RegisterInfoEmitter.cpp revision 2f02ed9a1f952e534807fae3c51de92ca0eacfd3 
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     << "const TargetRegisterClass* const *getCalleeSaveRegClasses() const;\n"
63     << "};\n\n";
64
65  const std::vector<CodeGenRegisterClass> &RegisterClasses =
66    Target.getRegisterClasses();
67
68  if (!RegisterClasses.empty()) {
69    OS << "namespace " << RegisterClasses[0].Namespace
70       << " { // Register classes\n";
71    for (unsigned i = 0, e = RegisterClasses.size(); i != e; ++i) {
72      const std::string &Name = RegisterClasses[i].getName();
73
74      // Output the register class definition.
75      OS << "  struct " << Name << "Class : public TargetRegisterClass {\n"
76         << "    " << Name << "Class();\n"
77         << RegisterClasses[i].MethodProtos << "  };\n";
78
79      // Output the extern for the instance.
80      OS << "  extern " << Name << "Class\t" << Name << "RegClass;\n";
81      // Output the extern for the pointer to the instance (should remove).
82      OS << "  static TargetRegisterClass * const "<< Name <<"RegisterClass = &"
83         << Name << "RegClass;\n";
84    }
85    OS << "} // end of namespace " << TargetName << "\n\n";
86  }
87  OS << "} // End llvm namespace \n";
88}
89
90// RegisterInfoEmitter::run - Main register file description emitter.
91//
92void RegisterInfoEmitter::run(std::ostream &OS) {
93  CodeGenTarget Target;
94  EmitSourceFileHeader("Register Information Source Fragment", OS);
95
96  OS << "namespace llvm {\n\n";
97
98  // Start out by emitting each of the register classes... to do this, we build
99  // a set of registers which belong to a register class, this is to ensure that
100  // each register is only in a single register class.
101  //
102  const std::vector<CodeGenRegisterClass> &RegisterClasses =
103    Target.getRegisterClasses();
104
105  // Loop over all of the register classes... emitting each one.
106  OS << "namespace {     // Register classes...\n";
107
108  // RegClassesBelongedTo - Keep track of which register classes each reg
109  // belongs to.
110  std::multimap<Record*, const CodeGenRegisterClass*> RegClassesBelongedTo;
111
112  for (unsigned rc = 0, e = RegisterClasses.size(); rc != e; ++rc) {
113    const CodeGenRegisterClass &RC = RegisterClasses[rc];
114
115    // Give the register class a legal C name if it's anonymous.
116    std::string Name = RC.TheDef->getName();
117
118    // Emit the register list now.
119    OS << "  // " << Name << " Register Class...\n  const unsigned " << Name
120       << "[] = {\n    ";
121    for (unsigned i = 0, e = RC.Elements.size(); i != e; ++i) {
122      Record *Reg = RC.Elements[i];
123      OS << getQualifiedName(Reg) << ", ";
124
125      // Keep track of which regclasses this register is in.
126      RegClassesBelongedTo.insert(std::make_pair(Reg, &RC));
127    }
128    OS << "\n  };\n\n";
129  }
130  OS << "}  // end anonymous namespace\n\n";
131
132  // Now that all of the structs have been emitted, emit the instances.
133  if (!RegisterClasses.empty()) {
134    OS << "namespace " << RegisterClasses[0].Namespace
135       << " {   // Register class instances\n";
136    for (unsigned i = 0, e = RegisterClasses.size(); i != e; ++i)
137      OS << "  " << RegisterClasses[i].getName()  << "Class\t"
138         << RegisterClasses[i].getName() << "RegClass;\n";
139
140    for (unsigned i = 0, e = RegisterClasses.size(); i != e; ++i) {
141      const CodeGenRegisterClass &RC = RegisterClasses[i];
142      OS << RC.MethodBodies << "\n";
143      OS << RC.getName() << "Class::" << RC.getName()
144        << "Class()  : TargetRegisterClass(" << RC.SpillSize/8 << ", "
145        << RC.SpillAlignment/8 << ", " << RC.getName() << ", "
146        << RC.getName() << " + " << RC.Elements.size() << ") {}\n";
147    }
148
149    OS << "}\n";
150  }
151
152  OS << "\nnamespace {\n";
153  OS << "  const TargetRegisterClass* const RegisterClasses[] = {\n";
154  for (unsigned i = 0, e = RegisterClasses.size(); i != e; ++i)
155    OS << "    &" << getQualifiedName(RegisterClasses[i].TheDef)
156       << "RegClass,\n";
157  OS << "  };\n";
158
159  // Emit register class aliases...
160  std::map<Record*, std::set<Record*> > RegisterAliases;
161  const std::vector<CodeGenRegister> &Regs = Target.getRegisters();
162
163  for (unsigned i = 0, e = Regs.size(); i != e; ++i) {
164    Record *R = Regs[i].TheDef;
165    ListInit *LI = Regs[i].TheDef->getValueAsListInit("Aliases");
166    // Add information that R aliases all of the elements in the list... and
167    // that everything in the list aliases R.
168    for (unsigned j = 0, e = LI->getSize(); j != e; ++j) {
169      DefInit *Reg = dynamic_cast<DefInit*>(LI->getElement(j));
170      if (!Reg) throw "ERROR: Alias list element is not a def!";
171      if (RegisterAliases[R].count(Reg->getDef()))
172        std::cerr << "Warning: register alias between " << getQualifiedName(R)
173                  << " and " << getQualifiedName(Reg->getDef())
174                  << " specified multiple times!\n";
175      RegisterAliases[R].insert(Reg->getDef());
176
177      if (RegisterAliases[Reg->getDef()].count(R))
178        std::cerr << "Warning: register alias between " << getQualifiedName(R)
179                  << " and " << getQualifiedName(Reg->getDef())
180                  << " specified multiple times!\n";
181      RegisterAliases[Reg->getDef()].insert(R);
182    }
183  }
184
185  if (!RegisterAliases.empty())
186    OS << "\n\n  // Register Alias Sets...\n";
187
188  // Emit the empty alias list
189  OS << "  const unsigned Empty_AliasSet[] = { 0 };\n";
190  // Loop over all of the registers which have aliases, emitting the alias list
191  // to memory.
192  for (std::map<Record*, std::set<Record*> >::iterator
193         I = RegisterAliases.begin(), E = RegisterAliases.end(); I != E; ++I) {
194    OS << "  const unsigned " << I->first->getName() << "_AliasSet[] = { ";
195    for (std::set<Record*>::iterator ASI = I->second.begin(),
196           E = I->second.end(); ASI != E; ++ASI)
197      OS << getQualifiedName(*ASI) << ", ";
198    OS << "0 };\n";
199  }
200
201  OS << "\n  const MRegisterDesc RegisterDescriptors[] = { // Descriptors\n";
202  OS << "    { \"NOREG\",\t0,\t\t0,\t0 },\n";
203
204
205  // Now that register alias sets have been emitted, emit the register
206  // descriptors now.
207  const std::vector<CodeGenRegister> &Registers = Target.getRegisters();
208  for (unsigned i = 0, e = Registers.size(); i != e; ++i) {
209    const CodeGenRegister &Reg = Registers[i];
210    OS << "    { \"";
211    if (!Reg.TheDef->getValueAsString("Name").empty())
212      OS << Reg.TheDef->getValueAsString("Name");
213    else
214      OS << Reg.getName();
215    OS << "\",\t";
216    if (RegisterAliases.count(Reg.TheDef))
217      OS << Reg.getName() << "_AliasSet },\n";
218    else
219      OS << "Empty_AliasSet },\n";
220  }
221  OS << "  };\n";      // End of register descriptors...
222  OS << "}\n\n";       // End of anonymous namespace...
223
224  std::string ClassName = Target.getName() + "GenRegisterInfo";
225
226  // Emit the constructor of the class...
227  OS << ClassName << "::" << ClassName
228     << "(int CallFrameSetupOpcode, int CallFrameDestroyOpcode)\n"
229     << "  : MRegisterInfo(RegisterDescriptors, " << Registers.size()+1
230     << ", RegisterClasses, RegisterClasses+" << RegisterClasses.size() <<",\n "
231     << "                 CallFrameSetupOpcode, CallFrameDestroyOpcode) {}\n\n";
232
233  // Emit the getCalleeSaveRegs method.
234  OS << "const unsigned* " << ClassName << "::getCalleeSaveRegs() const {\n"
235     << "  static const unsigned CalleeSaveRegs[] = {\n    ";
236
237  const std::vector<Record*> &CSR = Target.getCalleeSavedRegisters();
238  for (unsigned i = 0, e = CSR.size(); i != e; ++i)
239    OS << getQualifiedName(CSR[i]) << ", ";
240  OS << " 0\n  };\n  return CalleeSaveRegs;\n}\n\n";
241
242  // Emit information about the callee saved register classes.
243  OS << "const TargetRegisterClass* const*\n" << ClassName
244     << "::getCalleeSaveRegClasses() const {\n"
245     << "  static const TargetRegisterClass * const "
246     << "CalleeSaveRegClasses[] = {\n    ";
247
248  for (unsigned i = 0, e = CSR.size(); i != e; ++i) {
249    Record *R = CSR[i];
250    std::multimap<Record*, const CodeGenRegisterClass*>::iterator I, E;
251    tie(I, E) = RegClassesBelongedTo.equal_range(R);
252    if (I == E)
253      throw "Callee saved register '" + R->getName() +
254            "' must belong to a register class for spilling.\n";
255    const CodeGenRegisterClass *RC = (I++)->second;
256    for (; I != E; ++I)
257      if (RC->SpillSize < I->second->SpillSize)
258        RC = I->second;
259    OS << "&" << getQualifiedName(RC->TheDef) << "RegClass, ";
260  }
261  OS << " 0\n  };\n  return CalleeSaveRegClasses;\n}\n\n";
262
263  OS << "} // End llvm namespace \n";
264}
265