bool Inliner::runOnSCC(CallGraphSCC &SCC) { CallGraph &CG = getAnalysis<CallGraphWrapperPass>().getCallGraph(); AssumptionCacheTracker *ACT = &getAnalysis<AssumptionCacheTracker>(); auto *TLIP = getAnalysisIfAvailable<TargetLibraryInfoWrapperPass>(); const TargetLibraryInfo *TLI = TLIP ? &TLIP->getTLI() : nullptr; AliasAnalysis *AA = &getAnalysis<AliasAnalysis>(); SmallPtrSet<Function*, 8> SCCFunctions; DEBUG(dbgs() << "Inliner visiting SCC:"); for (CallGraphSCC::iterator I = SCC.begin(), E = SCC.end(); I != E; ++I) { Function *F = (*I)->getFunction(); if (F) SCCFunctions.insert(F); DEBUG(dbgs() << " " << (F ? F->getName() : "INDIRECTNODE")); } // Scan through and identify all call sites ahead of time so that we only // inline call sites in the original functions, not call sites that result // from inlining other functions. SmallVector<std::pair<CallSite, int>, 16> CallSites; // When inlining a callee produces new call sites, we want to keep track of // the fact that they were inlined from the callee. This allows us to avoid // infinite inlining in some obscure cases. To represent this, we use an // index into the InlineHistory vector. SmallVector<std::pair<Function*, int>, 8> InlineHistory; for (CallGraphSCC::iterator I = SCC.begin(), E = SCC.end(); I != E; ++I) { Function *F = (*I)->getFunction(); if (!F) continue; for (Function::iterator BB = F->begin(), E = F->end(); BB != E; ++BB) for (BasicBlock::iterator I = BB->begin(), E = BB->end(); I != E; ++I) { CallSite CS(cast<Value>(I)); // If this isn't a call, or it is a call to an intrinsic, it can // never be inlined. if (!CS || isa<IntrinsicInst>(I)) continue; // If this is a direct call to an external function, we can never inline // it. If it is an indirect call, inlining may resolve it to be a // direct call, so we keep it. if (CS.getCalledFunction() && CS.getCalledFunction()->isDeclaration()) continue; CallSites.push_back(std::make_pair(CS, -1)); } } DEBUG(dbgs() << ": " << CallSites.size() << " call sites.\n"); // If there are no calls in this function, exit early. if (CallSites.empty()) return false; // Now that we have all of the call sites, move the ones to functions in the // current SCC to the end of the list. unsigned FirstCallInSCC = CallSites.size(); for (unsigned i = 0; i < FirstCallInSCC; ++i) if (Function *F = CallSites[i].first.getCalledFunction()) if (SCCFunctions.count(F)) std::swap(CallSites[i--], CallSites[--FirstCallInSCC]); InlinedArrayAllocasTy InlinedArrayAllocas; InlineFunctionInfo InlineInfo(&CG, AA, ACT); // Now that we have all of the call sites, loop over them and inline them if // it looks profitable to do so. bool Changed = false; bool LocalChange; do { LocalChange = false; // Iterate over the outer loop because inlining functions can cause indirect // calls to become direct calls. for (unsigned CSi = 0; CSi != CallSites.size(); ++CSi) { CallSite CS = CallSites[CSi].first; Function *Caller = CS.getCaller(); Function *Callee = CS.getCalledFunction(); // If this call site is dead and it is to a readonly function, we should // just delete the call instead of trying to inline it, regardless of // size. This happens because IPSCCP propagates the result out of the // call and then we're left with the dead call. if (isInstructionTriviallyDead(CS.getInstruction(), TLI)) { DEBUG(dbgs() << " -> Deleting dead call: " << *CS.getInstruction() << "\n"); // Update the call graph by deleting the edge from Callee to Caller. CG[Caller]->removeCallEdgeFor(CS); CS.getInstruction()->eraseFromParent(); ++NumCallsDeleted; } else { // We can only inline direct calls to non-declarations. if (!Callee || Callee->isDeclaration()) continue; // If this call site was obtained by inlining another function, verify // that the include path for the function did not include the callee // itself. If so, we'd be recursively inlining the same function, // which would provide the same callsites, which would cause us to // infinitely inline. int InlineHistoryID = CallSites[CSi].second; if (InlineHistoryID != -1 && InlineHistoryIncludes(Callee, InlineHistoryID, InlineHistory)) continue; LLVMContext &CallerCtx = Caller->getContext(); // Get DebugLoc to report. CS will be invalid after Inliner. DebugLoc DLoc = CS.getInstruction()->getDebugLoc(); // If the policy determines that we should inline this function, // try to do so. if (!shouldInline(CS)) { emitOptimizationRemarkMissed(CallerCtx, DEBUG_TYPE, *Caller, DLoc, Twine(Callee->getName() + " will not be inlined into " + Caller->getName())); continue; } // Attempt to inline the function. if (!InlineCallIfPossible(CS, InlineInfo, InlinedArrayAllocas, InlineHistoryID, InsertLifetime)) { emitOptimizationRemarkMissed(CallerCtx, DEBUG_TYPE, *Caller, DLoc, Twine(Callee->getName() + " will not be inlined into " + Caller->getName())); continue; } ++NumInlined; // Report the inline decision. emitOptimizationRemark( CallerCtx, DEBUG_TYPE, *Caller, DLoc, Twine(Callee->getName() + " inlined into " + Caller->getName())); // If inlining this function gave us any new call sites, throw them // onto our worklist to process. They are useful inline candidates. if (!InlineInfo.InlinedCalls.empty()) { // Create a new inline history entry for this, so that we remember // that these new callsites came about due to inlining Callee. int NewHistoryID = InlineHistory.size(); InlineHistory.push_back(std::make_pair(Callee, InlineHistoryID)); for (unsigned i = 0, e = InlineInfo.InlinedCalls.size(); i != e; ++i) { Value *Ptr = InlineInfo.InlinedCalls[i]; CallSites.push_back(std::make_pair(CallSite(Ptr), NewHistoryID)); } } } // If we inlined or deleted the last possible call site to the function, // delete the function body now. if (Callee && Callee->use_empty() && Callee->hasLocalLinkage() && // TODO: Can remove if in SCC now. !SCCFunctions.count(Callee) && // The function may be apparently dead, but if there are indirect // callgraph references to the node, we cannot delete it yet, this // could invalidate the CGSCC iterator. CG[Callee]->getNumReferences() == 0) { DEBUG(dbgs() << " -> Deleting dead function: " << Callee->getName() << "\n"); CallGraphNode *CalleeNode = CG[Callee]; // Remove any call graph edges from the callee to its callees. CalleeNode->removeAllCalledFunctions(); // Removing the node for callee from the call graph and delete it. delete CG.removeFunctionFromModule(CalleeNode); ++NumDeleted; } // Remove this call site from the list. If possible, use // swap/pop_back for efficiency, but do not use it if doing so would // move a call site to a function in this SCC before the // 'FirstCallInSCC' barrier. if (SCC.isSingular()) { CallSites[CSi] = CallSites.back(); CallSites.pop_back(); } else { CallSites.erase(CallSites.begin()+CSi); } --CSi; Changed = true; LocalChange = true; } } while (LocalChange); return Changed; }
void WinEHNumbering::processCallSite(ArrayRef<ActionHandler *> Actions, ImmutableCallSite CS) { int FirstMismatch = 0; for (int E = std::min(HandlerStack.size(), Actions.size()); FirstMismatch < E; ++FirstMismatch) { if (HandlerStack[FirstMismatch]->getHandlerBlockOrFunc() != Actions[FirstMismatch]->getHandlerBlockOrFunc()) break; delete Actions[FirstMismatch]; } bool EnteringScope = (int)Actions.size() > FirstMismatch; // Don't recurse while we are looping over the handler stack. Instead, defer // the numbering of the catch handlers until we are done popping. SmallVector<CatchHandler *, 4> PoppedCatches; for (int I = HandlerStack.size() - 1; I >= FirstMismatch; --I) { if (auto *CH = dyn_cast<CatchHandler>(HandlerStack.back())) { PoppedCatches.push_back(CH); } else { // Delete cleanup handlers delete HandlerStack.back(); } HandlerStack.pop_back(); } // We need to create a new state number if we are exiting a try scope and we // will not push any more actions. int TryHigh = NextState - 1; if (!EnteringScope && !PoppedCatches.empty()) { createUnwindMapEntry(currentEHNumber(), nullptr); ++NextState; } int LastTryLowIdx = 0; for (int I = 0, E = PoppedCatches.size(); I != E; ++I) { CatchHandler *CH = PoppedCatches[I]; if (I + 1 == E || CH->getEHState() != PoppedCatches[I + 1]->getEHState()) { int TryLow = CH->getEHState(); auto Handlers = makeArrayRef(&PoppedCatches[LastTryLowIdx], I - LastTryLowIdx + 1); createTryBlockMapEntry(TryLow, TryHigh, Handlers); LastTryLowIdx = I + 1; } } for (CatchHandler *CH : PoppedCatches) { if (auto *F = dyn_cast<Function>(CH->getHandlerBlockOrFunc())) calculateStateNumbers(*F); delete CH; } bool LastActionWasCatch = false; for (size_t I = FirstMismatch; I != Actions.size(); ++I) { // We can reuse eh states when pushing two catches for the same invoke. bool CurrActionIsCatch = isa<CatchHandler>(Actions[I]); // FIXME: Reenable this optimization! if (CurrActionIsCatch && LastActionWasCatch && false) { Actions[I]->setEHState(currentEHNumber()); } else { createUnwindMapEntry(currentEHNumber(), Actions[I]); Actions[I]->setEHState(NextState); NextState++; DEBUG(dbgs() << "Creating unwind map entry for: ("); print_name(Actions[I]->getHandlerBlockOrFunc()); DEBUG(dbgs() << ", " << currentEHNumber() << ")\n"); } HandlerStack.push_back(Actions[I]); LastActionWasCatch = CurrActionIsCatch; } DEBUG(dbgs() << "In EHState " << currentEHNumber() << " for CallSite: "); print_name(CS ? CS.getCalledValue() : nullptr); DEBUG(dbgs() << '\n'); }
MachineBasicBlock * MachineBasicBlock::SplitCriticalEdge(MachineBasicBlock *Succ, Pass *P) { // Splitting the critical edge to a landing pad block is non-trivial. Don't do // it in this generic function. if (Succ->isLandingPad()) return NULL; MachineFunction *MF = getParent(); DebugLoc dl; // FIXME: this is nowhere // We may need to update this's terminator, but we can't do that if // AnalyzeBranch fails. If this uses a jump table, we won't touch it. const TargetInstrInfo *TII = MF->getTarget().getInstrInfo(); MachineBasicBlock *TBB = 0, *FBB = 0; SmallVector<MachineOperand, 4> Cond; if (TII->AnalyzeBranch(*this, TBB, FBB, Cond)) return NULL; // Avoid bugpoint weirdness: A block may end with a conditional branch but // jumps to the same MBB is either case. We have duplicate CFG edges in that // case that we can't handle. Since this never happens in properly optimized // code, just skip those edges. if (TBB && TBB == FBB) { DEBUG(dbgs() << "Won't split critical edge after degenerate BB#" << getNumber() << '\n'); return NULL; } MachineBasicBlock *NMBB = MF->CreateMachineBasicBlock(); MF->insert(llvm::next(MachineFunction::iterator(this)), NMBB); DEBUG(dbgs() << "Splitting critical edge:" " BB#" << getNumber() << " -- BB#" << NMBB->getNumber() << " -- BB#" << Succ->getNumber() << '\n'); // On some targets like Mips, branches may kill virtual registers. Make sure // that LiveVariables is properly updated after updateTerminator replaces the // terminators. LiveVariables *LV = P->getAnalysisIfAvailable<LiveVariables>(); // Collect a list of virtual registers killed by the terminators. SmallVector<unsigned, 4> KilledRegs; if (LV) for (instr_iterator I = getFirstInstrTerminator(), E = instr_end(); I != E; ++I) { MachineInstr *MI = I; for (MachineInstr::mop_iterator OI = MI->operands_begin(), OE = MI->operands_end(); OI != OE; ++OI) { if (!OI->isReg() || OI->getReg() == 0 || !OI->isUse() || !OI->isKill() || OI->isUndef()) continue; unsigned Reg = OI->getReg(); if (TargetRegisterInfo::isPhysicalRegister(Reg) || LV->getVarInfo(Reg).removeKill(MI)) { KilledRegs.push_back(Reg); DEBUG(dbgs() << "Removing terminator kill: " << *MI); OI->setIsKill(false); } } } ReplaceUsesOfBlockWith(Succ, NMBB); updateTerminator(); // Insert unconditional "jump Succ" instruction in NMBB if necessary. NMBB->addSuccessor(Succ); if (!NMBB->isLayoutSuccessor(Succ)) { Cond.clear(); MF->getTarget().getInstrInfo()->InsertBranch(*NMBB, Succ, NULL, Cond, dl); } // Fix PHI nodes in Succ so they refer to NMBB instead of this for (MachineBasicBlock::instr_iterator i = Succ->instr_begin(),e = Succ->instr_end(); i != e && i->isPHI(); ++i) for (unsigned ni = 1, ne = i->getNumOperands(); ni != ne; ni += 2) if (i->getOperand(ni+1).getMBB() == this) i->getOperand(ni+1).setMBB(NMBB); // Inherit live-ins from the successor for (MachineBasicBlock::livein_iterator I = Succ->livein_begin(), E = Succ->livein_end(); I != E; ++I) NMBB->addLiveIn(*I); // Update LiveVariables. const TargetRegisterInfo *TRI = MF->getTarget().getRegisterInfo(); if (LV) { // Restore kills of virtual registers that were killed by the terminators. while (!KilledRegs.empty()) { unsigned Reg = KilledRegs.pop_back_val(); for (instr_iterator I = instr_end(), E = instr_begin(); I != E;) { if (!(--I)->addRegisterKilled(Reg, TRI, /* addIfNotFound= */ false)) continue; if (TargetRegisterInfo::isVirtualRegister(Reg)) LV->getVarInfo(Reg).Kills.push_back(I); DEBUG(dbgs() << "Restored terminator kill: " << *I); break; } } // Update relevant live-through information. LV->addNewBlock(NMBB, this, Succ); } if (MachineDominatorTree *MDT = P->getAnalysisIfAvailable<MachineDominatorTree>()) { // Update dominator information. MachineDomTreeNode *SucccDTNode = MDT->getNode(Succ); bool IsNewIDom = true; for (const_pred_iterator PI = Succ->pred_begin(), E = Succ->pred_end(); PI != E; ++PI) { MachineBasicBlock *PredBB = *PI; if (PredBB == NMBB) continue; if (!MDT->dominates(SucccDTNode, MDT->getNode(PredBB))) { IsNewIDom = false; break; } } // We know "this" dominates the newly created basic block. MachineDomTreeNode *NewDTNode = MDT->addNewBlock(NMBB, this); // If all the other predecessors of "Succ" are dominated by "Succ" itself // then the new block is the new immediate dominator of "Succ". Otherwise, // the new block doesn't dominate anything. if (IsNewIDom) MDT->changeImmediateDominator(SucccDTNode, NewDTNode); } if (MachineLoopInfo *MLI = P->getAnalysisIfAvailable<MachineLoopInfo>()) if (MachineLoop *TIL = MLI->getLoopFor(this)) { // If one or the other blocks were not in a loop, the new block is not // either, and thus LI doesn't need to be updated. if (MachineLoop *DestLoop = MLI->getLoopFor(Succ)) { if (TIL == DestLoop) { // Both in the same loop, the NMBB joins loop. DestLoop->addBasicBlockToLoop(NMBB, MLI->getBase()); } else if (TIL->contains(DestLoop)) { // Edge from an outer loop to an inner loop. Add to the outer loop. TIL->addBasicBlockToLoop(NMBB, MLI->getBase()); } else if (DestLoop->contains(TIL)) { // Edge from an inner loop to an outer loop. Add to the outer loop. DestLoop->addBasicBlockToLoop(NMBB, MLI->getBase()); } else { // Edge from two loops with no containment relation. Because these // are natural loops, we know that the destination block must be the // header of its loop (adding a branch into a loop elsewhere would // create an irreducible loop). assert(DestLoop->getHeader() == Succ && "Should not create irreducible loops!"); if (MachineLoop *P = DestLoop->getParentLoop()) P->addBasicBlockToLoop(NMBB, MLI->getBase()); } } } return NMBB; }
void cl::ParseCommandLineOptions(int argc, char **argv, const char *Overview, bool ReadResponseFiles) { // Process all registered options. SmallVector<Option*, 4> PositionalOpts; SmallVector<Option*, 4> SinkOpts; StringMap<Option*> Opts; GetOptionInfo(PositionalOpts, SinkOpts, Opts); assert((!Opts.empty() || !PositionalOpts.empty()) && "No options specified!"); // Expand response files. std::vector<char*> newArgv; if (ReadResponseFiles) { newArgv.push_back(strdup(argv[0])); ExpandResponseFiles(argc, argv, newArgv); argv = &newArgv[0]; argc = static_cast<int>(newArgv.size()); } // Copy the program name into ProgName, making sure not to overflow it. std::string ProgName = sys::Path(argv[0]).getLast(); size_t Len = std::min(ProgName.size(), size_t(79)); memcpy(ProgramName, ProgName.data(), Len); ProgramName[Len] = '\0'; ProgramOverview = Overview; bool ErrorParsing = false; // Check out the positional arguments to collect information about them. unsigned NumPositionalRequired = 0; // Determine whether or not there are an unlimited number of positionals bool HasUnlimitedPositionals = false; Option *ConsumeAfterOpt = 0; if (!PositionalOpts.empty()) { if (PositionalOpts[0]->getNumOccurrencesFlag() == cl::ConsumeAfter) { assert(PositionalOpts.size() > 1 && "Cannot specify cl::ConsumeAfter without a positional argument!"); ConsumeAfterOpt = PositionalOpts[0]; } // Calculate how many positional values are _required_. bool UnboundedFound = false; for (size_t i = ConsumeAfterOpt != 0, e = PositionalOpts.size(); i != e; ++i) { Option *Opt = PositionalOpts[i]; if (RequiresValue(Opt)) ++NumPositionalRequired; else if (ConsumeAfterOpt) { // ConsumeAfter cannot be combined with "optional" positional options // unless there is only one positional argument... if (PositionalOpts.size() > 2) ErrorParsing |= Opt->error("error - this positional option will never be matched, " "because it does not Require a value, and a " "cl::ConsumeAfter option is active!"); } else if (UnboundedFound && !Opt->ArgStr[0]) { // This option does not "require" a value... Make sure this option is // not specified after an option that eats all extra arguments, or this // one will never get any! // ErrorParsing |= Opt->error("error - option can never match, because " "another positional argument will match an " "unbounded number of values, and this option" " does not require a value!"); } UnboundedFound |= EatsUnboundedNumberOfValues(Opt); } HasUnlimitedPositionals = UnboundedFound || ConsumeAfterOpt; } // PositionalVals - A vector of "positional" arguments we accumulate into // the process at the end. // SmallVector<std::pair<StringRef,unsigned>, 4> PositionalVals; // If the program has named positional arguments, and the name has been run // across, keep track of which positional argument was named. Otherwise put // the positional args into the PositionalVals list... Option *ActivePositionalArg = 0; // Loop over all of the arguments... processing them. bool DashDashFound = false; // Have we read '--'? for (int i = 1; i < argc; ++i) { Option *Handler = 0; StringRef Value; StringRef ArgName = ""; // If the option list changed, this means that some command line // option has just been registered or deregistered. This can occur in // response to things like -load, etc. If this happens, rescan the options. if (OptionListChanged) { PositionalOpts.clear(); SinkOpts.clear(); Opts.clear(); GetOptionInfo(PositionalOpts, SinkOpts, Opts); OptionListChanged = false; } // Check to see if this is a positional argument. This argument is // considered to be positional if it doesn't start with '-', if it is "-" // itself, or if we have seen "--" already. // if (argv[i][0] != '-' || argv[i][1] == 0 || DashDashFound) { // Positional argument! if (ActivePositionalArg) { ProvidePositionalOption(ActivePositionalArg, argv[i], i); continue; // We are done! } if (!PositionalOpts.empty()) { PositionalVals.push_back(std::make_pair(argv[i],i)); // All of the positional arguments have been fulfulled, give the rest to // the consume after option... if it's specified... // if (PositionalVals.size() >= NumPositionalRequired && ConsumeAfterOpt != 0) { for (++i; i < argc; ++i) PositionalVals.push_back(std::make_pair(argv[i],i)); break; // Handle outside of the argument processing loop... } // Delay processing positional arguments until the end... continue; } } else if (argv[i][0] == '-' && argv[i][1] == '-' && argv[i][2] == 0 && !DashDashFound) { DashDashFound = true; // This is the mythical "--"? continue; // Don't try to process it as an argument itself. } else if (ActivePositionalArg && (ActivePositionalArg->getMiscFlags() & PositionalEatsArgs)) { // If there is a positional argument eating options, check to see if this // option is another positional argument. If so, treat it as an argument, // otherwise feed it to the eating positional. ArgName = argv[i]+1; // Eat leading dashes. while (!ArgName.empty() && ArgName[0] == '-') ArgName = ArgName.substr(1); Handler = LookupOption(ArgName, Value, Opts); if (!Handler || Handler->getFormattingFlag() != cl::Positional) { ProvidePositionalOption(ActivePositionalArg, argv[i], i); continue; // We are done! } } else { // We start with a '-', must be an argument. ArgName = argv[i]+1; // Eat leading dashes. while (!ArgName.empty() && ArgName[0] == '-') ArgName = ArgName.substr(1); Handler = LookupOption(ArgName, Value, Opts); // Check to see if this "option" is really a prefixed or grouped argument. if (Handler == 0) Handler = HandlePrefixedOrGroupedOption(ArgName, Value, ErrorParsing, Opts); } if (Handler == 0) { if (SinkOpts.empty()) { errs() << ProgramName << ": Unknown command line argument '" << argv[i] << "'. Try: '" << argv[0] << " -help'\n"; ErrorParsing = true; } else { for (SmallVectorImpl<Option*>::iterator I = SinkOpts.begin(), E = SinkOpts.end(); I != E ; ++I) (*I)->addOccurrence(i, "", argv[i]); } continue; } // If this is a named positional argument, just remember that it is the // active one... if (Handler->getFormattingFlag() == cl::Positional) ActivePositionalArg = Handler; else ErrorParsing |= ProvideOption(Handler, ArgName, Value, argc, argv, i); } // Check and handle positional arguments now... if (NumPositionalRequired > PositionalVals.size()) { errs() << ProgramName << ": Not enough positional command line arguments specified!\n" << "Must specify at least " << NumPositionalRequired << " positional arguments: See: " << argv[0] << " -help\n"; ErrorParsing = true; } else if (!HasUnlimitedPositionals && PositionalVals.size() > PositionalOpts.size()) { errs() << ProgramName << ": Too many positional arguments specified!\n" << "Can specify at most " << PositionalOpts.size() << " positional arguments: See: " << argv[0] << " -help\n"; ErrorParsing = true; } else if (ConsumeAfterOpt == 0) { // Positional args have already been handled if ConsumeAfter is specified. unsigned ValNo = 0, NumVals = static_cast<unsigned>(PositionalVals.size()); for (size_t i = 0, e = PositionalOpts.size(); i != e; ++i) { if (RequiresValue(PositionalOpts[i])) { ProvidePositionalOption(PositionalOpts[i], PositionalVals[ValNo].first, PositionalVals[ValNo].second); ValNo++; --NumPositionalRequired; // We fulfilled our duty... } // If we _can_ give this option more arguments, do so now, as long as we // do not give it values that others need. 'Done' controls whether the // option even _WANTS_ any more. // bool Done = PositionalOpts[i]->getNumOccurrencesFlag() == cl::Required; while (NumVals-ValNo > NumPositionalRequired && !Done) { switch (PositionalOpts[i]->getNumOccurrencesFlag()) { case cl::Optional: Done = true; // Optional arguments want _at most_ one value // FALL THROUGH case cl::ZeroOrMore: // Zero or more will take all they can get... case cl::OneOrMore: // One or more will take all they can get... ProvidePositionalOption(PositionalOpts[i], PositionalVals[ValNo].first, PositionalVals[ValNo].second); ValNo++; break; default: llvm_unreachable("Internal error, unexpected NumOccurrences flag in " "positional argument processing!"); } } } } else { assert(ConsumeAfterOpt && NumPositionalRequired <= PositionalVals.size()); unsigned ValNo = 0; for (size_t j = 1, e = PositionalOpts.size(); j != e; ++j) if (RequiresValue(PositionalOpts[j])) { ErrorParsing |= ProvidePositionalOption(PositionalOpts[j], PositionalVals[ValNo].first, PositionalVals[ValNo].second); ValNo++; } // Handle the case where there is just one positional option, and it's // optional. In this case, we want to give JUST THE FIRST option to the // positional option and keep the rest for the consume after. The above // loop would have assigned no values to positional options in this case. // if (PositionalOpts.size() == 2 && ValNo == 0 && !PositionalVals.empty()) { ErrorParsing |= ProvidePositionalOption(PositionalOpts[1], PositionalVals[ValNo].first, PositionalVals[ValNo].second); ValNo++; } // Handle over all of the rest of the arguments to the // cl::ConsumeAfter command line option... for (; ValNo != PositionalVals.size(); ++ValNo) ErrorParsing |= ProvidePositionalOption(ConsumeAfterOpt, PositionalVals[ValNo].first, PositionalVals[ValNo].second); } // Loop over args and make sure all required args are specified! for (StringMap<Option*>::iterator I = Opts.begin(), E = Opts.end(); I != E; ++I) { switch (I->second->getNumOccurrencesFlag()) { case Required: case OneOrMore: if (I->second->getNumOccurrences() == 0) { I->second->error("must be specified at least once!"); ErrorParsing = true; } // Fall through default: break; } } // Free all of the memory allocated to the map. Command line options may only // be processed once! Opts.clear(); PositionalOpts.clear(); MoreHelp->clear(); // Free the memory allocated by ExpandResponseFiles. if (ReadResponseFiles) { // Free all the strdup()ed strings. for (std::vector<char*>::iterator i = newArgv.begin(), e = newArgv.end(); i != e; ++i) free(*i); } DEBUG(dbgs() << "Args: "; for (int i = 0; i < argc; ++i) dbgs() << argv[i] << ' '; dbgs() << '\n'; );
bool TailDuplicatePass::duplicateSimpleBB(MachineBasicBlock *TailBB, SmallVector<MachineBasicBlock*, 8> &TDBBs, const DenseSet<unsigned> &UsedByPhi, SmallVector<MachineInstr*, 16> &Copies) { SmallPtrSet<MachineBasicBlock*, 8> Succs(TailBB->succ_begin(), TailBB->succ_end()); SmallVector<MachineBasicBlock*, 8> Preds(TailBB->pred_begin(), TailBB->pred_end()); bool Changed = false; for (SmallSetVector<MachineBasicBlock *, 8>::iterator PI = Preds.begin(), PE = Preds.end(); PI != PE; ++PI) { MachineBasicBlock *PredBB = *PI; if (PredBB->getLandingPadSuccessor()) continue; if (bothUsedInPHI(*PredBB, Succs)) continue; MachineBasicBlock *PredTBB = NULL, *PredFBB = NULL; SmallVector<MachineOperand, 4> PredCond; if (TII->AnalyzeBranch(*PredBB, PredTBB, PredFBB, PredCond, true)) continue; Changed = true; DEBUG(dbgs() << "\nTail-duplicating into PredBB: " << *PredBB << "From simple Succ: " << *TailBB); MachineBasicBlock *NewTarget = *TailBB->succ_begin(); MachineBasicBlock *NextBB = llvm::next(MachineFunction::iterator(PredBB)); // Make PredFBB explicit. if (PredCond.empty()) PredFBB = PredTBB; // Make fall through explicit. if (!PredTBB) PredTBB = NextBB; if (!PredFBB) PredFBB = NextBB; // Redirect if (PredFBB == TailBB) PredFBB = NewTarget; if (PredTBB == TailBB) PredTBB = NewTarget; // Make the branch unconditional if possible if (PredTBB == PredFBB) { PredCond.clear(); PredFBB = NULL; } // Avoid adding fall through branches. if (PredFBB == NextBB) PredFBB = NULL; if (PredTBB == NextBB && PredFBB == NULL) PredTBB = NULL; TII->RemoveBranch(*PredBB); if (PredTBB) TII->InsertBranch(*PredBB, PredTBB, PredFBB, PredCond, DebugLoc()); PredBB->removeSuccessor(TailBB); unsigned NumSuccessors = PredBB->succ_size(); assert(NumSuccessors <= 1); if (NumSuccessors == 0 || *PredBB->succ_begin() != NewTarget) PredBB->addSuccessor(NewTarget); TDBBs.push_back(PredBB); } return Changed; }
// Test whether it's safe to move Def to just before Insert. // TODO: Compute memory dependencies in a way that doesn't require always // walking the block. // TODO: Compute memory dependencies in a way that uses AliasAnalysis to be // more precise. static bool IsSafeToMove(const MachineInstr *Def, const MachineInstr *Insert, AliasAnalysis &AA, const MachineRegisterInfo &MRI) { assert(Def->getParent() == Insert->getParent()); // Check for register dependencies. SmallVector<unsigned, 4> MutableRegisters; for (const MachineOperand &MO : Def->operands()) { if (!MO.isReg() || MO.isUndef()) continue; unsigned Reg = MO.getReg(); // If the register is dead here and at Insert, ignore it. if (MO.isDead() && Insert->definesRegister(Reg) && !Insert->readsRegister(Reg)) continue; if (TargetRegisterInfo::isPhysicalRegister(Reg)) { // Ignore ARGUMENTS; it's just used to keep the ARGUMENT_* instructions // from moving down, and we've already checked for that. if (Reg == WebAssembly::ARGUMENTS) continue; // If the physical register is never modified, ignore it. if (!MRI.isPhysRegModified(Reg)) continue; // Otherwise, it's a physical register with unknown liveness. return false; } // If one of the operands isn't in SSA form, it has different values at // different times, and we need to make sure we don't move our use across // a different def. if (!MO.isDef() && !MRI.hasOneDef(Reg)) MutableRegisters.push_back(Reg); } bool Read = false, Write = false, Effects = false, StackPointer = false; Query(*Def, AA, Read, Write, Effects, StackPointer); // If the instruction does not access memory and has no side effects, it has // no additional dependencies. bool HasMutableRegisters = !MutableRegisters.empty(); if (!Read && !Write && !Effects && !StackPointer && !HasMutableRegisters) return true; // Scan through the intervening instructions between Def and Insert. MachineBasicBlock::const_iterator D(Def), I(Insert); for (--I; I != D; --I) { bool InterveningRead = false; bool InterveningWrite = false; bool InterveningEffects = false; bool InterveningStackPointer = false; Query(*I, AA, InterveningRead, InterveningWrite, InterveningEffects, InterveningStackPointer); if (Effects && InterveningEffects) return false; if (Read && InterveningWrite) return false; if (Write && (InterveningRead || InterveningWrite)) return false; if (StackPointer && InterveningStackPointer) return false; for (unsigned Reg : MutableRegisters) for (const MachineOperand &MO : I->operands()) if (MO.isReg() && MO.isDef() && MO.getReg() == Reg) return false; } return true; }
/// splitLiveRangesAcrossInvokes - Each value that is live across an unwind edge /// we spill into a stack location, guaranteeing that there is nothing live /// across the unwind edge. This process also splits all critical edges /// coming out of invoke's. /// FIXME: Move this function to a common utility file (Local.cpp?) so /// both SjLj and LowerInvoke can use it. void SjLjEHPass:: splitLiveRangesAcrossInvokes(SmallVector<InvokeInst*,16> &Invokes) { // First step, split all critical edges from invoke instructions. for (unsigned i = 0, e = Invokes.size(); i != e; ++i) { InvokeInst *II = Invokes[i]; SplitCriticalEdge(II, 0, this); SplitCriticalEdge(II, 1, this); assert(!isa<PHINode>(II->getNormalDest()) && !isa<PHINode>(II->getUnwindDest()) && "critical edge splitting left single entry phi nodes?"); } Function *F = Invokes.back()->getParent()->getParent(); // To avoid having to handle incoming arguments specially, we lower each arg // to a copy instruction in the entry block. This ensures that the argument // value itself cannot be live across the entry block. BasicBlock::iterator AfterAllocaInsertPt = F->begin()->begin(); while (isa<AllocaInst>(AfterAllocaInsertPt) && isa<ConstantInt>(cast<AllocaInst>(AfterAllocaInsertPt)->getArraySize())) ++AfterAllocaInsertPt; for (Function::arg_iterator AI = F->arg_begin(), E = F->arg_end(); AI != E; ++AI) { const Type *Ty = AI->getType(); // Aggregate types can't be cast, but are legal argument types, so we have // to handle them differently. We use an extract/insert pair as a // lightweight method to achieve the same goal. if (isa<StructType>(Ty) || isa<ArrayType>(Ty) || isa<VectorType>(Ty)) { Instruction *EI = ExtractValueInst::Create(AI, 0, "",AfterAllocaInsertPt); Instruction *NI = InsertValueInst::Create(AI, EI, 0); NI->insertAfter(EI); AI->replaceAllUsesWith(NI); // Set the operand of the instructions back to the AllocaInst. EI->setOperand(0, AI); NI->setOperand(0, AI); } else { // This is always a no-op cast because we're casting AI to AI->getType() // so src and destination types are identical. BitCast is the only // possibility. CastInst *NC = new BitCastInst( AI, AI->getType(), AI->getName()+".tmp", AfterAllocaInsertPt); AI->replaceAllUsesWith(NC); // Set the operand of the cast instruction back to the AllocaInst. // Normally it's forbidden to replace a CastInst's operand because it // could cause the opcode to reflect an illegal conversion. However, // we're replacing it here with the same value it was constructed with. // We do this because the above replaceAllUsesWith() clobbered the // operand, but we want this one to remain. NC->setOperand(0, AI); } } // Finally, scan the code looking for instructions with bad live ranges. for (Function::iterator BB = F->begin(), E = F->end(); BB != E; ++BB) for (BasicBlock::iterator II = BB->begin(), E = BB->end(); II != E; ++II) { // Ignore obvious cases we don't have to handle. In particular, most // instructions either have no uses or only have a single use inside the // current block. Ignore them quickly. Instruction *Inst = II; if (Inst->use_empty()) continue; if (Inst->hasOneUse() && cast<Instruction>(Inst->use_back())->getParent() == BB && !isa<PHINode>(Inst->use_back())) continue; // If this is an alloca in the entry block, it's not a real register // value. if (AllocaInst *AI = dyn_cast<AllocaInst>(Inst)) if (isa<ConstantInt>(AI->getArraySize()) && BB == F->begin()) continue; // Avoid iterator invalidation by copying users to a temporary vector. SmallVector<Instruction*,16> Users; for (Value::use_iterator UI = Inst->use_begin(), E = Inst->use_end(); UI != E; ++UI) { Instruction *User = cast<Instruction>(*UI); if (User->getParent() != BB || isa<PHINode>(User)) Users.push_back(User); } // Find all of the blocks that this value is live in. std::set<BasicBlock*> LiveBBs; LiveBBs.insert(Inst->getParent()); while (!Users.empty()) { Instruction *U = Users.back(); Users.pop_back(); if (!isa<PHINode>(U)) { MarkBlocksLiveIn(U->getParent(), LiveBBs); } else { // Uses for a PHI node occur in their predecessor block. PHINode *PN = cast<PHINode>(U); for (unsigned i = 0, e = PN->getNumIncomingValues(); i != e; ++i) if (PN->getIncomingValue(i) == Inst) MarkBlocksLiveIn(PN->getIncomingBlock(i), LiveBBs); } } // Now that we know all of the blocks that this thing is live in, see if // it includes any of the unwind locations. bool NeedsSpill = false; for (unsigned i = 0, e = Invokes.size(); i != e; ++i) { BasicBlock *UnwindBlock = Invokes[i]->getUnwindDest(); if (UnwindBlock != BB && LiveBBs.count(UnwindBlock)) { NeedsSpill = true; } } // If we decided we need a spill, do it. // FIXME: Spilling this way is overkill, as it forces all uses of // the value to be reloaded from the stack slot, even those that aren't // in the unwind blocks. We should be more selective. if (NeedsSpill) { ++NumSpilled; DemoteRegToStack(*Inst, true); } } }
void ScheduleDAGSDNodes::BuildSchedUnits() { // During scheduling, the NodeId field of SDNode is used to map SDNodes // to their associated SUnits by holding SUnits table indices. A value // of -1 means the SDNode does not yet have an associated SUnit. unsigned NumNodes = 0; for (SelectionDAG::allnodes_iterator NI = DAG->allnodes_begin(), E = DAG->allnodes_end(); NI != E; ++NI) { NI->setNodeId(-1); ++NumNodes; } // Reserve entries in the vector for each of the SUnits we are creating. This // ensure that reallocation of the vector won't happen, so SUnit*'s won't get // invalidated. // FIXME: Multiply by 2 because we may clone nodes during scheduling. // This is a temporary workaround. SUnits.reserve(NumNodes * 2); // Add all nodes in depth first order. SmallVector<SDNode*, 64> Worklist; SmallPtrSet<SDNode*, 64> Visited; Worklist.push_back(DAG->getRoot().getNode()); Visited.insert(DAG->getRoot().getNode()); SmallVector<SUnit*, 8> CallSUnits; while (!Worklist.empty()) { SDNode *NI = Worklist.pop_back_val(); // Add all operands to the worklist unless they've already been added. for (unsigned i = 0, e = NI->getNumOperands(); i != e; ++i) if (Visited.insert(NI->getOperand(i).getNode()).second) Worklist.push_back(NI->getOperand(i).getNode()); if (isPassiveNode(NI)) // Leaf node, e.g. a TargetImmediate. continue; // If this node has already been processed, stop now. if (NI->getNodeId() != -1) continue; SUnit *NodeSUnit = newSUnit(NI); // See if anything is glued to this node, if so, add them to glued // nodes. Nodes can have at most one glue input and one glue output. Glue // is required to be the last operand and result of a node. // Scan up to find glued preds. SDNode *N = NI; while (N->getNumOperands() && N->getOperand(N->getNumOperands()-1).getValueType() == MVT::Glue) { N = N->getOperand(N->getNumOperands()-1).getNode(); assert(N->getNodeId() == -1 && "Node already inserted!"); N->setNodeId(NodeSUnit->NodeNum); if (N->isMachineOpcode() && TII->get(N->getMachineOpcode()).isCall()) NodeSUnit->isCall = true; } // Scan down to find any glued succs. N = NI; while (N->getValueType(N->getNumValues()-1) == MVT::Glue) { SDValue GlueVal(N, N->getNumValues()-1); // There are either zero or one users of the Glue result. bool HasGlueUse = false; for (SDNode::use_iterator UI = N->use_begin(), E = N->use_end(); UI != E; ++UI) if (GlueVal.isOperandOf(*UI)) { HasGlueUse = true; assert(N->getNodeId() == -1 && "Node already inserted!"); N->setNodeId(NodeSUnit->NodeNum); N = *UI; if (N->isMachineOpcode() && TII->get(N->getMachineOpcode()).isCall()) NodeSUnit->isCall = true; break; } if (!HasGlueUse) break; } if (NodeSUnit->isCall) CallSUnits.push_back(NodeSUnit); // Schedule zero-latency TokenFactor below any nodes that may increase the // schedule height. Otherwise, ancestors of the TokenFactor may appear to // have false stalls. if (NI->getOpcode() == ISD::TokenFactor) NodeSUnit->isScheduleLow = true; // If there are glue operands involved, N is now the bottom-most node // of the sequence of nodes that are glued together. // Update the SUnit. NodeSUnit->setNode(N); assert(N->getNodeId() == -1 && "Node already inserted!"); N->setNodeId(NodeSUnit->NodeNum); // Compute NumRegDefsLeft. This must be done before AddSchedEdges. InitNumRegDefsLeft(NodeSUnit); // Assign the Latency field of NodeSUnit using target-provided information. computeLatency(NodeSUnit); } // Find all call operands. while (!CallSUnits.empty()) { SUnit *SU = CallSUnits.pop_back_val(); for (const SDNode *SUNode = SU->getNode(); SUNode; SUNode = SUNode->getGluedNode()) { if (SUNode->getOpcode() != ISD::CopyToReg) continue; SDNode *SrcN = SUNode->getOperand(2).getNode(); if (isPassiveNode(SrcN)) continue; // Not scheduled. SUnit *SrcSU = &SUnits[SrcN->getNodeId()]; SrcSU->isCallOp = true; } } }
/// EmitSchedule - Emit the machine code in scheduled order. Return the new /// InsertPos and MachineBasicBlock that contains this insertion /// point. ScheduleDAGSDNodes holds a BB pointer for convenience, but this does /// not necessarily refer to returned BB. The emitter may split blocks. MachineBasicBlock *ScheduleDAGSDNodes:: EmitSchedule(MachineBasicBlock::iterator &InsertPos) { InstrEmitter Emitter(BB, InsertPos); DenseMap<SDValue, unsigned> VRBaseMap; DenseMap<SUnit*, unsigned> CopyVRBaseMap; SmallVector<std::pair<unsigned, MachineInstr*>, 32> Orders; SmallSet<unsigned, 8> Seen; bool HasDbg = DAG->hasDebugValues(); // If this is the first BB, emit byval parameter dbg_value's. if (HasDbg && BB->getParent()->begin() == MachineFunction::iterator(BB)) { SDDbgInfo::DbgIterator PDI = DAG->ByvalParmDbgBegin(); SDDbgInfo::DbgIterator PDE = DAG->ByvalParmDbgEnd(); for (; PDI != PDE; ++PDI) { MachineInstr *DbgMI= Emitter.EmitDbgValue(*PDI, VRBaseMap); if (DbgMI) BB->insert(InsertPos, DbgMI); } } for (unsigned i = 0, e = Sequence.size(); i != e; i++) { SUnit *SU = Sequence[i]; if (!SU) { // Null SUnit* is a noop. TII->insertNoop(*Emitter.getBlock(), InsertPos); continue; } // For pre-regalloc scheduling, create instructions corresponding to the // SDNode and any glued SDNodes and append them to the block. if (!SU->getNode()) { // Emit a copy. EmitPhysRegCopy(SU, CopyVRBaseMap, InsertPos); continue; } SmallVector<SDNode *, 4> GluedNodes; for (SDNode *N = SU->getNode()->getGluedNode(); N; N = N->getGluedNode()) GluedNodes.push_back(N); while (!GluedNodes.empty()) { SDNode *N = GluedNodes.back(); Emitter.EmitNode(GluedNodes.back(), SU->OrigNode != SU, SU->isCloned, VRBaseMap); // Remember the source order of the inserted instruction. if (HasDbg) ProcessSourceNode(N, DAG, Emitter, VRBaseMap, Orders, Seen); GluedNodes.pop_back(); } Emitter.EmitNode(SU->getNode(), SU->OrigNode != SU, SU->isCloned, VRBaseMap); // Remember the source order of the inserted instruction. if (HasDbg) ProcessSourceNode(SU->getNode(), DAG, Emitter, VRBaseMap, Orders, Seen); } // Insert all the dbg_values which have not already been inserted in source // order sequence. if (HasDbg) { MachineBasicBlock::iterator BBBegin = BB->getFirstNonPHI(); // Sort the source order instructions and use the order to insert debug // values. std::sort(Orders.begin(), Orders.end(), less_first()); SDDbgInfo::DbgIterator DI = DAG->DbgBegin(); SDDbgInfo::DbgIterator DE = DAG->DbgEnd(); // Now emit the rest according to source order. unsigned LastOrder = 0; for (unsigned i = 0, e = Orders.size(); i != e && DI != DE; ++i) { unsigned Order = Orders[i].first; MachineInstr *MI = Orders[i].second; // Insert all SDDbgValue's whose order(s) are before "Order". if (!MI) continue; for (; DI != DE && (*DI)->getOrder() >= LastOrder && (*DI)->getOrder() < Order; ++DI) { if ((*DI)->isInvalidated()) continue; MachineInstr *DbgMI = Emitter.EmitDbgValue(*DI, VRBaseMap); if (DbgMI) { if (!LastOrder) // Insert to start of the BB (after PHIs). BB->insert(BBBegin, DbgMI); else { // Insert at the instruction, which may be in a different // block, if the block was split by a custom inserter. MachineBasicBlock::iterator Pos = MI; MI->getParent()->insert(Pos, DbgMI); } } } LastOrder = Order; } // Add trailing DbgValue's before the terminator. FIXME: May want to add // some of them before one or more conditional branches? SmallVector<MachineInstr*, 8> DbgMIs; while (DI != DE) { if (!(*DI)->isInvalidated()) if (MachineInstr *DbgMI = Emitter.EmitDbgValue(*DI, VRBaseMap)) DbgMIs.push_back(DbgMI); ++DI; } MachineBasicBlock *InsertBB = Emitter.getBlock(); MachineBasicBlock::iterator Pos = InsertBB->getFirstTerminator(); InsertBB->insert(Pos, DbgMIs.begin(), DbgMIs.end()); } InsertPos = Emitter.getInsertPos(); return Emitter.getBlock(); }
// LowerCCCCallTo - functions arguments are copied from virtual regs to // (physical regs)/(stack frame), CALLSEQ_START and CALLSEQ_END are emitted. SDValue LanaiTargetLowering::LowerCCCCallTo( SDValue Chain, SDValue Callee, CallingConv::ID CallConv, bool IsVarArg, bool IsTailCall, const SmallVectorImpl<ISD::OutputArg> &Outs, const SmallVectorImpl<SDValue> &OutVals, const SmallVectorImpl<ISD::InputArg> &Ins, const SDLoc &DL, SelectionDAG &DAG, SmallVectorImpl<SDValue> &InVals) const { // Analyze operands of the call, assigning locations to each operand. SmallVector<CCValAssign, 16> ArgLocs; CCState CCInfo(CallConv, IsVarArg, DAG.getMachineFunction(), ArgLocs, *DAG.getContext()); GlobalAddressSDNode *G = dyn_cast<GlobalAddressSDNode>(Callee); MachineFrameInfo *MFI = DAG.getMachineFunction().getFrameInfo(); NumFixedArgs = 0; if (IsVarArg && G) { const Function *CalleeFn = dyn_cast<Function>(G->getGlobal()); if (CalleeFn) NumFixedArgs = CalleeFn->getFunctionType()->getNumParams(); } if (NumFixedArgs) CCInfo.AnalyzeCallOperands(Outs, CC_Lanai32_VarArg); else { if (CallConv == CallingConv::Fast) CCInfo.AnalyzeCallOperands(Outs, CC_Lanai32_Fast); else CCInfo.AnalyzeCallOperands(Outs, CC_Lanai32); } // Get a count of how many bytes are to be pushed on the stack. unsigned NumBytes = CCInfo.getNextStackOffset(); // Create local copies for byval args. SmallVector<SDValue, 8> ByValArgs; for (unsigned I = 0, E = Outs.size(); I != E; ++I) { ISD::ArgFlagsTy Flags = Outs[I].Flags; if (!Flags.isByVal()) continue; SDValue Arg = OutVals[I]; unsigned Size = Flags.getByValSize(); unsigned Align = Flags.getByValAlign(); int FI = MFI->CreateStackObject(Size, Align, false); SDValue FIPtr = DAG.getFrameIndex(FI, getPointerTy(DAG.getDataLayout())); SDValue SizeNode = DAG.getConstant(Size, DL, MVT::i32); Chain = DAG.getMemcpy(Chain, DL, FIPtr, Arg, SizeNode, Align, /*IsVolatile=*/false, /*AlwaysInline=*/false, /*IsTailCall=*/false, MachinePointerInfo(), MachinePointerInfo()); ByValArgs.push_back(FIPtr); } Chain = DAG.getCALLSEQ_START( Chain, DAG.getConstant(NumBytes, DL, getPointerTy(DAG.getDataLayout()), true), DL); SmallVector<std::pair<unsigned, SDValue>, 4> RegsToPass; SmallVector<SDValue, 12> MemOpChains; SDValue StackPtr; // Walk the register/memloc assignments, inserting copies/loads. for (unsigned I = 0, J = 0, E = ArgLocs.size(); I != E; ++I) { CCValAssign &VA = ArgLocs[I]; SDValue Arg = OutVals[I]; ISD::ArgFlagsTy Flags = Outs[I].Flags; // Promote the value if needed. switch (VA.getLocInfo()) { case CCValAssign::Full: break; case CCValAssign::SExt: Arg = DAG.getNode(ISD::SIGN_EXTEND, DL, VA.getLocVT(), Arg); break; case CCValAssign::ZExt: Arg = DAG.getNode(ISD::ZERO_EXTEND, DL, VA.getLocVT(), Arg); break; case CCValAssign::AExt: Arg = DAG.getNode(ISD::ANY_EXTEND, DL, VA.getLocVT(), Arg); break; default: llvm_unreachable("Unknown loc info!"); } // Use local copy if it is a byval arg. if (Flags.isByVal()) Arg = ByValArgs[J++]; // Arguments that can be passed on register must be kept at RegsToPass // vector if (VA.isRegLoc()) { RegsToPass.push_back(std::make_pair(VA.getLocReg(), Arg)); } else { assert(VA.isMemLoc()); if (StackPtr.getNode() == 0) StackPtr = DAG.getCopyFromReg(Chain, DL, Lanai::SP, getPointerTy(DAG.getDataLayout())); SDValue PtrOff = DAG.getNode(ISD::ADD, DL, getPointerTy(DAG.getDataLayout()), StackPtr, DAG.getIntPtrConstant(VA.getLocMemOffset(), DL)); MemOpChains.push_back(DAG.getStore( Chain, DL, Arg, PtrOff, MachinePointerInfo(), false, false, 0)); } } // Transform all store nodes into one single node because all store nodes are // independent of each other. if (!MemOpChains.empty()) Chain = DAG.getNode(ISD::TokenFactor, DL, MVT::Other, ArrayRef<SDValue>(&MemOpChains[0], MemOpChains.size())); SDValue InFlag; // Build a sequence of copy-to-reg nodes chained together with token chain and // flag operands which copy the outgoing args into registers. The InFlag in // necessary since all emitted instructions must be stuck together. for (unsigned I = 0, E = RegsToPass.size(); I != E; ++I) { Chain = DAG.getCopyToReg(Chain, DL, RegsToPass[I].first, RegsToPass[I].second, InFlag); InFlag = Chain.getValue(1); } // If the callee is a GlobalAddress node (quite common, every direct call is) // turn it into a TargetGlobalAddress node so that legalize doesn't hack it. // Likewise ExternalSymbol -> TargetExternalSymbol. uint8_t OpFlag = LanaiII::MO_NO_FLAG; if (G) { Callee = DAG.getTargetGlobalAddress( G->getGlobal(), DL, getPointerTy(DAG.getDataLayout()), 0, OpFlag); } else if (ExternalSymbolSDNode *E = dyn_cast<ExternalSymbolSDNode>(Callee)) { Callee = DAG.getTargetExternalSymbol( E->getSymbol(), getPointerTy(DAG.getDataLayout()), OpFlag); } // Returns a chain & a flag for retval copy to use. SDVTList NodeTys = DAG.getVTList(MVT::Other, MVT::Glue); SmallVector<SDValue, 8> Ops; Ops.push_back(Chain); Ops.push_back(Callee); // Add a register mask operand representing the call-preserved registers. // TODO: Should return-twice functions be handled? const uint32_t *Mask = TRI->getCallPreservedMask(DAG.getMachineFunction(), CallConv); assert(Mask && "Missing call preserved mask for calling convention"); Ops.push_back(DAG.getRegisterMask(Mask)); // Add argument registers to the end of the list so that they are // known live into the call. for (unsigned I = 0, E = RegsToPass.size(); I != E; ++I) Ops.push_back(DAG.getRegister(RegsToPass[I].first, RegsToPass[I].second.getValueType())); if (InFlag.getNode()) Ops.push_back(InFlag); Chain = DAG.getNode(LanaiISD::CALL, DL, NodeTys, ArrayRef<SDValue>(&Ops[0], Ops.size())); InFlag = Chain.getValue(1); // Create the CALLSEQ_END node. Chain = DAG.getCALLSEQ_END( Chain, DAG.getConstant(NumBytes, DL, getPointerTy(DAG.getDataLayout()), true), DAG.getConstant(0, DL, getPointerTy(DAG.getDataLayout()), true), InFlag, DL); InFlag = Chain.getValue(1); // Handle result values, copying them out of physregs into vregs that we // return. return LowerCallResult(Chain, InFlag, CallConv, IsVarArg, Ins, DL, DAG, InVals); }
static bool mergeConstants(Module &M) { // Find all the globals that are marked "used". These cannot be merged. SmallPtrSet<const GlobalValue*, 8> UsedGlobals; FindUsedValues(M.getGlobalVariable("llvm.used"), UsedGlobals); FindUsedValues(M.getGlobalVariable("llvm.compiler.used"), UsedGlobals); // Map unique constants to globals. DenseMap<Constant *, GlobalVariable *> CMap; // Replacements - This vector contains a list of replacements to perform. SmallVector<std::pair<GlobalVariable*, GlobalVariable*>, 32> Replacements; bool MadeChange = false; // XXX EMSCRIPTEN: mark @__init_array_start as not to be touched const GlobalValue *InitArrayStart = M.getNamedGlobal("__init_array_start"); // Iterate constant merging while we are still making progress. Merging two // constants together may allow us to merge other constants together if the // second level constants have initializers which point to the globals that // were just merged. while (1) { // First: Find the canonical constants others will be merged with. for (Module::global_iterator GVI = M.global_begin(), E = M.global_end(); GVI != E; ) { GlobalVariable *GV = &*GVI++; // XXX EMSCRIPTEN: mark @__init_array_start as not to be touched if (GV == InitArrayStart) continue; // If this GV is dead, remove it. GV->removeDeadConstantUsers(); if (GV->use_empty() && GV->hasLocalLinkage()) { GV->eraseFromParent(); continue; } // Only process constants with initializers in the default address space. if (!GV->isConstant() || !GV->hasDefinitiveInitializer() || GV->getType()->getAddressSpace() != 0 || GV->hasSection() || // Don't touch values marked with attribute(used). UsedGlobals.count(GV)) continue; // This transformation is legal for weak ODR globals in the sense it // doesn't change semantics, but we really don't want to perform it // anyway; it's likely to pessimize code generation, and some tools // (like the Darwin linker in cases involving CFString) don't expect it. if (GV->isWeakForLinker()) continue; Constant *Init = GV->getInitializer(); // Check to see if the initializer is already known. GlobalVariable *&Slot = CMap[Init]; // If this is the first constant we find or if the old one is local, // replace with the current one. If the current is externally visible // it cannot be replace, but can be the canonical constant we merge with. if (!Slot || IsBetterCanonical(*GV, *Slot)) Slot = GV; } // Second: identify all globals that can be merged together, filling in // the Replacements vector. We cannot do the replacement in this pass // because doing so may cause initializers of other globals to be rewritten, // invalidating the Constant* pointers in CMap. for (Module::global_iterator GVI = M.global_begin(), E = M.global_end(); GVI != E; ) { GlobalVariable *GV = &*GVI++; // Only process constants with initializers in the default address space. if (!GV->isConstant() || !GV->hasDefinitiveInitializer() || GV->getType()->getAddressSpace() != 0 || GV->hasSection() || // Don't touch values marked with attribute(used). UsedGlobals.count(GV)) continue; // We can only replace constant with local linkage. if (!GV->hasLocalLinkage()) continue; Constant *Init = GV->getInitializer(); // Check to see if the initializer is already known. GlobalVariable *Slot = CMap[Init]; if (!Slot || Slot == GV) continue; if (!Slot->hasGlobalUnnamedAddr() && !GV->hasGlobalUnnamedAddr()) continue; if (!GV->hasGlobalUnnamedAddr()) Slot->setUnnamedAddr(GlobalValue::UnnamedAddr::None); // Make all uses of the duplicate constant use the canonical version. Replacements.push_back(std::make_pair(GV, Slot)); } if (Replacements.empty()) return MadeChange; CMap.clear(); // Now that we have figured out which replacements must be made, do them all // now. This avoid invalidating the pointers in CMap, which are unneeded // now. for (unsigned i = 0, e = Replacements.size(); i != e; ++i) { // Bump the alignment if necessary. if (Replacements[i].first->getAlignment() || Replacements[i].second->getAlignment()) { Replacements[i].second->setAlignment( std::max(getAlignment(Replacements[i].first), getAlignment(Replacements[i].second))); } // Eliminate any uses of the dead global. Replacements[i].first->replaceAllUsesWith(Replacements[i].second); // Delete the global value from the module. assert(Replacements[i].first->hasLocalLinkage() && "Refusing to delete an externally visible global variable."); Replacements[i].first->eraseFromParent(); } NumMerged += Replacements.size(); Replacements.clear(); } }
/// isSafeToPromoteArgument - As you might guess from the name of this method, /// it checks to see if it is both safe and useful to promote the argument. /// This method limits promotion of aggregates to only promote up to three /// elements of the aggregate in order to avoid exploding the number of /// arguments passed in. bool ArgPromotion::isSafeToPromoteArgument(Argument *Arg, bool isByVal) const { typedef std::set<IndicesVector> GEPIndicesSet; // Quick exit for unused arguments if (Arg->use_empty()) return true; // We can only promote this argument if all of the uses are loads, or are GEP // instructions (with constant indices) that are subsequently loaded. // // Promoting the argument causes it to be loaded in the caller // unconditionally. This is only safe if we can prove that either the load // would have happened in the callee anyway (ie, there is a load in the entry // block) or the pointer passed in at every call site is guaranteed to be // valid. // In the former case, invalid loads can happen, but would have happened // anyway, in the latter case, invalid loads won't happen. This prevents us // from introducing an invalid load that wouldn't have happened in the // original code. // // This set will contain all sets of indices that are loaded in the entry // block, and thus are safe to unconditionally load in the caller. GEPIndicesSet SafeToUnconditionallyLoad; // This set contains all the sets of indices that we are planning to promote. // This makes it possible to limit the number of arguments added. GEPIndicesSet ToPromote; // If the pointer is always valid, any load with first index 0 is valid. if (isByVal || AllCalleesPassInValidPointerForArgument(Arg)) SafeToUnconditionallyLoad.insert(IndicesVector(1, 0)); // First, iterate the entry block and mark loads of (geps of) arguments as // safe. BasicBlock *EntryBlock = Arg->getParent()->begin(); // Declare this here so we can reuse it IndicesVector Indices; for (BasicBlock::iterator I = EntryBlock->begin(), E = EntryBlock->end(); I != E; ++I) if (LoadInst *LI = dyn_cast<LoadInst>(I)) { Value *V = LI->getPointerOperand(); if (GetElementPtrInst *GEP = dyn_cast<GetElementPtrInst>(V)) { V = GEP->getPointerOperand(); if (V == Arg) { // This load actually loads (part of) Arg? Check the indices then. Indices.reserve(GEP->getNumIndices()); for (User::op_iterator II = GEP->idx_begin(), IE = GEP->idx_end(); II != IE; ++II) if (ConstantInt *CI = dyn_cast<ConstantInt>(*II)) Indices.push_back(CI->getSExtValue()); else // We found a non-constant GEP index for this argument? Bail out // right away, can't promote this argument at all. return false; // Indices checked out, mark them as safe MarkIndicesSafe(Indices, SafeToUnconditionallyLoad); Indices.clear(); } } else if (V == Arg) { // Direct loads are equivalent to a GEP with a single 0 index. MarkIndicesSafe(IndicesVector(1, 0), SafeToUnconditionallyLoad); } } // Now, iterate all uses of the argument to see if there are any uses that are // not (GEP+)loads, or any (GEP+)loads that are not safe to promote. SmallVector<LoadInst*, 16> Loads; IndicesVector Operands; for (Value::use_iterator UI = Arg->use_begin(), E = Arg->use_end(); UI != E; ++UI) { User *U = *UI; Operands.clear(); if (LoadInst *LI = dyn_cast<LoadInst>(U)) { if (LI->isVolatile()) return false; // Don't hack volatile loads Loads.push_back(LI); // Direct loads are equivalent to a GEP with a zero index and then a load. Operands.push_back(0); } else if (GetElementPtrInst *GEP = dyn_cast<GetElementPtrInst>(U)) { if (GEP->use_empty()) { // Dead GEP's cause trouble later. Just remove them if we run into // them. getAnalysis<AliasAnalysis>().deleteValue(GEP); GEP->eraseFromParent(); // TODO: This runs the above loop over and over again for dead GEPs // Couldn't we just do increment the UI iterator earlier and erase the // use? return isSafeToPromoteArgument(Arg, isByVal); } // Ensure that all of the indices are constants. for (User::op_iterator i = GEP->idx_begin(), e = GEP->idx_end(); i != e; ++i) if (ConstantInt *C = dyn_cast<ConstantInt>(*i)) Operands.push_back(C->getSExtValue()); else return false; // Not a constant operand GEP! // Ensure that the only users of the GEP are load instructions. for (Value::use_iterator UI = GEP->use_begin(), E = GEP->use_end(); UI != E; ++UI) if (LoadInst *LI = dyn_cast<LoadInst>(*UI)) { if (LI->isVolatile()) return false; // Don't hack volatile loads Loads.push_back(LI); } else { // Other uses than load? return false; } } else { return false; // Not a load or a GEP. } // Now, see if it is safe to promote this load / loads of this GEP. Loading // is safe if Operands, or a prefix of Operands, is marked as safe. if (!PrefixIn(Operands, SafeToUnconditionallyLoad)) return false; // See if we are already promoting a load with these indices. If not, check // to make sure that we aren't promoting too many elements. If so, nothing // to do. if (ToPromote.find(Operands) == ToPromote.end()) { if (maxElements > 0 && ToPromote.size() == maxElements) { DEBUG(dbgs() << "argpromotion not promoting argument '" << Arg->getName() << "' because it would require adding more " << "than " << maxElements << " arguments to the function.\n"); // We limit aggregate promotion to only promoting up to a fixed number // of elements of the aggregate. return false; } ToPromote.insert(Operands); } } if (Loads.empty()) return true; // No users, this is a dead argument. // Okay, now we know that the argument is only used by load instructions and // it is safe to unconditionally perform all of them. Use alias analysis to // check to see if the pointer is guaranteed to not be modified from entry of // the function to each of the load instructions. // Because there could be several/many load instructions, remember which // blocks we know to be transparent to the load. SmallPtrSet<BasicBlock*, 16> TranspBlocks; AliasAnalysis &AA = getAnalysis<AliasAnalysis>(); for (unsigned i = 0, e = Loads.size(); i != e; ++i) { // Check to see if the load is invalidated from the start of the block to // the load itself. LoadInst *Load = Loads[i]; BasicBlock *BB = Load->getParent(); AliasAnalysis::Location Loc = AA.getLocation(Load); if (AA.canInstructionRangeModify(BB->front(), *Load, Loc)) return false; // Pointer is invalidated! // Now check every path from the entry block to the load for transparency. // To do this, we perform a depth first search on the inverse CFG from the // loading block. for (pred_iterator PI = pred_begin(BB), E = pred_end(BB); PI != E; ++PI) { BasicBlock *P = *PI; for (idf_ext_iterator<BasicBlock*, SmallPtrSet<BasicBlock*, 16> > I = idf_ext_begin(P, TranspBlocks), E = idf_ext_end(P, TranspBlocks); I != E; ++I) if (AA.canBasicBlockModify(**I, Loc)) return false; } } // If the path from the entry of the function to each load is free of // instructions that potentially invalidate the load, we can make the // transformation! return true; }
/// PromoteArguments - This method checks the specified function to see if there /// are any promotable arguments and if it is safe to promote the function (for /// example, all callers are direct). If safe to promote some arguments, it /// calls the DoPromotion method. /// CallGraphNode *ArgPromotion::PromoteArguments(CallGraphNode *CGN) { Function *F = CGN->getFunction(); // Make sure that it is local to this module. if (!F || !F->hasLocalLinkage()) return 0; // First check: see if there are any pointer arguments! If not, quick exit. SmallVector<std::pair<Argument*, unsigned>, 16> PointerArgs; unsigned ArgNo = 0; for (Function::arg_iterator I = F->arg_begin(), E = F->arg_end(); I != E; ++I, ++ArgNo) if (I->getType()->isPointerTy()) PointerArgs.push_back(std::pair<Argument*, unsigned>(I, ArgNo)); if (PointerArgs.empty()) return 0; // Second check: make sure that all callers are direct callers. We can't // transform functions that have indirect callers. if (F->hasAddressTaken()) return 0; // Check to see which arguments are promotable. If an argument is promotable, // add it to ArgsToPromote. SmallPtrSet<Argument*, 8> ArgsToPromote; SmallPtrSet<Argument*, 8> ByValArgsToTransform; for (unsigned i = 0; i != PointerArgs.size(); ++i) { bool isByVal = F->paramHasAttr(PointerArgs[i].second+1, Attribute::ByVal); // If this is a byval argument, and if the aggregate type is small, just // pass the elements, which is always safe. Argument *PtrArg = PointerArgs[i].first; if (isByVal) { const Type *AgTy = cast<PointerType>(PtrArg->getType())->getElementType(); if (const StructType *STy = dyn_cast<StructType>(AgTy)) { if (maxElements > 0 && STy->getNumElements() > maxElements) { DEBUG(dbgs() << "argpromotion disable promoting argument '" << PtrArg->getName() << "' because it would require adding more" << " than " << maxElements << " arguments to the function.\n"); } else { // If all the elements are single-value types, we can promote it. bool AllSimple = true; for (unsigned i = 0, e = STy->getNumElements(); i != e; ++i) if (!STy->getElementType(i)->isSingleValueType()) { AllSimple = false; break; } // Safe to transform, don't even bother trying to "promote" it. // Passing the elements as a scalar will allow scalarrepl to hack on // the new alloca we introduce. if (AllSimple) { ByValArgsToTransform.insert(PtrArg); continue; } } } } // Otherwise, see if we can promote the pointer to its value. if (isSafeToPromoteArgument(PtrArg, isByVal)) ArgsToPromote.insert(PtrArg); } // No promotable pointer arguments. if (ArgsToPromote.empty() && ByValArgsToTransform.empty()) return 0; return DoPromotion(F, ArgsToPromote, ByValArgsToTransform); }
/// Remove dead functions that are not included in DNR (Do Not Remove) list. bool Inliner::removeDeadFunctions(CallGraph &CG, bool AlwaysInlineOnly) { SmallVector<CallGraphNode*, 16> FunctionsToRemove; // Scan for all of the functions, looking for ones that should now be removed // from the program. Insert the dead ones in the FunctionsToRemove set. for (CallGraph::iterator I = CG.begin(), E = CG.end(); I != E; ++I) { CallGraphNode *CGN = I->second; Function *F = CGN->getFunction(); if (!F || F->isDeclaration()) continue; // Handle the case when this function is called and we only want to care // about always-inline functions. This is a bit of a hack to share code // between here and the InlineAlways pass. if (AlwaysInlineOnly && !F->hasFnAttribute(Attribute::AlwaysInline)) continue; // If the only remaining users of the function are dead constants, remove // them. F->removeDeadConstantUsers(); if (!F->isDefTriviallyDead()) continue; // It is unsafe to drop a function with discardable linkage from a COMDAT // without also dropping the other members of the COMDAT. // The inliner doesn't visit non-function entities which are in COMDAT // groups so it is unsafe to do so *unless* the linkage is local. if (!F->hasLocalLinkage() && F->hasComdat()) continue; // Remove any call graph edges from the function to its callees. CGN->removeAllCalledFunctions(); // Remove any edges from the external node to the function's call graph // node. These edges might have been made irrelegant due to // optimization of the program. CG.getExternalCallingNode()->removeAnyCallEdgeTo(CGN); // Removing the node for callee from the call graph and delete it. FunctionsToRemove.push_back(CGN); } if (FunctionsToRemove.empty()) return false; // Now that we know which functions to delete, do so. We didn't want to do // this inline, because that would invalidate our CallGraph::iterator // objects. :( // // Note that it doesn't matter that we are iterating over a non-stable order // here to do this, it doesn't matter which order the functions are deleted // in. array_pod_sort(FunctionsToRemove.begin(), FunctionsToRemove.end()); FunctionsToRemove.erase(std::unique(FunctionsToRemove.begin(), FunctionsToRemove.end()), FunctionsToRemove.end()); for (SmallVectorImpl<CallGraphNode *>::iterator I = FunctionsToRemove.begin(), E = FunctionsToRemove.end(); I != E; ++I) { delete CG.removeFunctionFromModule(*I); ++NumDeleted; } return true; }
/// Returns Attribute::None, Attribute::ReadOnly or Attribute::ReadNone. static Attribute::AttrKind determinePointerReadAttrs(Argument *A, const SmallPtrSet<Argument *, 8> &SCCNodes) { SmallVector<Use *, 32> Worklist; SmallSet<Use *, 32> Visited; // inalloca arguments are always clobbered by the call. if (A->hasInAllocaAttr()) return Attribute::None; bool IsRead = false; // We don't need to track IsWritten. If A is written to, return immediately. for (Use &U : A->uses()) { Visited.insert(&U); Worklist.push_back(&U); } while (!Worklist.empty()) { Use *U = Worklist.pop_back_val(); Instruction *I = cast<Instruction>(U->getUser()); switch (I->getOpcode()) { case Instruction::BitCast: case Instruction::GetElementPtr: case Instruction::PHI: case Instruction::Select: case Instruction::AddrSpaceCast: // The original value is not read/written via this if the new value isn't. for (Use &UU : I->uses()) if (Visited.insert(&UU).second) Worklist.push_back(&UU); break; case Instruction::Call: case Instruction::Invoke: { bool Captures = true; if (I->getType()->isVoidTy()) Captures = false; auto AddUsersToWorklistIfCapturing = [&] { if (Captures) for (Use &UU : I->uses()) if (Visited.insert(&UU).second) Worklist.push_back(&UU); }; CallSite CS(I); if (CS.doesNotAccessMemory()) { AddUsersToWorklistIfCapturing(); continue; } Function *F = CS.getCalledFunction(); if (!F) { if (CS.onlyReadsMemory()) { IsRead = true; AddUsersToWorklistIfCapturing(); continue; } return Attribute::None; } // Note: the callee and the two successor blocks *follow* the argument // operands. This means there is no need to adjust UseIndex to account // for these. unsigned UseIndex = std::distance(CS.arg_begin(), U); // U cannot be the callee operand use: since we're exploring the // transitive uses of an Argument, having such a use be a callee would // imply the CallSite is an indirect call or invoke; and we'd take the // early exit above. assert(UseIndex < CS.data_operands_size() && "Data operand use expected!"); bool IsOperandBundleUse = UseIndex >= CS.getNumArgOperands(); if (UseIndex >= F->arg_size() && !IsOperandBundleUse) { assert(F->isVarArg() && "More params than args in non-varargs call"); return Attribute::None; } Captures &= !CS.doesNotCapture(UseIndex); // Since the optimizer (by design) cannot see the data flow corresponding // to a operand bundle use, these cannot participate in the optimistic SCC // analysis. Instead, we model the operand bundle uses as arguments in // call to a function external to the SCC. if (!SCCNodes.count(&*std::next(F->arg_begin(), UseIndex)) || IsOperandBundleUse) { // The accessors used on CallSite here do the right thing for calls and // invokes with operand bundles. if (!CS.onlyReadsMemory() && !CS.onlyReadsMemory(UseIndex)) return Attribute::None; if (!CS.doesNotAccessMemory(UseIndex)) IsRead = true; } AddUsersToWorklistIfCapturing(); break; } case Instruction::Load: IsRead = true; break; case Instruction::ICmp: case Instruction::Ret: break; default: return Attribute::None; } } return IsRead ? Attribute::ReadOnly : Attribute::ReadNone; }
void SILGenFunction::emitCaptures(SILLocation loc, AnyFunctionRef closure, CaptureEmission purpose, SmallVectorImpl<ManagedValue> &capturedArgs) { auto captureInfo = SGM.Types.getLoweredLocalCaptures(closure); // For boxed captures, we need to mark the contained variables as having // escaped for DI diagnostics. SmallVector<SILValue, 2> escapesToMark; // Partial applications take ownership of the context parameters, so we'll // need to pass ownership rather than merely guaranteeing parameters. bool canGuarantee; switch (purpose) { case CaptureEmission::PartialApplication: canGuarantee = false; break; case CaptureEmission::ImmediateApplication: canGuarantee = true; break; } for (auto capture : captureInfo.getCaptures()) { if (capture.isDynamicSelfMetadata()) { // The parameter type is the static Self type, but the value we // want to pass is the dynamic Self type, so upcast it. auto dynamicSelfMetatype = MetatypeType::get( captureInfo.getDynamicSelfType()); SILType dynamicSILType = getLoweredType(dynamicSelfMetatype); SILValue value = B.createMetatype(loc, dynamicSILType); capturedArgs.push_back(ManagedValue::forUnmanaged(value)); continue; } auto *vd = capture.getDecl(); switch (SGM.Types.getDeclCaptureKind(capture)) { case CaptureKind::None: break; case CaptureKind::Constant: { // let declarations. auto found = VarLocs.find(vd); assert(found != VarLocs.end()); auto Entry = found->second; auto *var = cast<VarDecl>(vd); auto &tl = getTypeLowering(var->getType()->getReferenceStorageReferent()); SILValue Val = Entry.value; if (!Val->getType().isAddress()) { // Our 'let' binding can guarantee the lifetime for the callee, // if we don't need to do anything more to it. if (canGuarantee && !var->getType()->is<ReferenceStorageType>()) { auto guaranteed = ManagedValue::forUnmanaged(Val).borrow(*this, loc); capturedArgs.push_back(guaranteed); break; } // Just retain a by-val let. Val = B.emitCopyValueOperation(loc, Val); } else { // If we have a mutable binding for a 'let', such as 'self' in an // 'init' method, load it. Val = emitLoad(loc, Val, tl, SGFContext(), IsNotTake).forward(*this); } // If we're capturing an unowned pointer by value, we will have just // loaded it into a normal retained class pointer, but we capture it as // an unowned pointer. Convert back now. if (var->getType()->is<ReferenceStorageType>()) { auto type = getLoweredType(var->getType()); Val = emitConversionFromSemanticValue(loc, Val, type); } capturedArgs.push_back(emitManagedRValueWithCleanup(Val)); break; } case CaptureKind::StorageAddress: { // No-escaping stored declarations are captured as the // address of the value. assert(VarLocs.count(vd) && "no location for captured var!"); VarLoc vl = VarLocs[vd]; assert(vl.value->getType().isAddress() && "no address for captured var!"); capturedArgs.push_back(ManagedValue::forLValue(vl.value)); break; } case CaptureKind::Box: { // LValues are captured as both the box owning the value and the // address of the value. assert(VarLocs.count(vd) && "no location for captured var!"); VarLoc vl = VarLocs[vd]; assert(vl.value->getType().isAddress() && "no address for captured var!"); // If this is a boxed variable, we can use it directly. if (vl.box) { // We can guarantee our own box to the callee. if (canGuarantee) { capturedArgs.push_back( ManagedValue::forUnmanaged(vl.box).borrow(*this, loc)); } else { capturedArgs.push_back(emitManagedRetain(loc, vl.box)); } escapesToMark.push_back(vl.value); } else { // Address only 'let' values are passed by box. This isn't great, in // that a variable captured by multiple closures will be boxed for each // one. This could be improved by doing an "isCaptured" analysis when // emitting address-only let constants, and emit them into an alloc_box // like a variable instead of into an alloc_stack. // // TODO: This might not be profitable anymore with guaranteed captures, // since we could conceivably forward the copied value into the // closure context and pass it down to the partially applied function // in-place. // TODO: Use immutable box for immutable captures. auto boxTy = SGM.Types.getContextBoxTypeForCapture(vd, vl.value->getType().getASTType(), F.getGenericEnvironment(), /*mutable*/ true); AllocBoxInst *allocBox = B.createAllocBox(loc, boxTy); ProjectBoxInst *boxAddress = B.createProjectBox(loc, allocBox, 0); B.createCopyAddr(loc, vl.value, boxAddress, IsNotTake, IsInitialization); if (canGuarantee) capturedArgs.push_back( emitManagedRValueWithCleanup(allocBox).borrow(*this, loc)); else capturedArgs.push_back(emitManagedRValueWithCleanup(allocBox)); } break; } } } // Mark box addresses as captured for DI purposes. The values must have // been fully initialized before we close over them. if (!escapesToMark.empty()) { B.createMarkFunctionEscape(loc, escapesToMark); } }
void StackAllocationPromoter::promoteAllocationToPhi() { DEBUG(llvm::dbgs() << "*** Placing Phis for : " << *ASI); // A list of blocks that will require new Phi values. BlockSet PhiBlocks; // The "piggy-bank" data-structure that we use for processing the dom-tree // bottom-up. NodePriorityQueue PQ; // Collect all of the stores into the AllocStack. We know that at this point // we have at most one store per block. for (auto UI = ASI->use_begin(), E = ASI->use_end(); UI != E; ++UI) { SILInstruction *II = UI->getUser(); // We need to place Phis for this block. if (isa<StoreInst>(II)) { // If the block is in the dom tree (dominated by the entry block). if (DomTreeNode *Node = DT->getNode(II->getParent())) PQ.push(std::make_pair(Node, DomTreeLevels[Node])); } } DEBUG(llvm::dbgs() << "*** Found: " << PQ.size() << " Defs\n"); // A list of nodes for which we already calculated the dominator frontier. llvm::SmallPtrSet<DomTreeNode *, 32> Visited; SmallVector<DomTreeNode *, 32> Worklist; // Scan all of the definitions in the function bottom-up using the priority // queue. while (!PQ.empty()) { DomTreeNodePair RootPair = PQ.top(); PQ.pop(); DomTreeNode *Root = RootPair.first; unsigned RootLevel = RootPair.second; // Walk all dom tree children of Root, inspecting their successors. Only // J-edges, whose target level is at most Root's level are added to the // dominance frontier. Worklist.clear(); Worklist.push_back(Root); while (!Worklist.empty()) { DomTreeNode *Node = Worklist.pop_back_val(); SILBasicBlock *BB = Node->getBlock(); // For all successors of the node: for (auto &Succ : BB->getSuccessors()) { DomTreeNode *SuccNode = DT->getNode(Succ); // Skip D-edges (edges that are dom-tree edges). if (SuccNode->getIDom() == Node) continue; // Ignore J-edges that point to nodes that are not smaller or equal // to the root level. unsigned SuccLevel = DomTreeLevels[SuccNode]; if (SuccLevel > RootLevel) continue; // Ignore visited nodes. if (!Visited.insert(SuccNode).second) continue; // If the new PHInode is not dominated by the allocation then it's dead. if (!DT->dominates(ASI->getParent(), SuccNode->getBlock())) continue; // If the new PHInode is properly dominated by the deallocation then it // is obviously a dead PHInode, so we don't need to insert it. if (DSI && DT->properlyDominates(DSI->getParent(), SuccNode->getBlock())) continue; // The successor node is a new PHINode. If this is a new PHI node // then it may require additional definitions, so add it to the PQ. if (PhiBlocks.insert(Succ).second) PQ.push(std::make_pair(SuccNode, SuccLevel)); } // Add the children in the dom-tree to the worklist. for (auto CI = Node->begin(), CE = Node->end(); CI != CE; ++CI) if (!Visited.count(*CI)) Worklist.push_back(*CI); } } DEBUG(llvm::dbgs() << "*** Found: " << PhiBlocks.size() << " new PHIs\n"); NumPhiPlaced += PhiBlocks.size(); // At this point we calculated the locations of all of the new Phi values. // Next, add the Phi values and promote all of the loads and stores into the // new locations. // Replace the dummy values with new block arguments. addBlockArguments(PhiBlocks); // Hook up the Phi nodes, loads, and debug_value_addr with incoming values. fixBranchesAndUses(PhiBlocks); DEBUG(llvm::dbgs() << "*** Finished placing Phis ***\n"); }
void SILGenFunction::emitArtificialTopLevel(ClassDecl *mainClass) { // Load argc and argv from the entry point arguments. SILValue argc = F.begin()->getArgument(0); SILValue argv = F.begin()->getArgument(1); switch (mainClass->getArtificialMainKind()) { case ArtificialMainKind::UIApplicationMain: { // Emit a UIKit main. // return UIApplicationMain(C_ARGC, C_ARGV, nil, ClassName); CanType NSStringTy = SGM.Types.getNSStringType(); CanType OptNSStringTy = OptionalType::get(NSStringTy)->getCanonicalType(); // Look up UIApplicationMain. // FIXME: Doing an AST lookup here is gross and not entirely sound; // we're getting away with it because the types are guaranteed to already // be imported. ASTContext &ctx = getASTContext(); ModuleDecl *UIKit = ctx.getLoadedModule(ctx.getIdentifier("UIKit")); SmallVector<ValueDecl *, 1> results; UIKit->lookupQualified(UIKit->getInterfaceType(), ctx.getIdentifier("UIApplicationMain"), NL_QualifiedDefault, /*resolver*/nullptr, results); assert(!results.empty() && "couldn't find UIApplicationMain in UIKit"); assert(results.size() == 1 && "more than one UIApplicationMain?"); auto mainRef = SILDeclRef(results.front()).asForeign(); auto UIApplicationMainFn = SGM.M.getOrCreateFunction(mainClass, mainRef, NotForDefinition); auto fnTy = UIApplicationMainFn->getLoweredFunctionType(); SILFunctionConventions fnConv(fnTy, SGM.M); // Get the class name as a string using NSStringFromClass. CanType mainClassTy = mainClass->getDeclaredInterfaceType() ->getCanonicalType(); CanType mainClassMetaty = CanMetatypeType::get(mainClassTy, MetatypeRepresentation::ObjC); CanType anyObjectTy = ctx.getAnyObjectType(); CanType anyObjectMetaTy = CanExistentialMetatypeType::get(anyObjectTy, MetatypeRepresentation::ObjC); auto NSStringFromClassType = SILFunctionType::get(nullptr, SILFunctionType::ExtInfo() .withRepresentation(SILFunctionType::Representation:: CFunctionPointer), SILCoroutineKind::None, ParameterConvention::Direct_Unowned, SILParameterInfo(anyObjectMetaTy, ParameterConvention::Direct_Unowned), /*yields*/ {}, SILResultInfo(OptNSStringTy, ResultConvention::Autoreleased), /*error result*/ None, ctx); auto NSStringFromClassFn = SGM.M.getOrCreateFunction(mainClass, "NSStringFromClass", SILLinkage::PublicExternal, NSStringFromClassType, IsBare, IsTransparent, IsNotSerialized); auto NSStringFromClass = B.createFunctionRef(mainClass, NSStringFromClassFn); SILValue metaTy = B.createMetatype(mainClass, SILType::getPrimitiveObjectType(mainClassMetaty)); metaTy = B.createInitExistentialMetatype(mainClass, metaTy, SILType::getPrimitiveObjectType(anyObjectMetaTy), {}); SILValue optName = B.createApply(mainClass, NSStringFromClass, NSStringFromClass->getType(), SILType::getPrimitiveObjectType(OptNSStringTy), {}, metaTy); // Fix up the string parameters to have the right type. SILType nameArgTy = fnConv.getSILArgumentType(3); assert(nameArgTy == fnConv.getSILArgumentType(2)); auto managedName = ManagedValue::forUnmanaged(optName); SILValue nilValue; assert(optName->getType() == nameArgTy); nilValue = getOptionalNoneValue(mainClass, getTypeLowering(OptNSStringTy)); // Fix up argv to have the right type. auto argvTy = fnConv.getSILArgumentType(1); SILType unwrappedTy = argvTy; if (Type innerTy = argvTy.getASTType()->getOptionalObjectType()) { auto canInnerTy = innerTy->getCanonicalType(); unwrappedTy = SILType::getPrimitiveObjectType(canInnerTy); } auto managedArgv = ManagedValue::forUnmanaged(argv); if (unwrappedTy != argv->getType()) { auto converted = emitPointerToPointer(mainClass, managedArgv, argv->getType().getASTType(), unwrappedTy.getASTType()); managedArgv = std::move(converted).getAsSingleValue(*this, mainClass); } if (unwrappedTy != argvTy) { managedArgv = getOptionalSomeValue(mainClass, managedArgv, getTypeLowering(argvTy)); } auto UIApplicationMain = B.createFunctionRef(mainClass, UIApplicationMainFn); SILValue args[] = {argc, managedArgv.getValue(), nilValue, managedName.getValue()}; B.createApply(mainClass, UIApplicationMain, UIApplicationMain->getType(), argc->getType(), {}, args); SILValue r = B.createIntegerLiteral(mainClass, SILType::getBuiltinIntegerType(32, ctx), 0); auto rType = F.getConventions().getSingleSILResultType(); if (r->getType() != rType) r = B.createStruct(mainClass, rType, r); Cleanups.emitCleanupsForReturn(mainClass); B.createReturn(mainClass, r); return; } case ArtificialMainKind::NSApplicationMain: { // Emit an AppKit main. // return NSApplicationMain(C_ARGC, C_ARGV); SILParameterInfo argTypes[] = { SILParameterInfo(argc->getType().getASTType(), ParameterConvention::Direct_Unowned), SILParameterInfo(argv->getType().getASTType(), ParameterConvention::Direct_Unowned), }; auto NSApplicationMainType = SILFunctionType::get(nullptr, SILFunctionType::ExtInfo() // Should be C calling convention, but NSApplicationMain // has an overlay to fix the type of argv. .withRepresentation(SILFunctionType::Representation::Thin), SILCoroutineKind::None, ParameterConvention::Direct_Unowned, argTypes, /*yields*/ {}, SILResultInfo(argc->getType().getASTType(), ResultConvention::Unowned), /*error result*/ None, getASTContext()); auto NSApplicationMainFn = SGM.M.getOrCreateFunction(mainClass, "NSApplicationMain", SILLinkage::PublicExternal, NSApplicationMainType, IsBare, IsTransparent, IsNotSerialized); auto NSApplicationMain = B.createFunctionRef(mainClass, NSApplicationMainFn); SILValue args[] = { argc, argv }; B.createApply(mainClass, NSApplicationMain, NSApplicationMain->getType(), argc->getType(), {}, args); SILValue r = B.createIntegerLiteral(mainClass, SILType::getBuiltinIntegerType(32, getASTContext()), 0); auto rType = F.getConventions().getSingleSILResultType(); if (r->getType() != rType) r = B.createStruct(mainClass, rType, r); B.createReturn(mainClass, r); return; } } }
SDValue Cpu0TargetLowering::LowerCall(SDValue InChain, SDValue Callee, CallingConv::ID CallConv, bool isVarArg, bool doesNotRet, bool &isTailCall, const SmallVectorImpl<ISD::OutputArg> &Outs, const SmallVectorImpl<SDValue> &OutVals, const SmallVectorImpl<ISD::InputArg> &Ins, DebugLoc dl, SelectionDAG &DAG, SmallVectorImpl<SDValue> &InVals) const { // Cpu0 target does not yet support tail call optimization. isTailCall = false; MachineFunction &MF = DAG.getMachineFunction(); MachineFrameInfo *MFI = MF.getFrameInfo(); const TargetFrameLowering *TFL = MF.getTarget().getFrameLowering(); bool IsPIC = getTargetMachine().getRelocationModel() == Reloc::PIC_; Cpu0FunctionInfo *Cpu0FI = MF.getInfo<Cpu0FunctionInfo>(); // Analyze operands of the call, assigning locations to each operand. SmallVector<CCValAssign, 16> ArgLocs; CCState CCInfo(CallConv, isVarArg, DAG.getMachineFunction(), getTargetMachine(), ArgLocs, *DAG.getContext()); CCInfo.AnalyzeCallOperands(Outs, CC_Cpu0); // Get a count of how many bytes are to be pushed on the stack. unsigned NextStackOffset = CCInfo.getNextStackOffset(); // If this is the first call, create a stack frame object that points to // a location to which .cprestore saves $gp. if (IsPIC && Cpu0FI->globalBaseRegFixed() && !Cpu0FI->getGPFI()) Cpu0FI->setGPFI(MFI->CreateFixedObject(4, 0, true)); // Get the frame index of the stack frame object that points to the location // of dynamically allocated area on the stack. int DynAllocFI = Cpu0FI->getDynAllocFI(); unsigned MaxCallFrameSize = Cpu0FI->getMaxCallFrameSize(); if (MaxCallFrameSize < NextStackOffset) { Cpu0FI->setMaxCallFrameSize(NextStackOffset); // Set the offsets relative to $sp of the $gp restore slot and dynamically // allocated stack space. These offsets must be aligned to a boundary // determined by the stack alignment of the ABI. unsigned StackAlignment = TFL->getStackAlignment(); NextStackOffset = (NextStackOffset + StackAlignment - 1) / StackAlignment * StackAlignment; if (Cpu0FI->needGPSaveRestore()) MFI->setObjectOffset(Cpu0FI->getGPFI(), NextStackOffset); MFI->setObjectOffset(DynAllocFI, NextStackOffset); } // Chain is the output chain of the last Load/Store or CopyToReg node. // ByValChain is the output chain of the last Memcpy node created for copying // byval arguments to the stack. SDValue Chain, CallSeqStart, ByValChain; SDValue NextStackOffsetVal = DAG.getIntPtrConstant(NextStackOffset, true); Chain = CallSeqStart = DAG.getCALLSEQ_START(InChain, NextStackOffsetVal); ByValChain = InChain; // With EABI is it possible to have 16 args on registers. SmallVector<std::pair<unsigned, SDValue>, 16> RegsToPass; SmallVector<SDValue, 8> MemOpChains; int FirstFI = -MFI->getNumFixedObjects() - 1, LastFI = 0; // Walk the register/memloc assignments, inserting copies/loads. for (unsigned i = 0, e = ArgLocs.size(); i != e; ++i) { SDValue Arg = OutVals[i]; CCValAssign &VA = ArgLocs[i]; MVT ValVT = VA.getValVT(), LocVT = VA.getLocVT(); ISD::ArgFlagsTy Flags = Outs[i].Flags; // ByVal Arg. if (Flags.isByVal()) { assert("!!!Error!!!, Flags.isByVal()==true"); assert(Flags.getByValSize() && "ByVal args of size 0 should have been ignored by front-end."); continue; } // Register can't get to this point... assert(VA.isMemLoc()); // Create the frame index object for this incoming parameter LastFI = MFI->CreateFixedObject(ValVT.getSizeInBits()/8, VA.getLocMemOffset(), true); SDValue PtrOff = DAG.getFrameIndex(LastFI, getPointerTy()); // emit ISD::STORE whichs stores the // parameter value to a stack Location MemOpChains.push_back(DAG.getStore(Chain, dl, Arg, PtrOff, MachinePointerInfo(), false, false, 0)); } // Extend range of indices of frame objects for outgoing arguments that were // created during this function call. Skip this step if no such objects were // created. if (LastFI) Cpu0FI->extendOutArgFIRange(FirstFI, LastFI); // If a memcpy has been created to copy a byval arg to a stack, replace the // chain input of CallSeqStart with ByValChain. if (InChain != ByValChain) DAG.UpdateNodeOperands(CallSeqStart.getNode(), ByValChain, NextStackOffsetVal); // Transform all store nodes into one single node because all store // nodes are independent of each other. if (!MemOpChains.empty()) Chain = DAG.getNode(ISD::TokenFactor, dl, MVT::Other, &MemOpChains[0], MemOpChains.size()); // If the callee is a GlobalAddress/ExternalSymbol node (quite common, every // direct call is) turn it into a TargetGlobalAddress/TargetExternalSymbol // node so that legalize doesn't hack it. unsigned char OpFlag; bool IsPICCall = IsPIC; // true if calls are translated to jalr $25 bool GlobalOrExternal = false; SDValue CalleeLo; if (GlobalAddressSDNode *G = dyn_cast<GlobalAddressSDNode>(Callee)) { OpFlag = IsPICCall ? Cpu0II::MO_GOT_CALL : Cpu0II::MO_NO_FLAG; Callee = DAG.getTargetGlobalAddress(G->getGlobal(), dl, getPointerTy(), 0, OpFlag); GlobalOrExternal = true; } else if (ExternalSymbolSDNode *S = dyn_cast<ExternalSymbolSDNode>(Callee)) { if (!IsPIC) // static OpFlag = Cpu0II::MO_NO_FLAG; else // O32 & PIC OpFlag = Cpu0II::MO_GOT_CALL; Callee = DAG.getTargetExternalSymbol(S->getSymbol(), getPointerTy(), OpFlag); GlobalOrExternal = true; } SDValue InFlag; // Create nodes that load address of callee and copy it to T9 if (IsPICCall) { if (GlobalOrExternal) { // Load callee address Callee = DAG.getNode(Cpu0ISD::Wrapper, dl, getPointerTy(), GetGlobalReg(DAG, getPointerTy()), Callee); SDValue LoadValue = DAG.getLoad(getPointerTy(), dl, DAG.getEntryNode(), Callee, MachinePointerInfo::getGOT(), false, false, false, 0); // Use GOT+LO if callee has internal linkage. if (CalleeLo.getNode()) { SDValue Lo = DAG.getNode(Cpu0ISD::Lo, dl, getPointerTy(), CalleeLo); Callee = DAG.getNode(ISD::ADD, dl, getPointerTy(), LoadValue, Lo); } else Callee = LoadValue; } } // T9 should contain the address of the callee function if // -reloction-model=pic or it is an indirect call. if (IsPICCall || !GlobalOrExternal) { // copy to T9 unsigned T9Reg = Cpu0::T9; Chain = DAG.getCopyToReg(Chain, dl, T9Reg, Callee, SDValue(0, 0)); InFlag = Chain.getValue(1); Callee = DAG.getRegister(T9Reg, getPointerTy()); } // Cpu0JmpLink = #chain, #target_address, #opt_in_flags... // = Chain, Callee, Reg#1, Reg#2, ... // // Returns a chain & a flag for retval copy to use. SDVTList NodeTys = DAG.getVTList(MVT::Other, MVT::Glue); SmallVector<SDValue, 8> Ops; Ops.push_back(Chain); Ops.push_back(Callee); // Add argument registers to the end of the list so that they are // known live into the call. for (unsigned i = 0, e = RegsToPass.size(); i != e; ++i) Ops.push_back(DAG.getRegister(RegsToPass[i].first, RegsToPass[i].second.getValueType())); // Add a register mask operand representing the call-preserved registers. const TargetRegisterInfo *TRI = getTargetMachine().getRegisterInfo(); const uint32_t *Mask = TRI->getCallPreservedMask(CallConv); assert(Mask && "Missing call preserved mask for calling convention"); Ops.push_back(DAG.getRegisterMask(Mask)); if (InFlag.getNode()) Ops.push_back(InFlag); Chain = DAG.getNode(Cpu0ISD::JmpLink, dl, NodeTys, &Ops[0], Ops.size()); InFlag = Chain.getValue(1); // Create the CALLSEQ_END node. Chain = DAG.getCALLSEQ_END(Chain, DAG.getIntPtrConstant(NextStackOffset, true), DAG.getIntPtrConstant(0, true), InFlag); InFlag = Chain.getValue(1); // Handle result values, copying them out of physregs into vregs that we // return. return LowerCallResult(Chain, InFlag, CallConv, isVarArg, Ins, dl, DAG, InVals); }
MachineBasicBlock * MachineBasicBlock::SplitCriticalEdge(MachineBasicBlock *Succ, Pass *P) { // Splitting the critical edge to a landing pad block is non-trivial. Don't do // it in this generic function. if (Succ->isLandingPad()) return NULL; MachineFunction *MF = getParent(); DebugLoc dl; // FIXME: this is nowhere // We may need to update this's terminator, but we can't do that if // AnalyzeBranch fails. If this uses a jump table, we won't touch it. const TargetInstrInfo *TII = MF->getTarget().getInstrInfo(); MachineBasicBlock *TBB = 0, *FBB = 0; SmallVector<MachineOperand, 4> Cond; if (TII->AnalyzeBranch(*this, TBB, FBB, Cond)) return NULL; // Avoid bugpoint weirdness: A block may end with a conditional branch but // jumps to the same MBB is either case. We have duplicate CFG edges in that // case that we can't handle. Since this never happens in properly optimized // code, just skip those edges. if (TBB && TBB == FBB) { DEBUG(dbgs() << "Won't split critical edge after degenerate BB#" << getNumber() << '\n'); return NULL; } MachineBasicBlock *NMBB = MF->CreateMachineBasicBlock(); MF->insert(llvm::next(MachineFunction::iterator(this)), NMBB); DEBUG(dbgs() << "Splitting critical edge:" " BB#" << getNumber() << " -- BB#" << NMBB->getNumber() << " -- BB#" << Succ->getNumber() << '\n'); LiveIntervals *LIS = P->getAnalysisIfAvailable<LiveIntervals>(); SlotIndexes *Indexes = P->getAnalysisIfAvailable<SlotIndexes>(); if (LIS) LIS->insertMBBInMaps(NMBB); else if (Indexes) Indexes->insertMBBInMaps(NMBB); // On some targets like Mips, branches may kill virtual registers. Make sure // that LiveVariables is properly updated after updateTerminator replaces the // terminators. LiveVariables *LV = P->getAnalysisIfAvailable<LiveVariables>(); // Collect a list of virtual registers killed by the terminators. SmallVector<unsigned, 4> KilledRegs; if (LV) for (instr_iterator I = getFirstInstrTerminator(), E = instr_end(); I != E; ++I) { MachineInstr *MI = I; for (MachineInstr::mop_iterator OI = MI->operands_begin(), OE = MI->operands_end(); OI != OE; ++OI) { if (!OI->isReg() || OI->getReg() == 0 || !OI->isUse() || !OI->isKill() || OI->isUndef()) continue; unsigned Reg = OI->getReg(); if (TargetRegisterInfo::isPhysicalRegister(Reg) || LV->getVarInfo(Reg).removeKill(MI)) { KilledRegs.push_back(Reg); DEBUG(dbgs() << "Removing terminator kill: " << *MI); OI->setIsKill(false); } } } SmallVector<unsigned, 4> UsedRegs; if (LIS) { for (instr_iterator I = getFirstInstrTerminator(), E = instr_end(); I != E; ++I) { MachineInstr *MI = I; for (MachineInstr::mop_iterator OI = MI->operands_begin(), OE = MI->operands_end(); OI != OE; ++OI) { if (!OI->isReg() || OI->getReg() == 0) continue; unsigned Reg = OI->getReg(); if (std::find(UsedRegs.begin(), UsedRegs.end(), Reg) == UsedRegs.end()) UsedRegs.push_back(Reg); } } } ReplaceUsesOfBlockWith(Succ, NMBB); // If updateTerminator() removes instructions, we need to remove them from // SlotIndexes. SmallVector<MachineInstr*, 4> Terminators; if (Indexes) { for (instr_iterator I = getFirstInstrTerminator(), E = instr_end(); I != E; ++I) Terminators.push_back(I); } updateTerminator(); if (Indexes) { SmallVector<MachineInstr*, 4> NewTerminators; for (instr_iterator I = getFirstInstrTerminator(), E = instr_end(); I != E; ++I) NewTerminators.push_back(I); for (SmallVectorImpl<MachineInstr*>::iterator I = Terminators.begin(), E = Terminators.end(); I != E; ++I) { if (std::find(NewTerminators.begin(), NewTerminators.end(), *I) == NewTerminators.end()) Indexes->removeMachineInstrFromMaps(*I); } } // Insert unconditional "jump Succ" instruction in NMBB if necessary. NMBB->addSuccessor(Succ); if (!NMBB->isLayoutSuccessor(Succ)) { Cond.clear(); MF->getTarget().getInstrInfo()->InsertBranch(*NMBB, Succ, NULL, Cond, dl); if (Indexes) { for (instr_iterator I = NMBB->instr_begin(), E = NMBB->instr_end(); I != E; ++I) { // Some instructions may have been moved to NMBB by updateTerminator(), // so we first remove any instruction that already has an index. if (Indexes->hasIndex(I)) Indexes->removeMachineInstrFromMaps(I); Indexes->insertMachineInstrInMaps(I); } } } // Fix PHI nodes in Succ so they refer to NMBB instead of this for (MachineBasicBlock::instr_iterator i = Succ->instr_begin(),e = Succ->instr_end(); i != e && i->isPHI(); ++i) for (unsigned ni = 1, ne = i->getNumOperands(); ni != ne; ni += 2) if (i->getOperand(ni+1).getMBB() == this) i->getOperand(ni+1).setMBB(NMBB); // Inherit live-ins from the successor for (MachineBasicBlock::livein_iterator I = Succ->livein_begin(), E = Succ->livein_end(); I != E; ++I) NMBB->addLiveIn(*I); // Update LiveVariables. const TargetRegisterInfo *TRI = MF->getTarget().getRegisterInfo(); if (LV) { // Restore kills of virtual registers that were killed by the terminators. while (!KilledRegs.empty()) { unsigned Reg = KilledRegs.pop_back_val(); for (instr_iterator I = instr_end(), E = instr_begin(); I != E;) { if (!(--I)->addRegisterKilled(Reg, TRI, /* addIfNotFound= */ false)) continue; if (TargetRegisterInfo::isVirtualRegister(Reg)) LV->getVarInfo(Reg).Kills.push_back(I); DEBUG(dbgs() << "Restored terminator kill: " << *I); break; } } // Update relevant live-through information. LV->addNewBlock(NMBB, this, Succ); } if (LIS) { // After splitting the edge and updating SlotIndexes, live intervals may be // in one of two situations, depending on whether this block was the last in // the function. If the original block was the last in the function, all live // intervals will end prior to the beginning of the new split block. If the // original block was not at the end of the function, all live intervals will // extend to the end of the new split block. bool isLastMBB = llvm::next(MachineFunction::iterator(NMBB)) == getParent()->end(); SlotIndex StartIndex = Indexes->getMBBEndIdx(this); SlotIndex PrevIndex = StartIndex.getPrevSlot(); SlotIndex EndIndex = Indexes->getMBBEndIdx(NMBB); // Find the registers used from NMBB in PHIs in Succ. SmallSet<unsigned, 8> PHISrcRegs; for (MachineBasicBlock::instr_iterator I = Succ->instr_begin(), E = Succ->instr_end(); I != E && I->isPHI(); ++I) { for (unsigned ni = 1, ne = I->getNumOperands(); ni != ne; ni += 2) { if (I->getOperand(ni+1).getMBB() == NMBB) { MachineOperand &MO = I->getOperand(ni); unsigned Reg = MO.getReg(); PHISrcRegs.insert(Reg); if (MO.isUndef()) continue; LiveInterval &LI = LIS->getInterval(Reg); VNInfo *VNI = LI.getVNInfoAt(PrevIndex); assert(VNI && "PHI sources should be live out of their predecessors."); LI.addRange(LiveRange(StartIndex, EndIndex, VNI)); } } } MachineRegisterInfo *MRI = &getParent()->getRegInfo(); for (unsigned i = 0, e = MRI->getNumVirtRegs(); i != e; ++i) { unsigned Reg = TargetRegisterInfo::index2VirtReg(i); if (PHISrcRegs.count(Reg) || !LIS->hasInterval(Reg)) continue; LiveInterval &LI = LIS->getInterval(Reg); if (!LI.liveAt(PrevIndex)) continue; bool isLiveOut = LI.liveAt(LIS->getMBBStartIdx(Succ)); if (isLiveOut && isLastMBB) { VNInfo *VNI = LI.getVNInfoAt(PrevIndex); assert(VNI && "LiveInterval should have VNInfo where it is live."); LI.addRange(LiveRange(StartIndex, EndIndex, VNI)); } else if (!isLiveOut && !isLastMBB) { LI.removeRange(StartIndex, EndIndex); } } // Update all intervals for registers whose uses may have been modified by // updateTerminator(). LIS->repairIntervalsInRange(this, getFirstTerminator(), end(), UsedRegs); } if (MachineDominatorTree *MDT = P->getAnalysisIfAvailable<MachineDominatorTree>()) { // Update dominator information. MachineDomTreeNode *SucccDTNode = MDT->getNode(Succ); bool IsNewIDom = true; for (const_pred_iterator PI = Succ->pred_begin(), E = Succ->pred_end(); PI != E; ++PI) { MachineBasicBlock *PredBB = *PI; if (PredBB == NMBB) continue; if (!MDT->dominates(SucccDTNode, MDT->getNode(PredBB))) { IsNewIDom = false; break; } } // We know "this" dominates the newly created basic block. MachineDomTreeNode *NewDTNode = MDT->addNewBlock(NMBB, this); // If all the other predecessors of "Succ" are dominated by "Succ" itself // then the new block is the new immediate dominator of "Succ". Otherwise, // the new block doesn't dominate anything. if (IsNewIDom) MDT->changeImmediateDominator(SucccDTNode, NewDTNode); } if (MachineLoopInfo *MLI = P->getAnalysisIfAvailable<MachineLoopInfo>()) if (MachineLoop *TIL = MLI->getLoopFor(this)) { // If one or the other blocks were not in a loop, the new block is not // either, and thus LI doesn't need to be updated. if (MachineLoop *DestLoop = MLI->getLoopFor(Succ)) { if (TIL == DestLoop) { // Both in the same loop, the NMBB joins loop. DestLoop->addBasicBlockToLoop(NMBB, MLI->getBase()); } else if (TIL->contains(DestLoop)) { // Edge from an outer loop to an inner loop. Add to the outer loop. TIL->addBasicBlockToLoop(NMBB, MLI->getBase()); } else if (DestLoop->contains(TIL)) { // Edge from an inner loop to an outer loop. Add to the outer loop. DestLoop->addBasicBlockToLoop(NMBB, MLI->getBase()); } else { // Edge from two loops with no containment relation. Because these // are natural loops, we know that the destination block must be the // header of its loop (adding a branch into a loop elsewhere would // create an irreducible loop). assert(DestLoop->getHeader() == Succ && "Should not create irreducible loops!"); if (MachineLoop *P = DestLoop->getParentLoop()) P->addBasicBlockToLoop(NMBB, MLI->getBase()); } } } return NMBB; }
bool SjLjEHPass::insertSjLjEHSupport(Function &F) { SmallVector<ReturnInst*,16> Returns; SmallVector<UnwindInst*,16> Unwinds; SmallVector<InvokeInst*,16> Invokes; // Look through the terminators of the basic blocks to find invokes, returns // and unwinds. for (Function::iterator BB = F.begin(), E = F.end(); BB != E; ++BB) { if (ReturnInst *RI = dyn_cast<ReturnInst>(BB->getTerminator())) { // Remember all return instructions in case we insert an invoke into this // function. Returns.push_back(RI); } else if (InvokeInst *II = dyn_cast<InvokeInst>(BB->getTerminator())) { Invokes.push_back(II); } else if (UnwindInst *UI = dyn_cast<UnwindInst>(BB->getTerminator())) { Unwinds.push_back(UI); } } // If we don't have any invokes or unwinds, there's nothing to do. if (Unwinds.empty() && Invokes.empty()) return false; // Find the eh.selector.*, eh.exception and alloca calls. // // Remember any allocas() that aren't in the entry block, as the // jmpbuf saved SP will need to be updated for them. // // We'll use the first eh.selector to determine the right personality // function to use. For SJLJ, we always use the same personality for the // whole function, not on a per-selector basis. // FIXME: That's a bit ugly. Better way? SmallVector<CallInst*,16> EH_Selectors; SmallVector<CallInst*,16> EH_Exceptions; SmallVector<Instruction*,16> JmpbufUpdatePoints; // Note: Skip the entry block since there's nothing there that interests // us. eh.selector and eh.exception shouldn't ever be there, and we // want to disregard any allocas that are there. for (Function::iterator BB = F.begin(), E = F.end(); ++BB != E;) { for (BasicBlock::iterator I = BB->begin(), E = BB->end(); I != E; ++I) { if (CallInst *CI = dyn_cast<CallInst>(I)) { if (CI->getCalledFunction() == SelectorFn) { if (!PersonalityFn) PersonalityFn = CI->getArgOperand(1); EH_Selectors.push_back(CI); } else if (CI->getCalledFunction() == ExceptionFn) { EH_Exceptions.push_back(CI); } else if (CI->getCalledFunction() == StackRestoreFn) { JmpbufUpdatePoints.push_back(CI); } } else if (AllocaInst *AI = dyn_cast<AllocaInst>(I)) { JmpbufUpdatePoints.push_back(AI); } } } // If we don't have any eh.selector calls, we can't determine the personality // function. Without a personality function, we can't process exceptions. if (!PersonalityFn) return false; NumInvokes += Invokes.size(); NumUnwinds += Unwinds.size(); if (!Invokes.empty()) { // We have invokes, so we need to add register/unregister calls to get // this function onto the global unwind stack. // // First thing we need to do is scan the whole function for values that are // live across unwind edges. Each value that is live across an unwind edge // we spill into a stack location, guaranteeing that there is nothing live // across the unwind edge. This process also splits all critical edges // coming out of invoke's. splitLiveRangesAcrossInvokes(Invokes); BasicBlock *EntryBB = F.begin(); // Create an alloca for the incoming jump buffer ptr and the new jump buffer // that needs to be restored on all exits from the function. This is an // alloca because the value needs to be added to the global context list. unsigned Align = 4; // FIXME: Should be a TLI check? AllocaInst *FunctionContext = new AllocaInst(FunctionContextTy, 0, Align, "fcn_context", F.begin()->begin()); Value *Idxs[2]; const Type *Int32Ty = Type::getInt32Ty(F.getContext()); Value *Zero = ConstantInt::get(Int32Ty, 0); // We need to also keep around a reference to the call_site field Idxs[0] = Zero; Idxs[1] = ConstantInt::get(Int32Ty, 1); CallSite = GetElementPtrInst::Create(FunctionContext, Idxs, Idxs+2, "call_site", EntryBB->getTerminator()); // The exception selector comes back in context->data[1] Idxs[1] = ConstantInt::get(Int32Ty, 2); Value *FCData = GetElementPtrInst::Create(FunctionContext, Idxs, Idxs+2, "fc_data", EntryBB->getTerminator()); Idxs[1] = ConstantInt::get(Int32Ty, 1); Value *SelectorAddr = GetElementPtrInst::Create(FCData, Idxs, Idxs+2, "exc_selector_gep", EntryBB->getTerminator()); // The exception value comes back in context->data[0] Idxs[1] = Zero; Value *ExceptionAddr = GetElementPtrInst::Create(FCData, Idxs, Idxs+2, "exception_gep", EntryBB->getTerminator()); // The result of the eh.selector call will be replaced with a // a reference to the selector value returned in the function // context. We leave the selector itself so the EH analysis later // can use it. for (int i = 0, e = EH_Selectors.size(); i < e; ++i) { CallInst *I = EH_Selectors[i]; Value *SelectorVal = new LoadInst(SelectorAddr, "select_val", true, I); I->replaceAllUsesWith(SelectorVal); } // eh.exception calls are replaced with references to the proper // location in the context. Unlike eh.selector, the eh.exception // calls are removed entirely. for (int i = 0, e = EH_Exceptions.size(); i < e; ++i) { CallInst *I = EH_Exceptions[i]; // Possible for there to be duplicates, so check to make sure // the instruction hasn't already been removed. if (!I->getParent()) continue; Value *Val = new LoadInst(ExceptionAddr, "exception", true, I); const Type *Ty = Type::getInt8PtrTy(F.getContext()); Val = CastInst::Create(Instruction::IntToPtr, Val, Ty, "", I); I->replaceAllUsesWith(Val); I->eraseFromParent(); } // The entry block changes to have the eh.sjlj.setjmp, with a conditional // branch to a dispatch block for non-zero returns. If we return normally, // we're not handling an exception and just register the function context // and continue. // Create the dispatch block. The dispatch block is basically a big switch // statement that goes to all of the invoke landing pads. BasicBlock *DispatchBlock = BasicBlock::Create(F.getContext(), "eh.sjlj.setjmp.catch", &F); // Insert a load in the Catch block, and a switch on its value. By default, // we go to a block that just does an unwind (which is the correct action // for a standard call). BasicBlock *UnwindBlock = BasicBlock::Create(F.getContext(), "unwindbb", &F); Unwinds.push_back(new UnwindInst(F.getContext(), UnwindBlock)); Value *DispatchLoad = new LoadInst(CallSite, "invoke.num", true, DispatchBlock); SwitchInst *DispatchSwitch = SwitchInst::Create(DispatchLoad, UnwindBlock, Invokes.size(), DispatchBlock); // Split the entry block to insert the conditional branch for the setjmp. BasicBlock *ContBlock = EntryBB->splitBasicBlock(EntryBB->getTerminator(), "eh.sjlj.setjmp.cont"); // Populate the Function Context // 1. LSDA address // 2. Personality function address // 3. jmpbuf (save SP, FP and call eh.sjlj.setjmp) // LSDA address Idxs[0] = Zero; Idxs[1] = ConstantInt::get(Int32Ty, 4); Value *LSDAFieldPtr = GetElementPtrInst::Create(FunctionContext, Idxs, Idxs+2, "lsda_gep", EntryBB->getTerminator()); Value *LSDA = CallInst::Create(LSDAAddrFn, "lsda_addr", EntryBB->getTerminator()); new StoreInst(LSDA, LSDAFieldPtr, true, EntryBB->getTerminator()); Idxs[1] = ConstantInt::get(Int32Ty, 3); Value *PersonalityFieldPtr = GetElementPtrInst::Create(FunctionContext, Idxs, Idxs+2, "lsda_gep", EntryBB->getTerminator()); new StoreInst(PersonalityFn, PersonalityFieldPtr, true, EntryBB->getTerminator()); // Save the frame pointer. Idxs[1] = ConstantInt::get(Int32Ty, 5); Value *JBufPtr = GetElementPtrInst::Create(FunctionContext, Idxs, Idxs+2, "jbuf_gep", EntryBB->getTerminator()); Idxs[1] = ConstantInt::get(Int32Ty, 0); Value *FramePtr = GetElementPtrInst::Create(JBufPtr, Idxs, Idxs+2, "jbuf_fp_gep", EntryBB->getTerminator()); Value *Val = CallInst::Create(FrameAddrFn, ConstantInt::get(Int32Ty, 0), "fp", EntryBB->getTerminator()); new StoreInst(Val, FramePtr, true, EntryBB->getTerminator()); // Save the stack pointer. Idxs[1] = ConstantInt::get(Int32Ty, 2); Value *StackPtr = GetElementPtrInst::Create(JBufPtr, Idxs, Idxs+2, "jbuf_sp_gep", EntryBB->getTerminator()); Val = CallInst::Create(StackAddrFn, "sp", EntryBB->getTerminator()); new StoreInst(Val, StackPtr, true, EntryBB->getTerminator()); // Call the setjmp instrinsic. It fills in the rest of the jmpbuf. Value *SetjmpArg = CastInst::Create(Instruction::BitCast, JBufPtr, Type::getInt8PtrTy(F.getContext()), "", EntryBB->getTerminator()); Value *DispatchVal = CallInst::Create(BuiltinSetjmpFn, SetjmpArg, "dispatch", EntryBB->getTerminator()); // check the return value of the setjmp. non-zero goes to dispatcher. Value *IsNormal = new ICmpInst(EntryBB->getTerminator(), ICmpInst::ICMP_EQ, DispatchVal, Zero, "notunwind"); // Nuke the uncond branch. EntryBB->getTerminator()->eraseFromParent(); // Put in a new condbranch in its place. BranchInst::Create(ContBlock, DispatchBlock, IsNormal, EntryBB); // Register the function context and make sure it's known to not throw CallInst *Register = CallInst::Create(RegisterFn, FunctionContext, "", ContBlock->getTerminator()); Register->setDoesNotThrow(); // At this point, we are all set up, update the invoke instructions // to mark their call_site values, and fill in the dispatch switch // accordingly. for (unsigned i = 0, e = Invokes.size(); i != e; ++i) markInvokeCallSite(Invokes[i], i+1, CallSite, DispatchSwitch); // Mark call instructions that aren't nounwind as no-action // (call_site == -1). Skip the entry block, as prior to then, no function // context has been created for this function and any unexpected exceptions // thrown will go directly to the caller's context, which is what we want // anyway, so no need to do anything here. for (Function::iterator BB = F.begin(), E = F.end(); ++BB != E;) { for (BasicBlock::iterator I = BB->begin(), end = BB->end(); I != end; ++I) if (CallInst *CI = dyn_cast<CallInst>(I)) { // Ignore calls to the EH builtins (eh.selector, eh.exception) Constant *Callee = CI->getCalledFunction(); if (Callee != SelectorFn && Callee != ExceptionFn && !CI->doesNotThrow()) insertCallSiteStore(CI, -1, CallSite); } } // Replace all unwinds with a branch to the unwind handler. // ??? Should this ever happen with sjlj exceptions? for (unsigned i = 0, e = Unwinds.size(); i != e; ++i) { BranchInst::Create(UnwindBlock, Unwinds[i]); Unwinds[i]->eraseFromParent(); } // Following any allocas not in the entry block, update the saved SP // in the jmpbuf to the new value. for (unsigned i = 0, e = JmpbufUpdatePoints.size(); i != e; ++i) { Instruction *AI = JmpbufUpdatePoints[i]; Instruction *StackAddr = CallInst::Create(StackAddrFn, "sp"); StackAddr->insertAfter(AI); Instruction *StoreStackAddr = new StoreInst(StackAddr, StackPtr, true); StoreStackAddr->insertAfter(StackAddr); } // Finally, for any returns from this function, if this function contains an // invoke, add a call to unregister the function context. for (unsigned i = 0, e = Returns.size(); i != e; ++i) CallInst::Create(UnregisterFn, FunctionContext, "", Returns[i]); } return true; }
void UserValue::addDefsFromCopies(LiveInterval *LI, unsigned LocNo, const SmallVectorImpl<SlotIndex> &Kills, SmallVectorImpl<std::pair<SlotIndex, unsigned> > &NewDefs, MachineRegisterInfo &MRI, LiveIntervals &LIS) { if (Kills.empty()) return; // Don't track copies from physregs, there are too many uses. if (!TargetRegisterInfo::isVirtualRegister(LI->reg)) return; // Collect all the (vreg, valno) pairs that are copies of LI. SmallVector<std::pair<LiveInterval*, const VNInfo*>, 8> CopyValues; for (MachineOperand &MO : MRI.use_nodbg_operands(LI->reg)) { MachineInstr *MI = MO.getParent(); // Copies of the full value. if (MO.getSubReg() || !MI->isCopy()) continue; unsigned DstReg = MI->getOperand(0).getReg(); // Don't follow copies to physregs. These are usually setting up call // arguments, and the argument registers are always call clobbered. We are // better off in the source register which could be a callee-saved register, // or it could be spilled. if (!TargetRegisterInfo::isVirtualRegister(DstReg)) continue; // Is LocNo extended to reach this copy? If not, another def may be blocking // it, or we are looking at a wrong value of LI. SlotIndex Idx = LIS.getInstructionIndex(MI); LocMap::iterator I = locInts.find(Idx.getRegSlot(true)); if (!I.valid() || I.value() != LocNo) continue; if (!LIS.hasInterval(DstReg)) continue; LiveInterval *DstLI = &LIS.getInterval(DstReg); const VNInfo *DstVNI = DstLI->getVNInfoAt(Idx.getRegSlot()); assert(DstVNI && DstVNI->def == Idx.getRegSlot() && "Bad copy value"); CopyValues.push_back(std::make_pair(DstLI, DstVNI)); } if (CopyValues.empty()) return; DEBUG(dbgs() << "Got " << CopyValues.size() << " copies of " << *LI << '\n'); // Try to add defs of the copied values for each kill point. for (unsigned i = 0, e = Kills.size(); i != e; ++i) { SlotIndex Idx = Kills[i]; for (unsigned j = 0, e = CopyValues.size(); j != e; ++j) { LiveInterval *DstLI = CopyValues[j].first; const VNInfo *DstVNI = CopyValues[j].second; if (DstLI->getVNInfoAt(Idx) != DstVNI) continue; // Check that there isn't already a def at Idx LocMap::iterator I = locInts.find(Idx); if (I.valid() && I.start() <= Idx) continue; DEBUG(dbgs() << "Kill at " << Idx << " covered by valno #" << DstVNI->id << " in " << *DstLI << '\n'); MachineInstr *CopyMI = LIS.getInstructionFromIndex(DstVNI->def); assert(CopyMI && CopyMI->isCopy() && "Bad copy value"); unsigned LocNo = getLocationNo(CopyMI->getOperand(0)); I.insert(Idx, Idx.getNextSlot(), LocNo); NewDefs.push_back(std::make_pair(Idx, LocNo)); break; } } }
bool SIInsertSkips::runOnMachineFunction(MachineFunction &MF) { const GCNSubtarget &ST = MF.getSubtarget<GCNSubtarget>(); TII = ST.getInstrInfo(); TRI = &TII->getRegisterInfo(); SkipThreshold = SkipThresholdFlag; bool HaveKill = false; bool MadeChange = false; // Track depth of exec mask, divergent branches. SmallVector<MachineBasicBlock *, 16> ExecBranchStack; MachineFunction::iterator NextBB; MachineBasicBlock *EmptyMBBAtEnd = nullptr; for (MachineFunction::iterator BI = MF.begin(), BE = MF.end(); BI != BE; BI = NextBB) { NextBB = std::next(BI); MachineBasicBlock &MBB = *BI; bool HaveSkipBlock = false; if (!ExecBranchStack.empty() && ExecBranchStack.back() == &MBB) { // Reached convergence point for last divergent branch. ExecBranchStack.pop_back(); } if (HaveKill && ExecBranchStack.empty()) { HaveKill = false; // TODO: Insert skip if exec is 0? } MachineBasicBlock::iterator I, Next; for (I = MBB.begin(); I != MBB.end(); I = Next) { Next = std::next(I); MachineInstr &MI = *I; switch (MI.getOpcode()) { case AMDGPU::SI_MASK_BRANCH: ExecBranchStack.push_back(MI.getOperand(0).getMBB()); MadeChange |= skipMaskBranch(MI, MBB); break; case AMDGPU::S_BRANCH: // Optimize out branches to the next block. // FIXME: Shouldn't this be handled by BranchFolding? if (MBB.isLayoutSuccessor(MI.getOperand(0).getMBB())) { MI.eraseFromParent(); } else if (HaveSkipBlock) { // Remove the given unconditional branch when a skip block has been // inserted after the current one and let skip the two instructions // performing the kill if the exec mask is non-zero. MI.eraseFromParent(); } break; case AMDGPU::SI_KILL_F32_COND_IMM_TERMINATOR: case AMDGPU::SI_KILL_I1_TERMINATOR: MadeChange = true; kill(MI); if (ExecBranchStack.empty()) { if (skipIfDead(MI, *NextBB)) { HaveSkipBlock = true; NextBB = std::next(BI); BE = MF.end(); } } else { HaveKill = true; } MI.eraseFromParent(); break; case AMDGPU::SI_RETURN_TO_EPILOG: // FIXME: Should move somewhere else assert(!MF.getInfo<SIMachineFunctionInfo>()->returnsVoid()); // Graphics shaders returning non-void shouldn't contain S_ENDPGM, // because external bytecode will be appended at the end. if (BI != --MF.end() || I != MBB.getFirstTerminator()) { // SI_RETURN_TO_EPILOG is not the last instruction. Add an empty block at // the end and jump there. if (!EmptyMBBAtEnd) { EmptyMBBAtEnd = MF.CreateMachineBasicBlock(); MF.insert(MF.end(), EmptyMBBAtEnd); } MBB.addSuccessor(EmptyMBBAtEnd); BuildMI(*BI, I, MI.getDebugLoc(), TII->get(AMDGPU::S_BRANCH)) .addMBB(EmptyMBBAtEnd); I->eraseFromParent(); } break; default: break; } } } return MadeChange; }
static unsigned scanFromBlock(const CFGBlock *Start, llvm::BitVector &Reachable, Preprocessor *PP, bool IncludeSometimesUnreachableEdges) { unsigned count = 0; // Prep work queue SmallVector<const CFGBlock*, 32> WL; // The entry block may have already been marked reachable // by the caller. if (!Reachable[Start->getBlockID()]) { ++count; Reachable[Start->getBlockID()] = true; } WL.push_back(Start); // Find the reachable blocks from 'Start'. while (!WL.empty()) { const CFGBlock *item = WL.pop_back_val(); // There are cases where we want to treat all successors as reachable. // The idea is that some "sometimes unreachable" code is not interesting, // and that we should forge ahead and explore those branches anyway. // This allows us to potentially uncover some "always unreachable" code // within the "sometimes unreachable" code. // Look at the successors and mark then reachable. Optional<bool> TreatAllSuccessorsAsReachable; if (!IncludeSometimesUnreachableEdges) TreatAllSuccessorsAsReachable = false; for (CFGBlock::const_succ_iterator I = item->succ_begin(), E = item->succ_end(); I != E; ++I) { const CFGBlock *B = *I; if (!B) do { const CFGBlock *UB = I->getPossiblyUnreachableBlock(); if (!UB) break; if (!TreatAllSuccessorsAsReachable.hasValue()) { assert(PP); TreatAllSuccessorsAsReachable = shouldTreatSuccessorsAsReachable(item, *PP); } if (TreatAllSuccessorsAsReachable.getValue()) { B = UB; break; } } while (false); if (B) { unsigned blockID = B->getBlockID(); if (!Reachable[blockID]) { Reachable.set(blockID); WL.push_back(B); ++count; } } } } return count; }
/// TailDuplicate - If it is profitable, duplicate TailBB's contents in each /// of its predecessors. bool TailDuplicatePass::TailDuplicate(MachineBasicBlock *TailBB, bool IsSimple, MachineFunction &MF, SmallVector<MachineBasicBlock*, 8> &TDBBs, SmallVector<MachineInstr*, 16> &Copies) { DEBUG(dbgs() << "\n*** Tail-duplicating BB#" << TailBB->getNumber() << '\n'); DenseSet<unsigned> UsedByPhi; getRegsUsedByPHIs(*TailBB, &UsedByPhi); if (IsSimple) return duplicateSimpleBB(TailBB, TDBBs, UsedByPhi, Copies); // Iterate through all the unique predecessors and tail-duplicate this // block into them, if possible. Copying the list ahead of time also // avoids trouble with the predecessor list reallocating. bool Changed = false; SmallSetVector<MachineBasicBlock*, 8> Preds(TailBB->pred_begin(), TailBB->pred_end()); for (SmallSetVector<MachineBasicBlock *, 8>::iterator PI = Preds.begin(), PE = Preds.end(); PI != PE; ++PI) { MachineBasicBlock *PredBB = *PI; assert(TailBB != PredBB && "Single-block loop should have been rejected earlier!"); // EH edges are ignored by AnalyzeBranch. if (PredBB->succ_size() > 1) continue; MachineBasicBlock *PredTBB, *PredFBB; SmallVector<MachineOperand, 4> PredCond; if (TII->AnalyzeBranch(*PredBB, PredTBB, PredFBB, PredCond, true)) continue; if (!PredCond.empty()) continue; // Don't duplicate into a fall-through predecessor (at least for now). if (PredBB->isLayoutSuccessor(TailBB) && PredBB->canFallThrough()) continue; DEBUG(dbgs() << "\nTail-duplicating into PredBB: " << *PredBB << "From Succ: " << *TailBB); TDBBs.push_back(PredBB); // Remove PredBB's unconditional branch. TII->RemoveBranch(*PredBB); if (RS && !TailBB->livein_empty()) { // Update PredBB livein. RS->enterBasicBlock(PredBB); if (!PredBB->empty()) RS->forward(prior(PredBB->end())); BitVector RegsLiveAtExit(TRI->getNumRegs()); RS->getRegsUsed(RegsLiveAtExit, false); for (MachineBasicBlock::livein_iterator I = TailBB->livein_begin(), E = TailBB->livein_end(); I != E; ++I) { if (!RegsLiveAtExit[*I]) // If a register is previously livein to the tail but it's not live // at the end of predecessor BB, then it should be added to its // livein list. PredBB->addLiveIn(*I); } } // Clone the contents of TailBB into PredBB. DenseMap<unsigned, unsigned> LocalVRMap; SmallVector<std::pair<unsigned,unsigned>, 4> CopyInfos; // Use instr_iterator here to properly handle bundles, e.g. // ARM Thumb2 IT block. MachineBasicBlock::instr_iterator I = TailBB->instr_begin(); while (I != TailBB->instr_end()) { MachineInstr *MI = &*I; ++I; if (MI->isPHI()) { // Replace the uses of the def of the PHI with the register coming // from PredBB. ProcessPHI(MI, TailBB, PredBB, LocalVRMap, CopyInfos, UsedByPhi, true); } else { // Replace def of virtual registers with new registers, and update // uses with PHI source register or the new registers. DuplicateInstruction(MI, TailBB, PredBB, MF, LocalVRMap, UsedByPhi); } } MachineBasicBlock::iterator Loc = PredBB->getFirstTerminator(); for (unsigned i = 0, e = CopyInfos.size(); i != e; ++i) { Copies.push_back(BuildMI(*PredBB, Loc, DebugLoc(), TII->get(TargetOpcode::COPY), CopyInfos[i].first).addReg(CopyInfos[i].second)); } // Simplify TII->AnalyzeBranch(*PredBB, PredTBB, PredFBB, PredCond, true); NumInstrDups += TailBB->size() - 1; // subtract one for removed branch // Update the CFG. PredBB->removeSuccessor(PredBB->succ_begin()); assert(PredBB->succ_empty() && "TailDuplicate called on block with multiple successors!"); for (MachineBasicBlock::succ_iterator I = TailBB->succ_begin(), E = TailBB->succ_end(); I != E; ++I) PredBB->addSuccessor(*I); Changed = true; ++NumTailDups; } // If TailBB was duplicated into all its predecessors except for the prior // block, which falls through unconditionally, move the contents of this // block into the prior block. MachineBasicBlock *PrevBB = prior(MachineFunction::iterator(TailBB)); MachineBasicBlock *PriorTBB = 0, *PriorFBB = 0; SmallVector<MachineOperand, 4> PriorCond; // This has to check PrevBB->succ_size() because EH edges are ignored by // AnalyzeBranch. if (PrevBB->succ_size() == 1 && !TII->AnalyzeBranch(*PrevBB, PriorTBB, PriorFBB, PriorCond, true) && PriorCond.empty() && !PriorTBB && TailBB->pred_size() == 1 && !TailBB->hasAddressTaken()) { DEBUG(dbgs() << "\nMerging into block: " << *PrevBB << "From MBB: " << *TailBB); if (PreRegAlloc) { DenseMap<unsigned, unsigned> LocalVRMap; SmallVector<std::pair<unsigned,unsigned>, 4> CopyInfos; MachineBasicBlock::iterator I = TailBB->begin(); // Process PHI instructions first. while (I != TailBB->end() && I->isPHI()) { // Replace the uses of the def of the PHI with the register coming // from PredBB. MachineInstr *MI = &*I++; ProcessPHI(MI, TailBB, PrevBB, LocalVRMap, CopyInfos, UsedByPhi, true); if (MI->getParent()) MI->eraseFromParent(); } // Now copy the non-PHI instructions. while (I != TailBB->end()) { // Replace def of virtual registers with new registers, and update // uses with PHI source register or the new registers. MachineInstr *MI = &*I++; assert(!MI->isBundle() && "Not expecting bundles before regalloc!"); DuplicateInstruction(MI, TailBB, PrevBB, MF, LocalVRMap, UsedByPhi); MI->eraseFromParent(); } MachineBasicBlock::iterator Loc = PrevBB->getFirstTerminator(); for (unsigned i = 0, e = CopyInfos.size(); i != e; ++i) { Copies.push_back(BuildMI(*PrevBB, Loc, DebugLoc(), TII->get(TargetOpcode::COPY), CopyInfos[i].first) .addReg(CopyInfos[i].second)); } } else { // No PHIs to worry about, just splice the instructions over. PrevBB->splice(PrevBB->end(), TailBB, TailBB->begin(), TailBB->end()); } PrevBB->removeSuccessor(PrevBB->succ_begin()); assert(PrevBB->succ_empty()); PrevBB->transferSuccessors(TailBB); TDBBs.push_back(PrevBB); Changed = true; } // If this is after register allocation, there are no phis to fix. if (!PreRegAlloc) return Changed; // If we made no changes so far, we are safe. if (!Changed) return Changed; // Handle the nasty case in that we duplicated a block that is part of a loop // into some but not all of its predecessors. For example: // 1 -> 2 <-> 3 | // \ | // \---> rest | // if we duplicate 2 into 1 but not into 3, we end up with // 12 -> 3 <-> 2 -> rest | // \ / | // \----->-----/ | // If there was a "var = phi(1, 3)" in 2, it has to be ultimately replaced // with a phi in 3 (which now dominates 2). // What we do here is introduce a copy in 3 of the register defined by the // phi, just like when we are duplicating 2 into 3, but we don't copy any // real instructions or remove the 3 -> 2 edge from the phi in 2. for (SmallSetVector<MachineBasicBlock *, 8>::iterator PI = Preds.begin(), PE = Preds.end(); PI != PE; ++PI) { MachineBasicBlock *PredBB = *PI; if (std::find(TDBBs.begin(), TDBBs.end(), PredBB) != TDBBs.end()) continue; // EH edges if (PredBB->succ_size() != 1) continue; DenseMap<unsigned, unsigned> LocalVRMap; SmallVector<std::pair<unsigned,unsigned>, 4> CopyInfos; MachineBasicBlock::iterator I = TailBB->begin(); // Process PHI instructions first. while (I != TailBB->end() && I->isPHI()) { // Replace the uses of the def of the PHI with the register coming // from PredBB. MachineInstr *MI = &*I++; ProcessPHI(MI, TailBB, PredBB, LocalVRMap, CopyInfos, UsedByPhi, false); } MachineBasicBlock::iterator Loc = PredBB->getFirstTerminator(); for (unsigned i = 0, e = CopyInfos.size(); i != e; ++i) { Copies.push_back(BuildMI(*PredBB, Loc, DebugLoc(), TII->get(TargetOpcode::COPY), CopyInfos[i].first).addReg(CopyInfos[i].second)); } } return Changed; }
static bool markAliveBlocks(BasicBlock *BB, SmallPtrSet<BasicBlock*, 128> &Reachable) { SmallVector<BasicBlock*, 128> Worklist; Worklist.push_back(BB); bool Changed = false; do { BB = Worklist.pop_back_val(); if (!Reachable.insert(BB)) continue; // Do a quick scan of the basic block, turning any obviously unreachable // instructions into LLVM unreachable insts. The instruction combining pass // canonicalizes unreachable insts into stores to null or undef. for (BasicBlock::iterator BBI = BB->begin(), E = BB->end(); BBI != E;++BBI){ if (CallInst *CI = dyn_cast<CallInst>(BBI)) { if (CI->doesNotReturn()) { // If we found a call to a no-return function, insert an unreachable // instruction after it. Make sure there isn't *already* one there // though. ++BBI; if (!isa<UnreachableInst>(BBI)) { // Don't insert a call to llvm.trap right before the unreachable. changeToUnreachable(BBI, false); Changed = true; } break; } } // Store to undef and store to null are undefined and used to signal that // they should be changed to unreachable by passes that can't modify the // CFG. if (StoreInst *SI = dyn_cast<StoreInst>(BBI)) { // Don't touch volatile stores. if (SI->isVolatile()) continue; Value *Ptr = SI->getOperand(1); if (isa<UndefValue>(Ptr) || (isa<ConstantPointerNull>(Ptr) && SI->getPointerAddressSpace() == 0)) { changeToUnreachable(SI, true); Changed = true; break; } } } // Turn invokes that call 'nounwind' functions into ordinary calls. if (InvokeInst *II = dyn_cast<InvokeInst>(BB->getTerminator())) { Value *Callee = II->getCalledValue(); if (isa<ConstantPointerNull>(Callee) || isa<UndefValue>(Callee)) { changeToUnreachable(II, true); Changed = true; } else if (II->doesNotThrow()) { if (II->use_empty() && II->onlyReadsMemory()) { // jump to the normal destination branch. BranchInst::Create(II->getNormalDest(), II); II->getUnwindDest()->removePredecessor(II->getParent()); II->eraseFromParent(); } else changeToCall(II); Changed = true; } } Changed |= ConstantFoldTerminator(BB, true); for (succ_iterator SI = succ_begin(BB), SE = succ_end(BB); SI != SE; ++SI) Worklist.push_back(*SI); } while (!Worklist.empty()); return Changed; }
void MachineBasicBlock::updateTerminator() { const TargetInstrInfo *TII = getParent()->getTarget().getInstrInfo(); // A block with no successors has no concerns with fall-through edges. if (this->succ_empty()) return; MachineBasicBlock *TBB = 0, *FBB = 0; SmallVector<MachineOperand, 4> Cond; DebugLoc dl; // FIXME: this is nowhere bool B = TII->AnalyzeBranch(*this, TBB, FBB, Cond); (void) B; assert(!B && "UpdateTerminators requires analyzable predecessors!"); if (Cond.empty()) { if (TBB) { // The block has an unconditional branch. If its successor is now // its layout successor, delete the branch. if (isLayoutSuccessor(TBB)) TII->RemoveBranch(*this); } else { // The block has an unconditional fallthrough. If its successor is not // its layout successor, insert a branch. First we have to locate the // only non-landing-pad successor, as that is the fallthrough block. for (succ_iterator SI = succ_begin(), SE = succ_end(); SI != SE; ++SI) { if ((*SI)->isLandingPad()) continue; assert(!TBB && "Found more than one non-landing-pad successor!"); TBB = *SI; } // If there is no non-landing-pad successor, the block has no // fall-through edges to be concerned with. if (!TBB) return; // Finally update the unconditional successor to be reached via a branch // if it would not be reached by fallthrough. if (!isLayoutSuccessor(TBB)) TII->InsertBranch(*this, TBB, 0, Cond, dl); } } else { if (FBB) { // The block has a non-fallthrough conditional branch. If one of its // successors is its layout successor, rewrite it to a fallthrough // conditional branch. if (isLayoutSuccessor(TBB)) { if (TII->ReverseBranchCondition(Cond)) return; TII->RemoveBranch(*this); TII->InsertBranch(*this, FBB, 0, Cond, dl); } else if (isLayoutSuccessor(FBB)) { TII->RemoveBranch(*this); TII->InsertBranch(*this, TBB, 0, Cond, dl); } } else { // Walk through the successors and find the successor which is not // a landing pad and is not the conditional branch destination (in TBB) // as the fallthrough successor. MachineBasicBlock *FallthroughBB = 0; for (succ_iterator SI = succ_begin(), SE = succ_end(); SI != SE; ++SI) { if ((*SI)->isLandingPad() || *SI == TBB) continue; assert(!FallthroughBB && "Found more than one fallthrough successor."); FallthroughBB = *SI; } if (!FallthroughBB && canFallThrough()) { // We fallthrough to the same basic block as the conditional jump // targets. Remove the conditional jump, leaving unconditional // fallthrough. // FIXME: This does not seem like a reasonable pattern to support, but it // has been seen in the wild coming out of degenerate ARM test cases. TII->RemoveBranch(*this); // Finally update the unconditional successor to be reached via a branch // if it would not be reached by fallthrough. if (!isLayoutSuccessor(TBB)) TII->InsertBranch(*this, TBB, 0, Cond, dl); return; } // The block has a fallthrough conditional branch. if (isLayoutSuccessor(TBB)) { if (TII->ReverseBranchCondition(Cond)) { // We can't reverse the condition, add an unconditional branch. Cond.clear(); TII->InsertBranch(*this, FallthroughBB, 0, Cond, dl); return; } TII->RemoveBranch(*this); TII->InsertBranch(*this, FallthroughBB, 0, Cond, dl); } else if (!isLayoutSuccessor(FallthroughBB)) { TII->RemoveBranch(*this); TII->InsertBranch(*this, TBB, FallthroughBB, Cond, dl); } } } }
RequirementCheckResult TypeChecker::checkGenericArguments( DeclContext *dc, SourceLoc loc, SourceLoc noteLoc, Type owner, GenericSignature *genericSig, TypeSubstitutionFn substitutions, LookupConformanceFn conformances, UnsatisfiedDependency *unsatisfiedDependency, ConformanceCheckOptions conformanceOptions, GenericRequirementsCheckListener *listener, SubstOptions options) { bool valid = true; struct RequirementSet { ArrayRef<Requirement> Requirements; SmallVector<ParentConditionalConformance, 4> Parents; }; SmallVector<RequirementSet, 8> pendingReqs; pendingReqs.push_back({genericSig->getRequirements(), {}}); while (!pendingReqs.empty()) { auto current = pendingReqs.pop_back_val(); for (const auto &rawReq : current.Requirements) { auto req = rawReq; if (current.Parents.empty()) { auto substed = rawReq.subst(substitutions, conformances, options); if (!substed) { // Another requirement will fail later; just continue. valid = false; continue; } req = *substed; } auto kind = req.getKind(); Type rawFirstType = rawReq.getFirstType(); Type firstType = req.getFirstType(); Type rawSecondType, secondType; if (kind != RequirementKind::Layout) { rawSecondType = rawReq.getSecondType(); secondType = req.getSecondType(); } bool requirementFailure = false; if (listener && !listener->shouldCheck(kind, firstType, secondType)) continue; Diag<Type, Type, Type> diagnostic; Diag<Type, Type, StringRef> diagnosticNote; switch (kind) { case RequirementKind::Conformance: { // Protocol conformance requirements. auto proto = secondType->castTo<ProtocolType>(); // FIXME: This should track whether this should result in a private // or non-private dependency. // FIXME: Do we really need "used" at this point? // FIXME: Poor location information. How much better can we do here? // FIXME: This call should support listener to be able to properly // diagnose problems with conformances. auto result = conformsToProtocol(firstType, proto->getDecl(), dc, conformanceOptions, loc, unsatisfiedDependency); // Unsatisfied dependency case. auto status = result.getStatus(); switch (status) { case RequirementCheckResult::Failure: // A failure at the top level is diagnosed elsewhere. if (current.Parents.empty()) return status; diagnostic = diag::type_does_not_conform_owner; diagnosticNote = diag::type_does_not_inherit_or_conform_requirement; requirementFailure = true; break; case RequirementCheckResult::UnsatisfiedDependency: case RequirementCheckResult::SubstitutionFailure: // pass it on up. return status; case RequirementCheckResult::Success: { auto conformance = result.getConformance(); // Report the conformance. if (listener && valid && current.Parents.empty()) { listener->satisfiedConformance(rawFirstType, firstType, conformance); } auto conditionalReqs = conformance.getConditionalRequirements(); if (!conditionalReqs.empty()) { auto history = current.Parents; history.push_back({firstType, proto}); pendingReqs.push_back({conditionalReqs, std::move(history)}); } continue; } } // Failure needs to emit a diagnostic. break; } case RequirementKind::Layout: { // TODO: Statically check if a the first type // conforms to the layout constraint, once we // support such static checks. continue; } case RequirementKind::Superclass: // Superclass requirements. if (!isSubclassOf(firstType, secondType, dc)) { diagnostic = diag::type_does_not_inherit; diagnosticNote = diag::type_does_not_inherit_or_conform_requirement; requirementFailure = true; } break; case RequirementKind::SameType: if (!firstType->isEqual(secondType)) { diagnostic = diag::types_not_equal; diagnosticNote = diag::types_not_equal_requirement; requirementFailure = true; } break; } if (!requirementFailure) continue; if (listener && listener->diagnoseUnsatisfiedRequirement(rawReq, firstType, secondType, current.Parents)) return RequirementCheckResult::Failure; if (loc.isValid()) { // FIXME: Poor source-location information. diagnose(loc, diagnostic, owner, firstType, secondType); diagnose(noteLoc, diagnosticNote, rawFirstType, rawSecondType, genericSig->gatherGenericParamBindingsText( {rawFirstType, rawSecondType}, substitutions)); ParentConditionalConformance::diagnoseConformanceStack(Diags, noteLoc, current.Parents); } return RequirementCheckResult::Failure; } } if (valid) return RequirementCheckResult::Success; return RequirementCheckResult::SubstitutionFailure; }
/// InlineFunction - This function inlines the called function into the basic /// block of the caller. This returns false if it is not possible to inline /// this call. The program is still in a well defined state if this occurs /// though. /// /// Note that this only does one level of inlining. For example, if the /// instruction 'call B' is inlined, and 'B' calls 'C', then the call to 'C' now /// exists in the instruction stream. Similarly this will inline a recursive /// function by one level. bool llvm::InlineFunction(CallSite CS, InlineFunctionInfo &IFI, bool InsertLifetime) { Instruction *TheCall = CS.getInstruction(); assert(TheCall->getParent() && TheCall->getParent()->getParent() && "Instruction not in function!"); // If IFI has any state in it, zap it before we fill it in. IFI.reset(); const Function *CalledFunc = CS.getCalledFunction(); if (CalledFunc == 0 || // Can't inline external function or indirect CalledFunc->isDeclaration() || // call, or call to a vararg function! CalledFunc->getFunctionType()->isVarArg()) return false; // If the call to the callee is not a tail call, we must clear the 'tail' // flags on any calls that we inline. bool MustClearTailCallFlags = !(isa<CallInst>(TheCall) && cast<CallInst>(TheCall)->isTailCall()); // If the call to the callee cannot throw, set the 'nounwind' flag on any // calls that we inline. bool MarkNoUnwind = CS.doesNotThrow(); BasicBlock *OrigBB = TheCall->getParent(); Function *Caller = OrigBB->getParent(); // GC poses two hazards to inlining, which only occur when the callee has GC: // 1. If the caller has no GC, then the callee's GC must be propagated to the // caller. // 2. If the caller has a differing GC, it is invalid to inline. if (CalledFunc->hasGC()) { if (!Caller->hasGC()) Caller->setGC(CalledFunc->getGC()); else if (CalledFunc->getGC() != Caller->getGC()) return false; } // Get the personality function from the callee if it contains a landing pad. Value *CalleePersonality = 0; for (Function::const_iterator I = CalledFunc->begin(), E = CalledFunc->end(); I != E; ++I) if (const InvokeInst *II = dyn_cast<InvokeInst>(I->getTerminator())) { const BasicBlock *BB = II->getUnwindDest(); const LandingPadInst *LP = BB->getLandingPadInst(); CalleePersonality = LP->getPersonalityFn(); break; } // Find the personality function used by the landing pads of the caller. If it // exists, then check to see that it matches the personality function used in // the callee. if (CalleePersonality) { for (Function::const_iterator I = Caller->begin(), E = Caller->end(); I != E; ++I) if (const InvokeInst *II = dyn_cast<InvokeInst>(I->getTerminator())) { const BasicBlock *BB = II->getUnwindDest(); const LandingPadInst *LP = BB->getLandingPadInst(); // If the personality functions match, then we can perform the // inlining. Otherwise, we can't inline. // TODO: This isn't 100% true. Some personality functions are proper // supersets of others and can be used in place of the other. if (LP->getPersonalityFn() != CalleePersonality) return false; break; } } // Get an iterator to the last basic block in the function, which will have // the new function inlined after it. Function::iterator LastBlock = &Caller->back(); // Make sure to capture all of the return instructions from the cloned // function. SmallVector<ReturnInst*, 8> Returns; ClonedCodeInfo InlinedFunctionInfo; Function::iterator FirstNewBlock; { // Scope to destroy VMap after cloning. ValueToValueMapTy VMap; assert(CalledFunc->arg_size() == CS.arg_size() && "No varargs calls can be inlined!"); // Calculate the vector of arguments to pass into the function cloner, which // matches up the formal to the actual argument values. CallSite::arg_iterator AI = CS.arg_begin(); unsigned ArgNo = 0; for (Function::const_arg_iterator I = CalledFunc->arg_begin(), E = CalledFunc->arg_end(); I != E; ++I, ++AI, ++ArgNo) { Value *ActualArg = *AI; // When byval arguments actually inlined, we need to make the copy implied // by them explicit. However, we don't do this if the callee is readonly // or readnone, because the copy would be unneeded: the callee doesn't // modify the struct. if (CS.isByValArgument(ArgNo)) { ActualArg = HandleByValArgument(ActualArg, TheCall, CalledFunc, IFI, CalledFunc->getParamAlignment(ArgNo+1)); // Calls that we inline may use the new alloca, so we need to clear // their 'tail' flags if HandleByValArgument introduced a new alloca and // the callee has calls. MustClearTailCallFlags |= ActualArg != *AI; } VMap[I] = ActualArg; } // We want the inliner to prune the code as it copies. We would LOVE to // have no dead or constant instructions leftover after inlining occurs // (which can happen, e.g., because an argument was constant), but we'll be // happy with whatever the cloner can do. CloneAndPruneFunctionInto(Caller, CalledFunc, VMap, /*ModuleLevelChanges=*/false, Returns, ".i", &InlinedFunctionInfo, IFI.TD, TheCall); // Remember the first block that is newly cloned over. FirstNewBlock = LastBlock; ++FirstNewBlock; // Update the callgraph if requested. if (IFI.CG) UpdateCallGraphAfterInlining(CS, FirstNewBlock, VMap, IFI); // Update inlined instructions' line number information. fixupLineNumbers(Caller, FirstNewBlock, TheCall); } // If there are any alloca instructions in the block that used to be the entry // block for the callee, move them to the entry block of the caller. First // calculate which instruction they should be inserted before. We insert the // instructions at the end of the current alloca list. { BasicBlock::iterator InsertPoint = Caller->begin()->begin(); for (BasicBlock::iterator I = FirstNewBlock->begin(), E = FirstNewBlock->end(); I != E; ) { AllocaInst *AI = dyn_cast<AllocaInst>(I++); if (AI == 0) continue; // If the alloca is now dead, remove it. This often occurs due to code // specialization. if (AI->use_empty()) { AI->eraseFromParent(); continue; } if (!isa<Constant>(AI->getArraySize())) continue; // Keep track of the static allocas that we inline into the caller. IFI.StaticAllocas.push_back(AI); // Scan for the block of allocas that we can move over, and move them // all at once. while (isa<AllocaInst>(I) && isa<Constant>(cast<AllocaInst>(I)->getArraySize())) { IFI.StaticAllocas.push_back(cast<AllocaInst>(I)); ++I; } // Transfer all of the allocas over in a block. Using splice means // that the instructions aren't removed from the symbol table, then // reinserted. Caller->getEntryBlock().getInstList().splice(InsertPoint, FirstNewBlock->getInstList(), AI, I); } } // Leave lifetime markers for the static alloca's, scoping them to the // function we just inlined. if (InsertLifetime && !IFI.StaticAllocas.empty()) { IRBuilder<> builder(FirstNewBlock->begin()); for (unsigned ai = 0, ae = IFI.StaticAllocas.size(); ai != ae; ++ai) { AllocaInst *AI = IFI.StaticAllocas[ai]; // If the alloca is already scoped to something smaller than the whole // function then there's no need to add redundant, less accurate markers. if (hasLifetimeMarkers(AI)) continue; builder.CreateLifetimeStart(AI); for (unsigned ri = 0, re = Returns.size(); ri != re; ++ri) { IRBuilder<> builder(Returns[ri]); builder.CreateLifetimeEnd(AI); } } } // If the inlined code contained dynamic alloca instructions, wrap the inlined // code with llvm.stacksave/llvm.stackrestore intrinsics. if (InlinedFunctionInfo.ContainsDynamicAllocas) { Module *M = Caller->getParent(); // Get the two intrinsics we care about. Function *StackSave = Intrinsic::getDeclaration(M, Intrinsic::stacksave); Function *StackRestore=Intrinsic::getDeclaration(M,Intrinsic::stackrestore); // Insert the llvm.stacksave. CallInst *SavedPtr = IRBuilder<>(FirstNewBlock, FirstNewBlock->begin()) .CreateCall(StackSave, "savedstack"); // Insert a call to llvm.stackrestore before any return instructions in the // inlined function. for (unsigned i = 0, e = Returns.size(); i != e; ++i) { IRBuilder<>(Returns[i]).CreateCall(StackRestore, SavedPtr); } } // If we are inlining tail call instruction through a call site that isn't // marked 'tail', we must remove the tail marker for any calls in the inlined // code. Also, calls inlined through a 'nounwind' call site should be marked // 'nounwind'. if (InlinedFunctionInfo.ContainsCalls && (MustClearTailCallFlags || MarkNoUnwind)) { for (Function::iterator BB = FirstNewBlock, E = Caller->end(); BB != E; ++BB) for (BasicBlock::iterator I = BB->begin(), E = BB->end(); I != E; ++I) if (CallInst *CI = dyn_cast<CallInst>(I)) { if (MustClearTailCallFlags) CI->setTailCall(false); if (MarkNoUnwind) CI->setDoesNotThrow(); } } // If we are inlining for an invoke instruction, we must make sure to rewrite // any call instructions into invoke instructions. if (InvokeInst *II = dyn_cast<InvokeInst>(TheCall)) HandleInlinedInvoke(II, FirstNewBlock, InlinedFunctionInfo); // If we cloned in _exactly one_ basic block, and if that block ends in a // return instruction, we splice the body of the inlined callee directly into // the calling basic block. if (Returns.size() == 1 && std::distance(FirstNewBlock, Caller->end()) == 1) { // Move all of the instructions right before the call. OrigBB->getInstList().splice(TheCall, FirstNewBlock->getInstList(), FirstNewBlock->begin(), FirstNewBlock->end()); // Remove the cloned basic block. Caller->getBasicBlockList().pop_back(); // If the call site was an invoke instruction, add a branch to the normal // destination. if (InvokeInst *II = dyn_cast<InvokeInst>(TheCall)) BranchInst::Create(II->getNormalDest(), TheCall); // If the return instruction returned a value, replace uses of the call with // uses of the returned value. if (!TheCall->use_empty()) { ReturnInst *R = Returns[0]; if (TheCall == R->getReturnValue()) TheCall->replaceAllUsesWith(UndefValue::get(TheCall->getType())); else TheCall->replaceAllUsesWith(R->getReturnValue()); } // Since we are now done with the Call/Invoke, we can delete it. TheCall->eraseFromParent(); // Since we are now done with the return instruction, delete it also. Returns[0]->eraseFromParent(); // We are now done with the inlining. return true; } // Otherwise, we have the normal case, of more than one block to inline or // multiple return sites. // We want to clone the entire callee function into the hole between the // "starter" and "ender" blocks. How we accomplish this depends on whether // this is an invoke instruction or a call instruction. BasicBlock *AfterCallBB; if (InvokeInst *II = dyn_cast<InvokeInst>(TheCall)) { // Add an unconditional branch to make this look like the CallInst case... BranchInst *NewBr = BranchInst::Create(II->getNormalDest(), TheCall); // Split the basic block. This guarantees that no PHI nodes will have to be // updated due to new incoming edges, and make the invoke case more // symmetric to the call case. AfterCallBB = OrigBB->splitBasicBlock(NewBr, CalledFunc->getName()+".exit"); } else { // It's a call // If this is a call instruction, we need to split the basic block that // the call lives in. // AfterCallBB = OrigBB->splitBasicBlock(TheCall, CalledFunc->getName()+".exit"); } // Change the branch that used to go to AfterCallBB to branch to the first // basic block of the inlined function. // TerminatorInst *Br = OrigBB->getTerminator(); assert(Br && Br->getOpcode() == Instruction::Br && "splitBasicBlock broken!"); Br->setOperand(0, FirstNewBlock); // Now that the function is correct, make it a little bit nicer. In // particular, move the basic blocks inserted from the end of the function // into the space made by splitting the source basic block. Caller->getBasicBlockList().splice(AfterCallBB, Caller->getBasicBlockList(), FirstNewBlock, Caller->end()); // Handle all of the return instructions that we just cloned in, and eliminate // any users of the original call/invoke instruction. Type *RTy = CalledFunc->getReturnType(); PHINode *PHI = 0; if (Returns.size() > 1) { // The PHI node should go at the front of the new basic block to merge all // possible incoming values. if (!TheCall->use_empty()) { PHI = PHINode::Create(RTy, Returns.size(), TheCall->getName(), AfterCallBB->begin()); // Anything that used the result of the function call should now use the // PHI node as their operand. TheCall->replaceAllUsesWith(PHI); } // Loop over all of the return instructions adding entries to the PHI node // as appropriate. if (PHI) { for (unsigned i = 0, e = Returns.size(); i != e; ++i) { ReturnInst *RI = Returns[i]; assert(RI->getReturnValue()->getType() == PHI->getType() && "Ret value not consistent in function!"); PHI->addIncoming(RI->getReturnValue(), RI->getParent()); } } // Add a branch to the merge points and remove return instructions. for (unsigned i = 0, e = Returns.size(); i != e; ++i) { ReturnInst *RI = Returns[i]; BranchInst::Create(AfterCallBB, RI); RI->eraseFromParent(); } } else if (!Returns.empty()) { // Otherwise, if there is exactly one return value, just replace anything // using the return value of the call with the computed value. if (!TheCall->use_empty()) { if (TheCall == Returns[0]->getReturnValue()) TheCall->replaceAllUsesWith(UndefValue::get(TheCall->getType())); else TheCall->replaceAllUsesWith(Returns[0]->getReturnValue()); } // Update PHI nodes that use the ReturnBB to use the AfterCallBB. BasicBlock *ReturnBB = Returns[0]->getParent(); ReturnBB->replaceAllUsesWith(AfterCallBB); // Splice the code from the return block into the block that it will return // to, which contains the code that was after the call. AfterCallBB->getInstList().splice(AfterCallBB->begin(), ReturnBB->getInstList()); // Delete the return instruction now and empty ReturnBB now. Returns[0]->eraseFromParent(); ReturnBB->eraseFromParent(); } else if (!TheCall->use_empty()) { // No returns, but something is using the return value of the call. Just // nuke the result. TheCall->replaceAllUsesWith(UndefValue::get(TheCall->getType())); } // Since we are now done with the Call/Invoke, we can delete it. TheCall->eraseFromParent(); // We should always be able to fold the entry block of the function into the // single predecessor of the block... assert(cast<BranchInst>(Br)->isUnconditional() && "splitBasicBlock broken!"); BasicBlock *CalleeEntry = cast<BranchInst>(Br)->getSuccessor(0); // Splice the code entry block into calling block, right before the // unconditional branch. CalleeEntry->replaceAllUsesWith(OrigBB); // Update PHI nodes OrigBB->getInstList().splice(Br, CalleeEntry->getInstList()); // Remove the unconditional branch. OrigBB->getInstList().erase(Br); // Now we can remove the CalleeEntry block, which is now empty. Caller->getBasicBlockList().erase(CalleeEntry); // If we inserted a phi node, check to see if it has a single value (e.g. all // the entries are the same or undef). If so, remove the PHI so it doesn't // block other optimizations. if (PHI) { if (Value *V = SimplifyInstruction(PHI, IFI.TD)) { PHI->replaceAllUsesWith(V); PHI->eraseFromParent(); } } return true; }
/// Iteratively perform simplification on a worklist of users /// of the specified induction variable. Each successive simplification may push /// more users which may themselves be candidates for simplification. /// /// This algorithm does not require IVUsers analysis. Instead, it simplifies /// instructions in-place during analysis. Rather than rewriting induction /// variables bottom-up from their users, it transforms a chain of IVUsers /// top-down, updating the IR only when it encounters a clear optimization /// opportunity. /// /// Once DisableIVRewrite is default, LSR will be the only client of IVUsers. /// void SimplifyIndvar::simplifyUsers(PHINode *CurrIV, IVVisitor *V) { if (!SE->isSCEVable(CurrIV->getType())) return; // Instructions processed by SimplifyIndvar for CurrIV. SmallPtrSet<Instruction*,16> Simplified; // Use-def pairs if IV users waiting to be processed for CurrIV. SmallVector<std::pair<Instruction*, Instruction*>, 8> SimpleIVUsers; // Push users of the current LoopPhi. In rare cases, pushIVUsers may be // called multiple times for the same LoopPhi. This is the proper thing to // do for loop header phis that use each other. pushIVUsers(CurrIV, L, Simplified, SimpleIVUsers); while (!SimpleIVUsers.empty()) { std::pair<Instruction*, Instruction*> UseOper = SimpleIVUsers.pop_back_val(); Instruction *UseInst = UseOper.first; // Bypass back edges to avoid extra work. if (UseInst == CurrIV) continue; // Try to replace UseInst with a loop invariant before any other // simplifications. if (replaceIVUserWithLoopInvariant(UseInst)) continue; Instruction *IVOperand = UseOper.second; for (unsigned N = 0; IVOperand; ++N) { assert(N <= Simplified.size() && "runaway iteration"); Value *NewOper = foldIVUser(UseOper.first, IVOperand); if (!NewOper) break; // done folding IVOperand = dyn_cast<Instruction>(NewOper); } if (!IVOperand) continue; if (eliminateIVUser(UseOper.first, IVOperand)) { pushIVUsers(IVOperand, L, Simplified, SimpleIVUsers); continue; } if (BinaryOperator *BO = dyn_cast<BinaryOperator>(UseOper.first)) { if ((isa<OverflowingBinaryOperator>(BO) && strengthenOverflowingOperation(BO, IVOperand)) || (isa<ShlOperator>(BO) && strengthenRightShift(BO, IVOperand))) { // re-queue uses of the now modified binary operator and fall // through to the checks that remain. pushIVUsers(IVOperand, L, Simplified, SimpleIVUsers); } } CastInst *Cast = dyn_cast<CastInst>(UseOper.first); if (V && Cast) { V->visitCast(Cast); continue; } if (isSimpleIVUser(UseOper.first, L, SE)) { pushIVUsers(UseOper.first, L, Simplified, SimpleIVUsers); } } }