterator UI = ChainedNode->use_begin(),
1639 E = ChainedNode->use_end(); UI != E; ++UI) {
1640 // Make sure the use is of the chain, not some other value we produce.
1641 if (UI.getUse().getValueType() != MVT::Other) continue;
1645 // If we see an already-selected machine node, then we've gone beyond the
1646 // pattern that we're selecting down into the already selected chunk of the
1648 if (User->isMachineOpcode() ||
1649 User->getOpcode() == ISD::HANDLENODE) // Root of the graph.
1652 if (User->getOpcode() == ISD::CopyToReg ||
1653 User->getOpcode() == ISD::CopyFromReg ||
1654 User->getOpcode() == ISD::INLINEASM ||
1655 User->getOpcode() == ISD::EH_LABEL) {
1656 // If their node ID got reset to -1 then they've already been selected.
1657 // Treat them like a MachineOpcode.
1658 if (User->getNodeId() == -1)
1662 // If we have a TokenFactor, we handle it specially.
1663 if (User->getOpcode() != ISD::TokenFactor) {
1664 // If the node isn't a token factor and isn't part of our pattern, then it
1665 // must be a random chained node in between two nodes we're selecting.
1666 // This happens when we have something like:
1671 // Because we structurally match the load/store as a read/modify/write,
1672 // but the call is chained between them. We cannot fold in this case
1673 // because it would induce a cycle in the graph.
1674 if (!std::count(ChainedNodesInPattern.begin(),
1675 ChainedNodesInPattern.end(), User))
1676 return CR_InducesCycle;
1678 // Otherwise we found a node that is part of our pattern. For example in:
1682 // This would happen when we're scanning down from the load and see the
1683 // store as a user. Record that there is a use of ChainedNode that is
1684 // part of the pattern and keep scanning uses.
1685 Result = CR_LeadsToInteriorNode;
1686 InteriorChainedNodes.push_back(User);
1690 // If we found a TokenFactor, there are two cases to consider: first if the
1691 // TokenFactor is just hanging "below" the pattern we're matching (i.e. no
1692 // uses of the TF are in our pattern) we just want to ignore it. Second,
1693 // the TokenFactor can be sandwiched in between two chained nodes, like so:
1699 // | \ DAG's like cheese
1702 // [TokenFactor] [Op]
1709 // In this case, the TokenFactor becomes part of our match and we rewrite it
1710 // as a new TokenFactor.
1712 // To distinguish these two cases, do a recursive walk down the uses.
1713 switch (WalkChainUsers(User, ChainedNodesInPattern, InteriorChainedNodes)) {
1715 // If the uses of the TokenFactor are just already-selected nodes, ignore
1716 // it, it is "below" our pattern.
1718 case CR_InducesCycle:
1719 // If the uses of the TokenFactor lead to nodes that are not part of our
1720 // pattern that are not selected, folding would turn this into a cycle,
1722 return CR_InducesCycle;
1723 case CR_LeadsToInteriorNode:
1724 break; // Otherwise, keep processing.
1727 // Okay, we know we're in the interesting interior case. The TokenFactor
1728 // is now going to be considered part of the pattern so that we rewrite its
1729 // uses (it may have uses that are not part of the pattern) with the
1730 // ultimate chain result of the generated code. We will also add its chain
1731 // inputs as inputs to the ultimate TokenFactor we create.
1732 Result = CR_LeadsToInteriorNode;
1733 ChainedNodesInPattern.push_back(User);
1734 InteriorChainedNodes.push_back(User);
1741 /// HandleMergeInputChains - This implements the OPC_EmitMergeInputChains
1742 /// operation for when the pattern matched at least one node with a chains. The
1743 /// input vector contains a list of all of the chained nodes that we match. We
1744 /// must determine if this is a valid thing to cover (i.e. matching it won't
1745 /// induce cycles in the DAG) and if so, creating a TokenFactor node. that will
1746 /// be used as the input node chain for the generated nodes.
1748 HandleMergeInputChains(SmallVectorImpl<SDNode*> &ChainNodesMatched,
1749 SelectionDAG *CurDAG) {
1750 // Walk all of the chained nodes we've matched, recursively scanning down the
1751 // users of the chain result. This adds any TokenFactor nodes that are caught
1752 // in between chained nodes to the chained and interior nodes list.
1753 SmallVector<SDNode*, 3> InteriorChainedNodes;
1754 for (unsigned i = 0, e = ChainNodesMatched.size(); i != e; ++i) {
1755 if (WalkChainUsers(ChainNodesMatched[i], ChainNodesMatched,
1756 InteriorChainedNodes) == CR_InducesCycle)
1757 return SDValue(); // Would induce a cycle.
1760 // Okay, we have walked all the matched nodes and collected TokenFactor nodes
1761 // that we are interested in. Form our input TokenFactor node.
1762 SmallVector<SDValue, 3> InputChains;
1763 for (unsigned i = 0, e = ChainNodesMatched.size(); i != e; ++i) {
1764 // Add the input chain of this node to the InputChains list (which will be
1765 // the operands of the generated TokenFactor) if it's not an interior node.
1766 SDNode *N = ChainNodesMatched[i];
1767 if (N->getOpcode() != ISD::TokenFactor) {
1768 if (std::count(InteriorChainedNodes.begin(),InteriorChainedNodes.end(),N))
1771 // Otherwise, add the input chain.
1772 SDValue InChain = ChainNodesMatched[i]->getOperand(0);
1773 assert(InChain.getValueType() == MVT::Other && "Not a chain");
1774 InputChains.push_back(InChain);
1778 // If we have a token factor, we want to add all inputs of the token factor
1779 // that are not part of the pattern we're matching.
1780 for (unsigned op = 0, e = N->getNumOperands(); op != e; ++op) {
1781 if (!std::count(ChainNodesMatched.begin(), ChainNodesMatched.end(),
1782 N->getOperand(op).getNode()))
1783 InputChains.push_back(N->getOperand(op));
1788 if (InputChains.size() == 1)
1789 return InputChains[0];
1790 return CurDAG->getNode(ISD::TokenFactor, ChainNodesMatched[0]->getDebugLoc(),
1791 MVT::Other, &InputChains[0], InputChains.size());
1794 /// MorphNode - Handle morphing a node in place for the selector.
1795 SDNode *SelectionDAGISel::
1796 MorphNode(SDNode *Node, unsigned TargetOpc, SDVTList VTList,
1797 const SDValue *Ops, unsigned NumOps, unsigned EmitNodeInfo) {
1798 // It is possible we're using MorphNodeTo to replace a node with no
1799 // normal results with one that has a normal result (or we could be
1800 // adding a chain) and the input could have glue and chains as well.
1801 // In this case we need to shift the operands down.
1802 // FIXME: This is a horrible hack and broken in obscure cases, no worse
1803 // than the old isel though.
1804 int OldGlueResultNo = -1, OldChainResultNo = -1;
1806 unsigned NTMNumResults = Node->getNumValues();
1807 if (Node->getValueType(NTMNumResults-1) == MVT::Glue) {
1808 OldGlueResultNo = NTMNumResults-1;
1809 if (NTMNumResults != 1 &&
1810 Node->getValueType(NTMNumResults-2) == MVT::Other)
1811 OldChainResultNo = NTMNumResults-2;
1812 } else if (Node->getValueType(NTMNumResults-1) == MVT::Other)
1813 OldChainResultNo = NTMNumResults-1;
1815 // Call the underlying SelectionDAG routine to do the transmogrification. Note
1816 // that this deletes operands of the old node that become dead.
1817 SDNode *Res = CurDAG->MorphNodeTo(Node, ~TargetOpc, VTList, Ops, NumOps);
1819 // MorphNodeTo can operate in two ways: if an existing node with the
1820 // specified operands exists, it can just return it. Otherwise, it
1821 // updates the node in place to have the requested operands.
1823 // If we updated the node in place, reset the node ID. To the isel,
1824 // this should be just like a newly allocated machine node.
1828 unsigned ResNumResults = Res->getNumValues();
1829 // Move the glue if needed.
1830 if ((EmitNodeInfo & OPFL_GlueOutput) && OldGlueResultNo != -1 &&
1831 (unsigned)OldGlueResultNo != ResNumResults-1)
1832 CurDAG->ReplaceAllUsesOfValueWith(SDValue(Node, OldGlueResultNo),
1833 SDValue(Res, ResNumResults-1));
1835 if ((EmitNodeInfo & OPFL_GlueOutput) != 0)
1838 // Move the chain reference if needed.
1839 if ((EmitNodeInfo & OPFL_Chain) && OldChainResultNo != -1 &&
1840 (unsigned)OldChainResultNo != ResNumResults-1)
1841 CurDAG->ReplaceAllUsesOfValueWith(SDValue(Node, OldChainResultNo),
1842 SDValue(Res, ResNumResults-1));
1844 // Otherwise, no replacement happened because the node already exists. Replace
1845 // Uses of the old node with the new one.
1847 CurDAG->ReplaceAllUsesWith(Node, Res);
1852 /// CheckPatternPredicate - Implements OP_CheckPatternPredicate.
1853 LLVM_ATTRIBUTE_ALWAYS_INLINE static bool
1854 CheckSame(const unsigned char *MatcherTable, unsigned &MatcherIndex,
1856 const SmallVectorImpl<std::pair<SDValue, SDNode*> > &RecordedNodes) {
1857 // Accept if it is exactly the same as a previously recorded node.
1858 unsigned RecNo = MatcherTable[MatcherIndex++];
1859 assert(RecNo < RecordedNodes.size() && "Invalid CheckSame");
1860 return N == RecordedNodes[RecNo].first;
1863 /// CheckPatternPredicate - Implements OP_CheckPatternPredicate.
1864 LLVM_ATTRIBUTE_ALWAYS_INLINE static bool
1865 CheckPatternPredicate(const unsigned char *MatcherTable, unsigned &MatcherIndex,
1866 SelectionDAGISel &SDISel) {
1867 return SDISel.CheckPatternPredicate(MatcherTable[MatcherIndex++]);
1870 /// CheckNodePredicate - Implements OP_CheckNodePredicate.
1871 LLVM_ATTRIBUTE_ALWAYS_INLINE static bool
1872 CheckNodePredicate(const unsigned char *MatcherTable, unsigned &MatcherIndex,
1873 SelectionDAGISel &SDISel, SDNode *N) {
1874 return SDISel.CheckNodePredicate(N, MatcherTable[MatcherIndex++]);
1877 LLVM_ATTRIBUTE_ALWAYS_INLINE static bool
1878 CheckOpcode(const unsigned char *MatcherTable, unsigned &MatcherIndex,
1880 uint16_t Opc = MatcherTable[MatcherIndex++];
1881 Opc |= (unsigned short)MatcherTable[MatcherIndex++] << 8;
1882 return N->getOpcode() == Opc;
1885 LLVM_ATTRIBUTE_ALWAYS_INLINE static bool
1886 CheckType(const unsigned char *MatcherTable, unsigned &MatcherIndex,
1887 SDValue N, const TargetLowering &TLI) {
1888 MVT::SimpleValueType VT = (MVT::SimpleValueType)MatcherTable[MatcherIndex++];
1889 if (N.getValueType() == VT) return true;
1891 // Handle the case when VT is iPTR.
1892 return VT == MVT::iPTR && N.getValueType() == TLI.getPointerTy();
1895 LLVM_ATTRIBUTE_ALWAYS_INLINE static bool
1896 CheckChildType(const unsigned char *MatcherTable, unsigned &MatcherIndex,
1897 SDValue N, const TargetLowering &TLI,
1899 if (ChildNo >= N.getNumOperands())
1900 return false; // Match fails if out of range child #.
1901 return ::CheckType(MatcherTable, MatcherIndex, N.getOperand(ChildNo), TLI);
1905 LLVM_ATTRIBUTE_ALWAYS_INLINE static bool
1906 CheckCondCode(const unsigned char *MatcherTable, unsigned &MatcherIndex,
1908 return cast<CondCodeSDNode>(N)->get() ==
1909 (ISD::CondCode)MatcherTable[MatcherIndex++];
1912 LLVM_ATTRIBUTE_ALWAYS_INLINE static bool
1913 CheckValueType(const unsigned char *MatcherTable, unsigned &MatcherIndex,
1914 SDValue N, const TargetLowering &TLI) {
1915 MVT::SimpleValueType VT = (MVT::SimpleValueType)MatcherTable[MatcherIndex++];
1916 if (cast<VTSDNode>(N)->getVT() == VT)
1919 // Handle the case when VT is iPTR.
1920 return VT == MVT::iPTR && cast<VTSDNode>(N)->getVT() == TLI.getPointerTy();
1923 LLVM_ATTRIBUTE_ALWAYS_INLINE static bool
1924 CheckInteger(const unsigned char *MatcherTable, unsigned &MatcherIndex,
1926 int64_t Val = MatcherTable[MatcherIndex++];
1928 Val = GetVBR(Val, MatcherTable, MatcherIndex);
1930 ConstantSDNode *C = dyn_cast<ConstantSDNode>(N);
1931 return C != 0 && C->getSExtValue() == Val;
1934 LLVM_ATTRIBUTE_ALWAYS_INLINE static bool
1935 CheckAndImm(const unsigned char *MatcherTable, unsigned &MatcherIndex,
1936 SDValue N, SelectionDAGISel &SDISel) {
1937 int64_t Val = MatcherTable[MatcherIndex++];
1939 Val = GetVBR(Val, MatcherTable, MatcherIndex);
1941 if (N->getOpcode() != ISD::AND) return false;
1943 ConstantSDNode *C = dyn_cast<ConstantSDNode>(N->getOperand(1));
1944 return C != 0 && SDISel.CheckAndMask(N.getOperand(0), C, Val);
1947 LLVM_ATTRIBUTE_ALWAYS_INLINE static bool
1948 CheckOrImm(const unsigned char *MatcherTable, unsigned &MatcherIndex,
1949 SDValue N, SelectionDAGISel &SDISel) {
1950 int64_t Val = MatcherTable[MatcherIndex++];
1952 Val = GetVBR(Val, MatcherTable, MatcherIndex);
1954 if (N->getOpcode() != ISD::OR) return false;
1956 ConstantSDNode *C = dyn_cast<ConstantSDNode>(N->getOperand(1));
1957 return C != 0 && SDISel.CheckOrMask(N.getOperand(0), C, Val);
1960 /// IsPredicateKnownToFail - If we know how and can do so without pushing a
1961 /// scope, evaluate the current node. If the current predicate is known to
1962 /// fail, set Result=true and return anything. If the current predicate is
1963 /// known to pass, set Result=false and return the MatcherIndex to continue
1964 /// with. If the current predicate is unknown, set Result=false and return the
1965 /// MatcherIndex to continue with.
1966 static unsigned IsPredicateKnownToFail(const unsigned char *Table,
1967 unsigned Index, SDValue N,
1968 bool &Result, SelectionDAGISel &SDISel,
1969 SmallVectorImpl<std::pair<SDValue, SDNode*> > &RecordedNodes) {
1970 switch (Table[Index++]) {
1973 return Index-1; // Could not evaluate this predicate.
1974 case SelectionDAGISel::OPC_CheckSame:
1975 Result = !::CheckSame(Table, Index, N, RecordedNodes);
1977 case SelectionDAGISel::OPC_CheckPatternPredicate:
1978 Result = !::CheckPatternPredicate(Table, Index, SDISel);
1980 case SelectionDAGISel::OPC_CheckPredicate:
1981 Result = !::CheckNodePredicate(Table, Index, SDISel, N.getNode());
1983 case SelectionDAGISel::OPC_CheckOpcode:
1984 Result = !::CheckOpcode(Table, Index, N.getNode());
1986 case SelectionDAGISel::OPC_CheckType:
1987 Result = !::CheckType(Table, Index, N, SDISel.TLI);
1989 case SelectionDAGISel::OPC_CheckChild0Type:
1990 case SelectionDAGISel::OPC_CheckChild1Type:
1991 case SelectionDAGISel::OPC_CheckChild2Type:
1992 case SelectionDAGISel::OPC_CheckChild3Type:
1993 case SelectionDAGISel::OPC_CheckChild4Type:
1994 case SelectionDAGISel::OPC_CheckChild5Type:
1995 case SelectionDAGISel::OPC_CheckChild6Type:
1996 case SelectionDAGISel::OPC_CheckChild7Type:
1997 Result = !::CheckChildType(Table, Index, N, SDISel.TLI,
1998 Table[Index-1] - SelectionDAGISel::OPC_CheckChild0Type);
2000 case SelectionDAGISel::OPC_CheckCondCode:
2001 Result = !::CheckCondCode(Table, Index, N);
2003 case SelectionDAGISel::OPC_CheckValueType:
2004 Result = !::CheckValueType(Table, Index, N, SDISel.TLI);
2006 case SelectionDAGISel::OPC_CheckInteger:
2007 Result = !::CheckInteger(Table, Index, N);
2009 case SelectionDAGISel::OPC_CheckAndImm:
2010 Result = !::CheckAndImm(Table, Index, N, SDISel);
2012 case SelectionDAGISel::OPC_CheckOrImm:
2013 Result = !::CheckOrImm(Table, Index, N, SDISel);
2021 /// FailIndex - If this match fails, this is the index to continue with.
2024 /// NodeStack - The node stack when the scope was formed.
2025 SmallVector<SDValue, 4> NodeStack;
2027 /// NumRecordedNodes - The number of recorded nodes when the scope was formed.
2028 unsigned NumRecordedNodes;
2030 /// NumMatchedMemRefs - The number of matched memref entries.
2031 unsigned NumMatchedMemRefs;
2033 /// InputChain/InputGlue - The current chain/glue
2034 SDValue InputChain, InputGlue;
2036 /// HasChainNodesMatched - True if the ChainNodesMatched list is non-empty.
2037 bool HasChainNodesMatched, HasGlueResultNodesMatched;
2042 SDNode *SelectionDAGISel::
2043 SelectCodeCommon(SDNode *NodeToMatch, const unsigned char *MatcherTable,
2044 unsigned TableSize) {
2045 // FIXME: Should these even be selected? Handle these cases in the caller?
2046 switch (NodeToMatch->getOpcode()) {
2049 case ISD::EntryToken: // These nodes remain the same.
2050 case ISD::BasicBlock:
2052 //case ISD::VALUETYPE:
2053 //case ISD::CONDCODE:
2054 case ISD::HANDLENODE:
2055 case ISD::MDNODE_SDNODE:
2056 case ISD::TargetConstant:
2057 case ISD::TargetConstantFP:
2058 case ISD::TargetConstantPool:
2059 case ISD::TargetFrameIndex:
2060 case ISD::TargetExternalSymbol:
2061 case ISD::TargetBlockAddress:
2062 case ISD::TargetJumpTable:
2063 case ISD::TargetGlobalTLSAddress:
2064 case ISD::TargetGlobalAddress:
2065 case ISD::TokenFactor:
2066 case ISD::CopyFromReg:
2067 case ISD::CopyToReg:
2069 NodeToMatch->setNodeId(-1); // Mark selected.
2071 case ISD::AssertSext:
2072 case ISD::AssertZext:
2073 CurDAG->ReplaceAllUsesOfValueWith(SDValue(NodeToMatch, 0),
2074 NodeToMatch->getOperand(0));
2076 case ISD::INLINEASM: return Select_INLINEASM(NodeToMatch);
2077 case ISD::UNDEF: return Select_UNDEF(NodeToMatch);
2080 assert(!NodeToMatch->isMachineOpcode() && "Node already selected!");
2082 // Set up the node stack with NodeToMatch as the only node on the stack.
2083 SmallVector<SDValue, 8> NodeStack;
2084 SDValue N = SDValue(NodeToMatch, 0);
2085 NodeStack.push_back(N);
2087 // MatchScopes - Scopes used when matching, if a match failure happens, this
2088 // indicates where to continue checking.
2089 SmallVector<MatchScope, 8> MatchScopes;
2091 // RecordedNodes - This is the set of nodes that have been recorded by the
2092 // state machine. The second value is the parent of the node, or null if the
2093 // root is recorded.
2094 SmallVector<std::pair<SDValue, SDNode*>, 8> RecordedNodes;
2096 // MatchedMemRefs - This is the set of MemRef's we've seen in the input
2098 SmallVector<MachineMemOperand*, 2> MatchedMemRefs;
2100 // These are the current input chain and glue for use when generating nodes.
2101 // Various Emit operations change these. For example, emitting a copytoreg
2102 // uses and updates these.
2103 SDValue InputChain, InputGlue;
2105 // ChainNodesMatched - If a pattern matches nodes that have input/output
2106 // chains, the OPC_EmitMergeInputChains operation is emitted which indicates
2107 // which ones they are. The result is captured into this list so that we can
2108 // update the chain results when the pattern is complete.
2109 SmallVector<SDNode*, 3> ChainNodesMatched;
2110 SmallVector<SDNode*, 3> GlueResultNodesMatched;
2112 DEBUG(errs() << "ISEL: Starting pattern match on root node: ";
2113 NodeToMatch->dump(CurDAG);
2116 // Determine where to start the interpreter. Normally we start at opcode #0,
2117 // but if the state machine starts with an OPC_SwitchOpcode, then we
2118 // accelerate the first lookup (which is guaranteed to be hot) with the
2119 // OpcodeOffset table.
2120 unsigned MatcherIndex = 0;
2122 if (!OpcodeOffset.empty()) {
2123 // Already computed the OpcodeOffset table, just index into it.
2124 if (N.getOpcode() < OpcodeOffset.size())
2125 MatcherIndex = OpcodeOffset[N.getOpcode()];
2126 DEBUG(errs() << " Initial Opcode index to " << MatcherIndex << "\n");
2128 } else if (MatcherTable[0] == OPC_SwitchOpcode) {
2129 // Otherwise, the table isn't computed, but the state machine does start
2130 // with an OPC_SwitchOpcode instruction. Populate the table now, since this
2131 // is the first time we're selecting an instruction.
2134 // Get the size of this case.
2135 unsigned CaseSize = MatcherTable[Idx++];
2137 CaseSize = GetVBR(CaseSize, MatcherTable, Idx);
2138 if (CaseSize == 0) break;
2140 // Get the opcode, add the index to the table.
2141 uint16_t Opc = MatcherTable[Idx++];
2142 Opc |= (unsigned short)MatcherTable[Idx++] << 8;
2143 if (Opc >= OpcodeOffset.size())
2144 OpcodeOffset.resize((Opc+1)*2);
2145 OpcodeOffset[Opc] = Idx;
2149 // Okay, do the lookup for the first opcode.
2150 if (N.getOpcode() < OpcodeOffset.size())
2151 MatcherIndex = OpcodeOffset[N.getOpcode()];
2155 assert(MatcherIndex < TableSize && "Invalid index");
2157 unsigned CurrentOpcodeIndex = MatcherIndex;
2159 BuiltinOpcodes Opcode = (BuiltinOpcodes)MatcherTable[MatcherIndex++];
2162 // Okay, the semantics of this operation are that we should push a scope
2163 // then evaluate the first child. However, pushing a scope only to have
2164 // the first check fail (which then pops it) is inefficient. If we can
2165 // determine immediately that the first check (or first several) will
2166 // immediately fail, don't even bother pushing a scope for them.
2170 unsigned NumToSkip = MatcherTable[MatcherIndex++];
2171 if (NumToSkip & 128)
2172 NumToSkip = GetVBR(NumToSkip, MatcherTable, MatcherIndex);
2173 // Found the end of the scope with no match.
2174 if (NumToSkip == 0) {
2179 FailIndex = MatcherIndex+NumToSkip;
2181 unsigned MatcherIndexOfPredicate = MatcherIndex;
2182 (void)MatcherIndexOfPredicate; // silence warning.
2184 // If we can't evaluate this predicate without pushing a scope (e.g. if
2185 // it is a 'MoveParent') or if the predicate succeeds on this node, we
2186 // push the scope and evaluate the full predicate chain.
2188 MatcherIndex = IsPredicateKnownToFail(MatcherTable, MatcherIndex, N,
2189 Result, *this, RecordedNodes);
2193 DEBUG(errs() << " Skipped scope entry (due to false predicate) at "
2194 << "index " << MatcherIndexOfPredicate
2195 << ", continuing at " << FailIndex << "\n");
2196 ++NumDAGIselRetries;
2198 // Otherwise, we know that this case of the Scope is guaranteed to fail,
2199 // move to the next case.
2200 MatcherIndex = FailIndex;
2203 // If the whole scope failed to match, bail.
2204 if (FailIndex == 0) break;
2206 // Push a MatchScope which indicates where to go if the first child fails
2208 MatchScope NewEntry;
2209 NewEntry.FailIndex = FailIndex;
2210 NewEntry.NodeStack.append(NodeStack.begin(), NodeStack.end());
2211 NewEntry.NumRecordedNodes = RecordedNodes.size();
2212 NewEntry.NumMatchedMemRefs = MatchedMemRefs.size();
2213 NewEntry.InputChain = InputChain;
2214 NewEntry.InputGlue = InputGlue;
2215 NewEntry.HasChainNodesMatched = !ChainNodesMatched.empty();
2216 NewEntry.HasGlueResultNodesMatched = !GlueResultNodesMatched.empty();
2217 MatchScopes.push_back(NewEntry);
2220 case OPC_RecordNode: {
2221 // Remember this node, it may end up being an operand in the pattern.
2223 if (NodeStack.size() > 1)
2224 Parent = NodeStack[NodeStack.size()-2].getNode();
2225 RecordedNodes.push_back(std::make_pair(N, Parent));
2229 case OPC_RecordChild0: case OPC_RecordChild1:
2230 case OPC_RecordChild2: case OPC_RecordChild3:
2231 case OPC_RecordChild4: case OPC_RecordChild5:
2232 case OPC_RecordChild6: case OPC_RecordChild7: {
2233 unsigned ChildNo = Opcode-OPC_RecordChild0;
2234 if (ChildNo >= N.getNumOperands())
2235 break; // Match fails if out of range child #.
2237 RecordedNodes.push_back(std::make_pair(N->getOperand(ChildNo),
2241 case OPC_RecordMemRef:
2242 MatchedMemRefs.push_back(cast<MemSDNode>(N)->getMemOperand());
2245 case OPC_CaptureGlueInput:
2246 // If the current node has an input glue, capture it in InputGlue.
2247 if (N->getNumOperands() != 0 &&
2248 N->getOperand(N->getNumOperands()-1).getValueType() == MVT::Glue)
2249 InputGlue = N->getOperand(N->getNumOperands()-1);
2252 case OPC_MoveChild: {
2253 unsigned ChildNo = MatcherTable[MatcherIndex++];
2254 if (ChildNo >= N.getNumOperands())
2255 break; // Match fails if out of range child #.
2256 N = N.getOperand(ChildNo);
2257 NodeStack.push_back(N);
2261 case OPC_MoveParent:
2262 // Pop the current node off the NodeStack.
2263 NodeStack.pop_back();
2264 assert(!NodeStack.empty() && "Node stack imbalance!");
2265 N = NodeStack.back();
2269 if (!::CheckSame(MatcherTable, MatcherIndex, N, RecordedNodes)) break;
2271 case OPC_CheckPatternPredicate:
2272 if (!::CheckPatternPredicate(MatcherTable, MatcherIndex, *this)) break;
2274 case OPC_CheckPredicate:
2275 if (!::CheckNodePredicate(MatcherTable, MatcherIndex, *this,
2279 case OPC_CheckComplexPat: {
2280 unsigned CPNum = MatcherTable[MatcherIndex++];
2281 unsigned RecNo = MatcherTable[MatcherIndex++];
2282 assert(RecNo < RecordedNodes.size() && "Invalid CheckComplexPat");
2283 if (!CheckComplexPattern(NodeToMatch, RecordedNodes[RecNo].second,
2284 RecordedNodes[RecNo].first, CPNum,
2289 case OPC_CheckOpcode:
2290 if (!::CheckOpcode(MatcherTable, MatcherIndex, N.getNode())) break;
2294 if (!::CheckType(MatcherTable, MatcherIndex, N, TLI)) break;
2297 case OPC_SwitchOpcode: {
2298 unsigned CurNodeOpcode = N.getOpcode();
2299 unsigned SwitchStart = MatcherIndex-1; (void)SwitchStart;
2302 // Get the size of this case.
2303 CaseSize = MatcherTable[MatcherIndex++];
2305 CaseSize = GetVBR(CaseSize, MatcherTable, MatcherIndex);
2306 if (CaseSize == 0) break;
2308 uint16_t Opc = MatcherTable[MatcherIndex++];
2309 Opc |= (unsigned short)MatcherTable[MatcherIndex++] << 8;
2311 // If the opcode matches, then we will execute this case.
2312 if (CurNodeOpcode == Opc)
2315 // Otherwise, skip over this case.
2316 MatcherIndex += CaseSize;
2319 // If no cases matched, bail out.
2320 if (CaseSize == 0) break;
2322 // Otherwise, execute the case we found.
2323 DEBUG(errs() << " OpcodeSwitch from " << SwitchStart
2324 << " to " << MatcherIndex << "\n");
2328 case OPC_SwitchType: {
2329 MVT CurNodeVT = N.getValueType().getSimpleVT();
2330 unsigned SwitchStart = MatcherIndex-1; (void)SwitchStart;
2333 // Get the size of this case.
2334 CaseSize = MatcherTable[MatcherIndex++];
2336 CaseSize = GetVBR(CaseSize, MatcherTable, MatcherIndex);
2337 if (CaseSize == 0) break;
2339 MVT CaseVT = (MVT::SimpleValueType)MatcherTable[MatcherIndex++];
2340 if (CaseVT == MVT::iPTR)
2341 CaseVT = TLI.getPointerTy();
2343 // If the VT matches, then we will execute this case.
2344 if (CurNodeVT == CaseVT)
2347 // Otherwise, skip over this case.
2348 MatcherIndex += CaseSize;
2351 // If no cases matched, bail out.
2352 if (CaseSize == 0) break;
2354 // Otherwise, execute the case we found.
2355 DEBUG(errs() << " TypeSwitch[" << EVT(CurNodeVT).getEVTString()
2356 << "] from " << SwitchStart << " to " << MatcherIndex<<'\n');
2359 case OPC_CheckChild0Type: case OPC_CheckChild1Type:
2360 case OPC_CheckChild2Type: case OPC_CheckChild3Type:
2361 case OPC_CheckChild4Type: case OPC_CheckChild5Type:
2362 case OPC_CheckChild6Type: case OPC_CheckChild7Type:
2363 if (!::CheckChildType(MatcherTable, MatcherIndex, N, TLI,
2364 Opcode-OPC_CheckChild0Type))
2367 case OPC_CheckCondCode:
2368 if (!::CheckCondCode(MatcherTable, MatcherIndex, N)) break;
2370 case OPC_CheckValueType:
2371 if (!::CheckValueType(MatcherTable, MatcherIndex, N, TLI)) break;
2373 case OPC_CheckInteger:
2374 if (!::CheckInteger(MatcherTable, MatcherIndex, N)) break;
2376 case OPC_CheckAndImm:
2377 if (!::CheckAndImm(MatcherTable, MatcherIndex, N, *this)) break;
2379 case OPC_CheckOrImm:
2380 if (!::CheckOrImm(MatcherTable, MatcherIndex, N, *this)) break;
2383 case OPC_CheckFoldableChainNode: {
2384 assert(NodeStack.size() != 1 && "No parent node");
2385 // Verify that all intermediate nodes between the root and this one have
2387 bool HasMultipleUses = false;
2388 for (unsigned i = 1, e = NodeStack.size()-1; i != e; ++i)
2389 if (!NodeStack[i].hasOneUse()) {
2390 HasMultipleUses = true;
2393 if (HasMultipleUses) break;
2395 // Check to see that the target thinks this is profitable to fold and that
2396 // we can fold it without inducing cycles in the graph.
2397 if (!IsProfitableToFold(N, NodeStack[NodeStack.size()-2].getNode(),
2399 !IsLegalToFold(N, NodeStack[NodeStack.size()-2].getNode(),
2400 NodeToMatch, OptLevel,
2401 true/*We validate our own chains*/))
2406 case OPC_EmitInteger: {
2407 MVT::SimpleValueType VT =
2408 (MVT::SimpleValueType)MatcherTable[MatcherIndex++];
2409 int64_t Val = MatcherTable[MatcherIndex++];
2411 Val = GetVBR(Val, MatcherTable, MatcherIndex);
2412 RecordedNodes.push_back(std::pair<SDValue, SDNode*>(
2413 CurDAG->getTargetConstant(Val, VT), (SDNode*)0));
2416 case OPC_EmitRegister: {
2417 MVT::SimpleValueType VT =
2418 (MVT::SimpleValueType)MatcherTable[MatcherIndex++];
2419 unsigned RegNo = MatcherTable[MatcherIndex++];
2420 RecordedNodes.push_back(std::pair<SDValue, SDNode*>(
2421 CurDAG->getRegister(RegNo, VT), (SDNode*)0));
2424 case OPC_EmitRegister2: {
2425 // For targets w/ more than 256 register names, the register enum
2426 // values are stored in two bytes in the matcher table (just like
2428 MVT::SimpleValueType VT =
2429 (MVT::SimpleValueType)MatcherTable[MatcherIndex++];
2430 unsigned RegNo = MatcherTable[MatcherIndex++];
2431 RegNo |= MatcherTable[MatcherIndex++] << 8;
2432 RecordedNodes.push_back(std::pair<SDValue, SDNode*>(
2433 CurDAG->getRegister(RegNo, VT), (SDNode*)0));
2437 case OPC_EmitConvertToTarget: {
2438 // Convert from IMM/FPIMM to target version.
2439 unsigned RecNo = MatcherTable[MatcherIndex++];
2440 assert(RecNo < RecordedNodes.size() && "Invalid CheckSame");
2441 SDValue Imm = RecordedNodes[RecNo].first;
2443 if (Imm->getOpcode() == ISD::Constant) {
2444 int64_t Val = cast<ConstantSDNode>(Imm)->getZExtValue();
2445 Imm = CurDAG->getTargetConstant(Val, Imm.getValueType());
2446 } else if (Imm->getOpcode() == ISD::ConstantFP) {
2447 const ConstantFP *Val=cast<ConstantFPSDNode>(Imm)->getConstantFPValue();
2448 Imm = CurDAG->getTargetConstantFP(*Val, Imm.getValueType());
2451 RecordedNodes.push_back(std::make_pair(Imm, RecordedNodes[RecNo].second));
2455 case OPC_EmitMergeInputChains1_0: // OPC_EmitMergeInputChains, 1, 0
2456 case OPC_EmitMergeInputChains1_1: { // OPC_EmitMergeInputChains, 1, 1
2457 // These are space-optimized forms of OPC_EmitMergeInputChains.
2458 assert(InputChain.getNode() == 0 &&
2459 "EmitMergeInputChains should be the first chain producing node");
2460 assert(ChainNodesMatched.empty() &&
2461 "Should only have one EmitMergeInputChains per match");
2463 // Read all of the chained nodes.
2464 unsigned RecNo = Opcode == OPC_EmitMergeInputChains1_1;
2465 assert(RecNo < RecordedNodes.size() && "Invalid CheckSame");
2466 ChainNodesMatched.push_back(RecordedNodes[RecNo].first.getNode());
2468 // FIXME: What if other value results of the node have uses not matched
2470 if (ChainNodesMatched.back() != NodeToMatch &&
2471 !RecordedNodes[RecNo].first.hasOneUse()) {
2472 ChainNodesMatched.clear();
2476 // Merge the input chains if they are not intra-pattern references.
2477 InputChain = HandleMergeInputChains(ChainNodesMatched, CurDAG);
2479 if (InputChain.getNode() == 0)
2480 break; // Failed to merge.
2484 case OPC_EmitMergeInputChains: {
2485 assert(InputChain.getNode() == 0 &&
2486 "EmitMergeInputChains should be the first chain producing node");
2487 // This node gets a list of nodes we matched in the input that have
2488 // chains. We want to token factor all of the input chains to these nodes
2489 // together. However, if any of the input chains is actually one of the
2490 // nodes matched in this pattern, then we have an intra-match reference.
2491 // Ignore these because the newly token factored chain should not refer to
2493 unsigned NumChains = MatcherTable[MatcherIndex++];
2494 assert(NumChains != 0 && "Can't TF zero chains");
2496 assert(ChainNodesMatched.empty() &&
2497 "Should only have one EmitMergeInputChains per match");
2499 // Read all of the chained nodes.
2500 for (unsigned i = 0; i != NumChains; ++i) {
2501 unsigned RecNo = MatcherTable[MatcherIndex++];
2502 assert(RecNo < RecordedNodes.size() && "Invalid CheckSame");
2503 ChainNodesMatched.push_back(RecordedNodes[RecNo].first.getNode());
2505 // FIXME: What if other value results of the node have uses not matched
2507 if (ChainNodesMatched.back() != NodeToMatch &&
2508 !RecordedNodes[RecNo].first.hasOneUse()) {
2509 ChainNodesMatched.clear();
2514 // If the inner loop broke out, the match fails.
2515 if (ChainNodesMatched.empty())
2518 // Merge the input chains if they are not intra-pattern references.
2519 InputChain = HandleMergeInputChains(ChainNodesMatched, CurDAG);
2521 if (InputChain.getNode() == 0)
2522 break; // Failed to merge.
2527 case OPC_EmitCopyToReg: {
2528 unsigned RecNo = MatcherTable[MatcherIndex++];
2529 assert(RecNo < RecordedNodes.size() && "Invalid CheckSame");
2530 unsigned DestPhysReg = MatcherTable[MatcherIndex++];
2532 if (InputChain.getNode() == 0)
2533 InputChain = CurDAG->getEntryNode();
2535 InputChain = CurDAG->getCopyToReg(InputChain, NodeToMatch->getDebugLoc(),
2536 DestPhysReg, RecordedNodes[RecNo].first,
2539 InputGlue = InputChain.getValue(1);
2543 case OPC_EmitNodeXForm: {
2544 unsigned XFormNo = MatcherTable[MatcherIndex++];
2545 unsigned RecNo = MatcherTable[MatcherIndex++];
2546 assert(RecNo < RecordedNodes.size() && "Invalid CheckSame");
2547 SDValue Res = RunSDNodeXForm(RecordedNodes[RecNo].first, XFormNo);
2548 RecordedNodes.push_back(std::pair<SDValue,SDNode*>(Res, (SDNode*) 0));
2553 case OPC_MorphNodeTo: {
2554 uint16_t TargetOpc = MatcherTable[MatcherIndex++];
2555 TargetOpc |= (unsigned short)MatcherTable[MatcherIndex++] << 8;
2556 unsigned EmitNodeInfo = MatcherTable[MatcherIndex++];
2557 // Get the result VT list.
2558 unsigned NumVTs = MatcherTable[MatcherIndex++];
2559 SmallVector<EVT, 4> VTs;
2560 for (unsigned i = 0; i != NumVTs; ++i) {
2561 MVT::SimpleValueType VT =
2562 (MVT::SimpleValueType)MatcherTable[MatcherIndex++];
2563 if (VT == MVT::iPTR) VT = TLI.getPointerTy().SimpleTy;
2567 if (EmitNodeInfo & OPFL_Chain)
2568 VTs.push_back(MVT::Other);
2569 if (EmitNodeInfo & OPFL_GlueOutput)
2570 VTs.push_back(MVT::Glue);
2572 // This is hot code, so optimize the two most common cases of 1 and 2
2575 if (VTs.size() == 1)
2576 VTList = CurDAG->getVTList(VTs[0]);
2577 else if (VTs.size() == 2)
2578 VTList = CurDAG->getVTList(VTs[0], VTs[1]);
2580 VTList = CurDAG->getVTList(VTs.data(), VTs.size());
2582 // Get the operand list.
2583 unsigned NumOps = MatcherTable[MatcherIndex++];
2584 SmallVector<SDValue, 8> Ops;
2585 for (unsigned i = 0; i != NumOps; ++i) {
2586 unsigned RecNo = MatcherTable[MatcherIndex++];
2588 RecNo = GetVBR(RecNo, MatcherTable, MatcherIndex);
2590 assert(RecNo < RecordedNodes.size() && "Invalid EmitNode");
2591 Ops.push_back(RecordedNodes[RecNo].first);
2594 // If there are variadic operands to add, handle them now.
2595 if (EmitNodeInfo & OPFL_VariadicInfo) {
2596 // Determine the start index to copy from.
2597 unsigned FirstOpToCopy = getNumFixedFromVariadicInfo(EmitNodeInfo);
2598 FirstOpToCopy += (EmitNodeInfo & OPFL_Chain) ? 1 : 0;
2599 assert(NodeToMatch->getNumOperands() >= FirstOpToCopy &&
2600 "Invalid variadic node");
2601 // Copy all of the variadic operands, not including a potential glue
2603 for (unsigned i = FirstOpToCopy, e = NodeToMatch->getNumOperands();
2605 SDValue V = NodeToMatch->getOperand(i);
2606 if (V.getValueType() == MVT::Glue) break;
2611 // If this has chain/glue inputs, add them.
2612 if (EmitNodeInfo & OPFL_Chain)
2613 Ops.push_back(InputChain);
2614 if ((EmitNodeInfo & OPFL_GlueInput) && InputGlue.getNode() != 0)
2615 Ops.push_back(InputGlue);
2619 if (Opcode != OPC_MorphNodeTo) {
2620 // If this is a normal EmitNode command, just create the new node and
2621 // add the results to the RecordedNodes list.
2622 Res = CurDAG->getMachineNode(TargetOpc, NodeToMatch->getDebugLoc(),
2623 VTList, Ops.data(), Ops.size());
2625 // Add all the non-glue/non-chain results to the RecordedNodes list.
2626 for (unsigned i = 0, e = VTs.size(); i != e; ++i) {
2627 if (VTs[i] == MVT::Other || VTs[i] == MVT::Glue) break;
2628 RecordedNodes.push_back(std::pair<SDValue,SDNode*>(SDValue(Res, i),
2633 Res = MorphNode(NodeToMatch, TargetOpc, VTList, Ops.data(), Ops.size(),
2637 // If the node had chain/glue results, update our notion of the current
2639 if (EmitNodeInfo & OPFL_GlueOutput) {
2640 InputGlue = SDValue(Res, VTs.size()-1);
2641 if (EmitNodeInfo & OPFL_Chain)
2642 InputChain = SDValue(Res, VTs.size()-2);
2643 } else if (EmitNodeInfo & OPFL_Chain)
2644 InputChain = SDValue(Res, VTs.size()-1);
2646 // If the OPFL_MemRefs glue is set on this node, slap all of the
2647 // accumulated memrefs onto it.
2649 // FIXME: This is vastly incorrect for patterns with multiple outputs
2650 // instructions that access memory and for ComplexPatterns that match
2652 if (EmitNodeInfo & OPFL_MemRefs) {
2653 MachineSDNode::mmo_iterator MemRefs =
2654 MF->allocateMemRefsArray(MatchedMemRefs.size());
2655 std::copy(MatchedMemRefs.begin(), MatchedMemRefs.end(), MemRefs);
2656 cast<MachineSDNode>(Res)
2657 ->setMemRefs(MemRefs, MemRefs + MatchedMemRefs.size());
2661 << (Opcode == OPC_MorphNodeTo ? "Morphed" : "Created")
2662 << " node: "; Res->dump(CurDAG); errs() << "\n");
2664 // If this was a MorphNodeTo then we're completely done!
2665 if (Opcode == OPC_MorphNodeTo) {
2666 // Update chain and glue uses.
2667 UpdateChainsAndGlue(NodeToMatch, InputChain, ChainNodesMatched,
2668 InputGlue, GlueResultNodesMatched, true);
2675 case OPC_MarkGlueResults: {
2676 unsigned NumNodes = MatcherTable[MatcherIndex++];
2678 // Read and remember all the glue-result nodes.
2679 for (unsigned i = 0; i != NumNodes; ++i) {
2680 unsigned RecNo = MatcherTable[MatcherIndex++];
2682 RecNo = GetVBR(RecNo, MatcherTable, MatcherIndex);
2684 assert(RecNo < RecordedNodes.size() && "Invalid CheckSame");
2685 GlueResultNodesMatched.push_back(RecordedNodes[RecNo].first.getNode());
2690 case OPC_CompleteMatch: {
2691 // The match has been completed, and any new nodes (if any) have been
2692 // created. Patch up references to the matched dag to use the newly
2694 unsigned NumResults = MatcherTable[MatcherIndex++];
2696 for (unsigned i = 0; i != NumResults; ++i) {
2697 unsigned ResSlot = MatcherTable[MatcherIndex++];
2699 ResSlot = GetVBR(ResSlot, MatcherTable, MatcherIndex);
2701 assert(ResSlot < RecordedNodes.size() && "Invalid CheckSame");
2702 SDValue Res = RecordedNodes[ResSlot].first;
2704 assert(i < NodeToMatch->getNumValues() &&
2705 NodeToMatch->getValueType(i) != MVT::Other &&
2706 NodeToMatch->getValueType(i) != MVT::Glue &&
2707 "Invalid number of results to complete!");
2708 assert((NodeToMatch->getValueType(i) == Res.getValueType() ||
2709 NodeToMatch->getValueType(i) == MVT::iPTR ||
2710 Res.getValueType() == MVT::iPTR ||
2711 NodeToMatch->getValueType(i).getSizeInBits() ==
2712 Res.getValueType().getSizeInBits()) &&
2713 "invalid replacement");
2714 CurDAG->ReplaceAllUsesOfValueWith(SDValue(NodeToMatch, i), Res);
2717 // If the root node defines glue, add it to the glue nodes to update list.
2718 if (NodeToMatch->getValueType(NodeToMatch->getNumValues()-1) == MVT::Glue)
2719 GlueResultNodesMatched.push_back(NodeToMatch);
2721 // Update chain and glue uses.
2722 UpdateChainsAndGlue(NodeToMatch, InputChain, ChainNodesMatched,
2723 InputGlue, GlueResultNodesMatched, false);
2725 assert(NodeToMatch->use_empty() &&
2726 "Didn't replace all uses of the node?");
2728 // FIXME: We just return here, which interacts correctly with SelectRoot
2729 // above. We should fix this to not return an SDNode* anymore.
2734 // If the code reached this point, then the match failed. See if there is
2735 // another child to try in the current 'Scope', otherwise pop it until we
2736 // find a case to check.
2737 DEBUG(errs() << " Match failed at index " << CurrentOpcodeIndex << "\n");
2738 ++NumDAGIselRetries;
2740 if (MatchScopes.empty()) {
2741 CannotYetSelect(NodeToMatch);
2745 // Restore the interpreter state back to the point where the scope was
2747 MatchScope &LastScope = MatchScopes.back();
2748 RecordedNodes.resize(LastScope.NumRecordedNodes);
2750 NodeStack.append(LastScope.NodeStack.begin(), LastScope.NodeStack.end());
2751 N = NodeStack.back();
2753 if (LastScope.NumMatchedMemRefs != MatchedMemRefs.size())
2754 MatchedMemRefs.resize(LastScope.NumMatchedMemRefs);
2755 MatcherIndex = LastScope.FailIndex;
2757 DEBUG(errs() << " Continuing at " << MatcherIndex << "\n");
2759 InputChain = LastScope.InputChain;
2760 InputGlue = LastScope.InputGlue;
2761 if (!LastScope.HasChainNodesMatched)
2762 ChainNodesMatched.clear();
2763 if (!LastScope.HasGlueResultNodesMatched)
2764 GlueResultNodesMatched.clear();
2766 // Check to see what the offset is at the new MatcherIndex. If it is zero
2767 // we have reached the end of this scope, otherwise we have another child
2768 // in the current scope to try.
2769 unsigned NumToSkip = MatcherTable[MatcherIndex++];
2770 if (NumToSkip & 128)
2771 NumToSkip = GetVBR(NumToSkip, MatcherTable, MatcherIndex);
2773 // If we have another child in this scope to match, update FailIndex and
2775 if (NumToSkip != 0) {
2776 LastScope.FailIndex = MatcherIndex+NumToSkip;
2780 // End of this scope, pop it and try the next child in the containing
2782 MatchScopes.pop_back();
2789 void SelectionDAGISel::CannotYetSelect(SDNode *N) {
2791 raw_string_ostream Msg(msg);
2792 Msg << "Cannot select: ";
2794 if (N->getOpcode() != ISD::INTRINSIC_W_CHAIN &&
2795 N->getOpcode() != ISD::INTRINSIC_WO_CHAIN &&
2796 N->getOpcode() != ISD::INTRINSIC_VOID) {
2797 N->printrFull(Msg, CurDAG);
2799 bool HasInputChain = N->getOperand(0).getValueType() == MVT::Other;
2801 cast<ConstantSDNode>(N->getOperand(HasInputChain))->getZExtValue();
2802 if (iid < Intrinsic::num_intrinsics)
2803 Msg << "intrinsic %" << Intrinsic::getName((Intrinsic::ID)iid);
2804 else if (const TargetIntrinsicInfo *TII = TM.getIntrinsicInfo())
2805 Msg << "target intrinsic %" << TII->getName(iid);
2807 Msg << "unknown intrinsic #" << iid;
2809 report_fatal_error(Msg.str());
2812 char SelectionDAGISel::ID = 0;