395 lines · cpp
1//===- CallingConvEmitter.cpp - Generate calling conventions --------------===//2//3// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.4// See https://llvm.org/LICENSE.txt for license information.5// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception6//7//===----------------------------------------------------------------------===//8//9// This tablegen backend is responsible for emitting descriptions of the calling10// conventions supported by this target.11//12//===----------------------------------------------------------------------===//13 14#include "Common/CodeGenRegisters.h"15#include "Common/CodeGenTarget.h"16#include "llvm/Support/FormatVariadic.h"17#include "llvm/Support/InterleavedRange.h"18#include "llvm/TableGen/CodeGenHelpers.h"19#include "llvm/TableGen/Error.h"20#include "llvm/TableGen/Record.h"21#include "llvm/TableGen/TGTimer.h"22#include "llvm/TableGen/TableGenBackend.h"23#include <deque>24#include <set>25 26using namespace llvm;27 28namespace {29class CallingConvEmitter {30 const RecordKeeper &Records;31 const CodeGenTarget Target;32 unsigned Counter = 0u;33 std::string CurrentAction;34 bool SwiftAction = false;35 36 std::map<std::string, std::set<std::string>> AssignedRegsMap;37 std::map<std::string, std::set<std::string>> AssignedSwiftRegsMap;38 std::map<std::string, std::set<std::string>> DelegateToMap;39 40public:41 explicit CallingConvEmitter(const RecordKeeper &R) : Records(R), Target(R) {42 for (const CodeGenRegister &Reg : Target.getRegBank().getRegisters())43 RegistersByDefName.try_emplace(Reg.getName(), &Reg);44 }45 46 void run(raw_ostream &O);47 48private:49 void emitCallingConv(const Record *CC, raw_ostream &O);50 void emitAction(const Record *Action, indent Indent, raw_ostream &O);51 void emitArgRegisterLists(raw_ostream &O);52 53 StringMap<const CodeGenRegister *> RegistersByDefName;54 std::string getQualifiedRegisterName(const Init *I);55};56} // End anonymous namespace57 58static void emitCCHeader(raw_ostream &O, const Record *CC, StringRef Suffix) {59 unsigned Pad = CC->getName().size();60 if (CC->getValueAsBit("Entry")) {61 O << "bool llvm::";62 Pad += 12;63 } else {64 O << "static bool ";65 Pad += 13;66 }67 O << CC->getName() << "(unsigned ValNo, MVT ValVT,\n"68 << indent(Pad) << "MVT LocVT, CCValAssign::LocInfo LocInfo,\n"69 << indent(Pad) << "ISD::ArgFlagsTy ArgFlags, Type *OrigTy, CCState &State)"70 << Suffix;71}72 73void CallingConvEmitter::run(raw_ostream &O) {74 emitSourceFileHeader("Calling Convention Implementation Fragment", O);75 76 ArrayRef<const Record *> CCs =77 Records.getAllDerivedDefinitions("CallingConv");78 79 // Emit prototypes for all of the non-custom CC's so that they can forward ref80 // each other.81 Records.getTimer().startTimer("Emit prototypes");82 IfGuardEmitter IfGuard(O, "!defined(GET_CC_REGISTER_LISTS)");83 for (const Record *CC : CCs) {84 if (!CC->getValueAsBit("Custom"))85 emitCCHeader(O, CC, ";\n");86 }87 88 // Emit each non-custom calling convention description in full.89 Records.getTimer().startTimer("Emit full descriptions");90 for (const Record *CC : CCs) {91 if (!CC->getValueAsBit("Custom"))92 emitCallingConv(CC, O);93 }94 95 emitArgRegisterLists(O);96}97 98void CallingConvEmitter::emitCallingConv(const Record *CC, raw_ostream &O) {99 const ListInit *CCActions = CC->getValueAsListInit("Actions");100 Counter = 0;101 102 CurrentAction = CC->getName().str();103 // Call upon the creation of a map entry from the void!104 // We want an entry in AssignedRegsMap for every action, even if that105 // entry is empty.106 AssignedRegsMap[CurrentAction] = {};107 108 O << "\n\n";109 emitCCHeader(O, CC, " {\n");110 // Emit all of the actions, in order.111 for (unsigned I = 0, E = CCActions->size(); I != E; ++I) {112 const Record *Action = CCActions->getElementAsRecord(I);113 SwiftAction =114 llvm::any_of(Action->getSuperClasses(), [](const Record *Class) {115 std::string Name = Class->getNameInitAsString();116 return StringRef(Name).starts_with("CCIfSwift");117 });118 119 O << "\n";120 emitAction(Action, indent(2), O);121 }122 123 O << "\n return true; // CC didn't match.\n";124 O << "}\n";125}126 127// Return the name of the specified Init (DefInit or StringInit), with a128// namespace qualifier if the corresponding record contains one.129std::string CallingConvEmitter::getQualifiedRegisterName(const Init *I) {130 if (const auto *DI = dyn_cast<DefInit>(I))131 return getQualifiedName(DI->getDef());132 133 const auto *SI = cast<StringInit>(I);134 if (const CodeGenRegister *CGR = RegistersByDefName.lookup(SI->getValue()))135 return getQualifiedName(CGR->TheDef);136 137 PrintFatalError("register not defined: " + SI->getAsString());138 return "";139}140 141void CallingConvEmitter::emitAction(const Record *Action, indent Indent,142 raw_ostream &O) {143 144 auto EmitRegList = [&](const ListInit *RL, const StringRef RLName) {145 O << Indent << "static const MCPhysReg " << RLName << "[] = {\n";146 O << Indent << " ";147 ListSeparator LS;148 for (const Init *V : RL->getElements())149 O << LS << getQualifiedRegisterName(V);150 O << "\n" << Indent << "};\n";151 };152 153 auto EmitAllocateReg = [&](ArrayRef<const ListInit *> RegLists,154 ArrayRef<std::string> RLNames) {155 SmallVector<std::string> Parms;156 if (RegLists[0]->size() == 1) {157 for (const ListInit *LI : RegLists)158 Parms.push_back(getQualifiedRegisterName(LI->getElement(0)));159 } else {160 for (const std::string &S : RLNames)161 Parms.push_back(S + utostr(++Counter));162 for (const auto [Idx, LI] : enumerate(RegLists))163 EmitRegList(LI, Parms[Idx]);164 }165 O << formatv("{0}if (MCRegister Reg = State.AllocateReg({1})) {{\n", Indent,166 make_range(Parms.begin(), Parms.end()));167 O << Indent << " State.addLoc(CCValAssign::getReg(ValNo, ValVT, "168 << "Reg, LocVT, LocInfo));\n";169 };170 171 auto EmitAllocateStack = [&](bool EmitOffset = false) {172 int Size = Action->getValueAsInt("Size");173 int Align = Action->getValueAsInt("Align");174 if (EmitOffset)175 O << Indent << "int64_t Offset" << ++Counter << " = ";176 else177 O << Indent << " (void)";178 O << "State.AllocateStack(";179 180 const char *Fmt = " State.getMachineFunction().getDataLayout()."181 "{0}(EVT(LocVT).getTypeForEVT(State.getContext()))";182 if (Size)183 O << Size << ", ";184 else185 O << "\n" << Indent << formatv(Fmt, "getTypeAllocSize") << ", ";186 if (Align)187 O << "Align(" << Align << ")";188 else189 O << "\n" << Indent << formatv(Fmt, "getABITypeAlign");190 O << ");\n";191 };192 193 if (Action->isSubClassOf("CCPredicateAction")) {194 O << Indent << "if (";195 196 if (Action->isSubClassOf("CCIfType")) {197 const ListInit *VTs = Action->getValueAsListInit("VTs");198 for (unsigned I = 0, E = VTs->size(); I != E; ++I) {199 const Record *VT = VTs->getElementAsRecord(I);200 if (I != 0)201 O << " ||\n " << Indent;202 O << "LocVT == " << getEnumName(getValueType(VT));203 }204 205 } else if (Action->isSubClassOf("CCIf")) {206 O << Action->getValueAsString("Predicate");207 } else {208 errs() << *Action;209 PrintFatalError(Action->getLoc(), "Unknown CCPredicateAction!");210 }211 212 O << ") {\n";213 emitAction(Action->getValueAsDef("SubAction"), Indent + 2, O);214 O << Indent << "}\n";215 return;216 }217 218 if (Action->isSubClassOf("CCDelegateTo")) {219 const Record *CC = Action->getValueAsDef("CC");220 O << Indent << "if (!" << CC->getName()221 << "(ValNo, ValVT, LocVT, LocInfo, ArgFlags, OrigTy, State))\n"222 << Indent + 2 << "return false;\n";223 DelegateToMap[CurrentAction].insert(CC->getName().str());224 } else if (Action->isSubClassOf("CCAssignToReg") ||225 Action->isSubClassOf("CCAssignToRegTuple") ||226 Action->isSubClassOf("CCAssignToRegAndStack")) {227 const ListInit *RegList = Action->getValueAsListInit("RegList");228 for (unsigned I = 0, E = RegList->size(); I != E; ++I) {229 std::string Name = getQualifiedRegisterName(RegList->getElement(I));230 if (SwiftAction)231 AssignedSwiftRegsMap[CurrentAction].insert(std::move(Name));232 else233 AssignedRegsMap[CurrentAction].insert(std::move(Name));234 }235 EmitAllocateReg({RegList}, {"RegList"});236 237 if (Action->isSubClassOf("CCAssignToRegAndStack"))238 EmitAllocateStack();239 240 O << Indent << " return false;\n";241 O << Indent << "}\n";242 } else if (Action->isSubClassOf("CCAssignToRegWithShadow")) {243 const ListInit *RegList = Action->getValueAsListInit("RegList");244 const ListInit *ShadowRegList = Action->getValueAsListInit("ShadowRegList");245 if (!ShadowRegList->empty() && ShadowRegList->size() != RegList->size())246 PrintFatalError(Action->getLoc(),247 "Invalid length of list of shadowed registers");248 249 EmitAllocateReg({RegList, ShadowRegList}, {"RegList", "RegList"});250 251 O << Indent << " return false;\n";252 O << Indent << "}\n";253 } else if (Action->isSubClassOf("CCAssignToStack")) {254 EmitAllocateStack(/*EmitOffset=*/true);255 O << Indent << "State.addLoc(CCValAssign::getMem(ValNo, ValVT, Offset"256 << Counter << ", LocVT, LocInfo));\n";257 O << Indent << "return false;\n";258 } else if (Action->isSubClassOf("CCAssignToStackWithShadow")) {259 int Size = Action->getValueAsInt("Size");260 int Align = Action->getValueAsInt("Align");261 const ListInit *ShadowRegList = Action->getValueAsListInit("ShadowRegList");262 263 unsigned ShadowRegListNumber = ++Counter;264 EmitRegList(ShadowRegList, "ShadowRegList" + utostr(ShadowRegListNumber));265 266 O << Indent << "int64_t Offset" << ++Counter << " = State.AllocateStack("267 << Size << ", Align(" << Align << "), "268 << "ShadowRegList" << ShadowRegListNumber << ");\n";269 O << Indent << "State.addLoc(CCValAssign::getMem(ValNo, ValVT, Offset"270 << Counter << ", LocVT, LocInfo));\n";271 O << Indent << "return false;\n";272 } else if (Action->isSubClassOf("CCPromoteToType")) {273 const Record *DestTy = Action->getValueAsDef("DestTy");274 MVT DestVT = getValueType(DestTy);275 O << Indent << "LocVT = " << getEnumName(DestVT) << ";\n";276 if (DestVT.isFloatingPoint()) {277 O << Indent << "LocInfo = CCValAssign::FPExt;\n";278 } else {279 O << Indent << "if (ArgFlags.isSExt())\n"280 << Indent << " LocInfo = CCValAssign::SExt;\n"281 << Indent << "else if (ArgFlags.isZExt())\n"282 << Indent << " LocInfo = CCValAssign::ZExt;\n"283 << Indent << "else\n"284 << Indent << " LocInfo = CCValAssign::AExt;\n";285 }286 } else if (Action->isSubClassOf("CCPromoteToUpperBitsInType")) {287 const Record *DestTy = Action->getValueAsDef("DestTy");288 MVT DestVT = getValueType(DestTy);289 O << Indent << "LocVT = " << getEnumName(DestVT) << ";\n";290 if (DestVT.isFloatingPoint()) {291 PrintFatalError(Action->getLoc(),292 "CCPromoteToUpperBitsInType does not handle floating "293 "point");294 } else {295 O << Indent << "if (ArgFlags.isSExt())\n"296 << Indent << " LocInfo = CCValAssign::SExtUpper;\n"297 << Indent << "else if (ArgFlags.isZExt())\n"298 << Indent << " LocInfo = CCValAssign::ZExtUpper;\n"299 << Indent << "else\n"300 << Indent << " LocInfo = CCValAssign::AExtUpper;\n";301 }302 } else if (Action->isSubClassOf("CCBitConvertToType")) {303 const Record *DestTy = Action->getValueAsDef("DestTy");304 O << Indent << "LocVT = " << getEnumName(getValueType(DestTy)) << ";\n";305 O << Indent << "LocInfo = CCValAssign::BCvt;\n";306 } else if (Action->isSubClassOf("CCTruncToType")) {307 const Record *DestTy = Action->getValueAsDef("DestTy");308 O << Indent << "LocVT = " << getEnumName(getValueType(DestTy)) << ";\n";309 O << Indent << "LocInfo = CCValAssign::Trunc;\n";310 } else if (Action->isSubClassOf("CCPassIndirect")) {311 const Record *DestTy = Action->getValueAsDef("DestTy");312 O << Indent << "LocVT = " << getEnumName(getValueType(DestTy)) << ";\n";313 O << Indent << "LocInfo = CCValAssign::Indirect;\n";314 } else if (Action->isSubClassOf("CCPassByVal")) {315 int Size = Action->getValueAsInt("Size");316 int Align = Action->getValueAsInt("Align");317 O << Indent << "State.HandleByVal(ValNo, ValVT, LocVT, LocInfo, " << Size318 << ", Align(" << Align << "), ArgFlags);\n";319 O << Indent << "return false;\n";320 } else if (Action->isSubClassOf("CCCustom")) {321 O << Indent << "if (" << Action->getValueAsString("FuncName")322 << "(ValNo, ValVT, "323 << "LocVT, LocInfo, ArgFlags, State))\n";324 O << Indent << " return false;\n";325 } else {326 errs() << *Action;327 PrintFatalError(Action->getLoc(), "Unknown CCAction!");328 }329}330 331void CallingConvEmitter::emitArgRegisterLists(raw_ostream &O) {332 // Transitively merge all delegated CCs into AssignedRegsMap.333 using EntryTy = std::pair<std::string, std::set<std::string>>;334 bool Redo;335 do {336 Redo = false;337 std::deque<EntryTy> Worklist(DelegateToMap.begin(), DelegateToMap.end());338 339 while (!Worklist.empty()) {340 EntryTy Entry = Worklist.front();341 Worklist.pop_front();342 343 const std::string &CCName = Entry.first;344 std::set<std::string> &Registers = Entry.second;345 if (!Registers.empty())346 continue;347 348 for (auto &InnerEntry : Worklist) {349 const std::string &InnerCCName = InnerEntry.first;350 std::set<std::string> &InnerRegisters = InnerEntry.second;351 352 auto It = InnerRegisters.find(CCName);353 if (It != InnerRegisters.end()) {354 const auto &Src = AssignedRegsMap[CCName];355 AssignedRegsMap[InnerCCName].insert(Src.begin(), Src.end());356 InnerRegisters.erase(It);357 }358 }359 360 DelegateToMap.erase(CCName);361 Redo = true;362 }363 } while (Redo);364 365 if (AssignedRegsMap.empty())366 return;367 368 O << "\n#else\n\n";369 370 for (const auto &[RegName, Registers] : AssignedRegsMap) {371 if (RegName.empty())372 continue;373 374 O << "const MCRegister " << RegName << "_ArgRegs[] = { ";375 376 if (Registers.empty())377 O << "0";378 else379 O << llvm::interleaved(Registers);380 381 O << " };\n";382 }383 384 if (AssignedSwiftRegsMap.empty())385 return;386 387 O << "\n// Registers used by Swift.\n";388 for (const auto &[RegName, Registers] : AssignedSwiftRegsMap)389 O << "const MCRegister " << RegName << "_Swift_ArgRegs[] = { "390 << llvm::interleaved(Registers) << " };\n";391}392 393static TableGen::Emitter::OptClass<CallingConvEmitter>394 X("gen-callingconv", "Generate calling convention descriptions");395