RegisterInfoEmitter.cpp revision 3da94aec4d429b2ba0f65fa040c33650cade196b 
1//===- RegisterInfoEmitter.cpp - Generate a Register File Desc. -*- C++ -*-===//
2//
3//                     The LLVM Compiler Infrastructure
4//
5// This file was developed by the LLVM research group and is distributed under
6// the University of Illinois Open Source License. See LICENSE.TXT for details.
7//
8//===----------------------------------------------------------------------===//
9//
10// This tablegen backend is responsible for emitting a description of a target
11// register file for a code generator.  It uses instances of the Register,
12// RegisterAliases, and RegisterClass classes to gather this information.
13//
14//===----------------------------------------------------------------------===//
15
16#include "RegisterInfoEmitter.h"
17#include "CodeGenTarget.h"
18#include "CodeGenRegisters.h"
19#include "Record.h"
20#include "llvm/ADT/StringExtras.h"
21#include "llvm/ADT/STLExtras.h"
22#include <set>
23using namespace llvm;
24
25// runEnums - Print out enum values for all of the registers.
26void RegisterInfoEmitter::runEnums(std::ostream &OS) {
27  CodeGenTarget Target;
28  const std::vector<CodeGenRegister> &Registers = Target.getRegisters();
29
30  std::string Namespace = Registers[0].TheDef->getValueAsString("Namespace");
31
32  EmitSourceFileHeader("Target Register Enum Values", OS);
33  OS << "namespace llvm {\n\n";
34
35  if (!Namespace.empty())
36    OS << "namespace " << Namespace << " {\n";
37  OS << "  enum {\n    NoRegister,\n";
38
39  for (unsigned i = 0, e = Registers.size(); i != e; ++i)
40    OS << "    " << Registers[i].getName() << ", \t// " << i+1 << "\n";
41
42  OS << "  };\n";
43  if (!Namespace.empty())
44    OS << "}\n";
45  OS << "} // End llvm namespace \n";
46}
47
48void RegisterInfoEmitter::runHeader(std::ostream &OS) {
49  EmitSourceFileHeader("Register Information Header Fragment", OS);
50  CodeGenTarget Target;
51  const std::string &TargetName = Target.getName();
52  std::string ClassName = TargetName + "GenRegisterInfo";
53
54  OS << "#include \"llvm/Target/MRegisterInfo.h\"\n\n";
55
56  OS << "namespace llvm {\n\n";
57
58  OS << "struct " << ClassName << " : public MRegisterInfo {\n"
59     << "  " << ClassName
60     << "(int CallFrameSetupOpcode = -1, int CallFrameDestroyOpcode = -1);\n"
61     << "  const unsigned* getCalleeSaveRegs() const;\n"
62     << "};\n\n";
63
64  std::vector<Record*> RegisterClasses =
65    Records.getAllDerivedDefinitions("RegisterClass");
66
67  OS << "namespace " << TargetName << " { // Register classes\n";
68  for (unsigned i = 0, e = RegisterClasses.size(); i != e; ++i) {
69    const std::string &Name = RegisterClasses[i]->getName();
70    if (Name.size() < 9 || Name[9] != '.')       // Ignore anonymous classes
71      OS << "  extern TargetRegisterClass *" << Name << "RegisterClass;\n";
72  }
73  OS << "} // end of namespace " << TargetName << "\n\n";
74  OS << "} // End llvm namespace \n";
75}
76
77// RegisterInfoEmitter::run - Main register file description emitter.
78//
79void RegisterInfoEmitter::run(std::ostream &OS) {
80  CodeGenTarget Target;
81  EmitSourceFileHeader("Register Information Source Fragment", OS);
82
83  OS << "namespace llvm {\n\n";
84
85  // Start out by emitting each of the register classes... to do this, we build
86  // a set of registers which belong to a register class, this is to ensure that
87  // each register is only in a single register class.
88  //
89  const std::vector<CodeGenRegisterClass> &RegisterClasses =
90    Target.getRegisterClasses();
91
92  std::set<Record*> RegistersFound;
93  std::vector<std::string> RegClassNames;
94
95  // Loop over all of the register classes... emitting each one.
96  OS << "namespace {     // Register classes...\n";
97
98  // RegClassesBelongedTo - Keep track of which register classes each reg
99  // belongs to.
100  std::multimap<Record*, const CodeGenRegisterClass*> RegClassesBelongedTo;
101
102  for (unsigned rc = 0, e = RegisterClasses.size(); rc != e; ++rc) {
103    const CodeGenRegisterClass &RC = RegisterClasses[rc];
104
105    std::string Name = RC.getName();
106    if (Name.size() > 9 && Name[9] == '.') {
107      static unsigned AnonCounter = 0;
108      Name = "AnonRegClass_"+utostr(AnonCounter++);
109    }
110
111    RegClassNames.push_back(Name);
112
113    // Emit the register list now...
114    OS << "  // " << Name << " Register Class...\n  const unsigned " << Name
115       << "[] = {\n    ";
116    for (unsigned i = 0, e = RC.Elements.size(); i != e; ++i) {
117      Record *Reg = RC.Elements[i];
118      if (RegistersFound.count(Reg))
119        throw "Register '" + Reg->getName() +
120              "' included in multiple register classes!";
121      RegistersFound.insert(Reg);
122      OS << getQualifiedName(Reg) << ", ";
123
124      // Keep track of which regclasses this register is in.
125      RegClassesBelongedTo.insert(std::make_pair(Reg, &RC));
126    }
127    OS << "\n  };\n\n";
128
129    OS << "  struct " << Name << "Class : public TargetRegisterClass {\n"
130       << "    " << Name << "Class() : TargetRegisterClass("
131       << RC.SpillSize/8 << ", " << RC.SpillAlignment/8 << ", " << Name << ", "
132       << Name << " + " << RC.Elements.size() << ") {}\n"
133       << RC.MethodDefinitions << "  } " << Name << "Instance;\n\n";
134  }
135
136  OS << "  const TargetRegisterClass* const RegisterClasses[] = {\n";
137  for (unsigned i = 0, e = RegClassNames.size(); i != e; ++i)
138    OS << "    &" << RegClassNames[i] << "Instance,\n";
139  OS << "  };\n";
140
141  // Emit register class aliases...
142  std::map<Record*, std::set<Record*> > RegisterAliases;
143  const std::vector<CodeGenRegister> &Regs = Target.getRegisters();
144
145  for (unsigned i = 0, e = Regs.size(); i != e; ++i) {
146    Record *R = Regs[i].TheDef;
147    ListInit *LI = Regs[i].TheDef->getValueAsListInit("Aliases");
148    // Add information that R aliases all of the elements in the list... and
149    // that everything in the list aliases R.
150    for (unsigned j = 0, e = LI->getSize(); j != e; ++j) {
151      DefInit *Reg = dynamic_cast<DefInit*>(LI->getElement(j));
152      if (!Reg) throw "ERROR: Alias list element is not a def!";
153      if (RegisterAliases[R].count(Reg->getDef()))
154        std::cerr << "Warning: register alias between " << getQualifiedName(R)
155                  << " and " << getQualifiedName(Reg->getDef())
156                  << " specified multiple times!\n";
157      RegisterAliases[R].insert(Reg->getDef());
158
159      if (RegisterAliases[Reg->getDef()].count(R))
160        std::cerr << "Warning: register alias between " << getQualifiedName(R)
161                  << " and " << getQualifiedName(Reg->getDef())
162                  << " specified multiple times!\n";
163      RegisterAliases[Reg->getDef()].insert(R);
164    }
165  }
166
167  if (!RegisterAliases.empty())
168    OS << "\n\n  // Register Alias Sets...\n";
169
170  // Emit the empty alias list
171  OS << "  const unsigned Empty_AliasSet[] = { 0 };\n";
172  // Loop over all of the registers which have aliases, emitting the alias list
173  // to memory.
174  for (std::map<Record*, std::set<Record*> >::iterator
175         I = RegisterAliases.begin(), E = RegisterAliases.end(); I != E; ++I) {
176    OS << "  const unsigned " << I->first->getName() << "_AliasSet[] = { ";
177    for (std::set<Record*>::iterator ASI = I->second.begin(),
178           E = I->second.end(); ASI != E; ++ASI)
179      OS << getQualifiedName(*ASI) << ", ";
180    OS << "0 };\n";
181  }
182
183  OS << "\n  const MRegisterDesc RegisterDescriptors[] = { // Descriptors\n";
184  OS << "    { \"NOREG\",\t0,\t\t0,\t0 },\n";
185
186
187  // Now that register alias sets have been emitted, emit the register
188  // descriptors now.
189  const std::vector<CodeGenRegister> &Registers = Target.getRegisters();
190  for (unsigned i = 0, e = Registers.size(); i != e; ++i) {
191    const CodeGenRegister &Reg = Registers[i];
192    OS << "    { \"";
193    if (!Reg.TheDef->getValueAsString("Name").empty())
194      OS << Reg.TheDef->getValueAsString("Name");
195    else
196      OS << Reg.getName();
197    OS << "\",\t";
198    if (RegisterAliases.count(Reg.TheDef))
199      OS << Reg.getName() << "_AliasSet,\t";
200    else
201      OS << "Empty_AliasSet,\t";
202
203    // Figure out what the size and alignment of the spill slots are for this
204    // reg.  This may be explicitly declared in the register, or it may be
205    // inferred from the register classes it is part of.
206    std::multimap<Record*, const CodeGenRegisterClass*>::iterator I, E;
207    tie(I, E) = RegClassesBelongedTo.equal_range(Reg.TheDef);
208    unsigned SpillSize = Reg.DeclaredSpillSize;
209    unsigned SpillAlign = Reg.DeclaredSpillAlignment;
210    for (; I != E; ++I) {   // For each reg class this belongs to.
211      const CodeGenRegisterClass *RC = I->second;
212      if (SpillSize == 0)
213        SpillSize = RC->SpillSize;
214      else if (SpillSize != RC->SpillSize)
215        throw "Spill size for regclass '" + RC->getName() +
216              "' doesn't match spill sized already inferred for register '" +
217              Reg.getName() + "'!";
218      if (SpillAlign == 0)
219        SpillAlign = RC->SpillAlignment;
220      else if (SpillAlign != RC->SpillAlignment)
221        throw "Spill alignment for regclass '" + RC->getName() +
222              "' doesn't match spill sized already inferred for register '" +
223              Reg.getName() + "'!";
224    }
225
226    OS << SpillSize << ", " << SpillAlign << " },\n";
227  }
228  OS << "  };\n";      // End of register descriptors...
229  OS << "}\n\n";       // End of anonymous namespace...
230
231  OS << "namespace " << Target.getName() << " { // Register classes\n";
232  for (unsigned i = 0, e = RegisterClasses.size(); i != e; ++i) {
233    const std::string &Name = RegisterClasses[i].getName();
234    if (Name.size() < 9 || Name[9] != '.')    // Ignore anonymous classes
235      OS << "  TargetRegisterClass *" << Name << "RegisterClass = &"
236         << Name << "Instance;\n";
237  }
238  OS << "} // end of namespace " << Target.getName() << "\n\n";
239
240
241
242  std::string ClassName = Target.getName() + "GenRegisterInfo";
243
244  // Emit the constructor of the class...
245  OS << ClassName << "::" << ClassName
246     << "(int CallFrameSetupOpcode, int CallFrameDestroyOpcode)\n"
247     << "  : MRegisterInfo(RegisterDescriptors, " << Registers.size()+1
248     << ", RegisterClasses, RegisterClasses+" << RegClassNames.size() << ",\n "
249     << "                 CallFrameSetupOpcode, CallFrameDestroyOpcode) {}\n\n";
250
251  // Emit the getCalleeSaveRegs method...
252  OS << "const unsigned* " << ClassName << "::getCalleeSaveRegs() const {\n"
253     << "  static const unsigned CalleeSaveRegs[] = {\n    ";
254
255  const std::vector<Record*> &CSR = Target.getCalleeSavedRegisters();
256  for (unsigned i = 0, e = CSR.size(); i != e; ++i)
257    OS << getQualifiedName(CSR[i]) << ", ";
258  OS << " 0\n  };\n  return CalleeSaveRegs;\n}\n\n";
259  OS << "} // End llvm namespace \n";
260}
261