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 "CodeGenWrappers.h"
18 #include "Record.h"
19 #include "Support/StringExtras.h"
20 #include <set>
21 
22 namespace llvm {
23 
24 // runEnums - Print out enum values for all of the registers.
25 void RegisterInfoEmitter::runEnums(std::ostream &OS) {
26   std::vector<Record*> Registers = Records.getAllDerivedDefinitions("Register");
27 
28   if (Registers.size() == 0)
29     throw std::string("No 'Register' subclasses defined!");
30 
31   std::string Namespace = Registers[0]->getValueAsString("Namespace");
32 
33   EmitSourceFileHeader("Target Register Enum Values", OS);
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   EmitSourceFileTail(OS);
46 }
47 
48 void RegisterInfoEmitter::runHeader(std::ostream &OS) {
49   EmitSourceFileHeader("Register Information Header Fragment", OS);
50   const std::string &TargetName = CodeGenTarget().getName();
51   std::string ClassName = TargetName + "GenRegisterInfo";
52 
53   OS << "#include \"llvm/Target/MRegisterInfo.h\"\n\n";
54 
55   OS << "struct " << ClassName << " : public MRegisterInfo {\n"
56      << "  " << ClassName
57      << "(int CallFrameSetupOpcode = -1, int CallFrameDestroyOpcode = -1);\n"
58      << "  const unsigned* getCalleeSaveRegs() const;\n"
59      << "};\n\n";
60 
61   std::vector<Record*> RegisterClasses =
62     Records.getAllDerivedDefinitions("RegisterClass");
63 
64   OS << "namespace " << TargetName << " { // Register classes\n";
65   for (unsigned i = 0, e = RegisterClasses.size(); i != e; ++i) {
66     if (RegisterClasses[i]->getValueAsBit("isDummyClass"))
67       continue; // Ignore dummies
68 
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   EmitSourceFileTail(OS);
75 }
76 
77 // RegisterInfoEmitter::run - Main register file description emitter.
78 //
79 void RegisterInfoEmitter::run(std::ostream &OS) {
80   EmitSourceFileHeader("Register Information Source Fragment", OS);
81 
82   // Start out by emitting each of the register classes... to do this, we build
83   // a set of registers which belong to a register class, this is to ensure that
84   // each register is only in a single register class.
85   //
86   std::vector<Record*> RegisterClasses =
87     Records.getAllDerivedDefinitions("RegisterClass");
88 
89   std::vector<Record*> Registers = Records.getAllDerivedDefinitions("Register");
90 
91   std::set<Record*> RegistersFound;
92   std::vector<std::string> RegClassNames;
93 
94   // Loop over all of the register classes... emitting each one.
95   OS << "namespace {     // Register classes...\n";
96 
97   for (unsigned rc = 0, e = RegisterClasses.size(); rc != e; ++rc) {
98     Record *RC = RegisterClasses[rc];
99     if (RC->getValueAsBit("isDummyClass")) continue; // Ignore dummies
100 
101     std::string Name = RC->getName();
102     if (Name.size() > 9 && Name[9] == '.') {
103       static unsigned AnonCounter = 0;
104       Name = "AnonRegClass_"+utostr(AnonCounter++);
105     }
106 
107     RegClassNames.push_back(Name);
108 
109     // Emit the register list now...
110     OS << "  // " << Name << " Register Class...\n  const unsigned " << Name
111        << "[] = {\n    ";
112     ListInit *RegList = RC->getValueAsListInit("MemberList");
113     for (unsigned i = 0, e = RegList->getSize(); i != e; ++i) {
114       DefInit *RegDef = dynamic_cast<DefInit*>(RegList->getElement(i));
115       if (!RegDef) throw "Register class member is not a record!";
116       Record *Reg = RegDef->getDef();
117       if (!Reg->isSubClassOf("Register"))
118         throw "Register Class member '" + Reg->getName() +
119               " does not derive from the Register class!";
120       if (RegistersFound.count(Reg))
121         throw "Register '" + Reg->getName() +
122               "' included in multiple register classes!";
123       RegistersFound.insert(Reg);
124       OS << getQualifiedName(Reg) << ", ";
125     }
126     OS << "\n  };\n\n";
127 
128     OS << "  struct " << Name << "Class : public TargetRegisterClass {\n"
129        << "    " << Name << "Class() : TargetRegisterClass("
130        << RC->getValueAsInt("Size")/8 << ", " << RC->getValueAsInt("Alignment")
131        << ", " << Name << ", " << Name << " + " << RegList->getSize()
132        << ") {}\n";
133 
134     if (CodeInit *CI = dynamic_cast<CodeInit*>(RC->getValueInit("Methods")))
135       OS << CI->getValue();
136     else
137       throw "Expected 'code' fragment for 'Methods' value in register class '"+
138             RC->getName() + "'!";
139 
140     OS << "  } " << Name << "Instance;\n\n";
141   }
142 
143   OS << "  const TargetRegisterClass* const RegisterClasses[] = {\n";
144   for (unsigned i = 0, e = RegClassNames.size(); i != e; ++i)
145     OS << "    &" << RegClassNames[i] << "Instance,\n";
146   OS << "  };\n";
147 
148   // Emit register class aliases...
149   std::vector<Record*> RegisterAliasesRecs =
150     Records.getAllDerivedDefinitions("RegisterAliases");
151   std::map<Record*, std::set<Record*> > RegisterAliases;
152 
153   for (unsigned i = 0, e = RegisterAliasesRecs.size(); i != e; ++i) {
154     Record *AS = RegisterAliasesRecs[i];
155     Record *R = AS->getValueAsDef("Reg");
156     ListInit *LI = AS->getValueAsListInit("Aliases");
157 
158     // Add information that R aliases all of the elements in the list... and
159     // that everything in the list aliases R.
160     for (unsigned j = 0, e = LI->getSize(); j != e; ++j) {
161       DefInit *Reg = dynamic_cast<DefInit*>(LI->getElement(j));
162       if (!Reg) throw "ERROR: Alias list element is not a def!";
163       if (RegisterAliases[R].count(Reg->getDef()))
164         std::cerr << "Warning: register alias between " << getQualifiedName(R)
165                   << " and " << getQualifiedName(Reg->getDef())
166                   << " specified multiple times!\n";
167       RegisterAliases[R].insert(Reg->getDef());
168 
169       if (RegisterAliases[Reg->getDef()].count(R))
170         std::cerr << "Warning: register alias between " << getQualifiedName(R)
171                   << " and " << getQualifiedName(Reg->getDef())
172                   << " specified multiple times!\n";
173       RegisterAliases[Reg->getDef()].insert(R);
174     }
175   }
176 
177   if (!RegisterAliases.empty())
178     OS << "\n\n  // Register Alias Sets...\n";
179 
180   // Emit the empty alias list
181   OS << "  const unsigned Empty_AliasSet[] = { 0 };\n";
182   // Loop over all of the registers which have aliases, emitting the alias list
183   // to memory.
184   for (std::map<Record*, std::set<Record*> >::iterator
185          I = RegisterAliases.begin(), E = RegisterAliases.end(); I != E; ++I) {
186     OS << "  const unsigned " << I->first->getName() << "_AliasSet[] = { ";
187     for (std::set<Record*>::iterator ASI = I->second.begin(),
188            E = I->second.end(); ASI != E; ++ASI)
189       OS << getQualifiedName(*ASI) << ", ";
190     OS << "0 };\n";
191   }
192 
193   OS << "\n  const MRegisterDesc RegisterDescriptors[] = { // Descriptors\n";
194   OS << "    { \"NOREG\",\t0,\t\t0,\t0 },\n";
195   // Now that register alias sets have been emitted, emit the register
196   // descriptors now.
197   for (unsigned i = 0, e = Registers.size(); i != e; ++i) {
198     Record *Reg = Registers[i];
199     OS << "    { \"";
200     if (!Reg->getValueAsString("Name").empty())
201       OS << Reg->getValueAsString("Name");
202     else
203       OS << Reg->getName();
204     OS << "\",\t";
205     if (RegisterAliases.count(Reg))
206       OS << Reg->getName() << "_AliasSet,\t";
207     else
208       OS << "Empty_AliasSet,\t";
209     OS << "0, 0 },\n";
210   }
211   OS << "  };\n";      // End of register descriptors...
212   OS << "}\n\n";       // End of anonymous namespace...
213 
214   CodeGenTarget Target;
215 
216   OS << "namespace " << Target.getName() << " { // Register classes\n";
217   for (unsigned i = 0, e = RegisterClasses.size(); i != e; ++i) {
218     if (RegisterClasses[i]->getValueAsBit("isDummyClass"))
219       continue; // Ignore dummies
220 
221     const std::string &Name = RegisterClasses[i]->getName();
222     if (Name.size() < 9 || Name[9] != '.')    // Ignore anonymous classes
223       OS << "  TargetRegisterClass *" << Name << "RegisterClass = &"
224          << Name << "Instance;\n";
225   }
226   OS << "} // end of namespace " << Target.getName() << "\n\n";
227 
228 
229 
230   std::string ClassName = Target.getName() + "GenRegisterInfo";
231 
232   // Emit the constructor of the class...
233   OS << ClassName << "::" << ClassName
234      << "(int CallFrameSetupOpcode, int CallFrameDestroyOpcode)\n"
235      << "  : MRegisterInfo(RegisterDescriptors, " << Registers.size()+1
236      << ", RegisterClasses, RegisterClasses+" << RegClassNames.size() << ",\n "
237      << "                 CallFrameSetupOpcode, CallFrameDestroyOpcode) {}\n\n";
238 
239   // Emit the getCalleeSaveRegs method...
240   OS << "const unsigned* " << ClassName << "::getCalleeSaveRegs() const {\n"
241      << "  static const unsigned CalleeSaveRegs[] = {\n    ";
242 
243   const std::vector<Record*> &CSR = Target.getCalleeSavedRegisters();
244   for (unsigned i = 0, e = CSR.size(); i != e; ++i)
245     OS << getQualifiedName(CSR[i]) << ", ";
246   OS << " 0\n  };\n  return CalleeSaveRegs;\n}\n\n";
247   EmitSourceFileTail(OS);
248 }
249 
250 } // End llvm namespace
251