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1 //===- CallingConvEmitter.cpp - Generate calling conventions --------------===//
2 //
3 //                     The LLVM Compiler Infrastructure
4 //
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
7 //
8 //===----------------------------------------------------------------------===//
9 //
10 // This tablegen backend is responsible for emitting descriptions of the calling
11 // conventions supported by this target.
12 //
13 //===----------------------------------------------------------------------===//
14 
15 #include "CodeGenTarget.h"
16 #include "llvm/TableGen/Error.h"
17 #include "llvm/TableGen/Record.h"
18 #include "llvm/TableGen/TableGenBackend.h"
19 #include <cassert>
20 using namespace llvm;
21 
22 namespace {
23 class CallingConvEmitter {
24   RecordKeeper &Records;
25 public:
CallingConvEmitter(RecordKeeper & R)26   explicit CallingConvEmitter(RecordKeeper &R) : Records(R) {}
27 
28   void run(raw_ostream &o);
29 
30 private:
31   void EmitCallingConv(Record *CC, raw_ostream &O);
32   void EmitAction(Record *Action, unsigned Indent, raw_ostream &O);
33   unsigned Counter;
34 };
35 } // End anonymous namespace
36 
run(raw_ostream & O)37 void CallingConvEmitter::run(raw_ostream &O) {
38   std::vector<Record*> CCs = Records.getAllDerivedDefinitions("CallingConv");
39 
40   // Emit prototypes for all of the non-custom CC's so that they can forward ref
41   // each other.
42   for (unsigned i = 0, e = CCs.size(); i != e; ++i) {
43     if (!CCs[i]->getValueAsBit("Custom")) {
44       O << "static bool " << CCs[i]->getName()
45         << "(unsigned ValNo, MVT ValVT,\n"
46         << std::string(CCs[i]->getName().size() + 13, ' ')
47         << "MVT LocVT, CCValAssign::LocInfo LocInfo,\n"
48         << std::string(CCs[i]->getName().size() + 13, ' ')
49         << "ISD::ArgFlagsTy ArgFlags, CCState &State);\n";
50     }
51   }
52 
53   // Emit each non-custom calling convention description in full.
54   for (unsigned i = 0, e = CCs.size(); i != e; ++i) {
55     if (!CCs[i]->getValueAsBit("Custom"))
56       EmitCallingConv(CCs[i], O);
57   }
58 }
59 
60 
EmitCallingConv(Record * CC,raw_ostream & O)61 void CallingConvEmitter::EmitCallingConv(Record *CC, raw_ostream &O) {
62   ListInit *CCActions = CC->getValueAsListInit("Actions");
63   Counter = 0;
64 
65   O << "\n\nstatic bool " << CC->getName()
66     << "(unsigned ValNo, MVT ValVT,\n"
67     << std::string(CC->getName().size()+13, ' ')
68     << "MVT LocVT, CCValAssign::LocInfo LocInfo,\n"
69     << std::string(CC->getName().size()+13, ' ')
70     << "ISD::ArgFlagsTy ArgFlags, CCState &State) {\n";
71   // Emit all of the actions, in order.
72   for (unsigned i = 0, e = CCActions->size(); i != e; ++i) {
73     O << "\n";
74     EmitAction(CCActions->getElementAsRecord(i), 2, O);
75   }
76 
77   O << "\n  return true;  // CC didn't match.\n";
78   O << "}\n";
79 }
80 
EmitAction(Record * Action,unsigned Indent,raw_ostream & O)81 void CallingConvEmitter::EmitAction(Record *Action,
82                                     unsigned Indent, raw_ostream &O) {
83   std::string IndentStr = std::string(Indent, ' ');
84 
85   if (Action->isSubClassOf("CCPredicateAction")) {
86     O << IndentStr << "if (";
87 
88     if (Action->isSubClassOf("CCIfType")) {
89       ListInit *VTs = Action->getValueAsListInit("VTs");
90       for (unsigned i = 0, e = VTs->size(); i != e; ++i) {
91         Record *VT = VTs->getElementAsRecord(i);
92         if (i != 0) O << " ||\n    " << IndentStr;
93         O << "LocVT == " << getEnumName(getValueType(VT));
94       }
95 
96     } else if (Action->isSubClassOf("CCIf")) {
97       O << Action->getValueAsString("Predicate");
98     } else {
99       Action->dump();
100       PrintFatalError("Unknown CCPredicateAction!");
101     }
102 
103     O << ") {\n";
104     EmitAction(Action->getValueAsDef("SubAction"), Indent+2, O);
105     O << IndentStr << "}\n";
106   } else {
107     if (Action->isSubClassOf("CCDelegateTo")) {
108       Record *CC = Action->getValueAsDef("CC");
109       O << IndentStr << "if (!" << CC->getName()
110         << "(ValNo, ValVT, LocVT, LocInfo, ArgFlags, State))\n"
111         << IndentStr << "  return false;\n";
112     } else if (Action->isSubClassOf("CCAssignToReg")) {
113       ListInit *RegList = Action->getValueAsListInit("RegList");
114       if (RegList->size() == 1) {
115         O << IndentStr << "if (unsigned Reg = State.AllocateReg(";
116         O << getQualifiedName(RegList->getElementAsRecord(0)) << ")) {\n";
117       } else {
118         O << IndentStr << "static const MCPhysReg RegList" << ++Counter
119           << "[] = {\n";
120         O << IndentStr << "  ";
121         for (unsigned i = 0, e = RegList->size(); i != e; ++i) {
122           if (i != 0) O << ", ";
123           O << getQualifiedName(RegList->getElementAsRecord(i));
124         }
125         O << "\n" << IndentStr << "};\n";
126         O << IndentStr << "if (unsigned Reg = State.AllocateReg(RegList"
127           << Counter << ")) {\n";
128       }
129       O << IndentStr << "  State.addLoc(CCValAssign::getReg(ValNo, ValVT, "
130         << "Reg, LocVT, LocInfo));\n";
131       O << IndentStr << "  return false;\n";
132       O << IndentStr << "}\n";
133     } else if (Action->isSubClassOf("CCAssignToRegWithShadow")) {
134       ListInit *RegList = Action->getValueAsListInit("RegList");
135       ListInit *ShadowRegList = Action->getValueAsListInit("ShadowRegList");
136       if (!ShadowRegList->empty() && ShadowRegList->size() != RegList->size())
137         PrintFatalError("Invalid length of list of shadowed registers");
138 
139       if (RegList->size() == 1) {
140         O << IndentStr << "if (unsigned Reg = State.AllocateReg(";
141         O << getQualifiedName(RegList->getElementAsRecord(0));
142         O << ", " << getQualifiedName(ShadowRegList->getElementAsRecord(0));
143         O << ")) {\n";
144       } else {
145         unsigned RegListNumber = ++Counter;
146         unsigned ShadowRegListNumber = ++Counter;
147 
148         O << IndentStr << "static const MCPhysReg RegList" << RegListNumber
149           << "[] = {\n";
150         O << IndentStr << "  ";
151         for (unsigned i = 0, e = RegList->size(); i != e; ++i) {
152           if (i != 0) O << ", ";
153           O << getQualifiedName(RegList->getElementAsRecord(i));
154         }
155         O << "\n" << IndentStr << "};\n";
156 
157         O << IndentStr << "static const MCPhysReg RegList"
158           << ShadowRegListNumber << "[] = {\n";
159         O << IndentStr << "  ";
160         for (unsigned i = 0, e = ShadowRegList->size(); i != e; ++i) {
161           if (i != 0) O << ", ";
162           O << getQualifiedName(ShadowRegList->getElementAsRecord(i));
163         }
164         O << "\n" << IndentStr << "};\n";
165 
166         O << IndentStr << "if (unsigned Reg = State.AllocateReg(RegList"
167           << RegListNumber << ", " << "RegList" << ShadowRegListNumber
168           << ")) {\n";
169       }
170       O << IndentStr << "  State.addLoc(CCValAssign::getReg(ValNo, ValVT, "
171         << "Reg, LocVT, LocInfo));\n";
172       O << IndentStr << "  return false;\n";
173       O << IndentStr << "}\n";
174     } else if (Action->isSubClassOf("CCAssignToStack")) {
175       int Size = Action->getValueAsInt("Size");
176       int Align = Action->getValueAsInt("Align");
177 
178       O << IndentStr << "unsigned Offset" << ++Counter
179         << " = State.AllocateStack(";
180       if (Size)
181         O << Size << ", ";
182       else
183         O << "\n" << IndentStr
184           << "  State.getMachineFunction().getDataLayout()."
185              "getTypeAllocSize(EVT(LocVT).getTypeForEVT(State.getContext())),"
186              " ";
187       if (Align)
188         O << Align;
189       else
190         O << "\n" << IndentStr
191           << "  State.getMachineFunction().getDataLayout()."
192              "getABITypeAlignment(EVT(LocVT).getTypeForEVT(State.getContext()"
193              "))";
194       O << ");\n" << IndentStr
195         << "State.addLoc(CCValAssign::getMem(ValNo, ValVT, Offset"
196         << Counter << ", LocVT, LocInfo));\n";
197       O << IndentStr << "return false;\n";
198     } else if (Action->isSubClassOf("CCAssignToStackWithShadow")) {
199       int Size = Action->getValueAsInt("Size");
200       int Align = Action->getValueAsInt("Align");
201       ListInit *ShadowRegList = Action->getValueAsListInit("ShadowRegList");
202 
203       unsigned ShadowRegListNumber = ++Counter;
204 
205       O << IndentStr << "static const MCPhysReg ShadowRegList"
206           << ShadowRegListNumber << "[] = {\n";
207       O << IndentStr << "  ";
208       for (unsigned i = 0, e = ShadowRegList->size(); i != e; ++i) {
209         if (i != 0) O << ", ";
210         O << getQualifiedName(ShadowRegList->getElementAsRecord(i));
211       }
212       O << "\n" << IndentStr << "};\n";
213 
214       O << IndentStr << "unsigned Offset" << ++Counter
215         << " = State.AllocateStack("
216         << Size << ", " << Align << ", "
217         << "ShadowRegList" << ShadowRegListNumber << ");\n";
218       O << IndentStr << "State.addLoc(CCValAssign::getMem(ValNo, ValVT, Offset"
219         << Counter << ", LocVT, LocInfo));\n";
220       O << IndentStr << "return false;\n";
221     } else if (Action->isSubClassOf("CCPromoteToType")) {
222       Record *DestTy = Action->getValueAsDef("DestTy");
223       MVT::SimpleValueType DestVT = getValueType(DestTy);
224       O << IndentStr << "LocVT = " << getEnumName(DestVT) <<";\n";
225       if (MVT(DestVT).isFloatingPoint()) {
226         O << IndentStr << "LocInfo = CCValAssign::FPExt;\n";
227       } else {
228         O << IndentStr << "if (ArgFlags.isSExt())\n"
229           << IndentStr << IndentStr << "LocInfo = CCValAssign::SExt;\n"
230           << IndentStr << "else if (ArgFlags.isZExt())\n"
231           << IndentStr << IndentStr << "LocInfo = CCValAssign::ZExt;\n"
232           << IndentStr << "else\n"
233           << IndentStr << IndentStr << "LocInfo = CCValAssign::AExt;\n";
234       }
235     } else if (Action->isSubClassOf("CCPromoteToUpperBitsInType")) {
236       Record *DestTy = Action->getValueAsDef("DestTy");
237       MVT::SimpleValueType DestVT = getValueType(DestTy);
238       O << IndentStr << "LocVT = " << getEnumName(DestVT) << ";\n";
239       if (MVT(DestVT).isFloatingPoint()) {
240         PrintFatalError("CCPromoteToUpperBitsInType does not handle floating "
241                         "point");
242       } else {
243         O << IndentStr << "if (ArgFlags.isSExt())\n"
244           << IndentStr << IndentStr << "LocInfo = CCValAssign::SExtUpper;\n"
245           << IndentStr << "else if (ArgFlags.isZExt())\n"
246           << IndentStr << IndentStr << "LocInfo = CCValAssign::ZExtUpper;\n"
247           << IndentStr << "else\n"
248           << IndentStr << IndentStr << "LocInfo = CCValAssign::AExtUpper;\n";
249       }
250     } else if (Action->isSubClassOf("CCBitConvertToType")) {
251       Record *DestTy = Action->getValueAsDef("DestTy");
252       O << IndentStr << "LocVT = " << getEnumName(getValueType(DestTy)) <<";\n";
253       O << IndentStr << "LocInfo = CCValAssign::BCvt;\n";
254     } else if (Action->isSubClassOf("CCPassIndirect")) {
255       Record *DestTy = Action->getValueAsDef("DestTy");
256       O << IndentStr << "LocVT = " << getEnumName(getValueType(DestTy)) <<";\n";
257       O << IndentStr << "LocInfo = CCValAssign::Indirect;\n";
258     } else if (Action->isSubClassOf("CCPassByVal")) {
259       int Size = Action->getValueAsInt("Size");
260       int Align = Action->getValueAsInt("Align");
261       O << IndentStr
262         << "State.HandleByVal(ValNo, ValVT, LocVT, LocInfo, "
263         << Size << ", " << Align << ", ArgFlags);\n";
264       O << IndentStr << "return false;\n";
265     } else if (Action->isSubClassOf("CCCustom")) {
266       O << IndentStr
267         << "if (" << Action->getValueAsString("FuncName") << "(ValNo, ValVT, "
268         << "LocVT, LocInfo, ArgFlags, State))\n";
269       O << IndentStr << IndentStr << "return false;\n";
270     } else {
271       Action->dump();
272       PrintFatalError("Unknown CCAction!");
273     }
274   }
275 }
276 
277 namespace llvm {
278 
EmitCallingConv(RecordKeeper & RK,raw_ostream & OS)279 void EmitCallingConv(RecordKeeper &RK, raw_ostream &OS) {
280   emitSourceFileHeader("Calling Convention Implementation Fragment", OS);
281   CallingConvEmitter(RK).run(OS);
282 }
283 
284 } // End llvm namespace
285