RegisterInfoEmitter.cpp revision 2ca0efd71a5a25c1f3fa8b30dc5459fdaf8cd2a9 
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";
55  OS << "#include <string>\n\n";
56
57  OS << "namespace llvm {\n\n";
58
59  OS << "struct " << ClassName << " : public MRegisterInfo {\n"
60     << "  " << ClassName
61     << "(int CallFrameSetupOpcode = -1, int CallFrameDestroyOpcode = -1);\n"
62     << "  const unsigned* getCalleeSaveRegs() const;\n"
63     << "  const TargetRegisterClass* const *getCalleeSaveRegClasses() const;\n"
64     << "  int getDwarfRegNum(unsigned RegNum) const;\n"
65     << "};\n\n";
66
67  const std::vector<CodeGenRegisterClass> &RegisterClasses =
68    Target.getRegisterClasses();
69
70  if (!RegisterClasses.empty()) {
71    OS << "namespace " << RegisterClasses[0].Namespace
72       << " { // Register classes\n";
73    for (unsigned i = 0, e = RegisterClasses.size(); i != e; ++i) {
74      const std::string &Name = RegisterClasses[i].getName();
75
76      // Output the register class definition.
77      OS << "  struct " << Name << "Class : public TargetRegisterClass {\n"
78         << "    " << Name << "Class();\n"
79         << RegisterClasses[i].MethodProtos << "  };\n";
80
81      // Output the extern for the instance.
82      OS << "  extern " << Name << "Class\t" << Name << "RegClass;\n";
83      // Output the extern for the pointer to the instance (should remove).
84      OS << "  static TargetRegisterClass * const "<< Name <<"RegisterClass = &"
85         << Name << "RegClass;\n";
86    }
87    OS << "} // end of namespace " << TargetName << "\n\n";
88  }
89  OS << "} // End llvm namespace \n";
90}
91
92bool isSubRegisterClass(const CodeGenRegisterClass &RC,
93                        std::set<Record*> &RegSet) {
94  for (unsigned i = 0, e = RC.Elements.size(); i != e; ++i) {
95    Record *Reg = RC.Elements[i];
96    if (!RegSet.count(Reg))
97      return false;
98  }
99  return true;
100}
101
102// RegisterInfoEmitter::run - Main register file description emitter.
103//
104void RegisterInfoEmitter::run(std::ostream &OS) {
105  CodeGenTarget Target;
106  EmitSourceFileHeader("Register Information Source Fragment", OS);
107
108  OS << "namespace llvm {\n\n";
109
110  // Start out by emitting each of the register classes... to do this, we build
111  // a set of registers which belong to a register class, this is to ensure that
112  // each register is only in a single register class.
113  //
114  const std::vector<CodeGenRegisterClass> &RegisterClasses =
115    Target.getRegisterClasses();
116
117  // Loop over all of the register classes... emitting each one.
118  OS << "namespace {     // Register classes...\n";
119
120  // RegClassesBelongedTo - Keep track of which register classes each reg
121  // belongs to.
122  std::multimap<Record*, const CodeGenRegisterClass*> RegClassesBelongedTo;
123
124  // Emit the register enum value arrays for each RegisterClass
125  for (unsigned rc = 0, e = RegisterClasses.size(); rc != e; ++rc) {
126    const CodeGenRegisterClass &RC = RegisterClasses[rc];
127
128    // Give the register class a legal C name if it's anonymous.
129    std::string Name = RC.TheDef->getName();
130
131    // Emit the register list now.
132    OS << "  // " << Name << " Register Class...\n  const unsigned " << Name
133       << "[] = {\n    ";
134    for (unsigned i = 0, e = RC.Elements.size(); i != e; ++i) {
135      Record *Reg = RC.Elements[i];
136      OS << getQualifiedName(Reg) << ", ";
137
138      // Keep track of which regclasses this register is in.
139      RegClassesBelongedTo.insert(std::make_pair(Reg, &RC));
140    }
141    OS << "\n  };\n\n";
142  }
143
144  // Emit the ValueType arrays for each RegisterClass
145  for (unsigned rc = 0, e = RegisterClasses.size(); rc != e; ++rc) {
146    const CodeGenRegisterClass &RC = RegisterClasses[rc];
147
148    // Give the register class a legal C name if it's anonymous.
149    std::string Name = RC.TheDef->getName() + "VTs";
150
151    // Emit the register list now.
152    OS << "  // " << Name
153      << " Register Class Value Types...\n  const MVT::ValueType " << Name
154      << "[] = {\n    ";
155    for (unsigned i = 0, e = RC.VTs.size(); i != e; ++i)
156      OS << "MVT::" << RC.VTs[i] << ", ";
157    OS << "MVT::Other\n  };\n\n";
158  }
159  OS << "}  // end anonymous namespace\n\n";
160
161  // Now that all of the structs have been emitted, emit the instances.
162  if (!RegisterClasses.empty()) {
163    OS << "namespace " << RegisterClasses[0].Namespace
164       << " {   // Register class instances\n";
165    for (unsigned i = 0, e = RegisterClasses.size(); i != e; ++i)
166      OS << "  " << RegisterClasses[i].getName()  << "Class\t"
167         << RegisterClasses[i].getName() << "RegClass;\n";
168
169    std::map<unsigned, std::set<unsigned> > SuperClassMap;
170    OS << "\n";
171    // Emit the sub-classes array for each RegisterClass
172    for (unsigned rc = 0, e = RegisterClasses.size(); rc != e; ++rc) {
173      const CodeGenRegisterClass &RC = RegisterClasses[rc];
174
175      // Give the register class a legal C name if it's anonymous.
176      std::string Name = RC.TheDef->getName();
177
178      std::set<Record*> RegSet;
179      for (unsigned i = 0, e = RC.Elements.size(); i != e; ++i) {
180        Record *Reg = RC.Elements[i];
181        RegSet.insert(Reg);
182      }
183
184      OS << "  // " << Name
185         << " Register Class sub-classes...\n  const TargetRegisterClass* "
186         << Name << "Subclasses [] = {\n    ";
187
188      bool Empty = true;
189      for (unsigned rc2 = 0, e2 = RegisterClasses.size(); rc2 != e2; ++rc2) {
190        const CodeGenRegisterClass &RC2 = RegisterClasses[rc2];
191        if (rc == rc2 || RC2.Elements.size() > RC.Elements.size() ||
192            RC.SpillSize != RC2.SpillSize || !isSubRegisterClass(RC2, RegSet))
193          continue;
194
195        if (!Empty) OS << ", ";
196        OS << "&" << getQualifiedName(RC2.TheDef) << "RegClass";
197        Empty = false;
198
199        std::map<unsigned, std::set<unsigned> >::iterator SCMI =
200          SuperClassMap.find(rc2);
201        if (SCMI == SuperClassMap.end()) {
202          SuperClassMap.insert(std::make_pair(rc2, std::set<unsigned>()));
203          SCMI = SuperClassMap.find(rc2);
204        }
205        SCMI->second.insert(rc);
206      }
207
208      OS << (!Empty ? ", " : "") << "NULL";
209      OS << "\n  };\n\n";
210    }
211
212    for (unsigned rc = 0, e = RegisterClasses.size(); rc != e; ++rc) {
213      const CodeGenRegisterClass &RC = RegisterClasses[rc];
214
215      // Give the register class a legal C name if it's anonymous.
216      std::string Name = RC.TheDef->getName();
217
218      OS << "  // " << Name
219         << " Register Class super-classes...\n  const TargetRegisterClass* "
220         << Name << "Superclasses [] = {\n    ";
221
222      bool Empty = true;
223      std::map<unsigned, std::set<unsigned> >::iterator I =
224        SuperClassMap.find(rc);
225      if (I != SuperClassMap.end()) {
226        for (std::set<unsigned>::iterator II = I->second.begin(),
227               EE = I->second.end(); II != EE; ++II) {
228          const CodeGenRegisterClass &RC2 = RegisterClasses[*II];
229          if (!Empty) OS << ", ";
230          OS << "&" << getQualifiedName(RC2.TheDef) << "RegClass";
231          Empty = false;
232        }
233      }
234
235      OS << (!Empty ? ", " : "") << "NULL";
236      OS << "\n  };\n\n";
237    }
238
239
240    for (unsigned i = 0, e = RegisterClasses.size(); i != e; ++i) {
241      const CodeGenRegisterClass &RC = RegisterClasses[i];
242      OS << RC.MethodBodies << "\n";
243      OS << RC.getName() << "Class::" << RC.getName()
244         << "Class()  : TargetRegisterClass("
245         << RC.getName() + "VTs" << ", "
246         << RC.getName() + "Subclasses" << ", "
247         << RC.getName() + "Superclasses" << ", "
248         << RC.SpillSize/8 << ", "
249         << RC.SpillAlignment/8 << ", " << RC.getName() << ", "
250         << RC.getName() << " + " << RC.Elements.size() << ") {}\n";
251    }
252
253    OS << "}\n";
254  }
255
256  OS << "\nnamespace {\n";
257  OS << "  const TargetRegisterClass* const RegisterClasses[] = {\n";
258  for (unsigned i = 0, e = RegisterClasses.size(); i != e; ++i)
259    OS << "    &" << getQualifiedName(RegisterClasses[i].TheDef)
260       << "RegClass,\n";
261  OS << "  };\n";
262
263  // Emit register class aliases...
264  std::map<Record*, std::set<Record*> > RegisterAliases;
265  const std::vector<CodeGenRegister> &Regs = Target.getRegisters();
266
267  for (unsigned i = 0, e = Regs.size(); i != e; ++i) {
268    Record *R = Regs[i].TheDef;
269    std::vector<Record*> LI = Regs[i].TheDef->getValueAsListOfDefs("Aliases");
270    // Add information that R aliases all of the elements in the list... and
271    // that everything in the list aliases R.
272    for (unsigned j = 0, e = LI.size(); j != e; ++j) {
273      Record *Reg = LI[j];
274      if (RegisterAliases[R].count(Reg))
275        std::cerr << "Warning: register alias between " << getQualifiedName(R)
276                  << " and " << getQualifiedName(Reg)
277                  << " specified multiple times!\n";
278      RegisterAliases[R].insert(Reg);
279
280      if (RegisterAliases[Reg].count(R))
281        std::cerr << "Warning: register alias between " << getQualifiedName(R)
282                  << " and " << getQualifiedName(Reg)
283                  << " specified multiple times!\n";
284      RegisterAliases[Reg].insert(R);
285    }
286  }
287
288  if (!RegisterAliases.empty())
289    OS << "\n\n  // Register Alias Sets...\n";
290
291  // Emit the empty alias list
292  OS << "  const unsigned Empty_AliasSet[] = { 0 };\n";
293  // Loop over all of the registers which have aliases, emitting the alias list
294  // to memory.
295  for (std::map<Record*, std::set<Record*> >::iterator
296         I = RegisterAliases.begin(), E = RegisterAliases.end(); I != E; ++I) {
297    OS << "  const unsigned " << I->first->getName() << "_AliasSet[] = { ";
298    for (std::set<Record*>::iterator ASI = I->second.begin(),
299           E = I->second.end(); ASI != E; ++ASI)
300      OS << getQualifiedName(*ASI) << ", ";
301    OS << "0 };\n";
302  }
303
304  OS<<"\n  const TargetRegisterDesc RegisterDescriptors[] = { // Descriptors\n";
305  OS << "    { \"NOREG\",\t0 },\n";
306
307
308  // Now that register alias sets have been emitted, emit the register
309  // descriptors now.
310  const std::vector<CodeGenRegister> &Registers = Target.getRegisters();
311  for (unsigned i = 0, e = Registers.size(); i != e; ++i) {
312    const CodeGenRegister &Reg = Registers[i];
313    OS << "    { \"";
314    if (!Reg.TheDef->getValueAsString("Name").empty())
315      OS << Reg.TheDef->getValueAsString("Name");
316    else
317      OS << Reg.getName();
318    OS << "\",\t";
319    if (RegisterAliases.count(Reg.TheDef))
320      OS << Reg.getName() << "_AliasSet },\n";
321    else
322      OS << "Empty_AliasSet },\n";
323  }
324  OS << "  };\n";      // End of register descriptors...
325  OS << "}\n\n";       // End of anonymous namespace...
326
327  std::string ClassName = Target.getName() + "GenRegisterInfo";
328
329  // Emit the constructor of the class...
330  OS << ClassName << "::" << ClassName
331     << "(int CallFrameSetupOpcode, int CallFrameDestroyOpcode)\n"
332     << "  : MRegisterInfo(RegisterDescriptors, " << Registers.size()+1
333     << ", RegisterClasses, RegisterClasses+" << RegisterClasses.size() <<",\n "
334     << "                 CallFrameSetupOpcode, CallFrameDestroyOpcode) {}\n\n";
335
336  // Emit the getCalleeSaveRegs method.
337  OS << "const unsigned* " << ClassName << "::getCalleeSaveRegs() const {\n"
338     << "  static const unsigned CalleeSaveRegs[] = {\n    ";
339
340  const std::vector<Record*> &CSR = Target.getCalleeSavedRegisters();
341  for (unsigned i = 0, e = CSR.size(); i != e; ++i)
342    OS << getQualifiedName(CSR[i]) << ", ";
343  OS << " 0\n  };\n  return CalleeSaveRegs;\n}\n\n";
344
345  // Emit information about the callee saved register classes.
346  OS << "const TargetRegisterClass* const*\n" << ClassName
347     << "::getCalleeSaveRegClasses() const {\n"
348     << "  static const TargetRegisterClass * const "
349     << "CalleeSaveRegClasses[] = {\n    ";
350
351  for (unsigned i = 0, e = CSR.size(); i != e; ++i) {
352    Record *R = CSR[i];
353    std::multimap<Record*, const CodeGenRegisterClass*>::iterator I, E;
354    tie(I, E) = RegClassesBelongedTo.equal_range(R);
355    if (I == E)
356      throw "Callee saved register '" + R->getName() +
357            "' must belong to a register class for spilling.\n";
358    const CodeGenRegisterClass *RC = (I++)->second;
359    for (; I != E; ++I)
360      if (RC->SpillSize < I->second->SpillSize)
361        RC = I->second;
362    OS << "&" << getQualifiedName(RC->TheDef) << "RegClass, ";
363  }
364  OS << " 0\n  };\n  return CalleeSaveRegClasses;\n}\n\n";
365
366  // Emit information about the dwarf register numbers.
367  OS << "int " << ClassName << "::getDwarfRegNum(unsigned RegNum) const {\n";
368  OS << "  static const int DwarfRegNums[] = { -1, // NoRegister";
369  for (unsigned i = 0, e = Registers.size(); i != e; ++i) {
370    if (!(i % 16)) OS << "\n    ";
371    const CodeGenRegister &Reg = Registers[i];
372    int DwarfRegNum = Reg.TheDef->getValueAsInt("DwarfNumber");
373    OS << DwarfRegNum;
374    if ((i + 1) != e)  OS << ", ";
375  }
376  OS << "\n  };\n";
377  OS << "  assert(RegNum < (sizeof(DwarfRegNums)/sizeof(int)) &&\n";
378  OS << "         \"RegNum exceeds number of registers\");\n";
379  OS << "  return DwarfRegNums[RegNum];\n";
380  OS << "}\n\n";
381
382  OS << "} // End llvm namespace \n";
383}
384