1//===- CallingConvEmitter.cpp - Generate calling conventions --------------===//
2//
3// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4// See https://llvm.org/LICENSE.txt for license information.
5// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6//
7//===----------------------------------------------------------------------===//
8//
9// This tablegen backend is responsible for emitting descriptions of the calling
10// conventions supported by this target.
11//
12//===----------------------------------------------------------------------===//
13
14#include "CodeGenTarget.h"
15#include "llvm/TableGen/Error.h"
16#include "llvm/TableGen/Record.h"
17#include "llvm/TableGen/TableGenBackend.h"
18#include <cassert>
19using namespace llvm;
20
21namespace {
22class CallingConvEmitter {
23  RecordKeeper &Records;
24public:
25  explicit CallingConvEmitter(RecordKeeper &R) : Records(R) {}
26
27  void run(raw_ostream &o);
28
29private:
30  void EmitCallingConv(Record *CC, raw_ostream &O);
31  void EmitAction(Record *Action, unsigned Indent, raw_ostream &O);
32  unsigned Counter;
33};
34} // End anonymous namespace
35
36void CallingConvEmitter::run(raw_ostream &O) {
37  std::vector<Record*> CCs = Records.getAllDerivedDefinitions("CallingConv");
38
39  // Emit prototypes for all of the non-custom CC's so that they can forward ref
40  // each other.
41  Records.startTimer("Emit prototypes");
42  for (Record *CC : CCs) {
43    if (!CC->getValueAsBit("Custom")) {
44      unsigned Pad = CC->getName().size();
45      if (CC->getValueAsBit("Entry")) {
46        O << "bool llvm::";
47        Pad += 12;
48      } else {
49        O << "static bool ";
50        Pad += 13;
51      }
52      O << CC->getName() << "(unsigned ValNo, MVT ValVT,\n"
53        << std::string(Pad, ' ') << "MVT LocVT, CCValAssign::LocInfo LocInfo,\n"
54        << std::string(Pad, ' ')
55        << "ISD::ArgFlagsTy ArgFlags, CCState &State);\n";
56    }
57  }
58
59  // Emit each non-custom calling convention description in full.
60  Records.startTimer("Emit full descriptions");
61  for (Record *CC : CCs) {
62    if (!CC->getValueAsBit("Custom"))
63      EmitCallingConv(CC, O);
64  }
65}
66
67
68void CallingConvEmitter::EmitCallingConv(Record *CC, raw_ostream &O) {
69  ListInit *CCActions = CC->getValueAsListInit("Actions");
70  Counter = 0;
71
72  O << "\n\n";
73  unsigned Pad = CC->getName().size();
74  if (CC->getValueAsBit("Entry")) {
75    O << "bool llvm::";
76    Pad += 12;
77  } else {
78    O << "static bool ";
79    Pad += 13;
80  }
81  O << CC->getName() << "(unsigned ValNo, MVT ValVT,\n"
82    << std::string(Pad, ' ') << "MVT LocVT, CCValAssign::LocInfo LocInfo,\n"
83    << std::string(Pad, ' ') << "ISD::ArgFlagsTy ArgFlags, CCState &State) {\n";
84  // Emit all of the actions, in order.
85  for (unsigned i = 0, e = CCActions->size(); i != e; ++i) {
86    O << "\n";
87    EmitAction(CCActions->getElementAsRecord(i), 2, O);
88  }
89
90  O << "\n  return true; // CC didn't match.\n";
91  O << "}\n";
92}
93
94void CallingConvEmitter::EmitAction(Record *Action,
95                                    unsigned Indent, raw_ostream &O) {
96  std::string IndentStr = std::string(Indent, ' ');
97
98  if (Action->isSubClassOf("CCPredicateAction")) {
99    O << IndentStr << "if (";
100
101    if (Action->isSubClassOf("CCIfType")) {
102      ListInit *VTs = Action->getValueAsListInit("VTs");
103      for (unsigned i = 0, e = VTs->size(); i != e; ++i) {
104        Record *VT = VTs->getElementAsRecord(i);
105        if (i != 0) O << " ||\n    " << IndentStr;
106        O << "LocVT == " << getEnumName(getValueType(VT));
107      }
108
109    } else if (Action->isSubClassOf("CCIf")) {
110      O << Action->getValueAsString("Predicate");
111    } else {
112      errs() << *Action;
113      PrintFatalError(Action->getLoc(), "Unknown CCPredicateAction!");
114    }
115
116    O << ") {\n";
117    EmitAction(Action->getValueAsDef("SubAction"), Indent+2, O);
118    O << IndentStr << "}\n";
119  } else {
120    if (Action->isSubClassOf("CCDelegateTo")) {
121      Record *CC = Action->getValueAsDef("CC");
122      O << IndentStr << "if (!" << CC->getName()
123        << "(ValNo, ValVT, LocVT, LocInfo, ArgFlags, State))\n"
124        << IndentStr << "  return false;\n";
125    } else if (Action->isSubClassOf("CCAssignToReg")) {
126      ListInit *RegList = Action->getValueAsListInit("RegList");
127      if (RegList->size() == 1) {
128        O << IndentStr << "if (unsigned Reg = State.AllocateReg(";
129        O << getQualifiedName(RegList->getElementAsRecord(0)) << ")) {\n";
130      } else {
131        O << IndentStr << "static const MCPhysReg RegList" << ++Counter
132          << "[] = {\n";
133        O << IndentStr << "  ";
134        ListSeparator LS;
135        for (unsigned i = 0, e = RegList->size(); i != e; ++i)
136          O << LS << getQualifiedName(RegList->getElementAsRecord(i));
137        O << "\n" << IndentStr << "};\n";
138        O << IndentStr << "if (unsigned Reg = State.AllocateReg(RegList"
139          << Counter << ")) {\n";
140      }
141      O << IndentStr << "  State.addLoc(CCValAssign::getReg(ValNo, ValVT, "
142        << "Reg, LocVT, LocInfo));\n";
143      O << IndentStr << "  return false;\n";
144      O << IndentStr << "}\n";
145    } else if (Action->isSubClassOf("CCAssignToRegWithShadow")) {
146      ListInit *RegList = Action->getValueAsListInit("RegList");
147      ListInit *ShadowRegList = Action->getValueAsListInit("ShadowRegList");
148      if (!ShadowRegList->empty() && ShadowRegList->size() != RegList->size())
149        PrintFatalError(Action->getLoc(),
150                        "Invalid length of list of shadowed registers");
151
152      if (RegList->size() == 1) {
153        O << IndentStr << "if (unsigned Reg = State.AllocateReg(";
154        O << getQualifiedName(RegList->getElementAsRecord(0));
155        O << ", " << getQualifiedName(ShadowRegList->getElementAsRecord(0));
156        O << ")) {\n";
157      } else {
158        unsigned RegListNumber = ++Counter;
159        unsigned ShadowRegListNumber = ++Counter;
160
161        O << IndentStr << "static const MCPhysReg RegList" << RegListNumber
162          << "[] = {\n";
163        O << IndentStr << "  ";
164        ListSeparator LS;
165        for (unsigned i = 0, e = RegList->size(); i != e; ++i)
166          O << LS << getQualifiedName(RegList->getElementAsRecord(i));
167        O << "\n" << IndentStr << "};\n";
168
169        O << IndentStr << "static const MCPhysReg RegList"
170          << ShadowRegListNumber << "[] = {\n";
171        O << IndentStr << "  ";
172        ListSeparator LSS;
173        for (unsigned i = 0, e = ShadowRegList->size(); i != e; ++i)
174          O << LSS << getQualifiedName(ShadowRegList->getElementAsRecord(i));
175        O << "\n" << IndentStr << "};\n";
176
177        O << IndentStr << "if (unsigned Reg = State.AllocateReg(RegList"
178          << RegListNumber << ", " << "RegList" << ShadowRegListNumber
179          << ")) {\n";
180      }
181      O << IndentStr << "  State.addLoc(CCValAssign::getReg(ValNo, ValVT, "
182        << "Reg, LocVT, LocInfo));\n";
183      O << IndentStr << "  return false;\n";
184      O << IndentStr << "}\n";
185    } else if (Action->isSubClassOf("CCAssignToStack")) {
186      int Size = Action->getValueAsInt("Size");
187      int Align = Action->getValueAsInt("Align");
188
189      O << IndentStr << "unsigned Offset" << ++Counter
190        << " = State.AllocateStack(";
191      if (Size)
192        O << Size << ", ";
193      else
194        O << "\n" << IndentStr
195          << "  State.getMachineFunction().getDataLayout()."
196             "getTypeAllocSize(EVT(LocVT).getTypeForEVT(State.getContext())),"
197             " ";
198      if (Align)
199        O << "Align(" << Align << ")";
200      else
201        O << "\n"
202          << IndentStr
203          << "  State.getMachineFunction().getDataLayout()."
204             "getABITypeAlign(EVT(LocVT).getTypeForEVT(State.getContext()"
205             "))";
206      O << ");\n" << IndentStr
207        << "State.addLoc(CCValAssign::getMem(ValNo, ValVT, Offset"
208        << Counter << ", LocVT, LocInfo));\n";
209      O << IndentStr << "return false;\n";
210    } else if (Action->isSubClassOf("CCAssignToStackWithShadow")) {
211      int Size = Action->getValueAsInt("Size");
212      int Align = Action->getValueAsInt("Align");
213      ListInit *ShadowRegList = Action->getValueAsListInit("ShadowRegList");
214
215      unsigned ShadowRegListNumber = ++Counter;
216
217      O << IndentStr << "static const MCPhysReg ShadowRegList"
218          << ShadowRegListNumber << "[] = {\n";
219      O << IndentStr << "  ";
220      ListSeparator LS;
221      for (unsigned i = 0, e = ShadowRegList->size(); i != e; ++i)
222        O << LS << getQualifiedName(ShadowRegList->getElementAsRecord(i));
223      O << "\n" << IndentStr << "};\n";
224
225      O << IndentStr << "unsigned Offset" << ++Counter
226        << " = State.AllocateStack(" << Size << ", Align(" << Align << "), "
227        << "ShadowRegList" << ShadowRegListNumber << ");\n";
228      O << IndentStr << "State.addLoc(CCValAssign::getMem(ValNo, ValVT, Offset"
229        << Counter << ", LocVT, LocInfo));\n";
230      O << IndentStr << "return false;\n";
231    } else if (Action->isSubClassOf("CCPromoteToType")) {
232      Record *DestTy = Action->getValueAsDef("DestTy");
233      MVT::SimpleValueType DestVT = getValueType(DestTy);
234      O << IndentStr << "LocVT = " << getEnumName(DestVT) <<";\n";
235      if (MVT(DestVT).isFloatingPoint()) {
236        O << IndentStr << "LocInfo = CCValAssign::FPExt;\n";
237      } else {
238        O << IndentStr << "if (ArgFlags.isSExt())\n"
239          << IndentStr << "  LocInfo = CCValAssign::SExt;\n"
240          << IndentStr << "else if (ArgFlags.isZExt())\n"
241          << IndentStr << "  LocInfo = CCValAssign::ZExt;\n"
242          << IndentStr << "else\n"
243          << IndentStr << "  LocInfo = CCValAssign::AExt;\n";
244      }
245    } else if (Action->isSubClassOf("CCPromoteToUpperBitsInType")) {
246      Record *DestTy = Action->getValueAsDef("DestTy");
247      MVT::SimpleValueType DestVT = getValueType(DestTy);
248      O << IndentStr << "LocVT = " << getEnumName(DestVT) << ";\n";
249      if (MVT(DestVT).isFloatingPoint()) {
250        PrintFatalError(Action->getLoc(),
251                        "CCPromoteToUpperBitsInType does not handle floating "
252                        "point");
253      } else {
254        O << IndentStr << "if (ArgFlags.isSExt())\n"
255          << IndentStr << "  LocInfo = CCValAssign::SExtUpper;\n"
256          << IndentStr << "else if (ArgFlags.isZExt())\n"
257          << IndentStr << "  LocInfo = CCValAssign::ZExtUpper;\n"
258          << IndentStr << "else\n"
259          << IndentStr << "  LocInfo = CCValAssign::AExtUpper;\n";
260      }
261    } else if (Action->isSubClassOf("CCBitConvertToType")) {
262      Record *DestTy = Action->getValueAsDef("DestTy");
263      O << IndentStr << "LocVT = " << getEnumName(getValueType(DestTy)) <<";\n";
264      O << IndentStr << "LocInfo = CCValAssign::BCvt;\n";
265    } else if (Action->isSubClassOf("CCTruncToType")) {
266      Record *DestTy = Action->getValueAsDef("DestTy");
267      O << IndentStr << "LocVT = " << getEnumName(getValueType(DestTy)) <<";\n";
268      O << IndentStr << "LocInfo = CCValAssign::Trunc;\n";
269    } else if (Action->isSubClassOf("CCPassIndirect")) {
270      Record *DestTy = Action->getValueAsDef("DestTy");
271      O << IndentStr << "LocVT = " << getEnumName(getValueType(DestTy)) <<";\n";
272      O << IndentStr << "LocInfo = CCValAssign::Indirect;\n";
273    } else if (Action->isSubClassOf("CCPassByVal")) {
274      int Size = Action->getValueAsInt("Size");
275      int Align = Action->getValueAsInt("Align");
276      O << IndentStr << "State.HandleByVal(ValNo, ValVT, LocVT, LocInfo, "
277        << Size << ", Align(" << Align << "), ArgFlags);\n";
278      O << IndentStr << "return false;\n";
279    } else if (Action->isSubClassOf("CCCustom")) {
280      O << IndentStr
281        << "if (" << Action->getValueAsString("FuncName") << "(ValNo, ValVT, "
282        << "LocVT, LocInfo, ArgFlags, State))\n";
283      O << IndentStr << "  return false;\n";
284    } else {
285      errs() << *Action;
286      PrintFatalError(Action->getLoc(), "Unknown CCAction!");
287    }
288  }
289}
290
291namespace llvm {
292
293void EmitCallingConv(RecordKeeper &RK, raw_ostream &OS) {
294  emitSourceFileHeader("Calling Convention Implementation Fragment", OS);
295  CallingConvEmitter(RK).run(OS);
296}
297
298} // End llvm namespace
299