1 //===- Record.cpp - Record implementation ---------------------------------===//
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 // Implement the tablegen record classes.
11 //
12 //===----------------------------------------------------------------------===//
13 
14 #include "llvm/ADT/ArrayRef.h"
15 #include "llvm/ADT/DenseMap.h"
16 #include "llvm/ADT/FoldingSet.h"
17 #include "llvm/ADT/SmallString.h"
18 #include "llvm/ADT/SmallVector.h"
19 #include "llvm/ADT/StringExtras.h"
20 #include "llvm/ADT/StringMap.h"
21 #include "llvm/ADT/StringRef.h"
22 #include "llvm/Config/llvm-config.h"
23 #include "llvm/Support/Allocator.h"
24 #include "llvm/Support/Casting.h"
25 #include "llvm/Support/Compiler.h"
26 #include "llvm/Support/ErrorHandling.h"
27 #include "llvm/Support/SMLoc.h"
28 #include "llvm/Support/raw_ostream.h"
29 #include "llvm/TableGen/Error.h"
30 #include "llvm/TableGen/Record.h"
31 #include <cassert>
32 #include <cstdint>
33 #include <memory>
34 #include <string>
35 #include <utility>
36 #include <vector>
37 
38 using namespace llvm;
39 
40 static BumpPtrAllocator Allocator;
41 
42 //===----------------------------------------------------------------------===//
43 //    Type implementations
44 //===----------------------------------------------------------------------===//
45 
46 BitRecTy BitRecTy::Shared;
47 CodeRecTy CodeRecTy::Shared;
48 IntRecTy IntRecTy::Shared;
49 StringRecTy StringRecTy::Shared;
50 DagRecTy DagRecTy::Shared;
51 
52 #if !defined(NDEBUG) || defined(LLVM_ENABLE_DUMP)
53 LLVM_DUMP_METHOD void RecTy::dump() const { print(errs()); }
54 #endif
55 
56 ListRecTy *RecTy::getListTy() {
57   if (!ListTy)
58     ListTy = new(Allocator) ListRecTy(this);
59   return ListTy;
60 }
61 
62 bool RecTy::typeIsConvertibleTo(const RecTy *RHS) const {
63   assert(RHS && "NULL pointer");
64   return Kind == RHS->getRecTyKind();
65 }
66 
67 bool RecTy::typeIsA(const RecTy *RHS) const { return this == RHS; }
68 
69 bool BitRecTy::typeIsConvertibleTo(const RecTy *RHS) const{
70   if (RecTy::typeIsConvertibleTo(RHS) || RHS->getRecTyKind() == IntRecTyKind)
71     return true;
72   if (const BitsRecTy *BitsTy = dyn_cast<BitsRecTy>(RHS))
73     return BitsTy->getNumBits() == 1;
74   return false;
75 }
76 
77 BitsRecTy *BitsRecTy::get(unsigned Sz) {
78   static std::vector<BitsRecTy*> Shared;
79   if (Sz >= Shared.size())
80     Shared.resize(Sz + 1);
81   BitsRecTy *&Ty = Shared[Sz];
82   if (!Ty)
83     Ty = new(Allocator) BitsRecTy(Sz);
84   return Ty;
85 }
86 
87 std::string BitsRecTy::getAsString() const {
88   return "bits<" + utostr(Size) + ">";
89 }
90 
91 bool BitsRecTy::typeIsConvertibleTo(const RecTy *RHS) const {
92   if (RecTy::typeIsConvertibleTo(RHS)) //argument and the sender are same type
93     return cast<BitsRecTy>(RHS)->Size == Size;
94   RecTyKind kind = RHS->getRecTyKind();
95   return (kind == BitRecTyKind && Size == 1) || (kind == IntRecTyKind);
96 }
97 
98 bool BitsRecTy::typeIsA(const RecTy *RHS) const {
99   if (const BitsRecTy *RHSb = dyn_cast<BitsRecTy>(RHS))
100     return RHSb->Size == Size;
101   return false;
102 }
103 
104 bool IntRecTy::typeIsConvertibleTo(const RecTy *RHS) const {
105   RecTyKind kind = RHS->getRecTyKind();
106   return kind==BitRecTyKind || kind==BitsRecTyKind || kind==IntRecTyKind;
107 }
108 
109 bool CodeRecTy::typeIsConvertibleTo(const RecTy *RHS) const {
110   RecTyKind Kind = RHS->getRecTyKind();
111   return Kind == CodeRecTyKind || Kind == StringRecTyKind;
112 }
113 
114 std::string StringRecTy::getAsString() const {
115   return "string";
116 }
117 
118 bool StringRecTy::typeIsConvertibleTo(const RecTy *RHS) const {
119   RecTyKind Kind = RHS->getRecTyKind();
120   return Kind == StringRecTyKind || Kind == CodeRecTyKind;
121 }
122 
123 std::string ListRecTy::getAsString() const {
124   return "list<" + Ty->getAsString() + ">";
125 }
126 
127 bool ListRecTy::typeIsConvertibleTo(const RecTy *RHS) const {
128   if (const auto *ListTy = dyn_cast<ListRecTy>(RHS))
129     return Ty->typeIsConvertibleTo(ListTy->getElementType());
130   return false;
131 }
132 
133 bool ListRecTy::typeIsA(const RecTy *RHS) const {
134   if (const ListRecTy *RHSl = dyn_cast<ListRecTy>(RHS))
135     return getElementType()->typeIsA(RHSl->getElementType());
136   return false;
137 }
138 
139 std::string DagRecTy::getAsString() const {
140   return "dag";
141 }
142 
143 static void ProfileRecordRecTy(FoldingSetNodeID &ID,
144                                ArrayRef<Record *> Classes) {
145   ID.AddInteger(Classes.size());
146   for (Record *R : Classes)
147     ID.AddPointer(R);
148 }
149 
150 RecordRecTy *RecordRecTy::get(ArrayRef<Record *> UnsortedClasses) {
151   if (UnsortedClasses.empty()) {
152     static RecordRecTy AnyRecord(0);
153     return &AnyRecord;
154   }
155 
156   FoldingSet<RecordRecTy> &ThePool =
157       UnsortedClasses[0]->getRecords().RecordTypePool;
158 
159   SmallVector<Record *, 4> Classes(UnsortedClasses.begin(),
160                                    UnsortedClasses.end());
161   llvm::sort(Classes.begin(), Classes.end(),
162              [](Record *LHS, Record *RHS) {
163                return LHS->getNameInitAsString() < RHS->getNameInitAsString();
164              });
165 
166   FoldingSetNodeID ID;
167   ProfileRecordRecTy(ID, Classes);
168 
169   void *IP = nullptr;
170   if (RecordRecTy *Ty = ThePool.FindNodeOrInsertPos(ID, IP))
171     return Ty;
172 
173 #ifndef NDEBUG
174   // Check for redundancy.
175   for (unsigned i = 0; i < Classes.size(); ++i) {
176     for (unsigned j = 0; j < Classes.size(); ++j) {
177       assert(i == j || !Classes[i]->isSubClassOf(Classes[j]));
178     }
179     assert(&Classes[0]->getRecords() == &Classes[i]->getRecords());
180   }
181 #endif
182 
183   void *Mem = Allocator.Allocate(totalSizeToAlloc<Record *>(Classes.size()),
184                                  alignof(RecordRecTy));
185   RecordRecTy *Ty = new(Mem) RecordRecTy(Classes.size());
186   std::uninitialized_copy(Classes.begin(), Classes.end(),
187                           Ty->getTrailingObjects<Record *>());
188   ThePool.InsertNode(Ty, IP);
189   return Ty;
190 }
191 
192 void RecordRecTy::Profile(FoldingSetNodeID &ID) const {
193   ProfileRecordRecTy(ID, getClasses());
194 }
195 
196 std::string RecordRecTy::getAsString() const {
197   if (NumClasses == 1)
198     return getClasses()[0]->getNameInitAsString();
199 
200   std::string Str = "{";
201   bool First = true;
202   for (Record *R : getClasses()) {
203     if (!First)
204       Str += ", ";
205     First = false;
206     Str += R->getNameInitAsString();
207   }
208   Str += "}";
209   return Str;
210 }
211 
212 bool RecordRecTy::isSubClassOf(Record *Class) const {
213   return llvm::any_of(getClasses(), [Class](Record *MySuperClass) {
214                                       return MySuperClass == Class ||
215                                              MySuperClass->isSubClassOf(Class);
216                                     });
217 }
218 
219 bool RecordRecTy::typeIsConvertibleTo(const RecTy *RHS) const {
220   if (this == RHS)
221     return true;
222 
223   const RecordRecTy *RTy = dyn_cast<RecordRecTy>(RHS);
224   if (!RTy)
225     return false;
226 
227   return llvm::all_of(RTy->getClasses(), [this](Record *TargetClass) {
228                                            return isSubClassOf(TargetClass);
229                                          });
230 }
231 
232 bool RecordRecTy::typeIsA(const RecTy *RHS) const {
233   return typeIsConvertibleTo(RHS);
234 }
235 
236 static RecordRecTy *resolveRecordTypes(RecordRecTy *T1, RecordRecTy *T2) {
237   SmallVector<Record *, 4> CommonSuperClasses;
238   SmallVector<Record *, 4> Stack;
239 
240   Stack.insert(Stack.end(), T1->classes_begin(), T1->classes_end());
241 
242   while (!Stack.empty()) {
243     Record *R = Stack.back();
244     Stack.pop_back();
245 
246     if (T2->isSubClassOf(R)) {
247       CommonSuperClasses.push_back(R);
248     } else {
249       R->getDirectSuperClasses(Stack);
250     }
251   }
252 
253   return RecordRecTy::get(CommonSuperClasses);
254 }
255 
256 RecTy *llvm::resolveTypes(RecTy *T1, RecTy *T2) {
257   if (T1 == T2)
258     return T1;
259 
260   if (RecordRecTy *RecTy1 = dyn_cast<RecordRecTy>(T1)) {
261     if (RecordRecTy *RecTy2 = dyn_cast<RecordRecTy>(T2))
262       return resolveRecordTypes(RecTy1, RecTy2);
263   }
264 
265   if (T1->typeIsConvertibleTo(T2))
266     return T2;
267   if (T2->typeIsConvertibleTo(T1))
268     return T1;
269 
270   if (ListRecTy *ListTy1 = dyn_cast<ListRecTy>(T1)) {
271     if (ListRecTy *ListTy2 = dyn_cast<ListRecTy>(T2)) {
272       RecTy* NewType = resolveTypes(ListTy1->getElementType(),
273                                     ListTy2->getElementType());
274       if (NewType)
275         return NewType->getListTy();
276     }
277   }
278 
279   return nullptr;
280 }
281 
282 //===----------------------------------------------------------------------===//
283 //    Initializer implementations
284 //===----------------------------------------------------------------------===//
285 
286 void Init::anchor() {}
287 
288 #if !defined(NDEBUG) || defined(LLVM_ENABLE_DUMP)
289 LLVM_DUMP_METHOD void Init::dump() const { return print(errs()); }
290 #endif
291 
292 UnsetInit *UnsetInit::get() {
293   static UnsetInit TheInit;
294   return &TheInit;
295 }
296 
297 Init *UnsetInit::getCastTo(RecTy *Ty) const {
298   return const_cast<UnsetInit *>(this);
299 }
300 
301 Init *UnsetInit::convertInitializerTo(RecTy *Ty) const {
302   return const_cast<UnsetInit *>(this);
303 }
304 
305 BitInit *BitInit::get(bool V) {
306   static BitInit True(true);
307   static BitInit False(false);
308 
309   return V ? &True : &False;
310 }
311 
312 Init *BitInit::convertInitializerTo(RecTy *Ty) const {
313   if (isa<BitRecTy>(Ty))
314     return const_cast<BitInit *>(this);
315 
316   if (isa<IntRecTy>(Ty))
317     return IntInit::get(getValue());
318 
319   if (auto *BRT = dyn_cast<BitsRecTy>(Ty)) {
320     // Can only convert single bit.
321     if (BRT->getNumBits() == 1)
322       return BitsInit::get(const_cast<BitInit *>(this));
323   }
324 
325   return nullptr;
326 }
327 
328 static void
329 ProfileBitsInit(FoldingSetNodeID &ID, ArrayRef<Init *> Range) {
330   ID.AddInteger(Range.size());
331 
332   for (Init *I : Range)
333     ID.AddPointer(I);
334 }
335 
336 BitsInit *BitsInit::get(ArrayRef<Init *> Range) {
337   static FoldingSet<BitsInit> ThePool;
338 
339   FoldingSetNodeID ID;
340   ProfileBitsInit(ID, Range);
341 
342   void *IP = nullptr;
343   if (BitsInit *I = ThePool.FindNodeOrInsertPos(ID, IP))
344     return I;
345 
346   void *Mem = Allocator.Allocate(totalSizeToAlloc<Init *>(Range.size()),
347                                  alignof(BitsInit));
348   BitsInit *I = new(Mem) BitsInit(Range.size());
349   std::uninitialized_copy(Range.begin(), Range.end(),
350                           I->getTrailingObjects<Init *>());
351   ThePool.InsertNode(I, IP);
352   return I;
353 }
354 
355 void BitsInit::Profile(FoldingSetNodeID &ID) const {
356   ProfileBitsInit(ID, makeArrayRef(getTrailingObjects<Init *>(), NumBits));
357 }
358 
359 Init *BitsInit::convertInitializerTo(RecTy *Ty) const {
360   if (isa<BitRecTy>(Ty)) {
361     if (getNumBits() != 1) return nullptr; // Only accept if just one bit!
362     return getBit(0);
363   }
364 
365   if (auto *BRT = dyn_cast<BitsRecTy>(Ty)) {
366     // If the number of bits is right, return it.  Otherwise we need to expand
367     // or truncate.
368     if (getNumBits() != BRT->getNumBits()) return nullptr;
369     return const_cast<BitsInit *>(this);
370   }
371 
372   if (isa<IntRecTy>(Ty)) {
373     int64_t Result = 0;
374     for (unsigned i = 0, e = getNumBits(); i != e; ++i)
375       if (auto *Bit = dyn_cast<BitInit>(getBit(i)))
376         Result |= static_cast<int64_t>(Bit->getValue()) << i;
377       else
378         return nullptr;
379     return IntInit::get(Result);
380   }
381 
382   return nullptr;
383 }
384 
385 Init *
386 BitsInit::convertInitializerBitRange(ArrayRef<unsigned> Bits) const {
387   SmallVector<Init *, 16> NewBits(Bits.size());
388 
389   for (unsigned i = 0, e = Bits.size(); i != e; ++i) {
390     if (Bits[i] >= getNumBits())
391       return nullptr;
392     NewBits[i] = getBit(Bits[i]);
393   }
394   return BitsInit::get(NewBits);
395 }
396 
397 bool BitsInit::isConcrete() const {
398   for (unsigned i = 0, e = getNumBits(); i != e; ++i) {
399     if (!getBit(i)->isConcrete())
400       return false;
401   }
402   return true;
403 }
404 
405 std::string BitsInit::getAsString() const {
406   std::string Result = "{ ";
407   for (unsigned i = 0, e = getNumBits(); i != e; ++i) {
408     if (i) Result += ", ";
409     if (Init *Bit = getBit(e-i-1))
410       Result += Bit->getAsString();
411     else
412       Result += "*";
413   }
414   return Result + " }";
415 }
416 
417 // resolveReferences - If there are any field references that refer to fields
418 // that have been filled in, we can propagate the values now.
419 Init *BitsInit::resolveReferences(Resolver &R) const {
420   bool Changed = false;
421   SmallVector<Init *, 16> NewBits(getNumBits());
422 
423   Init *CachedBitVarRef = nullptr;
424   Init *CachedBitVarResolved = nullptr;
425 
426   for (unsigned i = 0, e = getNumBits(); i != e; ++i) {
427     Init *CurBit = getBit(i);
428     Init *NewBit = CurBit;
429 
430     if (VarBitInit *CurBitVar = dyn_cast<VarBitInit>(CurBit)) {
431       if (CurBitVar->getBitVar() != CachedBitVarRef) {
432         CachedBitVarRef = CurBitVar->getBitVar();
433         CachedBitVarResolved = CachedBitVarRef->resolveReferences(R);
434       }
435 
436       NewBit = CachedBitVarResolved->getBit(CurBitVar->getBitNum());
437     } else {
438       // getBit(0) implicitly converts int and bits<1> values to bit.
439       NewBit = CurBit->resolveReferences(R)->getBit(0);
440     }
441 
442     if (isa<UnsetInit>(NewBit) && R.keepUnsetBits())
443       NewBit = CurBit;
444     NewBits[i] = NewBit;
445     Changed |= CurBit != NewBit;
446   }
447 
448   if (Changed)
449     return BitsInit::get(NewBits);
450 
451   return const_cast<BitsInit *>(this);
452 }
453 
454 IntInit *IntInit::get(int64_t V) {
455   static DenseMap<int64_t, IntInit*> ThePool;
456 
457   IntInit *&I = ThePool[V];
458   if (!I) I = new(Allocator) IntInit(V);
459   return I;
460 }
461 
462 std::string IntInit::getAsString() const {
463   return itostr(Value);
464 }
465 
466 static bool canFitInBitfield(int64_t Value, unsigned NumBits) {
467   // For example, with NumBits == 4, we permit Values from [-7 .. 15].
468   return (NumBits >= sizeof(Value) * 8) ||
469          (Value >> NumBits == 0) || (Value >> (NumBits-1) == -1);
470 }
471 
472 Init *IntInit::convertInitializerTo(RecTy *Ty) const {
473   if (isa<IntRecTy>(Ty))
474     return const_cast<IntInit *>(this);
475 
476   if (isa<BitRecTy>(Ty)) {
477     int64_t Val = getValue();
478     if (Val != 0 && Val != 1) return nullptr;  // Only accept 0 or 1 for a bit!
479     return BitInit::get(Val != 0);
480   }
481 
482   if (auto *BRT = dyn_cast<BitsRecTy>(Ty)) {
483     int64_t Value = getValue();
484     // Make sure this bitfield is large enough to hold the integer value.
485     if (!canFitInBitfield(Value, BRT->getNumBits()))
486       return nullptr;
487 
488     SmallVector<Init *, 16> NewBits(BRT->getNumBits());
489     for (unsigned i = 0; i != BRT->getNumBits(); ++i)
490       NewBits[i] = BitInit::get(Value & (1LL << i));
491 
492     return BitsInit::get(NewBits);
493   }
494 
495   return nullptr;
496 }
497 
498 Init *
499 IntInit::convertInitializerBitRange(ArrayRef<unsigned> Bits) const {
500   SmallVector<Init *, 16> NewBits(Bits.size());
501 
502   for (unsigned i = 0, e = Bits.size(); i != e; ++i) {
503     if (Bits[i] >= 64)
504       return nullptr;
505 
506     NewBits[i] = BitInit::get(Value & (INT64_C(1) << Bits[i]));
507   }
508   return BitsInit::get(NewBits);
509 }
510 
511 CodeInit *CodeInit::get(StringRef V) {
512   static StringMap<CodeInit*, BumpPtrAllocator &> ThePool(Allocator);
513 
514   auto &Entry = *ThePool.insert(std::make_pair(V, nullptr)).first;
515   if (!Entry.second)
516     Entry.second = new(Allocator) CodeInit(Entry.getKey());
517   return Entry.second;
518 }
519 
520 StringInit *StringInit::get(StringRef V) {
521   static StringMap<StringInit*, BumpPtrAllocator &> ThePool(Allocator);
522 
523   auto &Entry = *ThePool.insert(std::make_pair(V, nullptr)).first;
524   if (!Entry.second)
525     Entry.second = new(Allocator) StringInit(Entry.getKey());
526   return Entry.second;
527 }
528 
529 Init *StringInit::convertInitializerTo(RecTy *Ty) const {
530   if (isa<StringRecTy>(Ty))
531     return const_cast<StringInit *>(this);
532   if (isa<CodeRecTy>(Ty))
533     return CodeInit::get(getValue());
534 
535   return nullptr;
536 }
537 
538 Init *CodeInit::convertInitializerTo(RecTy *Ty) const {
539   if (isa<CodeRecTy>(Ty))
540     return const_cast<CodeInit *>(this);
541   if (isa<StringRecTy>(Ty))
542     return StringInit::get(getValue());
543 
544   return nullptr;
545 }
546 
547 static void ProfileListInit(FoldingSetNodeID &ID,
548                             ArrayRef<Init *> Range,
549                             RecTy *EltTy) {
550   ID.AddInteger(Range.size());
551   ID.AddPointer(EltTy);
552 
553   for (Init *I : Range)
554     ID.AddPointer(I);
555 }
556 
557 ListInit *ListInit::get(ArrayRef<Init *> Range, RecTy *EltTy) {
558   static FoldingSet<ListInit> ThePool;
559 
560   FoldingSetNodeID ID;
561   ProfileListInit(ID, Range, EltTy);
562 
563   void *IP = nullptr;
564   if (ListInit *I = ThePool.FindNodeOrInsertPos(ID, IP))
565     return I;
566 
567   assert(Range.empty() || !isa<TypedInit>(Range[0]) ||
568          cast<TypedInit>(Range[0])->getType()->typeIsConvertibleTo(EltTy));
569 
570   void *Mem = Allocator.Allocate(totalSizeToAlloc<Init *>(Range.size()),
571                                  alignof(ListInit));
572   ListInit *I = new(Mem) ListInit(Range.size(), EltTy);
573   std::uninitialized_copy(Range.begin(), Range.end(),
574                           I->getTrailingObjects<Init *>());
575   ThePool.InsertNode(I, IP);
576   return I;
577 }
578 
579 void ListInit::Profile(FoldingSetNodeID &ID) const {
580   RecTy *EltTy = cast<ListRecTy>(getType())->getElementType();
581 
582   ProfileListInit(ID, getValues(), EltTy);
583 }
584 
585 Init *ListInit::convertInitializerTo(RecTy *Ty) const {
586   if (getType() == Ty)
587     return const_cast<ListInit*>(this);
588 
589   if (auto *LRT = dyn_cast<ListRecTy>(Ty)) {
590     SmallVector<Init*, 8> Elements;
591     Elements.reserve(getValues().size());
592 
593     // Verify that all of the elements of the list are subclasses of the
594     // appropriate class!
595     bool Changed = false;
596     RecTy *ElementType = LRT->getElementType();
597     for (Init *I : getValues())
598       if (Init *CI = I->convertInitializerTo(ElementType)) {
599         Elements.push_back(CI);
600         if (CI != I)
601           Changed = true;
602       } else
603         return nullptr;
604 
605     if (!Changed)
606       return const_cast<ListInit*>(this);
607     return ListInit::get(Elements, ElementType);
608   }
609 
610   return nullptr;
611 }
612 
613 Init *ListInit::convertInitListSlice(ArrayRef<unsigned> Elements) const {
614   SmallVector<Init*, 8> Vals;
615   Vals.reserve(Elements.size());
616   for (unsigned Element : Elements) {
617     if (Element >= size())
618       return nullptr;
619     Vals.push_back(getElement(Element));
620   }
621   return ListInit::get(Vals, getElementType());
622 }
623 
624 Record *ListInit::getElementAsRecord(unsigned i) const {
625   assert(i < NumValues && "List element index out of range!");
626   DefInit *DI = dyn_cast<DefInit>(getElement(i));
627   if (!DI)
628     PrintFatalError("Expected record in list!");
629   return DI->getDef();
630 }
631 
632 Init *ListInit::resolveReferences(Resolver &R) const {
633   SmallVector<Init*, 8> Resolved;
634   Resolved.reserve(size());
635   bool Changed = false;
636 
637   for (Init *CurElt : getValues()) {
638     Init *E = CurElt->resolveReferences(R);
639     Changed |= E != CurElt;
640     Resolved.push_back(E);
641   }
642 
643   if (Changed)
644     return ListInit::get(Resolved, getElementType());
645   return const_cast<ListInit *>(this);
646 }
647 
648 bool ListInit::isConcrete() const {
649   for (Init *Element : *this) {
650     if (!Element->isConcrete())
651       return false;
652   }
653   return true;
654 }
655 
656 std::string ListInit::getAsString() const {
657   std::string Result = "[";
658   const char *sep = "";
659   for (Init *Element : *this) {
660     Result += sep;
661     sep = ", ";
662     Result += Element->getAsString();
663   }
664   return Result + "]";
665 }
666 
667 Init *OpInit::getBit(unsigned Bit) const {
668   if (getType() == BitRecTy::get())
669     return const_cast<OpInit*>(this);
670   return VarBitInit::get(const_cast<OpInit*>(this), Bit);
671 }
672 
673 static void
674 ProfileUnOpInit(FoldingSetNodeID &ID, unsigned Opcode, Init *Op, RecTy *Type) {
675   ID.AddInteger(Opcode);
676   ID.AddPointer(Op);
677   ID.AddPointer(Type);
678 }
679 
680 UnOpInit *UnOpInit::get(UnaryOp Opc, Init *LHS, RecTy *Type) {
681   static FoldingSet<UnOpInit> ThePool;
682 
683   FoldingSetNodeID ID;
684   ProfileUnOpInit(ID, Opc, LHS, Type);
685 
686   void *IP = nullptr;
687   if (UnOpInit *I = ThePool.FindNodeOrInsertPos(ID, IP))
688     return I;
689 
690   UnOpInit *I = new(Allocator) UnOpInit(Opc, LHS, Type);
691   ThePool.InsertNode(I, IP);
692   return I;
693 }
694 
695 void UnOpInit::Profile(FoldingSetNodeID &ID) const {
696   ProfileUnOpInit(ID, getOpcode(), getOperand(), getType());
697 }
698 
699 Init *UnOpInit::Fold(Record *CurRec, bool IsFinal) const {
700   switch (getOpcode()) {
701   case CAST:
702     if (isa<StringRecTy>(getType())) {
703       if (StringInit *LHSs = dyn_cast<StringInit>(LHS))
704         return LHSs;
705 
706       if (DefInit *LHSd = dyn_cast<DefInit>(LHS))
707         return StringInit::get(LHSd->getAsString());
708 
709       if (IntInit *LHSi = dyn_cast<IntInit>(LHS))
710         return StringInit::get(LHSi->getAsString());
711     } else if (isa<RecordRecTy>(getType())) {
712       if (StringInit *Name = dyn_cast<StringInit>(LHS)) {
713         assert(CurRec && "NULL pointer");
714         Record *D;
715 
716         // Self-references are allowed, but their resolution is delayed until
717         // the final resolve to ensure that we get the correct type for them.
718         if (Name == CurRec->getNameInit()) {
719           if (!IsFinal)
720             break;
721           D = CurRec;
722         } else {
723           D = CurRec->getRecords().getDef(Name->getValue());
724           if (!D) {
725             if (IsFinal)
726               PrintFatalError(CurRec->getLoc(),
727                               Twine("Undefined reference to record: '") +
728                               Name->getValue() + "'\n");
729             break;
730           }
731         }
732 
733         DefInit *DI = DefInit::get(D);
734         if (!DI->getType()->typeIsA(getType())) {
735           PrintFatalError(CurRec->getLoc(),
736                           Twine("Expected type '") +
737                           getType()->getAsString() + "', got '" +
738                           DI->getType()->getAsString() + "' in: " +
739                           getAsString() + "\n");
740         }
741         return DI;
742       }
743     }
744 
745     if (Init *NewInit = LHS->convertInitializerTo(getType()))
746       return NewInit;
747     break;
748 
749   case HEAD:
750     if (ListInit *LHSl = dyn_cast<ListInit>(LHS)) {
751       assert(!LHSl->empty() && "Empty list in head");
752       return LHSl->getElement(0);
753     }
754     break;
755 
756   case TAIL:
757     if (ListInit *LHSl = dyn_cast<ListInit>(LHS)) {
758       assert(!LHSl->empty() && "Empty list in tail");
759       // Note the +1.  We can't just pass the result of getValues()
760       // directly.
761       return ListInit::get(LHSl->getValues().slice(1), LHSl->getElementType());
762     }
763     break;
764 
765   case SIZE:
766     if (ListInit *LHSl = dyn_cast<ListInit>(LHS))
767       return IntInit::get(LHSl->size());
768     break;
769 
770   case EMPTY:
771     if (ListInit *LHSl = dyn_cast<ListInit>(LHS))
772       return IntInit::get(LHSl->empty());
773     if (StringInit *LHSs = dyn_cast<StringInit>(LHS))
774       return IntInit::get(LHSs->getValue().empty());
775     break;
776   }
777   return const_cast<UnOpInit *>(this);
778 }
779 
780 Init *UnOpInit::resolveReferences(Resolver &R) const {
781   Init *lhs = LHS->resolveReferences(R);
782 
783   if (LHS != lhs || (R.isFinal() && getOpcode() == CAST))
784     return (UnOpInit::get(getOpcode(), lhs, getType()))
785         ->Fold(R.getCurrentRecord(), R.isFinal());
786   return const_cast<UnOpInit *>(this);
787 }
788 
789 std::string UnOpInit::getAsString() const {
790   std::string Result;
791   switch (getOpcode()) {
792   case CAST: Result = "!cast<" + getType()->getAsString() + ">"; break;
793   case HEAD: Result = "!head"; break;
794   case TAIL: Result = "!tail"; break;
795   case SIZE: Result = "!size"; break;
796   case EMPTY: Result = "!empty"; break;
797   }
798   return Result + "(" + LHS->getAsString() + ")";
799 }
800 
801 static void
802 ProfileBinOpInit(FoldingSetNodeID &ID, unsigned Opcode, Init *LHS, Init *RHS,
803                  RecTy *Type) {
804   ID.AddInteger(Opcode);
805   ID.AddPointer(LHS);
806   ID.AddPointer(RHS);
807   ID.AddPointer(Type);
808 }
809 
810 BinOpInit *BinOpInit::get(BinaryOp Opc, Init *LHS,
811                           Init *RHS, RecTy *Type) {
812   static FoldingSet<BinOpInit> ThePool;
813 
814   FoldingSetNodeID ID;
815   ProfileBinOpInit(ID, Opc, LHS, RHS, Type);
816 
817   void *IP = nullptr;
818   if (BinOpInit *I = ThePool.FindNodeOrInsertPos(ID, IP))
819     return I;
820 
821   BinOpInit *I = new(Allocator) BinOpInit(Opc, LHS, RHS, Type);
822   ThePool.InsertNode(I, IP);
823   return I;
824 }
825 
826 void BinOpInit::Profile(FoldingSetNodeID &ID) const {
827   ProfileBinOpInit(ID, getOpcode(), getLHS(), getRHS(), getType());
828 }
829 
830 static StringInit *ConcatStringInits(const StringInit *I0,
831                                      const StringInit *I1) {
832   SmallString<80> Concat(I0->getValue());
833   Concat.append(I1->getValue());
834   return StringInit::get(Concat);
835 }
836 
837 Init *BinOpInit::getStrConcat(Init *I0, Init *I1) {
838   // Shortcut for the common case of concatenating two strings.
839   if (const StringInit *I0s = dyn_cast<StringInit>(I0))
840     if (const StringInit *I1s = dyn_cast<StringInit>(I1))
841       return ConcatStringInits(I0s, I1s);
842   return BinOpInit::get(BinOpInit::STRCONCAT, I0, I1, StringRecTy::get());
843 }
844 
845 Init *BinOpInit::Fold(Record *CurRec) const {
846   switch (getOpcode()) {
847   case CONCAT: {
848     DagInit *LHSs = dyn_cast<DagInit>(LHS);
849     DagInit *RHSs = dyn_cast<DagInit>(RHS);
850     if (LHSs && RHSs) {
851       DefInit *LOp = dyn_cast<DefInit>(LHSs->getOperator());
852       DefInit *ROp = dyn_cast<DefInit>(RHSs->getOperator());
853       if (!LOp || !ROp)
854         break;
855       if (LOp->getDef() != ROp->getDef()) {
856         PrintFatalError(Twine("Concatenated Dag operators do not match: '") +
857                         LHSs->getAsString() + "' vs. '" + RHSs->getAsString() +
858                         "'");
859       }
860       SmallVector<Init*, 8> Args;
861       SmallVector<StringInit*, 8> ArgNames;
862       for (unsigned i = 0, e = LHSs->getNumArgs(); i != e; ++i) {
863         Args.push_back(LHSs->getArg(i));
864         ArgNames.push_back(LHSs->getArgName(i));
865       }
866       for (unsigned i = 0, e = RHSs->getNumArgs(); i != e; ++i) {
867         Args.push_back(RHSs->getArg(i));
868         ArgNames.push_back(RHSs->getArgName(i));
869       }
870       return DagInit::get(LHSs->getOperator(), nullptr, Args, ArgNames);
871     }
872     break;
873   }
874   case LISTCONCAT: {
875     ListInit *LHSs = dyn_cast<ListInit>(LHS);
876     ListInit *RHSs = dyn_cast<ListInit>(RHS);
877     if (LHSs && RHSs) {
878       SmallVector<Init *, 8> Args;
879       Args.insert(Args.end(), LHSs->begin(), LHSs->end());
880       Args.insert(Args.end(), RHSs->begin(), RHSs->end());
881       return ListInit::get(Args, LHSs->getElementType());
882     }
883     break;
884   }
885   case STRCONCAT: {
886     StringInit *LHSs = dyn_cast<StringInit>(LHS);
887     StringInit *RHSs = dyn_cast<StringInit>(RHS);
888     if (LHSs && RHSs)
889       return ConcatStringInits(LHSs, RHSs);
890     break;
891   }
892   case EQ:
893   case NE:
894   case LE:
895   case LT:
896   case GE:
897   case GT: {
898     // try to fold eq comparison for 'bit' and 'int', otherwise fallback
899     // to string objects.
900     IntInit *L =
901         dyn_cast_or_null<IntInit>(LHS->convertInitializerTo(IntRecTy::get()));
902     IntInit *R =
903         dyn_cast_or_null<IntInit>(RHS->convertInitializerTo(IntRecTy::get()));
904 
905     if (L && R) {
906       bool Result;
907       switch (getOpcode()) {
908       case EQ: Result = L->getValue() == R->getValue(); break;
909       case NE: Result = L->getValue() != R->getValue(); break;
910       case LE: Result = L->getValue() <= R->getValue(); break;
911       case LT: Result = L->getValue() < R->getValue(); break;
912       case GE: Result = L->getValue() >= R->getValue(); break;
913       case GT: Result = L->getValue() > R->getValue(); break;
914       default: llvm_unreachable("unhandled comparison");
915       }
916       return BitInit::get(Result);
917     }
918 
919     if (getOpcode() == EQ || getOpcode() == NE) {
920       StringInit *LHSs = dyn_cast<StringInit>(LHS);
921       StringInit *RHSs = dyn_cast<StringInit>(RHS);
922 
923       // Make sure we've resolved
924       if (LHSs && RHSs) {
925         bool Equal = LHSs->getValue() == RHSs->getValue();
926         return BitInit::get(getOpcode() == EQ ? Equal : !Equal);
927       }
928     }
929 
930     break;
931   }
932   case ADD:
933   case AND:
934   case OR:
935   case SHL:
936   case SRA:
937   case SRL: {
938     IntInit *LHSi =
939       dyn_cast_or_null<IntInit>(LHS->convertInitializerTo(IntRecTy::get()));
940     IntInit *RHSi =
941       dyn_cast_or_null<IntInit>(RHS->convertInitializerTo(IntRecTy::get()));
942     if (LHSi && RHSi) {
943       int64_t LHSv = LHSi->getValue(), RHSv = RHSi->getValue();
944       int64_t Result;
945       switch (getOpcode()) {
946       default: llvm_unreachable("Bad opcode!");
947       case ADD: Result = LHSv +  RHSv; break;
948       case AND: Result = LHSv &  RHSv; break;
949       case OR: Result = LHSv | RHSv; break;
950       case SHL: Result = LHSv << RHSv; break;
951       case SRA: Result = LHSv >> RHSv; break;
952       case SRL: Result = (uint64_t)LHSv >> (uint64_t)RHSv; break;
953       }
954       return IntInit::get(Result);
955     }
956     break;
957   }
958   }
959   return const_cast<BinOpInit *>(this);
960 }
961 
962 Init *BinOpInit::resolveReferences(Resolver &R) const {
963   Init *lhs = LHS->resolveReferences(R);
964   Init *rhs = RHS->resolveReferences(R);
965 
966   if (LHS != lhs || RHS != rhs)
967     return (BinOpInit::get(getOpcode(), lhs, rhs, getType()))
968         ->Fold(R.getCurrentRecord());
969   return const_cast<BinOpInit *>(this);
970 }
971 
972 std::string BinOpInit::getAsString() const {
973   std::string Result;
974   switch (getOpcode()) {
975   case CONCAT: Result = "!con"; break;
976   case ADD: Result = "!add"; break;
977   case AND: Result = "!and"; break;
978   case OR: Result = "!or"; break;
979   case SHL: Result = "!shl"; break;
980   case SRA: Result = "!sra"; break;
981   case SRL: Result = "!srl"; break;
982   case EQ: Result = "!eq"; break;
983   case NE: Result = "!ne"; break;
984   case LE: Result = "!le"; break;
985   case LT: Result = "!lt"; break;
986   case GE: Result = "!ge"; break;
987   case GT: Result = "!gt"; break;
988   case LISTCONCAT: Result = "!listconcat"; break;
989   case STRCONCAT: Result = "!strconcat"; break;
990   }
991   return Result + "(" + LHS->getAsString() + ", " + RHS->getAsString() + ")";
992 }
993 
994 static void
995 ProfileTernOpInit(FoldingSetNodeID &ID, unsigned Opcode, Init *LHS, Init *MHS,
996                   Init *RHS, RecTy *Type) {
997   ID.AddInteger(Opcode);
998   ID.AddPointer(LHS);
999   ID.AddPointer(MHS);
1000   ID.AddPointer(RHS);
1001   ID.AddPointer(Type);
1002 }
1003 
1004 TernOpInit *TernOpInit::get(TernaryOp Opc, Init *LHS, Init *MHS, Init *RHS,
1005                             RecTy *Type) {
1006   static FoldingSet<TernOpInit> ThePool;
1007 
1008   FoldingSetNodeID ID;
1009   ProfileTernOpInit(ID, Opc, LHS, MHS, RHS, Type);
1010 
1011   void *IP = nullptr;
1012   if (TernOpInit *I = ThePool.FindNodeOrInsertPos(ID, IP))
1013     return I;
1014 
1015   TernOpInit *I = new(Allocator) TernOpInit(Opc, LHS, MHS, RHS, Type);
1016   ThePool.InsertNode(I, IP);
1017   return I;
1018 }
1019 
1020 void TernOpInit::Profile(FoldingSetNodeID &ID) const {
1021   ProfileTernOpInit(ID, getOpcode(), getLHS(), getMHS(), getRHS(), getType());
1022 }
1023 
1024 static Init *ForeachApply(Init *LHS, Init *MHSe, Init *RHS, Record *CurRec) {
1025   MapResolver R(CurRec);
1026   R.set(LHS, MHSe);
1027   return RHS->resolveReferences(R);
1028 }
1029 
1030 static Init *ForeachDagApply(Init *LHS, DagInit *MHSd, Init *RHS,
1031                              Record *CurRec) {
1032   bool Change = false;
1033   Init *Val = ForeachApply(LHS, MHSd->getOperator(), RHS, CurRec);
1034   if (Val != MHSd->getOperator())
1035     Change = true;
1036 
1037   SmallVector<std::pair<Init *, StringInit *>, 8> NewArgs;
1038   for (unsigned int i = 0; i < MHSd->getNumArgs(); ++i) {
1039     Init *Arg = MHSd->getArg(i);
1040     Init *NewArg;
1041     StringInit *ArgName = MHSd->getArgName(i);
1042 
1043     if (DagInit *Argd = dyn_cast<DagInit>(Arg))
1044       NewArg = ForeachDagApply(LHS, Argd, RHS, CurRec);
1045     else
1046       NewArg = ForeachApply(LHS, Arg, RHS, CurRec);
1047 
1048     NewArgs.push_back(std::make_pair(NewArg, ArgName));
1049     if (Arg != NewArg)
1050       Change = true;
1051   }
1052 
1053   if (Change)
1054     return DagInit::get(Val, nullptr, NewArgs);
1055   return MHSd;
1056 }
1057 
1058 // Applies RHS to all elements of MHS, using LHS as a temp variable.
1059 static Init *ForeachHelper(Init *LHS, Init *MHS, Init *RHS, RecTy *Type,
1060                            Record *CurRec) {
1061   if (DagInit *MHSd = dyn_cast<DagInit>(MHS))
1062     return ForeachDagApply(LHS, MHSd, RHS, CurRec);
1063 
1064   if (ListInit *MHSl = dyn_cast<ListInit>(MHS)) {
1065     SmallVector<Init *, 8> NewList(MHSl->begin(), MHSl->end());
1066 
1067     for (Init *&Item : NewList) {
1068       Init *NewItem = ForeachApply(LHS, Item, RHS, CurRec);
1069       if (NewItem != Item)
1070         Item = NewItem;
1071     }
1072     return ListInit::get(NewList, cast<ListRecTy>(Type)->getElementType());
1073   }
1074 
1075   return nullptr;
1076 }
1077 
1078 Init *TernOpInit::Fold(Record *CurRec) const {
1079   switch (getOpcode()) {
1080   case SUBST: {
1081     DefInit *LHSd = dyn_cast<DefInit>(LHS);
1082     VarInit *LHSv = dyn_cast<VarInit>(LHS);
1083     StringInit *LHSs = dyn_cast<StringInit>(LHS);
1084 
1085     DefInit *MHSd = dyn_cast<DefInit>(MHS);
1086     VarInit *MHSv = dyn_cast<VarInit>(MHS);
1087     StringInit *MHSs = dyn_cast<StringInit>(MHS);
1088 
1089     DefInit *RHSd = dyn_cast<DefInit>(RHS);
1090     VarInit *RHSv = dyn_cast<VarInit>(RHS);
1091     StringInit *RHSs = dyn_cast<StringInit>(RHS);
1092 
1093     if (LHSd && MHSd && RHSd) {
1094       Record *Val = RHSd->getDef();
1095       if (LHSd->getAsString() == RHSd->getAsString())
1096         Val = MHSd->getDef();
1097       return DefInit::get(Val);
1098     }
1099     if (LHSv && MHSv && RHSv) {
1100       std::string Val = RHSv->getName();
1101       if (LHSv->getAsString() == RHSv->getAsString())
1102         Val = MHSv->getName();
1103       return VarInit::get(Val, getType());
1104     }
1105     if (LHSs && MHSs && RHSs) {
1106       std::string Val = RHSs->getValue();
1107 
1108       std::string::size_type found;
1109       std::string::size_type idx = 0;
1110       while (true) {
1111         found = Val.find(LHSs->getValue(), idx);
1112         if (found == std::string::npos)
1113           break;
1114         Val.replace(found, LHSs->getValue().size(), MHSs->getValue());
1115         idx = found + MHSs->getValue().size();
1116       }
1117 
1118       return StringInit::get(Val);
1119     }
1120     break;
1121   }
1122 
1123   case FOREACH: {
1124     if (Init *Result = ForeachHelper(LHS, MHS, RHS, getType(), CurRec))
1125       return Result;
1126     break;
1127   }
1128 
1129   case IF: {
1130     if (IntInit *LHSi = dyn_cast_or_null<IntInit>(
1131                             LHS->convertInitializerTo(IntRecTy::get()))) {
1132       if (LHSi->getValue())
1133         return MHS;
1134       return RHS;
1135     }
1136     break;
1137   }
1138 
1139   case DAG: {
1140     ListInit *MHSl = dyn_cast<ListInit>(MHS);
1141     ListInit *RHSl = dyn_cast<ListInit>(RHS);
1142     bool MHSok = MHSl || isa<UnsetInit>(MHS);
1143     bool RHSok = RHSl || isa<UnsetInit>(RHS);
1144 
1145     if (isa<UnsetInit>(MHS) && isa<UnsetInit>(RHS))
1146       break; // Typically prevented by the parser, but might happen with template args
1147 
1148     if (MHSok && RHSok && (!MHSl || !RHSl || MHSl->size() == RHSl->size())) {
1149       SmallVector<std::pair<Init *, StringInit *>, 8> Children;
1150       unsigned Size = MHSl ? MHSl->size() : RHSl->size();
1151       for (unsigned i = 0; i != Size; ++i) {
1152         Init *Node = MHSl ? MHSl->getElement(i) : UnsetInit::get();
1153         Init *Name = RHSl ? RHSl->getElement(i) : UnsetInit::get();
1154         if (!isa<StringInit>(Name) && !isa<UnsetInit>(Name))
1155           return const_cast<TernOpInit *>(this);
1156         Children.emplace_back(Node, dyn_cast<StringInit>(Name));
1157       }
1158       return DagInit::get(LHS, nullptr, Children);
1159     }
1160     break;
1161   }
1162   }
1163 
1164   return const_cast<TernOpInit *>(this);
1165 }
1166 
1167 Init *TernOpInit::resolveReferences(Resolver &R) const {
1168   Init *lhs = LHS->resolveReferences(R);
1169 
1170   if (getOpcode() == IF && lhs != LHS) {
1171     if (IntInit *Value = dyn_cast_or_null<IntInit>(
1172                              lhs->convertInitializerTo(IntRecTy::get()))) {
1173       // Short-circuit
1174       if (Value->getValue())
1175         return MHS->resolveReferences(R);
1176       return RHS->resolveReferences(R);
1177     }
1178   }
1179 
1180   Init *mhs = MHS->resolveReferences(R);
1181   Init *rhs;
1182 
1183   if (getOpcode() == FOREACH) {
1184     ShadowResolver SR(R);
1185     SR.addShadow(lhs);
1186     rhs = RHS->resolveReferences(SR);
1187   } else {
1188     rhs = RHS->resolveReferences(R);
1189   }
1190 
1191   if (LHS != lhs || MHS != mhs || RHS != rhs)
1192     return (TernOpInit::get(getOpcode(), lhs, mhs, rhs, getType()))
1193         ->Fold(R.getCurrentRecord());
1194   return const_cast<TernOpInit *>(this);
1195 }
1196 
1197 std::string TernOpInit::getAsString() const {
1198   std::string Result;
1199   bool UnquotedLHS = false;
1200   switch (getOpcode()) {
1201   case SUBST: Result = "!subst"; break;
1202   case FOREACH: Result = "!foreach"; UnquotedLHS = true; break;
1203   case IF: Result = "!if"; break;
1204   case DAG: Result = "!dag"; break;
1205   }
1206   return (Result + "(" +
1207           (UnquotedLHS ? LHS->getAsUnquotedString() : LHS->getAsString()) +
1208           ", " + MHS->getAsString() + ", " + RHS->getAsString() + ")");
1209 }
1210 
1211 static void ProfileFoldOpInit(FoldingSetNodeID &ID, Init *A, Init *B,
1212                               Init *Start, Init *List, Init *Expr,
1213                               RecTy *Type) {
1214   ID.AddPointer(Start);
1215   ID.AddPointer(List);
1216   ID.AddPointer(A);
1217   ID.AddPointer(B);
1218   ID.AddPointer(Expr);
1219   ID.AddPointer(Type);
1220 }
1221 
1222 FoldOpInit *FoldOpInit::get(Init *Start, Init *List, Init *A, Init *B,
1223                             Init *Expr, RecTy *Type) {
1224   static FoldingSet<FoldOpInit> ThePool;
1225 
1226   FoldingSetNodeID ID;
1227   ProfileFoldOpInit(ID, Start, List, A, B, Expr, Type);
1228 
1229   void *IP = nullptr;
1230   if (FoldOpInit *I = ThePool.FindNodeOrInsertPos(ID, IP))
1231     return I;
1232 
1233   FoldOpInit *I = new (Allocator) FoldOpInit(Start, List, A, B, Expr, Type);
1234   ThePool.InsertNode(I, IP);
1235   return I;
1236 }
1237 
1238 void FoldOpInit::Profile(FoldingSetNodeID &ID) const {
1239   ProfileFoldOpInit(ID, Start, List, A, B, Expr, getType());
1240 }
1241 
1242 Init *FoldOpInit::Fold(Record *CurRec) const {
1243   if (ListInit *LI = dyn_cast<ListInit>(List)) {
1244     Init *Accum = Start;
1245     for (Init *Elt : *LI) {
1246       MapResolver R(CurRec);
1247       R.set(A, Accum);
1248       R.set(B, Elt);
1249       Accum = Expr->resolveReferences(R);
1250     }
1251     return Accum;
1252   }
1253   return const_cast<FoldOpInit *>(this);
1254 }
1255 
1256 Init *FoldOpInit::resolveReferences(Resolver &R) const {
1257   Init *NewStart = Start->resolveReferences(R);
1258   Init *NewList = List->resolveReferences(R);
1259   ShadowResolver SR(R);
1260   SR.addShadow(A);
1261   SR.addShadow(B);
1262   Init *NewExpr = Expr->resolveReferences(SR);
1263 
1264   if (Start == NewStart && List == NewList && Expr == NewExpr)
1265     return const_cast<FoldOpInit *>(this);
1266 
1267   return get(NewStart, NewList, A, B, NewExpr, getType())
1268       ->Fold(R.getCurrentRecord());
1269 }
1270 
1271 Init *FoldOpInit::getBit(unsigned Bit) const {
1272   return VarBitInit::get(const_cast<FoldOpInit *>(this), Bit);
1273 }
1274 
1275 std::string FoldOpInit::getAsString() const {
1276   return (Twine("!foldl(") + Start->getAsString() + ", " + List->getAsString() +
1277           ", " + A->getAsUnquotedString() + ", " + B->getAsUnquotedString() +
1278           ", " + Expr->getAsString() + ")")
1279       .str();
1280 }
1281 
1282 static void ProfileIsAOpInit(FoldingSetNodeID &ID, RecTy *CheckType,
1283                              Init *Expr) {
1284   ID.AddPointer(CheckType);
1285   ID.AddPointer(Expr);
1286 }
1287 
1288 IsAOpInit *IsAOpInit::get(RecTy *CheckType, Init *Expr) {
1289   static FoldingSet<IsAOpInit> ThePool;
1290 
1291   FoldingSetNodeID ID;
1292   ProfileIsAOpInit(ID, CheckType, Expr);
1293 
1294   void *IP = nullptr;
1295   if (IsAOpInit *I = ThePool.FindNodeOrInsertPos(ID, IP))
1296     return I;
1297 
1298   IsAOpInit *I = new (Allocator) IsAOpInit(CheckType, Expr);
1299   ThePool.InsertNode(I, IP);
1300   return I;
1301 }
1302 
1303 void IsAOpInit::Profile(FoldingSetNodeID &ID) const {
1304   ProfileIsAOpInit(ID, CheckType, Expr);
1305 }
1306 
1307 Init *IsAOpInit::Fold() const {
1308   if (TypedInit *TI = dyn_cast<TypedInit>(Expr)) {
1309     // Is the expression type known to be (a subclass of) the desired type?
1310     if (TI->getType()->typeIsConvertibleTo(CheckType))
1311       return IntInit::get(1);
1312 
1313     if (isa<RecordRecTy>(CheckType)) {
1314       // If the target type is not a subclass of the expression type, or if
1315       // the expression has fully resolved to a record, we know that it can't
1316       // be of the required type.
1317       if (!CheckType->typeIsConvertibleTo(TI->getType()) || isa<DefInit>(Expr))
1318         return IntInit::get(0);
1319     } else {
1320       // We treat non-record types as not castable.
1321       return IntInit::get(0);
1322     }
1323   }
1324   return const_cast<IsAOpInit *>(this);
1325 }
1326 
1327 Init *IsAOpInit::resolveReferences(Resolver &R) const {
1328   Init *NewExpr = Expr->resolveReferences(R);
1329   if (Expr != NewExpr)
1330     return get(CheckType, NewExpr)->Fold();
1331   return const_cast<IsAOpInit *>(this);
1332 }
1333 
1334 Init *IsAOpInit::getBit(unsigned Bit) const {
1335   return VarBitInit::get(const_cast<IsAOpInit *>(this), Bit);
1336 }
1337 
1338 std::string IsAOpInit::getAsString() const {
1339   return (Twine("!isa<") + CheckType->getAsString() + ">(" +
1340           Expr->getAsString() + ")")
1341       .str();
1342 }
1343 
1344 RecTy *TypedInit::getFieldType(StringInit *FieldName) const {
1345   if (RecordRecTy *RecordType = dyn_cast<RecordRecTy>(getType())) {
1346     for (Record *Rec : RecordType->getClasses()) {
1347       if (RecordVal *Field = Rec->getValue(FieldName))
1348         return Field->getType();
1349     }
1350   }
1351   return nullptr;
1352 }
1353 
1354 Init *
1355 TypedInit::convertInitializerTo(RecTy *Ty) const {
1356   if (getType() == Ty || getType()->typeIsA(Ty))
1357     return const_cast<TypedInit *>(this);
1358 
1359   if (isa<BitRecTy>(getType()) && isa<BitsRecTy>(Ty) &&
1360       cast<BitsRecTy>(Ty)->getNumBits() == 1)
1361     return BitsInit::get({const_cast<TypedInit *>(this)});
1362 
1363   return nullptr;
1364 }
1365 
1366 Init *TypedInit::convertInitializerBitRange(ArrayRef<unsigned> Bits) const {
1367   BitsRecTy *T = dyn_cast<BitsRecTy>(getType());
1368   if (!T) return nullptr;  // Cannot subscript a non-bits variable.
1369   unsigned NumBits = T->getNumBits();
1370 
1371   SmallVector<Init *, 16> NewBits;
1372   NewBits.reserve(Bits.size());
1373   for (unsigned Bit : Bits) {
1374     if (Bit >= NumBits)
1375       return nullptr;
1376 
1377     NewBits.push_back(VarBitInit::get(const_cast<TypedInit *>(this), Bit));
1378   }
1379   return BitsInit::get(NewBits);
1380 }
1381 
1382 Init *TypedInit::getCastTo(RecTy *Ty) const {
1383   // Handle the common case quickly
1384   if (getType() == Ty || getType()->typeIsA(Ty))
1385     return const_cast<TypedInit *>(this);
1386 
1387   if (Init *Converted = convertInitializerTo(Ty)) {
1388     assert(!isa<TypedInit>(Converted) ||
1389            cast<TypedInit>(Converted)->getType()->typeIsA(Ty));
1390     return Converted;
1391   }
1392 
1393   if (!getType()->typeIsConvertibleTo(Ty))
1394     return nullptr;
1395 
1396   return UnOpInit::get(UnOpInit::CAST, const_cast<TypedInit *>(this), Ty)
1397       ->Fold(nullptr);
1398 }
1399 
1400 Init *TypedInit::convertInitListSlice(ArrayRef<unsigned> Elements) const {
1401   ListRecTy *T = dyn_cast<ListRecTy>(getType());
1402   if (!T) return nullptr;  // Cannot subscript a non-list variable.
1403 
1404   if (Elements.size() == 1)
1405     return VarListElementInit::get(const_cast<TypedInit *>(this), Elements[0]);
1406 
1407   SmallVector<Init*, 8> ListInits;
1408   ListInits.reserve(Elements.size());
1409   for (unsigned Element : Elements)
1410     ListInits.push_back(VarListElementInit::get(const_cast<TypedInit *>(this),
1411                                                 Element));
1412   return ListInit::get(ListInits, T->getElementType());
1413 }
1414 
1415 
1416 VarInit *VarInit::get(StringRef VN, RecTy *T) {
1417   Init *Value = StringInit::get(VN);
1418   return VarInit::get(Value, T);
1419 }
1420 
1421 VarInit *VarInit::get(Init *VN, RecTy *T) {
1422   using Key = std::pair<RecTy *, Init *>;
1423   static DenseMap<Key, VarInit*> ThePool;
1424 
1425   Key TheKey(std::make_pair(T, VN));
1426 
1427   VarInit *&I = ThePool[TheKey];
1428   if (!I)
1429     I = new(Allocator) VarInit(VN, T);
1430   return I;
1431 }
1432 
1433 StringRef VarInit::getName() const {
1434   StringInit *NameString = cast<StringInit>(getNameInit());
1435   return NameString->getValue();
1436 }
1437 
1438 Init *VarInit::getBit(unsigned Bit) const {
1439   if (getType() == BitRecTy::get())
1440     return const_cast<VarInit*>(this);
1441   return VarBitInit::get(const_cast<VarInit*>(this), Bit);
1442 }
1443 
1444 Init *VarInit::resolveReferences(Resolver &R) const {
1445   if (Init *Val = R.resolve(VarName))
1446     return Val;
1447   return const_cast<VarInit *>(this);
1448 }
1449 
1450 VarBitInit *VarBitInit::get(TypedInit *T, unsigned B) {
1451   using Key = std::pair<TypedInit *, unsigned>;
1452   static DenseMap<Key, VarBitInit*> ThePool;
1453 
1454   Key TheKey(std::make_pair(T, B));
1455 
1456   VarBitInit *&I = ThePool[TheKey];
1457   if (!I)
1458     I = new(Allocator) VarBitInit(T, B);
1459   return I;
1460 }
1461 
1462 std::string VarBitInit::getAsString() const {
1463   return TI->getAsString() + "{" + utostr(Bit) + "}";
1464 }
1465 
1466 Init *VarBitInit::resolveReferences(Resolver &R) const {
1467   Init *I = TI->resolveReferences(R);
1468   if (TI != I)
1469     return I->getBit(getBitNum());
1470 
1471   return const_cast<VarBitInit*>(this);
1472 }
1473 
1474 VarListElementInit *VarListElementInit::get(TypedInit *T,
1475                                             unsigned E) {
1476   using Key = std::pair<TypedInit *, unsigned>;
1477   static DenseMap<Key, VarListElementInit*> ThePool;
1478 
1479   Key TheKey(std::make_pair(T, E));
1480 
1481   VarListElementInit *&I = ThePool[TheKey];
1482   if (!I) I = new(Allocator) VarListElementInit(T, E);
1483   return I;
1484 }
1485 
1486 std::string VarListElementInit::getAsString() const {
1487   return TI->getAsString() + "[" + utostr(Element) + "]";
1488 }
1489 
1490 Init *VarListElementInit::resolveReferences(Resolver &R) const {
1491   Init *NewTI = TI->resolveReferences(R);
1492   if (ListInit *List = dyn_cast<ListInit>(NewTI)) {
1493     // Leave out-of-bounds array references as-is. This can happen without
1494     // being an error, e.g. in the untaken "branch" of an !if expression.
1495     if (getElementNum() < List->size())
1496       return List->getElement(getElementNum());
1497   }
1498   if (NewTI != TI && isa<TypedInit>(NewTI))
1499     return VarListElementInit::get(cast<TypedInit>(NewTI), getElementNum());
1500   return const_cast<VarListElementInit *>(this);
1501 }
1502 
1503 Init *VarListElementInit::getBit(unsigned Bit) const {
1504   if (getType() == BitRecTy::get())
1505     return const_cast<VarListElementInit*>(this);
1506   return VarBitInit::get(const_cast<VarListElementInit*>(this), Bit);
1507 }
1508 
1509 DefInit::DefInit(Record *D)
1510     : TypedInit(IK_DefInit, D->getType()), Def(D) {}
1511 
1512 DefInit *DefInit::get(Record *R) {
1513   return R->getDefInit();
1514 }
1515 
1516 Init *DefInit::convertInitializerTo(RecTy *Ty) const {
1517   if (auto *RRT = dyn_cast<RecordRecTy>(Ty))
1518     if (getType()->typeIsConvertibleTo(RRT))
1519       return const_cast<DefInit *>(this);
1520   return nullptr;
1521 }
1522 
1523 RecTy *DefInit::getFieldType(StringInit *FieldName) const {
1524   if (const RecordVal *RV = Def->getValue(FieldName))
1525     return RV->getType();
1526   return nullptr;
1527 }
1528 
1529 std::string DefInit::getAsString() const {
1530   return Def->getName();
1531 }
1532 
1533 static void ProfileVarDefInit(FoldingSetNodeID &ID,
1534                               Record *Class,
1535                               ArrayRef<Init *> Args) {
1536   ID.AddInteger(Args.size());
1537   ID.AddPointer(Class);
1538 
1539   for (Init *I : Args)
1540     ID.AddPointer(I);
1541 }
1542 
1543 VarDefInit *VarDefInit::get(Record *Class, ArrayRef<Init *> Args) {
1544   static FoldingSet<VarDefInit> ThePool;
1545 
1546   FoldingSetNodeID ID;
1547   ProfileVarDefInit(ID, Class, Args);
1548 
1549   void *IP = nullptr;
1550   if (VarDefInit *I = ThePool.FindNodeOrInsertPos(ID, IP))
1551     return I;
1552 
1553   void *Mem = Allocator.Allocate(totalSizeToAlloc<Init *>(Args.size()),
1554                                  alignof(VarDefInit));
1555   VarDefInit *I = new(Mem) VarDefInit(Class, Args.size());
1556   std::uninitialized_copy(Args.begin(), Args.end(),
1557                           I->getTrailingObjects<Init *>());
1558   ThePool.InsertNode(I, IP);
1559   return I;
1560 }
1561 
1562 void VarDefInit::Profile(FoldingSetNodeID &ID) const {
1563   ProfileVarDefInit(ID, Class, args());
1564 }
1565 
1566 DefInit *VarDefInit::instantiate() {
1567   if (!Def) {
1568     RecordKeeper &Records = Class->getRecords();
1569     auto NewRecOwner = make_unique<Record>(Records.getNewAnonymousName(),
1570                                            Class->getLoc(), Records,
1571                                            /*IsAnonymous=*/true);
1572     Record *NewRec = NewRecOwner.get();
1573 
1574     // Copy values from class to instance
1575     for (const RecordVal &Val : Class->getValues())
1576       NewRec->addValue(Val);
1577 
1578     // Substitute and resolve template arguments
1579     ArrayRef<Init *> TArgs = Class->getTemplateArgs();
1580     MapResolver R(NewRec);
1581 
1582     for (unsigned i = 0, e = TArgs.size(); i != e; ++i) {
1583       if (i < args_size())
1584         R.set(TArgs[i], getArg(i));
1585       else
1586         R.set(TArgs[i], NewRec->getValue(TArgs[i])->getValue());
1587 
1588       NewRec->removeValue(TArgs[i]);
1589     }
1590 
1591     NewRec->resolveReferences(R);
1592 
1593     // Add superclasses.
1594     ArrayRef<std::pair<Record *, SMRange>> SCs = Class->getSuperClasses();
1595     for (const auto &SCPair : SCs)
1596       NewRec->addSuperClass(SCPair.first, SCPair.second);
1597 
1598     NewRec->addSuperClass(Class,
1599                           SMRange(Class->getLoc().back(),
1600                                   Class->getLoc().back()));
1601 
1602     // Resolve internal references and store in record keeper
1603     NewRec->resolveReferences();
1604     Records.addDef(std::move(NewRecOwner));
1605 
1606     Def = DefInit::get(NewRec);
1607   }
1608 
1609   return Def;
1610 }
1611 
1612 Init *VarDefInit::resolveReferences(Resolver &R) const {
1613   TrackUnresolvedResolver UR(&R);
1614   bool Changed = false;
1615   SmallVector<Init *, 8> NewArgs;
1616   NewArgs.reserve(args_size());
1617 
1618   for (Init *Arg : args()) {
1619     Init *NewArg = Arg->resolveReferences(UR);
1620     NewArgs.push_back(NewArg);
1621     Changed |= NewArg != Arg;
1622   }
1623 
1624   if (Changed) {
1625     auto New = VarDefInit::get(Class, NewArgs);
1626     if (!UR.foundUnresolved())
1627       return New->instantiate();
1628     return New;
1629   }
1630   return const_cast<VarDefInit *>(this);
1631 }
1632 
1633 Init *VarDefInit::Fold() const {
1634   if (Def)
1635     return Def;
1636 
1637   TrackUnresolvedResolver R;
1638   for (Init *Arg : args())
1639     Arg->resolveReferences(R);
1640 
1641   if (!R.foundUnresolved())
1642     return const_cast<VarDefInit *>(this)->instantiate();
1643   return const_cast<VarDefInit *>(this);
1644 }
1645 
1646 std::string VarDefInit::getAsString() const {
1647   std::string Result = Class->getNameInitAsString() + "<";
1648   const char *sep = "";
1649   for (Init *Arg : args()) {
1650     Result += sep;
1651     sep = ", ";
1652     Result += Arg->getAsString();
1653   }
1654   return Result + ">";
1655 }
1656 
1657 FieldInit *FieldInit::get(Init *R, StringInit *FN) {
1658   using Key = std::pair<Init *, StringInit *>;
1659   static DenseMap<Key, FieldInit*> ThePool;
1660 
1661   Key TheKey(std::make_pair(R, FN));
1662 
1663   FieldInit *&I = ThePool[TheKey];
1664   if (!I) I = new(Allocator) FieldInit(R, FN);
1665   return I;
1666 }
1667 
1668 Init *FieldInit::getBit(unsigned Bit) const {
1669   if (getType() == BitRecTy::get())
1670     return const_cast<FieldInit*>(this);
1671   return VarBitInit::get(const_cast<FieldInit*>(this), Bit);
1672 }
1673 
1674 Init *FieldInit::resolveReferences(Resolver &R) const {
1675   Init *NewRec = Rec->resolveReferences(R);
1676   if (NewRec != Rec)
1677     return FieldInit::get(NewRec, FieldName)->Fold(R.getCurrentRecord());
1678   return const_cast<FieldInit *>(this);
1679 }
1680 
1681 Init *FieldInit::Fold(Record *CurRec) const {
1682   if (DefInit *DI = dyn_cast<DefInit>(Rec)) {
1683     Record *Def = DI->getDef();
1684     if (Def == CurRec)
1685       PrintFatalError(CurRec->getLoc(),
1686                       Twine("Attempting to access field '") +
1687                       FieldName->getAsUnquotedString() + "' of '" +
1688                       Rec->getAsString() + "' is a forbidden self-reference");
1689     Init *FieldVal = Def->getValue(FieldName)->getValue();
1690     if (FieldVal->isComplete())
1691       return FieldVal;
1692   }
1693   return const_cast<FieldInit *>(this);
1694 }
1695 
1696 static void ProfileDagInit(FoldingSetNodeID &ID, Init *V, StringInit *VN,
1697                            ArrayRef<Init *> ArgRange,
1698                            ArrayRef<StringInit *> NameRange) {
1699   ID.AddPointer(V);
1700   ID.AddPointer(VN);
1701 
1702   ArrayRef<Init *>::iterator Arg = ArgRange.begin();
1703   ArrayRef<StringInit *>::iterator Name = NameRange.begin();
1704   while (Arg != ArgRange.end()) {
1705     assert(Name != NameRange.end() && "Arg name underflow!");
1706     ID.AddPointer(*Arg++);
1707     ID.AddPointer(*Name++);
1708   }
1709   assert(Name == NameRange.end() && "Arg name overflow!");
1710 }
1711 
1712 DagInit *
1713 DagInit::get(Init *V, StringInit *VN, ArrayRef<Init *> ArgRange,
1714              ArrayRef<StringInit *> NameRange) {
1715   static FoldingSet<DagInit> ThePool;
1716 
1717   FoldingSetNodeID ID;
1718   ProfileDagInit(ID, V, VN, ArgRange, NameRange);
1719 
1720   void *IP = nullptr;
1721   if (DagInit *I = ThePool.FindNodeOrInsertPos(ID, IP))
1722     return I;
1723 
1724   void *Mem = Allocator.Allocate(totalSizeToAlloc<Init *, StringInit *>(ArgRange.size(), NameRange.size()), alignof(BitsInit));
1725   DagInit *I = new(Mem) DagInit(V, VN, ArgRange.size(), NameRange.size());
1726   std::uninitialized_copy(ArgRange.begin(), ArgRange.end(),
1727                           I->getTrailingObjects<Init *>());
1728   std::uninitialized_copy(NameRange.begin(), NameRange.end(),
1729                           I->getTrailingObjects<StringInit *>());
1730   ThePool.InsertNode(I, IP);
1731   return I;
1732 }
1733 
1734 DagInit *
1735 DagInit::get(Init *V, StringInit *VN,
1736              ArrayRef<std::pair<Init*, StringInit*>> args) {
1737   SmallVector<Init *, 8> Args;
1738   SmallVector<StringInit *, 8> Names;
1739 
1740   for (const auto &Arg : args) {
1741     Args.push_back(Arg.first);
1742     Names.push_back(Arg.second);
1743   }
1744 
1745   return DagInit::get(V, VN, Args, Names);
1746 }
1747 
1748 void DagInit::Profile(FoldingSetNodeID &ID) const {
1749   ProfileDagInit(ID, Val, ValName, makeArrayRef(getTrailingObjects<Init *>(), NumArgs), makeArrayRef(getTrailingObjects<StringInit *>(), NumArgNames));
1750 }
1751 
1752 Init *DagInit::resolveReferences(Resolver &R) const {
1753   SmallVector<Init*, 8> NewArgs;
1754   NewArgs.reserve(arg_size());
1755   bool ArgsChanged = false;
1756   for (const Init *Arg : getArgs()) {
1757     Init *NewArg = Arg->resolveReferences(R);
1758     NewArgs.push_back(NewArg);
1759     ArgsChanged |= NewArg != Arg;
1760   }
1761 
1762   Init *Op = Val->resolveReferences(R);
1763   if (Op != Val || ArgsChanged)
1764     return DagInit::get(Op, ValName, NewArgs, getArgNames());
1765 
1766   return const_cast<DagInit *>(this);
1767 }
1768 
1769 bool DagInit::isConcrete() const {
1770   if (!Val->isConcrete())
1771     return false;
1772   for (const Init *Elt : getArgs()) {
1773     if (!Elt->isConcrete())
1774       return false;
1775   }
1776   return true;
1777 }
1778 
1779 std::string DagInit::getAsString() const {
1780   std::string Result = "(" + Val->getAsString();
1781   if (ValName)
1782     Result += ":" + ValName->getAsUnquotedString();
1783   if (!arg_empty()) {
1784     Result += " " + getArg(0)->getAsString();
1785     if (getArgName(0)) Result += ":$" + getArgName(0)->getAsUnquotedString();
1786     for (unsigned i = 1, e = getNumArgs(); i != e; ++i) {
1787       Result += ", " + getArg(i)->getAsString();
1788       if (getArgName(i)) Result += ":$" + getArgName(i)->getAsUnquotedString();
1789     }
1790   }
1791   return Result + ")";
1792 }
1793 
1794 //===----------------------------------------------------------------------===//
1795 //    Other implementations
1796 //===----------------------------------------------------------------------===//
1797 
1798 RecordVal::RecordVal(Init *N, RecTy *T, bool P)
1799   : Name(N), TyAndPrefix(T, P) {
1800   setValue(UnsetInit::get());
1801   assert(Value && "Cannot create unset value for current type!");
1802 }
1803 
1804 StringRef RecordVal::getName() const {
1805   return cast<StringInit>(getNameInit())->getValue();
1806 }
1807 
1808 bool RecordVal::setValue(Init *V) {
1809   if (V) {
1810     Value = V->getCastTo(getType());
1811     if (Value) {
1812       assert(!isa<TypedInit>(Value) ||
1813              cast<TypedInit>(Value)->getType()->typeIsA(getType()));
1814       if (BitsRecTy *BTy = dyn_cast<BitsRecTy>(getType())) {
1815         if (!isa<BitsInit>(Value)) {
1816           SmallVector<Init *, 64> Bits;
1817           Bits.reserve(BTy->getNumBits());
1818           for (unsigned i = 0, e = BTy->getNumBits(); i < e; ++i)
1819             Bits.push_back(Value->getBit(i));
1820           Value = BitsInit::get(Bits);
1821         }
1822       }
1823     }
1824     return Value == nullptr;
1825   }
1826   Value = nullptr;
1827   return false;
1828 }
1829 
1830 #if !defined(NDEBUG) || defined(LLVM_ENABLE_DUMP)
1831 LLVM_DUMP_METHOD void RecordVal::dump() const { errs() << *this; }
1832 #endif
1833 
1834 void RecordVal::print(raw_ostream &OS, bool PrintSem) const {
1835   if (getPrefix()) OS << "field ";
1836   OS << *getType() << " " << getNameInitAsString();
1837 
1838   if (getValue())
1839     OS << " = " << *getValue();
1840 
1841   if (PrintSem) OS << ";\n";
1842 }
1843 
1844 unsigned Record::LastID = 0;
1845 
1846 void Record::checkName() {
1847   // Ensure the record name has string type.
1848   const TypedInit *TypedName = cast<const TypedInit>(Name);
1849   if (!isa<StringRecTy>(TypedName->getType()))
1850     PrintFatalError(getLoc(), Twine("Record name '") + Name->getAsString() +
1851                                   "' is not a string!");
1852 }
1853 
1854 RecordRecTy *Record::getType() {
1855   SmallVector<Record *, 4> DirectSCs;
1856   getDirectSuperClasses(DirectSCs);
1857   return RecordRecTy::get(DirectSCs);
1858 }
1859 
1860 DefInit *Record::getDefInit() {
1861   if (!TheInit)
1862     TheInit = new(Allocator) DefInit(this);
1863   return TheInit;
1864 }
1865 
1866 void Record::setName(Init *NewName) {
1867   Name = NewName;
1868   checkName();
1869   // DO NOT resolve record values to the name at this point because
1870   // there might be default values for arguments of this def.  Those
1871   // arguments might not have been resolved yet so we don't want to
1872   // prematurely assume values for those arguments were not passed to
1873   // this def.
1874   //
1875   // Nonetheless, it may be that some of this Record's values
1876   // reference the record name.  Indeed, the reason for having the
1877   // record name be an Init is to provide this flexibility.  The extra
1878   // resolve steps after completely instantiating defs takes care of
1879   // this.  See TGParser::ParseDef and TGParser::ParseDefm.
1880 }
1881 
1882 void Record::getDirectSuperClasses(SmallVectorImpl<Record *> &Classes) const {
1883   ArrayRef<std::pair<Record *, SMRange>> SCs = getSuperClasses();
1884   while (!SCs.empty()) {
1885     // Superclasses are in reverse preorder, so 'back' is a direct superclass,
1886     // and its transitive superclasses are directly preceding it.
1887     Record *SC = SCs.back().first;
1888     SCs = SCs.drop_back(1 + SC->getSuperClasses().size());
1889     Classes.push_back(SC);
1890   }
1891 }
1892 
1893 void Record::resolveReferences(Resolver &R, const RecordVal *SkipVal) {
1894   for (RecordVal &Value : Values) {
1895     if (SkipVal == &Value) // Skip resolve the same field as the given one
1896       continue;
1897     if (Init *V = Value.getValue()) {
1898       Init *VR = V->resolveReferences(R);
1899       if (Value.setValue(VR)) {
1900         std::string Type;
1901         if (TypedInit *VRT = dyn_cast<TypedInit>(VR))
1902           Type =
1903               (Twine("of type '") + VRT->getType()->getAsString() + "' ").str();
1904         PrintFatalError(getLoc(), Twine("Invalid value ") + Type +
1905                                       "is found when setting '" +
1906                                       Value.getNameInitAsString() +
1907                                       "' of type '" +
1908                                       Value.getType()->getAsString() +
1909                                       "' after resolving references: " +
1910                                       VR->getAsUnquotedString() + "\n");
1911       }
1912     }
1913   }
1914   Init *OldName = getNameInit();
1915   Init *NewName = Name->resolveReferences(R);
1916   if (NewName != OldName) {
1917     // Re-register with RecordKeeper.
1918     setName(NewName);
1919   }
1920 }
1921 
1922 void Record::resolveReferences() {
1923   RecordResolver R(*this);
1924   R.setFinal(true);
1925   resolveReferences(R);
1926 }
1927 
1928 void Record::resolveReferencesTo(const RecordVal *RV) {
1929   RecordValResolver R(*this, RV);
1930   resolveReferences(R, RV);
1931 }
1932 
1933 #if !defined(NDEBUG) || defined(LLVM_ENABLE_DUMP)
1934 LLVM_DUMP_METHOD void Record::dump() const { errs() << *this; }
1935 #endif
1936 
1937 raw_ostream &llvm::operator<<(raw_ostream &OS, const Record &R) {
1938   OS << R.getNameInitAsString();
1939 
1940   ArrayRef<Init *> TArgs = R.getTemplateArgs();
1941   if (!TArgs.empty()) {
1942     OS << "<";
1943     bool NeedComma = false;
1944     for (const Init *TA : TArgs) {
1945       if (NeedComma) OS << ", ";
1946       NeedComma = true;
1947       const RecordVal *RV = R.getValue(TA);
1948       assert(RV && "Template argument record not found??");
1949       RV->print(OS, false);
1950     }
1951     OS << ">";
1952   }
1953 
1954   OS << " {";
1955   ArrayRef<std::pair<Record *, SMRange>> SC = R.getSuperClasses();
1956   if (!SC.empty()) {
1957     OS << "\t//";
1958     for (const auto &SuperPair : SC)
1959       OS << " " << SuperPair.first->getNameInitAsString();
1960   }
1961   OS << "\n";
1962 
1963   for (const RecordVal &Val : R.getValues())
1964     if (Val.getPrefix() && !R.isTemplateArg(Val.getNameInit()))
1965       OS << Val;
1966   for (const RecordVal &Val : R.getValues())
1967     if (!Val.getPrefix() && !R.isTemplateArg(Val.getNameInit()))
1968       OS << Val;
1969 
1970   return OS << "}\n";
1971 }
1972 
1973 Init *Record::getValueInit(StringRef FieldName) const {
1974   const RecordVal *R = getValue(FieldName);
1975   if (!R || !R->getValue())
1976     PrintFatalError(getLoc(), "Record `" + getName() +
1977       "' does not have a field named `" + FieldName + "'!\n");
1978   return R->getValue();
1979 }
1980 
1981 StringRef Record::getValueAsString(StringRef FieldName) const {
1982   const RecordVal *R = getValue(FieldName);
1983   if (!R || !R->getValue())
1984     PrintFatalError(getLoc(), "Record `" + getName() +
1985       "' does not have a field named `" + FieldName + "'!\n");
1986 
1987   if (StringInit *SI = dyn_cast<StringInit>(R->getValue()))
1988     return SI->getValue();
1989   if (CodeInit *CI = dyn_cast<CodeInit>(R->getValue()))
1990     return CI->getValue();
1991 
1992   PrintFatalError(getLoc(), "Record `" + getName() + "', field `" +
1993     FieldName + "' does not have a string initializer!");
1994 }
1995 
1996 BitsInit *Record::getValueAsBitsInit(StringRef FieldName) const {
1997   const RecordVal *R = getValue(FieldName);
1998   if (!R || !R->getValue())
1999     PrintFatalError(getLoc(), "Record `" + getName() +
2000       "' does not have a field named `" + FieldName + "'!\n");
2001 
2002   if (BitsInit *BI = dyn_cast<BitsInit>(R->getValue()))
2003     return BI;
2004   PrintFatalError(getLoc(), "Record `" + getName() + "', field `" +
2005     FieldName + "' does not have a BitsInit initializer!");
2006 }
2007 
2008 ListInit *Record::getValueAsListInit(StringRef FieldName) const {
2009   const RecordVal *R = getValue(FieldName);
2010   if (!R || !R->getValue())
2011     PrintFatalError(getLoc(), "Record `" + getName() +
2012       "' does not have a field named `" + FieldName + "'!\n");
2013 
2014   if (ListInit *LI = dyn_cast<ListInit>(R->getValue()))
2015     return LI;
2016   PrintFatalError(getLoc(), "Record `" + getName() + "', field `" +
2017     FieldName + "' does not have a list initializer!");
2018 }
2019 
2020 std::vector<Record*>
2021 Record::getValueAsListOfDefs(StringRef FieldName) const {
2022   ListInit *List = getValueAsListInit(FieldName);
2023   std::vector<Record*> Defs;
2024   for (Init *I : List->getValues()) {
2025     if (DefInit *DI = dyn_cast<DefInit>(I))
2026       Defs.push_back(DI->getDef());
2027     else
2028       PrintFatalError(getLoc(), "Record `" + getName() + "', field `" +
2029         FieldName + "' list is not entirely DefInit!");
2030   }
2031   return Defs;
2032 }
2033 
2034 int64_t Record::getValueAsInt(StringRef FieldName) const {
2035   const RecordVal *R = getValue(FieldName);
2036   if (!R || !R->getValue())
2037     PrintFatalError(getLoc(), "Record `" + getName() +
2038       "' does not have a field named `" + FieldName + "'!\n");
2039 
2040   if (IntInit *II = dyn_cast<IntInit>(R->getValue()))
2041     return II->getValue();
2042   PrintFatalError(getLoc(), Twine("Record `") + getName() + "', field `" +
2043                                 FieldName +
2044                                 "' does not have an int initializer: " +
2045                                 R->getValue()->getAsString());
2046 }
2047 
2048 std::vector<int64_t>
2049 Record::getValueAsListOfInts(StringRef FieldName) const {
2050   ListInit *List = getValueAsListInit(FieldName);
2051   std::vector<int64_t> Ints;
2052   for (Init *I : List->getValues()) {
2053     if (IntInit *II = dyn_cast<IntInit>(I))
2054       Ints.push_back(II->getValue());
2055     else
2056       PrintFatalError(getLoc(),
2057                       Twine("Record `") + getName() + "', field `" + FieldName +
2058                           "' does not have a list of ints initializer: " +
2059                           I->getAsString());
2060   }
2061   return Ints;
2062 }
2063 
2064 std::vector<StringRef>
2065 Record::getValueAsListOfStrings(StringRef FieldName) const {
2066   ListInit *List = getValueAsListInit(FieldName);
2067   std::vector<StringRef> Strings;
2068   for (Init *I : List->getValues()) {
2069     if (StringInit *SI = dyn_cast<StringInit>(I))
2070       Strings.push_back(SI->getValue());
2071     else
2072       PrintFatalError(getLoc(),
2073                       Twine("Record `") + getName() + "', field `" + FieldName +
2074                           "' does not have a list of strings initializer: " +
2075                           I->getAsString());
2076   }
2077   return Strings;
2078 }
2079 
2080 Record *Record::getValueAsDef(StringRef FieldName) const {
2081   const RecordVal *R = getValue(FieldName);
2082   if (!R || !R->getValue())
2083     PrintFatalError(getLoc(), "Record `" + getName() +
2084       "' does not have a field named `" + FieldName + "'!\n");
2085 
2086   if (DefInit *DI = dyn_cast<DefInit>(R->getValue()))
2087     return DI->getDef();
2088   PrintFatalError(getLoc(), "Record `" + getName() + "', field `" +
2089     FieldName + "' does not have a def initializer!");
2090 }
2091 
2092 bool Record::getValueAsBit(StringRef FieldName) const {
2093   const RecordVal *R = getValue(FieldName);
2094   if (!R || !R->getValue())
2095     PrintFatalError(getLoc(), "Record `" + getName() +
2096       "' does not have a field named `" + FieldName + "'!\n");
2097 
2098   if (BitInit *BI = dyn_cast<BitInit>(R->getValue()))
2099     return BI->getValue();
2100   PrintFatalError(getLoc(), "Record `" + getName() + "', field `" +
2101     FieldName + "' does not have a bit initializer!");
2102 }
2103 
2104 bool Record::getValueAsBitOrUnset(StringRef FieldName, bool &Unset) const {
2105   const RecordVal *R = getValue(FieldName);
2106   if (!R || !R->getValue())
2107     PrintFatalError(getLoc(), "Record `" + getName() +
2108       "' does not have a field named `" + FieldName.str() + "'!\n");
2109 
2110   if (isa<UnsetInit>(R->getValue())) {
2111     Unset = true;
2112     return false;
2113   }
2114   Unset = false;
2115   if (BitInit *BI = dyn_cast<BitInit>(R->getValue()))
2116     return BI->getValue();
2117   PrintFatalError(getLoc(), "Record `" + getName() + "', field `" +
2118     FieldName + "' does not have a bit initializer!");
2119 }
2120 
2121 DagInit *Record::getValueAsDag(StringRef FieldName) const {
2122   const RecordVal *R = getValue(FieldName);
2123   if (!R || !R->getValue())
2124     PrintFatalError(getLoc(), "Record `" + getName() +
2125       "' does not have a field named `" + FieldName + "'!\n");
2126 
2127   if (DagInit *DI = dyn_cast<DagInit>(R->getValue()))
2128     return DI;
2129   PrintFatalError(getLoc(), "Record `" + getName() + "', field `" +
2130     FieldName + "' does not have a dag initializer!");
2131 }
2132 
2133 #if !defined(NDEBUG) || defined(LLVM_ENABLE_DUMP)
2134 LLVM_DUMP_METHOD void RecordKeeper::dump() const { errs() << *this; }
2135 #endif
2136 
2137 raw_ostream &llvm::operator<<(raw_ostream &OS, const RecordKeeper &RK) {
2138   OS << "------------- Classes -----------------\n";
2139   for (const auto &C : RK.getClasses())
2140     OS << "class " << *C.second;
2141 
2142   OS << "------------- Defs -----------------\n";
2143   for (const auto &D : RK.getDefs())
2144     OS << "def " << *D.second;
2145   return OS;
2146 }
2147 
2148 /// GetNewAnonymousName - Generate a unique anonymous name that can be used as
2149 /// an identifier.
2150 Init *RecordKeeper::getNewAnonymousName() {
2151   return StringInit::get("anonymous_" + utostr(AnonCounter++));
2152 }
2153 
2154 std::vector<Record *>
2155 RecordKeeper::getAllDerivedDefinitions(StringRef ClassName) const {
2156   Record *Class = getClass(ClassName);
2157   if (!Class)
2158     PrintFatalError("ERROR: Couldn't find the `" + ClassName + "' class!\n");
2159 
2160   std::vector<Record*> Defs;
2161   for (const auto &D : getDefs())
2162     if (D.second->isSubClassOf(Class))
2163       Defs.push_back(D.second.get());
2164 
2165   return Defs;
2166 }
2167 
2168 Init *MapResolver::resolve(Init *VarName) {
2169   auto It = Map.find(VarName);
2170   if (It == Map.end())
2171     return nullptr;
2172 
2173   Init *I = It->second.V;
2174 
2175   if (!It->second.Resolved && Map.size() > 1) {
2176     // Resolve mutual references among the mapped variables, but prevent
2177     // infinite recursion.
2178     Map.erase(It);
2179     I = I->resolveReferences(*this);
2180     Map[VarName] = {I, true};
2181   }
2182 
2183   return I;
2184 }
2185 
2186 Init *RecordResolver::resolve(Init *VarName) {
2187   Init *Val = Cache.lookup(VarName);
2188   if (Val)
2189     return Val;
2190 
2191   for (Init *S : Stack) {
2192     if (S == VarName)
2193       return nullptr; // prevent infinite recursion
2194   }
2195 
2196   if (RecordVal *RV = getCurrentRecord()->getValue(VarName)) {
2197     if (!isa<UnsetInit>(RV->getValue())) {
2198       Val = RV->getValue();
2199       Stack.push_back(VarName);
2200       Val = Val->resolveReferences(*this);
2201       Stack.pop_back();
2202     }
2203   }
2204 
2205   Cache[VarName] = Val;
2206   return Val;
2207 }
2208 
2209 Init *TrackUnresolvedResolver::resolve(Init *VarName) {
2210   Init *I = nullptr;
2211 
2212   if (R) {
2213     I = R->resolve(VarName);
2214     if (I && !FoundUnresolved) {
2215       // Do not recurse into the resolved initializer, as that would change
2216       // the behavior of the resolver we're delegating, but do check to see
2217       // if there are unresolved variables remaining.
2218       TrackUnresolvedResolver Sub;
2219       I->resolveReferences(Sub);
2220       FoundUnresolved |= Sub.FoundUnresolved;
2221     }
2222   }
2223 
2224   if (!I)
2225     FoundUnresolved = true;
2226   return I;
2227 }
2228 
2229 Init *HasReferenceResolver::resolve(Init *VarName)
2230 {
2231   if (VarName == VarNameToTrack)
2232     Found = true;
2233   return nullptr;
2234 }
2235