utils/TableGen/CallingConvEmitter.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-exception
   6 //
   7 //===----------------------------------------------------------------------===//
   8 //
   9 // This tablegen backend is responsible for emitting descriptions of the calling
  10 // conventions supported by this target.
  11 //
  12 //===----------------------------------------------------------------------===//
  13
  14 #include "CodeGenTarget.h"
  15 #include "llvm/TableGen/Error.h"
  16 #include "llvm/TableGen/Record.h"
  17 #include "llvm/TableGen/TableGenBackend.h"
  18 #include <cassert>
  19 using namespace llvm;
  20
  21 namespace {
  22 class CallingConvEmitter {
  23   RecordKeeper &Records;
  24 public:
  25   explicit CallingConvEmitter(RecordKeeper &R) : Records(R) {}
  26
  27   void run(raw_ostream &o);
  28
  29 private:
  30   void EmitCallingConv(Record *CC, raw_ostream &O);
  31   void EmitAction(Record *Action, unsigned Indent, raw_ostream &O);
  32   unsigned Counter;
  33 };
  34 } // End anonymous namespace
  35
  36 void CallingConvEmitter::run(raw_ostream &O) {
  37   std::vector<Record*> CCs = Records.getAllDerivedDefinitions("CallingConv");
  38
  39   // Emit prototypes for all of the non-custom CC's so that they can forward ref
  40   // each other.
  41   for (Record *CC : CCs) {
  42     if (!CC->getValueAsBit("Custom")) {
  43       unsigned Pad = CC->getName().size();
  44       if (CC->getValueAsBit("Entry")) {
  45         O << "bool llvm::";
  46         Pad += 12;
  47       } else {
  48         O << "static bool ";
  49         Pad += 13;
  50       }
  51       O << CC->getName() << "(unsigned ValNo, MVT ValVT,\n"
  52         << std::string(Pad, ' ') << "MVT LocVT, CCValAssign::LocInfo LocInfo,\n"
  53         << std::string(Pad, ' ')
  54         << "ISD::ArgFlagsTy ArgFlags, CCState &State);\n";
  55     }
  56   }
  57
  58   // Emit each non-custom calling convention description in full.
  59   for (Record *CC : CCs) {
  60     if (!CC->getValueAsBit("Custom"))
  61       EmitCallingConv(CC, O);
  62   }
  63 }
  64
  65
  66 void CallingConvEmitter::EmitCallingConv(Record *CC, raw_ostream &O) {
  67   ListInit *CCActions = CC->getValueAsListInit("Actions");
  68   Counter = 0;
  69
  70   O << "\n\n";
  71   unsigned Pad = CC->getName().size();
  72   if (CC->getValueAsBit("Entry")) {
  73     O << "bool llvm::";
  74     Pad += 12;
  75   } else {
  76     O << "static bool ";
  77     Pad += 13;
  78   }
  79   O << CC->getName() << "(unsigned ValNo, MVT ValVT,\n"
  80     << std::string(Pad, ' ') << "MVT LocVT, CCValAssign::LocInfo LocInfo,\n"
  81     << std::string(Pad, ' ') << "ISD::ArgFlagsTy ArgFlags, CCState &State) {\n";
  82   // Emit all of the actions, in order.
  83   for (unsigned i = 0, e = CCActions->size(); i != e; ++i) {
  84     O << "\n";
  85     EmitAction(CCActions->getElementAsRecord(i), 2, O);
  86   }
  87
  88   O << "\n  return true;  // CC didn't match.\n";
  89   O << "}\n";
  90 }
  91
  92 void CallingConvEmitter::EmitAction(Record *Action,
  93                                     unsigned Indent, raw_ostream &O) {
  94   std::string IndentStr = std::string(Indent, ' ');
  95
  96   if (Action->isSubClassOf("CCPredicateAction")) {
  97     O << IndentStr << "if (";
  98
  99     if (Action->isSubClassOf("CCIfType")) {
 100       ListInit *VTs = Action->getValueAsListInit("VTs");
 101       for (unsigned i = 0, e = VTs->size(); i != e; ++i) {
 102         Record *VT = VTs->getElementAsRecord(i);
 103         if (i != 0) O << " ||\n    " << IndentStr;
 104         O << "LocVT == " << getEnumName(getValueType(VT));
 105       }
 106
 107     } else if (Action->isSubClassOf("CCIf")) {
 108       O << Action->getValueAsString("Predicate");
 109     } else {
 110       errs() << *Action;
 111       PrintFatalError(Action->getLoc(), "Unknown CCPredicateAction!");
 112     }
 113
 114     O << ") {\n";
 115     EmitAction(Action->getValueAsDef("SubAction"), Indent+2, O);
 116     O << IndentStr << "}\n";
 117   } else {
 118     if (Action->isSubClassOf("CCDelegateTo")) {
 119       Record *CC = Action->getValueAsDef("CC");
 120       O << IndentStr << "if (!" << CC->getName()
 121         << "(ValNo, ValVT, LocVT, LocInfo, ArgFlags, State))\n"
 122         << IndentStr << "  return false;\n";
 123     } else if (Action->isSubClassOf("CCAssignToReg")) {
 124       ListInit *RegList = Action->getValueAsListInit("RegList");
 125       if (RegList->size() == 1) {
 126         O << IndentStr << "if (unsigned Reg = State.AllocateReg(";
 127         O << getQualifiedName(RegList->getElementAsRecord(0)) << ")) {\n";
 128       } else {
 129         O << IndentStr << "static const MCPhysReg RegList" << ++Counter
 130           << "[] = {\n";
 131         O << IndentStr << "  ";
 132         for (unsigned i = 0, e = RegList->size(); i != e; ++i) {
 133           if (i != 0) O << ", ";
 134           O << getQualifiedName(RegList->getElementAsRecord(i));
 135         }
 136         O << "\n" << IndentStr << "};\n";
 137         O << IndentStr << "if (unsigned Reg = State.AllocateReg(RegList"
 138           << Counter << ")) {\n";
 139       }
 140       O << IndentStr << "  State.addLoc(CCValAssign::getReg(ValNo, ValVT, "
 141         << "Reg, LocVT, LocInfo));\n";
 142       O << IndentStr << "  return false;\n";
 143       O << IndentStr << "}\n";
 144     } else if (Action->isSubClassOf("CCAssignToRegWithShadow")) {
 145       ListInit *RegList = Action->getValueAsListInit("RegList");
 146       ListInit *ShadowRegList = Action->getValueAsListInit("ShadowRegList");
 147       if (!ShadowRegList->empty() && ShadowRegList->size() != RegList->size())
 148         PrintFatalError(Action->getLoc(),
 149                         "Invalid length of list of shadowed registers");
 150
 151       if (RegList->size() == 1) {
 152         O << IndentStr << "if (unsigned Reg = State.AllocateReg(";
 153         O << getQualifiedName(RegList->getElementAsRecord(0));
 154         O << ", " << getQualifiedName(ShadowRegList->getElementAsRecord(0));
 155         O << ")) {\n";
 156       } else {
 157         unsigned RegListNumber = ++Counter;
 158         unsigned ShadowRegListNumber = ++Counter;
 159
 160         O << IndentStr << "static const MCPhysReg RegList" << RegListNumber
 161           << "[] = {\n";
 162         O << IndentStr << "  ";
 163         for (unsigned i = 0, e = RegList->size(); i != e; ++i) {
 164           if (i != 0) O << ", ";
 165           O << getQualifiedName(RegList->getElementAsRecord(i));
 166         }
 167         O << "\n" << IndentStr << "};\n";
 168
 169         O << IndentStr << "static const MCPhysReg RegList"
 170           << ShadowRegListNumber << "[] = {\n";
 171         O << IndentStr << "  ";
 172         for (unsigned i = 0, e = ShadowRegList->size(); i != e; ++i) {
 173           if (i != 0) O << ", ";
 174           O << getQualifiedName(ShadowRegList->getElementAsRecord(i));
 175         }
 176         O << "\n" << IndentStr << "};\n";
 177
 178         O << IndentStr << "if (unsigned Reg = State.AllocateReg(RegList"
 179           << RegListNumber << ", " << "RegList" << ShadowRegListNumber
 180           << ")) {\n";
 181       }
 182       O << IndentStr << "  State.addLoc(CCValAssign::getReg(ValNo, ValVT, "
 183         << "Reg, LocVT, LocInfo));\n";
 184       O << IndentStr << "  return false;\n";
 185       O << IndentStr << "}\n";
 186     } else if (Action->isSubClassOf("CCAssignToStack")) {
 187       int Size = Action->getValueAsInt("Size");
 188       int Align = Action->getValueAsInt("Align");
 189
 190       O << IndentStr << "unsigned Offset" << ++Counter
 191         << " = State.AllocateStack(";
 192       if (Size)
 193         O << Size << ", ";
 194       else
 195         O << "\n" << IndentStr
 196           << "  State.getMachineFunction().getDataLayout()."
 197              "getTypeAllocSize(EVT(LocVT).getTypeForEVT(State.getContext())),"
 198              " ";
 199       if (Align)
 200         O << Align;
 201       else
 202         O << "\n" << IndentStr
 203           << "  State.getMachineFunction().getDataLayout()."
 204              "getABITypeAlignment(EVT(LocVT).getTypeForEVT(State.getContext()"
 205              "))";
 206       O << ");\n" << IndentStr
 207         << "State.addLoc(CCValAssign::getMem(ValNo, ValVT, Offset"
 208         << Counter << ", LocVT, LocInfo));\n";
 209       O << IndentStr << "return false;\n";
 210     } else if (Action->isSubClassOf("CCAssignToStackWithShadow")) {
 211       int Size = Action->getValueAsInt("Size");
 212       int Align = Action->getValueAsInt("Align");
 213       ListInit *ShadowRegList = Action->getValueAsListInit("ShadowRegList");
 214
 215       unsigned ShadowRegListNumber = ++Counter;
 216
 217       O << IndentStr << "static const MCPhysReg ShadowRegList"
 218           << ShadowRegListNumber << "[] = {\n";
 219       O << IndentStr << "  ";
 220       for (unsigned i = 0, e = ShadowRegList->size(); i != e; ++i) {
 221         if (i != 0) O << ", ";
 222         O << getQualifiedName(ShadowRegList->getElementAsRecord(i));
 223       }
 224       O << "\n" << IndentStr << "};\n";
 225
 226       O << IndentStr << "unsigned Offset" << ++Counter
 227         << " = State.AllocateStack("
 228         << Size << ", " << Align << ", "
 229         << "ShadowRegList" << ShadowRegListNumber << ");\n";
 230       O << IndentStr << "State.addLoc(CCValAssign::getMem(ValNo, ValVT, Offset"
 231         << Counter << ", LocVT, LocInfo));\n";
 232       O << IndentStr << "return false;\n";
 233     } else if (Action->isSubClassOf("CCPromoteToType")) {
 234       Record *DestTy = Action->getValueAsDef("DestTy");
 235       MVT::SimpleValueType DestVT = getValueType(DestTy);
 236       O << IndentStr << "LocVT = " << getEnumName(DestVT) <<";\n";
 237       if (MVT(DestVT).isFloatingPoint()) {
 238         O << IndentStr << "LocInfo = CCValAssign::FPExt;\n";
 239       } else {
 240         O << IndentStr << "if (ArgFlags.isSExt())\n"
 241           << IndentStr << IndentStr << "LocInfo = CCValAssign::SExt;\n"
 242           << IndentStr << "else if (ArgFlags.isZExt())\n"
 243           << IndentStr << IndentStr << "LocInfo = CCValAssign::ZExt;\n"
 244           << IndentStr << "else\n"
 245           << IndentStr << IndentStr << "LocInfo = CCValAssign::AExt;\n";
 246       }
 247     } else if (Action->isSubClassOf("CCPromoteToUpperBitsInType")) {
 248       Record *DestTy = Action->getValueAsDef("DestTy");
 249       MVT::SimpleValueType DestVT = getValueType(DestTy);
 250       O << IndentStr << "LocVT = " << getEnumName(DestVT) << ";\n";
 251       if (MVT(DestVT).isFloatingPoint()) {
 252         PrintFatalError(Action->getLoc(),
 253                         "CCPromoteToUpperBitsInType does not handle floating "
 254                         "point");
 255       } else {
 256         O << IndentStr << "if (ArgFlags.isSExt())\n"
 257           << IndentStr << IndentStr << "LocInfo = CCValAssign::SExtUpper;\n"
 258           << IndentStr << "else if (ArgFlags.isZExt())\n"
 259           << IndentStr << IndentStr << "LocInfo = CCValAssign::ZExtUpper;\n"
 260           << IndentStr << "else\n"
 261           << IndentStr << IndentStr << "LocInfo = CCValAssign::AExtUpper;\n";
 262       }
 263     } else if (Action->isSubClassOf("CCBitConvertToType")) {
 264       Record *DestTy = Action->getValueAsDef("DestTy");
 265       O << IndentStr << "LocVT = " << getEnumName(getValueType(DestTy)) <<";\n";
 266       O << IndentStr << "LocInfo = CCValAssign::BCvt;\n";
 267     } else if (Action->isSubClassOf("CCTruncToType")) {
 268       Record *DestTy = Action->getValueAsDef("DestTy");
 269       O << IndentStr << "LocVT = " << getEnumName(getValueType(DestTy)) <<";\n";
 270       O << IndentStr << "LocInfo = CCValAssign::Trunc;\n";
 271     } else if (Action->isSubClassOf("CCPassIndirect")) {
 272       Record *DestTy = Action->getValueAsDef("DestTy");
 273       O << IndentStr << "LocVT = " << getEnumName(getValueType(DestTy)) <<";\n";
 274       O << IndentStr << "LocInfo = CCValAssign::Indirect;\n";
 275     } else if (Action->isSubClassOf("CCPassByVal")) {
 276       int Size = Action->getValueAsInt("Size");
 277       int Align = Action->getValueAsInt("Align");
 278       O << IndentStr
 279         << "State.HandleByVal(ValNo, ValVT, LocVT, LocInfo, "
 280         << Size << ", " << Align << ", ArgFlags);\n";
 281       O << IndentStr << "return false;\n";
 282     } else if (Action->isSubClassOf("CCCustom")) {
 283       O << IndentStr
 284         << "if (" << Action->getValueAsString("FuncName") << "(ValNo, ValVT, "
 285         << "LocVT, LocInfo, ArgFlags, State))\n";
 286       O << IndentStr << IndentStr << "return false;\n";
 287     } else {
 288       errs() << *Action;
 289       PrintFatalError(Action->getLoc(), "Unknown CCAction!");
 290     }
 291   }
 292 }
 293
 294 namespace llvm {
 295
 296 void EmitCallingConv(RecordKeeper &RK, raw_ostream &OS) {
 297   emitSourceFileHeader("Calling Convention Implementation Fragment", OS);
 298   CallingConvEmitter(RK).run(OS);
 299 }
 300
 301 } // End llvm namespace