RegisterInfoEmitter.cpp revision 13c5b4cdc8b601bdb464bf31f316233fd02e1d49 
1//===- RegisterInfoEmitter.cpp - Generate a Register File Desc. -*- C++ -*-===//
2//
3// This tablegen backend is responsible for emitting a description of a target
4// register file for a code generator.  It uses instances of the Register,
5// RegisterAliases, and RegisterClass classes to gather this information.
6//
7//===----------------------------------------------------------------------===//
8
9#include "RegisterInfoEmitter.h"
10#include "Record.h"
11#include "Support/StringExtras.h"
12#include <set>
13
14static void EmitSourceHeader(const std::string &Desc, std::ostream &o) {
15  o << "//===- TableGen'erated file -------------------------------------*-"
16       " C++ -*-===//\n//\n// " << Desc << "\n//\n// Automatically generate"
17       "d file, do not edit!\n//\n//===------------------------------------"
18       "----------------------------------===//\n\n";
19}
20
21// runEnums - Print out enum values for all of the registers.
22void RegisterInfoEmitter::runEnums(std::ostream &OS) {
23  std::vector<Record*> Registers = Records.getAllDerivedDefinitions("Register");
24
25  if (Registers.size() == 0)
26    throw std::string("No 'Register' subclasses defined!");
27
28  std::string Namespace = Registers[0]->getValueAsString("Namespace");
29
30  EmitSourceHeader("Target Register Enum Values", OS);
31
32  if (!Namespace.empty())
33    OS << "namespace " << Namespace << " {\n";
34  OS << "  enum {\n    NoRegister,\n";
35
36  for (unsigned i = 0, e = Registers.size(); i != e; ++i)
37    OS << "    " << Registers[i]->getName() << ", \t// " << i+1 << "\n";
38
39  OS << "  };\n";
40  if (!Namespace.empty())
41    OS << "}\n";
42}
43
44static Record *getTarget(RecordKeeper &RC) {
45  std::vector<Record*> Targets = RC.getAllDerivedDefinitions("Target");
46
47  if (Targets.size() != 1)
48    throw std::string("ERROR: Multiple subclasses of Target defined!");
49  return Targets[0];
50}
51
52static std::string getQualifiedName(Record *R) {
53  std::string Namespace = R->getValueAsString("Namespace");
54  if (Namespace.empty()) return R->getName();
55  return Namespace + "::" + R->getName();
56}
57
58void RegisterInfoEmitter::runHeader(std::ostream &OS) {
59  EmitSourceHeader("Register Information Header Fragment", OS);
60
61  std::string ClassName = getTarget(Records)->getName() + "GenRegisterInfo";
62
63  OS << "#include \"llvm/Target/MRegisterInfo.h\"\n\n";
64
65  OS << "struct " << ClassName << " : public MRegisterInfo {\n"
66     << "  " << ClassName
67     << "(int CallFrameSetupOpcode = -1, int CallFrameDestroyOpcode = -1);\n"
68     << "  const unsigned* getCalleeSaveRegs() const;\n"
69     << "};\n\n";
70}
71
72// RegisterInfoEmitter::run - Main register file description emitter.
73//
74void RegisterInfoEmitter::run(std::ostream &OS) {
75  EmitSourceHeader("Register Information Source Fragment", OS);
76
77  // Start out by emitting each of the register classes... to do this, we build
78  // a set of registers which belong to a register class, this is to ensure that
79  // each register is only in a single register class.
80  //
81  std::vector<Record*> RegisterClasses =
82    Records.getAllDerivedDefinitions("RegisterClass");
83
84  std::vector<Record*> Registers = Records.getAllDerivedDefinitions("Register");
85  Record *RegisterClass = Records.getClass("Register");
86
87  std::set<Record*> RegistersFound;
88  std::vector<std::string> RegClassNames;
89
90  // Loop over all of the register classes... emitting each one.
91  OS << "namespace {     // Register classes...\n";
92
93  for (unsigned rc = 0, e = RegisterClasses.size(); rc != e; ++rc) {
94    Record *RC = RegisterClasses[rc];
95    std::string Name = RC->getName();
96    if (Name.size() > 9 && Name[9] == '.') {
97      static unsigned AnonCounter = 0;
98      Name = "AnonRegClass_"+utostr(AnonCounter++);
99    }
100
101    RegClassNames.push_back(Name);
102
103    // Emit the register list now...
104    OS << "  // " << Name << " Register Class...\n  const unsigned " << Name
105       << "[] = {\n    ";
106    ListInit *RegList = RC->getValueAsListInit("MemberList");
107    for (unsigned i = 0, e = RegList->getSize(); i != e; ++i) {
108      DefInit *RegDef = dynamic_cast<DefInit*>(RegList->getElement(i));
109      if (!RegDef) throw "Register class member is not a record!";
110      Record *Reg = RegDef->getDef();
111      if (!Reg->isSubClassOf(RegisterClass))
112        throw "Register Class member '" + Reg->getName() +
113              " does not derive from the Register class!";
114      if (RegistersFound.count(Reg))
115        throw "Register '" + Reg->getName() +
116              "' included in multiple register classes!";
117      RegistersFound.insert(Reg);
118      OS << getQualifiedName(Reg) << ", ";
119    }
120    OS << "\n  };\n\n";
121
122    OS << "  struct " << Name << "Class : public TargetRegisterClass {\n"
123       << "    " << Name << "Class() : TargetRegisterClass("
124       << RC->getValueAsInt("Size")/8 << ", " << RC->getValueAsInt("Alignment")
125       << ", " << Name << ", " << Name << " + " << RegList->getSize()
126       << ") {}\n";
127
128    if (CodeInit *CI = dynamic_cast<CodeInit*>(RC->getValueInit("Methods")))
129      OS << CI->getValue();
130    else
131      throw "Expected 'code' fragment for 'Methods' value in register class '"+
132            RC->getName() + "'!";
133
134    OS << "  } " << Name << "Instance;\n\n";
135  }
136
137  OS << "  const TargetRegisterClass* const RegisterClasses[] = {\n";
138  for (unsigned i = 0, e = RegClassNames.size(); i != e; ++i)
139    OS << "    &" << RegClassNames[i] << "Instance,\n";
140  OS << "  };\n";
141
142  // Emit register class aliases...
143  std::vector<Record*> RegisterAliasesRecs =
144    Records.getAllDerivedDefinitions("RegisterAliases");
145  std::map<Record*, std::set<Record*> > RegisterAliases;
146
147  for (unsigned i = 0, e = RegisterAliasesRecs.size(); i != e; ++i) {
148    Record *AS = RegisterAliasesRecs[i];
149    Record *R = AS->getValueAsDef("Reg");
150    ListInit *LI = AS->getValueAsListInit("Aliases");
151
152    // Add information that R aliases all of the elements in the list... and
153    // that everything in the list aliases R.
154    for (unsigned j = 0, e = LI->getSize(); j != e; ++j) {
155      DefInit *Reg = dynamic_cast<DefInit*>(LI->getElement(j));
156      if (!Reg) throw "ERROR: Alias list element is not a def!";
157      if (RegisterAliases[R].count(Reg->getDef()))
158        std::cerr << "Warning: register alias between " << getQualifiedName(R)
159                  << " and " << getQualifiedName(Reg->getDef())
160                  << " specified multiple times!\n";
161      RegisterAliases[R].insert(Reg->getDef());
162
163      if (RegisterAliases[Reg->getDef()].count(R))
164        std::cerr << "Warning: register alias between " << getQualifiedName(R)
165                  << " and " << getQualifiedName(Reg->getDef())
166                  << " specified multiple times!\n";
167      RegisterAliases[Reg->getDef()].insert(R);
168    }
169  }
170
171  if (!RegisterAliases.empty())
172    OS << "\n\n  // Register Alias Sets...\n";
173
174  // Loop over all of the registers which have aliases, emitting the alias list
175  // to memory.
176  for (std::map<Record*, std::set<Record*> >::iterator
177         I = RegisterAliases.begin(), E = RegisterAliases.end(); I != E; ++I) {
178    OS << "  const unsigned " << I->first->getName() << "_AliasSet[] = { ";
179    for (std::set<Record*>::iterator ASI = I->second.begin(),
180           E = I->second.end(); ASI != E; ++ASI)
181      OS << getQualifiedName(*ASI) << ", ";
182    OS << "0 };\n";
183  }
184
185  OS << "\n  const MRegisterDesc RegisterDescriptors[] = { // Descriptors\n";
186  OS << "    { \"NOREG\",\t0,\t\t0,\t0 },\n";
187  // Now that register alias sets have been emitted, emit the register
188  // descriptors now.
189  for (unsigned i = 0, e = Registers.size(); i != e; ++i) {
190    Record *Reg = Registers[i];
191    OS << "    { \"" << Reg->getName() << "\",\t";
192    if (RegisterAliases.count(Reg))
193      OS << Reg->getName() << "_AliasSet,\t";
194    else
195      OS << "0,\t\t";
196    OS << "0, 0 },\n";
197  }
198  OS << "  };\n";      // End of register descriptors...
199  OS << "}\n\n";       // End of anonymous namespace...
200
201  Record *Target = getTarget(Records);
202  std::string ClassName = Target->getName() + "GenRegisterInfo";
203
204  // Emit the constructor of the class...
205  OS << ClassName << "::" << ClassName
206     << "(int CallFrameSetupOpcode, int CallFrameDestroyOpcode)\n"
207     << "  : MRegisterInfo(RegisterDescriptors, " << Registers.size()+1
208     << ", RegisterClasses, RegisterClasses+" << RegClassNames.size() << ",\n "
209     << "                 CallFrameSetupOpcode, CallFrameDestroyOpcode) {}\n\n";
210
211  // Emit the getCalleeSaveRegs method...
212  OS << "const unsigned* " << ClassName << "::getCalleeSaveRegs() const {\n"
213     << "  static const unsigned CalleeSaveRegs[] = {\n    ";
214
215  ListInit *LI = Target->getValueAsListInit("CalleeSavedRegisters");
216  for (unsigned i = 0, e = LI->getSize(); i != e; ++i)
217    if (DefInit *DI = dynamic_cast<DefInit*>(LI->getElement(i)))
218      OS << getQualifiedName(DI->getDef()) << ", ";
219    else
220      throw "Expected register definition in CalleeSavedRegisters list!";
221  OS << " 0\n  };\n  return CalleeSaveRegs;\n}\n\n";
222}
223