Restoring authorship annotation for <orivej@yandex-team.ru>. Commit 1 of 2.

1 files changed, 333 insertions, 333 deletions

diff --git a/contrib/libs/llvm12/lib/TableGen/SetTheory.cpp b/contrib/libs/llvm12/lib/TableGen/SetTheory.cpp
index 0389bd3ac8..6af4764ce8 100644
--- a/contrib/libs/llvm12/lib/TableGen/SetTheory.cpp
+++ b/contrib/libs/llvm12/lib/TableGen/SetTheory.cpp
@@ -1,333 +1,333 @@
-//===- SetTheory.cpp - Generate ordered sets from DAG expressions ---------===//
-//
-// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
-// See https://llvm.org/LICENSE.txt for license information.
-// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
-//
-//===----------------------------------------------------------------------===//
-//
-// This file implements the SetTheory class that computes ordered sets of
-// Records from DAG expressions.
-//
-//===----------------------------------------------------------------------===//
-
-#include "llvm/ADT/ArrayRef.h"
-#include "llvm/ADT/SmallVector.h"
-#include "llvm/ADT/STLExtras.h"
-#include "llvm/ADT/StringRef.h"
-#include "llvm/Support/Casting.h"
-#include "llvm/Support/Format.h"
-#include "llvm/Support/SMLoc.h"
-#include "llvm/Support/raw_ostream.h"
-#include "llvm/TableGen/Error.h"
-#include "llvm/TableGen/Record.h"
-#include "llvm/TableGen/SetTheory.h"
-#include <algorithm>
-#include <cstdint>
-#include <string>
-#include <utility>
-
-using namespace llvm;
-
-// Define the standard operators.
-namespace {
-
-using RecSet = SetTheory::RecSet;
-using RecVec = SetTheory::RecVec;
-
-// (add a, b, ...) Evaluate and union all arguments.
-struct AddOp : public SetTheory::Operator {
-  void apply(SetTheory &ST, DagInit *Expr, RecSet &Elts,
-             ArrayRef<SMLoc> Loc) override {
-    ST.evaluate(Expr->arg_begin(), Expr->arg_end(), Elts, Loc);
-  }
-};
-
-// (sub Add, Sub, ...) Set difference.
-struct SubOp : public SetTheory::Operator {
-  void apply(SetTheory &ST, DagInit *Expr, RecSet &Elts,
-             ArrayRef<SMLoc> Loc) override {
-    if (Expr->arg_size() < 2)
-      PrintFatalError(Loc, "Set difference needs at least two arguments: " +
-        Expr->getAsString());
-    RecSet Add, Sub;
-    ST.evaluate(*Expr->arg_begin(), Add, Loc);
-    ST.evaluate(Expr->arg_begin() + 1, Expr->arg_end(), Sub, Loc);
-    for (RecSet::iterator I = Add.begin(), E = Add.end(); I != E; ++I)
-      if (!Sub.count(*I))
-        Elts.insert(*I);
-  }
-};
-
-// (and S1, S2) Set intersection.
-struct AndOp : public SetTheory::Operator {
-  void apply(SetTheory &ST, DagInit *Expr, RecSet &Elts,
-             ArrayRef<SMLoc> Loc) override {
-    if (Expr->arg_size() != 2)
-      PrintFatalError(Loc, "Set intersection requires two arguments: " +
-        Expr->getAsString());
-    RecSet S1, S2;
-    ST.evaluate(Expr->arg_begin()[0], S1, Loc);
-    ST.evaluate(Expr->arg_begin()[1], S2, Loc);
-    for (RecSet::iterator I = S1.begin(), E = S1.end(); I != E; ++I)
-      if (S2.count(*I))
-        Elts.insert(*I);
-  }
-};
-
-// SetIntBinOp - Abstract base class for (Op S, N) operators.
-struct SetIntBinOp : public SetTheory::Operator {
-  virtual void apply2(SetTheory &ST, DagInit *Expr, RecSet &Set, int64_t N,
-                      RecSet &Elts, ArrayRef<SMLoc> Loc) = 0;
-
-  void apply(SetTheory &ST, DagInit *Expr, RecSet &Elts,
-             ArrayRef<SMLoc> Loc) override {
-    if (Expr->arg_size() != 2)
-      PrintFatalError(Loc, "Operator requires (Op Set, Int) arguments: " +
-        Expr->getAsString());
-    RecSet Set;
-    ST.evaluate(Expr->arg_begin()[0], Set, Loc);
-    IntInit *II = dyn_cast<IntInit>(Expr->arg_begin()[1]);
-    if (!II)
-      PrintFatalError(Loc, "Second argument must be an integer: " +
-        Expr->getAsString());
-    apply2(ST, Expr, Set, II->getValue(), Elts, Loc);
-  }
-};
-
-// (shl S, N) Shift left, remove the first N elements.
-struct ShlOp : public SetIntBinOp {
-  void apply2(SetTheory &ST, DagInit *Expr, RecSet &Set, int64_t N,
-              RecSet &Elts, ArrayRef<SMLoc> Loc) override {
-    if (N < 0)
-      PrintFatalError(Loc, "Positive shift required: " +
-        Expr->getAsString());
-    if (unsigned(N) < Set.size())
-      Elts.insert(Set.begin() + N, Set.end());
-  }
-};
-
-// (trunc S, N) Truncate after the first N elements.
-struct TruncOp : public SetIntBinOp {
-  void apply2(SetTheory &ST, DagInit *Expr, RecSet &Set, int64_t N,
-              RecSet &Elts, ArrayRef<SMLoc> Loc) override {
-    if (N < 0)
-      PrintFatalError(Loc, "Positive length required: " +
-        Expr->getAsString());
-    if (unsigned(N) > Set.size())
-      N = Set.size();
-    Elts.insert(Set.begin(), Set.begin() + N);
-  }
-};
-
-// Left/right rotation.
-struct RotOp : public SetIntBinOp {
-  const bool Reverse;
-
-  RotOp(bool Rev) : Reverse(Rev) {}
-
-  void apply2(SetTheory &ST, DagInit *Expr, RecSet &Set, int64_t N,
-              RecSet &Elts, ArrayRef<SMLoc> Loc) override {
-    if (Reverse)
-      N = -N;
-    // N > 0 -> rotate left, N < 0 -> rotate right.
-    if (Set.empty())
-      return;
-    if (N < 0)
-      N = Set.size() - (-N % Set.size());
-    else
-      N %= Set.size();
-    Elts.insert(Set.begin() + N, Set.end());
-    Elts.insert(Set.begin(), Set.begin() + N);
-  }
-};
-
-// (decimate S, N) Pick every N'th element of S.
-struct DecimateOp : public SetIntBinOp {
-  void apply2(SetTheory &ST, DagInit *Expr, RecSet &Set, int64_t N,
-              RecSet &Elts, ArrayRef<SMLoc> Loc) override {
-    if (N <= 0)
-      PrintFatalError(Loc, "Positive stride required: " +
-        Expr->getAsString());
-    for (unsigned I = 0; I < Set.size(); I += N)
-      Elts.insert(Set[I]);
-  }
-};
-
-// (interleave S1, S2, ...) Interleave elements of the arguments.
-struct InterleaveOp : public SetTheory::Operator {
-  void apply(SetTheory &ST, DagInit *Expr, RecSet &Elts,
-             ArrayRef<SMLoc> Loc) override {
-    // Evaluate the arguments individually.
-    SmallVector<RecSet, 4> Args(Expr->getNumArgs());
-    unsigned MaxSize = 0;
-    for (unsigned i = 0, e = Expr->getNumArgs(); i != e; ++i) {
-      ST.evaluate(Expr->getArg(i), Args[i], Loc);
-      MaxSize = std::max(MaxSize, unsigned(Args[i].size()));
-    }
-    // Interleave arguments into Elts.
-    for (unsigned n = 0; n != MaxSize; ++n)
-      for (unsigned i = 0, e = Expr->getNumArgs(); i != e; ++i)
-        if (n < Args[i].size())
-          Elts.insert(Args[i][n]);
-  }
-};
-
-// (sequence "Format", From, To) Generate a sequence of records by name.
-struct SequenceOp : public SetTheory::Operator {
-  void apply(SetTheory &ST, DagInit *Expr, RecSet &Elts,
-             ArrayRef<SMLoc> Loc) override {
-    int Step = 1;
-    if (Expr->arg_size() > 4)
-      PrintFatalError(Loc, "Bad args to (sequence \"Format\", From, To): " +
-        Expr->getAsString());
-    else if (Expr->arg_size() == 4) {
-      if (IntInit *II = dyn_cast<IntInit>(Expr->arg_begin()[3])) {
-        Step = II->getValue();
-      } else
-        PrintFatalError(Loc, "Stride must be an integer: " +
-          Expr->getAsString());
-    }
-
-    std::string Format;
-    if (StringInit *SI = dyn_cast<StringInit>(Expr->arg_begin()[0]))
-      Format = std::string(SI->getValue());
-    else
-      PrintFatalError(Loc,  "Format must be a string: " + Expr->getAsString());
-
-    int64_t From, To;
-    if (IntInit *II = dyn_cast<IntInit>(Expr->arg_begin()[1]))
-      From = II->getValue();
-    else
-      PrintFatalError(Loc, "From must be an integer: " + Expr->getAsString());
-    if (From < 0 || From >= (1 << 30))
-      PrintFatalError(Loc, "From out of range");
-
-    if (IntInit *II = dyn_cast<IntInit>(Expr->arg_begin()[2]))
-      To = II->getValue();
-    else
-      PrintFatalError(Loc, "To must be an integer: " + Expr->getAsString());
-    if (To < 0 || To >= (1 << 30))
-      PrintFatalError(Loc, "To out of range");
-
-    RecordKeeper &Records =
-      cast<DefInit>(Expr->getOperator())->getDef()->getRecords();
-
-    Step *= From <= To ? 1 : -1;
-    while (true) {
-      if (Step > 0 && From > To)
-        break;
-      else if (Step < 0 && From < To)
-        break;
-      std::string Name;
-      raw_string_ostream OS(Name);
-      OS << format(Format.c_str(), unsigned(From));
-      Record *Rec = Records.getDef(OS.str());
-      if (!Rec)
-        PrintFatalError(Loc, "No def named '" + Name + "': " +
-          Expr->getAsString());
-      // Try to reevaluate Rec in case it is a set.
-      if (const RecVec *Result = ST.expand(Rec))
-        Elts.insert(Result->begin(), Result->end());
-      else
-        Elts.insert(Rec);
-
-      From += Step;
-    }
-  }
-};
-
-// Expand a Def into a set by evaluating one of its fields.
-struct FieldExpander : public SetTheory::Expander {
-  StringRef FieldName;
-
-  FieldExpander(StringRef fn) : FieldName(fn) {}
-
-  void expand(SetTheory &ST, Record *Def, RecSet &Elts) override {
-    ST.evaluate(Def->getValueInit(FieldName), Elts, Def->getLoc());
-  }
-};
-
-} // end anonymous namespace
-
-// Pin the vtables to this file.
-void SetTheory::Operator::anchor() {}
-void SetTheory::Expander::anchor() {}
-
-SetTheory::SetTheory() {
-  addOperator("add", std::make_unique<AddOp>());
-  addOperator("sub", std::make_unique<SubOp>());
-  addOperator("and", std::make_unique<AndOp>());
-  addOperator("shl", std::make_unique<ShlOp>());
-  addOperator("trunc", std::make_unique<TruncOp>());
-  addOperator("rotl", std::make_unique<RotOp>(false));
-  addOperator("rotr", std::make_unique<RotOp>(true));
-  addOperator("decimate", std::make_unique<DecimateOp>());
-  addOperator("interleave", std::make_unique<InterleaveOp>());
-  addOperator("sequence", std::make_unique<SequenceOp>());
-}
-
-void SetTheory::addOperator(StringRef Name, std::unique_ptr<Operator> Op) {
-  Operators[Name] = std::move(Op);
-}
-
-void SetTheory::addExpander(StringRef ClassName, std::unique_ptr<Expander> E) {
-  Expanders[ClassName] = std::move(E);
-}
-
-void SetTheory::addFieldExpander(StringRef ClassName, StringRef FieldName) {
-  addExpander(ClassName, std::make_unique<FieldExpander>(FieldName));
-}
-
-void SetTheory::evaluate(Init *Expr, RecSet &Elts, ArrayRef<SMLoc> Loc) {
-  // A def in a list can be a just an element, or it may expand.
-  if (DefInit *Def = dyn_cast<DefInit>(Expr)) {
-    if (const RecVec *Result = expand(Def->getDef()))
-      return Elts.insert(Result->begin(), Result->end());
-    Elts.insert(Def->getDef());
-    return;
-  }
-
-  // Lists simply expand.
-  if (ListInit *LI = dyn_cast<ListInit>(Expr))
-    return evaluate(LI->begin(), LI->end(), Elts, Loc);
-
-  // Anything else must be a DAG.
-  DagInit *DagExpr = dyn_cast<DagInit>(Expr);
-  if (!DagExpr)
-    PrintFatalError(Loc, "Invalid set element: " + Expr->getAsString());
-  DefInit *OpInit = dyn_cast<DefInit>(DagExpr->getOperator());
-  if (!OpInit)
-    PrintFatalError(Loc, "Bad set expression: " + Expr->getAsString());
-  auto I = Operators.find(OpInit->getDef()->getName());
-  if (I == Operators.end())
-    PrintFatalError(Loc, "Unknown set operator: " + Expr->getAsString());
-  I->second->apply(*this, DagExpr, Elts, Loc);
-}
-
-const RecVec *SetTheory::expand(Record *Set) {
-  // Check existing entries for Set and return early.
-  ExpandMap::iterator I = Expansions.find(Set);
-  if (I != Expansions.end())
-    return &I->second;
-
-  // This is the first time we see Set. Find a suitable expander.
-  ArrayRef<std::pair<Record *, SMRange>> SC = Set->getSuperClasses();
-  for (const auto &SCPair : SC) {
-    // Skip unnamed superclasses.
-    if (!isa<StringInit>(SCPair.first->getNameInit()))
-      continue;
-    auto I = Expanders.find(SCPair.first->getName());
-    if (I != Expanders.end()) {
-      // This breaks recursive definitions.
-      RecVec &EltVec = Expansions[Set];
-      RecSet Elts;
-      I->second->expand(*this, Set, Elts);
-      EltVec.assign(Elts.begin(), Elts.end());
-      return &EltVec;
-    }
-  }
-
-  // Set is not expandable.
-  return nullptr;
-}
+//===- SetTheory.cpp - Generate ordered sets from DAG expressions ---------===// 
+// 
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. 
+// See https://llvm.org/LICENSE.txt for license information. 
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception 
+// 
+//===----------------------------------------------------------------------===// 
+// 
+// This file implements the SetTheory class that computes ordered sets of 
+// Records from DAG expressions. 
+// 
+//===----------------------------------------------------------------------===// 
+ 
+#include "llvm/ADT/ArrayRef.h" 
+#include "llvm/ADT/SmallVector.h" 
+#include "llvm/ADT/STLExtras.h" 
+#include "llvm/ADT/StringRef.h" 
+#include "llvm/Support/Casting.h" 
+#include "llvm/Support/Format.h" 
+#include "llvm/Support/SMLoc.h" 
+#include "llvm/Support/raw_ostream.h" 
+#include "llvm/TableGen/Error.h" 
+#include "llvm/TableGen/Record.h" 
+#include "llvm/TableGen/SetTheory.h" 
+#include <algorithm> 
+#include <cstdint> 
+#include <string> 
+#include <utility> 
+ 
+using namespace llvm; 
+ 
+// Define the standard operators. 
+namespace { 
+ 
+using RecSet = SetTheory::RecSet; 
+using RecVec = SetTheory::RecVec; 
+ 
+// (add a, b, ...) Evaluate and union all arguments. 
+struct AddOp : public SetTheory::Operator { 
+  void apply(SetTheory &ST, DagInit *Expr, RecSet &Elts, 
+             ArrayRef<SMLoc> Loc) override { 
+    ST.evaluate(Expr->arg_begin(), Expr->arg_end(), Elts, Loc); 
+  } 
+}; 
+ 
+// (sub Add, Sub, ...) Set difference. 
+struct SubOp : public SetTheory::Operator { 
+  void apply(SetTheory &ST, DagInit *Expr, RecSet &Elts, 
+             ArrayRef<SMLoc> Loc) override { 
+    if (Expr->arg_size() < 2) 
+      PrintFatalError(Loc, "Set difference needs at least two arguments: " + 
+        Expr->getAsString()); 
+    RecSet Add, Sub; 
+    ST.evaluate(*Expr->arg_begin(), Add, Loc); 
+    ST.evaluate(Expr->arg_begin() + 1, Expr->arg_end(), Sub, Loc); 
+    for (RecSet::iterator I = Add.begin(), E = Add.end(); I != E; ++I) 
+      if (!Sub.count(*I)) 
+        Elts.insert(*I); 
+  } 
+}; 
+ 
+// (and S1, S2) Set intersection. 
+struct AndOp : public SetTheory::Operator { 
+  void apply(SetTheory &ST, DagInit *Expr, RecSet &Elts, 
+             ArrayRef<SMLoc> Loc) override { 
+    if (Expr->arg_size() != 2) 
+      PrintFatalError(Loc, "Set intersection requires two arguments: " + 
+        Expr->getAsString()); 
+    RecSet S1, S2; 
+    ST.evaluate(Expr->arg_begin()[0], S1, Loc); 
+    ST.evaluate(Expr->arg_begin()[1], S2, Loc); 
+    for (RecSet::iterator I = S1.begin(), E = S1.end(); I != E; ++I) 
+      if (S2.count(*I)) 
+        Elts.insert(*I); 
+  } 
+}; 
+ 
+// SetIntBinOp - Abstract base class for (Op S, N) operators. 
+struct SetIntBinOp : public SetTheory::Operator { 
+  virtual void apply2(SetTheory &ST, DagInit *Expr, RecSet &Set, int64_t N, 
+                      RecSet &Elts, ArrayRef<SMLoc> Loc) = 0; 
+ 
+  void apply(SetTheory &ST, DagInit *Expr, RecSet &Elts, 
+             ArrayRef<SMLoc> Loc) override { 
+    if (Expr->arg_size() != 2) 
+      PrintFatalError(Loc, "Operator requires (Op Set, Int) arguments: " + 
+        Expr->getAsString()); 
+    RecSet Set; 
+    ST.evaluate(Expr->arg_begin()[0], Set, Loc); 
+    IntInit *II = dyn_cast<IntInit>(Expr->arg_begin()[1]); 
+    if (!II) 
+      PrintFatalError(Loc, "Second argument must be an integer: " + 
+        Expr->getAsString()); 
+    apply2(ST, Expr, Set, II->getValue(), Elts, Loc); 
+  } 
+}; 
+ 
+// (shl S, N) Shift left, remove the first N elements. 
+struct ShlOp : public SetIntBinOp { 
+  void apply2(SetTheory &ST, DagInit *Expr, RecSet &Set, int64_t N, 
+              RecSet &Elts, ArrayRef<SMLoc> Loc) override { 
+    if (N < 0) 
+      PrintFatalError(Loc, "Positive shift required: " + 
+        Expr->getAsString()); 
+    if (unsigned(N) < Set.size()) 
+      Elts.insert(Set.begin() + N, Set.end()); 
+  } 
+}; 
+ 
+// (trunc S, N) Truncate after the first N elements. 
+struct TruncOp : public SetIntBinOp { 
+  void apply2(SetTheory &ST, DagInit *Expr, RecSet &Set, int64_t N, 
+              RecSet &Elts, ArrayRef<SMLoc> Loc) override { 
+    if (N < 0) 
+      PrintFatalError(Loc, "Positive length required: " + 
+        Expr->getAsString()); 
+    if (unsigned(N) > Set.size()) 
+      N = Set.size(); 
+    Elts.insert(Set.begin(), Set.begin() + N); 
+  } 
+}; 
+ 
+// Left/right rotation. 
+struct RotOp : public SetIntBinOp { 
+  const bool Reverse; 
+ 
+  RotOp(bool Rev) : Reverse(Rev) {} 
+ 
+  void apply2(SetTheory &ST, DagInit *Expr, RecSet &Set, int64_t N, 
+              RecSet &Elts, ArrayRef<SMLoc> Loc) override { 
+    if (Reverse) 
+      N = -N; 
+    // N > 0 -> rotate left, N < 0 -> rotate right. 
+    if (Set.empty()) 
+      return; 
+    if (N < 0) 
+      N = Set.size() - (-N % Set.size()); 
+    else 
+      N %= Set.size(); 
+    Elts.insert(Set.begin() + N, Set.end()); 
+    Elts.insert(Set.begin(), Set.begin() + N); 
+  } 
+}; 
+ 
+// (decimate S, N) Pick every N'th element of S. 
+struct DecimateOp : public SetIntBinOp { 
+  void apply2(SetTheory &ST, DagInit *Expr, RecSet &Set, int64_t N, 
+              RecSet &Elts, ArrayRef<SMLoc> Loc) override { 
+    if (N <= 0) 
+      PrintFatalError(Loc, "Positive stride required: " + 
+        Expr->getAsString()); 
+    for (unsigned I = 0; I < Set.size(); I += N) 
+      Elts.insert(Set[I]); 
+  } 
+}; 
+ 
+// (interleave S1, S2, ...) Interleave elements of the arguments. 
+struct InterleaveOp : public SetTheory::Operator { 
+  void apply(SetTheory &ST, DagInit *Expr, RecSet &Elts, 
+             ArrayRef<SMLoc> Loc) override { 
+    // Evaluate the arguments individually. 
+    SmallVector<RecSet, 4> Args(Expr->getNumArgs()); 
+    unsigned MaxSize = 0; 
+    for (unsigned i = 0, e = Expr->getNumArgs(); i != e; ++i) { 
+      ST.evaluate(Expr->getArg(i), Args[i], Loc); 
+      MaxSize = std::max(MaxSize, unsigned(Args[i].size())); 
+    } 
+    // Interleave arguments into Elts. 
+    for (unsigned n = 0; n != MaxSize; ++n) 
+      for (unsigned i = 0, e = Expr->getNumArgs(); i != e; ++i) 
+        if (n < Args[i].size()) 
+          Elts.insert(Args[i][n]); 
+  } 
+}; 
+ 
+// (sequence "Format", From, To) Generate a sequence of records by name. 
+struct SequenceOp : public SetTheory::Operator { 
+  void apply(SetTheory &ST, DagInit *Expr, RecSet &Elts, 
+             ArrayRef<SMLoc> Loc) override { 
+    int Step = 1; 
+    if (Expr->arg_size() > 4) 
+      PrintFatalError(Loc, "Bad args to (sequence \"Format\", From, To): " + 
+        Expr->getAsString()); 
+    else if (Expr->arg_size() == 4) { 
+      if (IntInit *II = dyn_cast<IntInit>(Expr->arg_begin()[3])) { 
+        Step = II->getValue(); 
+      } else 
+        PrintFatalError(Loc, "Stride must be an integer: " + 
+          Expr->getAsString()); 
+    } 
+ 
+    std::string Format; 
+    if (StringInit *SI = dyn_cast<StringInit>(Expr->arg_begin()[0])) 
+      Format = std::string(SI->getValue()); 
+    else 
+      PrintFatalError(Loc,  "Format must be a string: " + Expr->getAsString()); 
+ 
+    int64_t From, To; 
+    if (IntInit *II = dyn_cast<IntInit>(Expr->arg_begin()[1])) 
+      From = II->getValue(); 
+    else 
+      PrintFatalError(Loc, "From must be an integer: " + Expr->getAsString()); 
+    if (From < 0 || From >= (1 << 30)) 
+      PrintFatalError(Loc, "From out of range"); 
+ 
+    if (IntInit *II = dyn_cast<IntInit>(Expr->arg_begin()[2])) 
+      To = II->getValue(); 
+    else 
+      PrintFatalError(Loc, "To must be an integer: " + Expr->getAsString()); 
+    if (To < 0 || To >= (1 << 30)) 
+      PrintFatalError(Loc, "To out of range"); 
+ 
+    RecordKeeper &Records = 
+      cast<DefInit>(Expr->getOperator())->getDef()->getRecords(); 
+ 
+    Step *= From <= To ? 1 : -1; 
+    while (true) { 
+      if (Step > 0 && From > To) 
+        break; 
+      else if (Step < 0 && From < To) 
+        break; 
+      std::string Name; 
+      raw_string_ostream OS(Name); 
+      OS << format(Format.c_str(), unsigned(From)); 
+      Record *Rec = Records.getDef(OS.str()); 
+      if (!Rec) 
+        PrintFatalError(Loc, "No def named '" + Name + "': " + 
+          Expr->getAsString()); 
+      // Try to reevaluate Rec in case it is a set. 
+      if (const RecVec *Result = ST.expand(Rec)) 
+        Elts.insert(Result->begin(), Result->end()); 
+      else 
+        Elts.insert(Rec); 
+ 
+      From += Step; 
+    } 
+  } 
+}; 
+ 
+// Expand a Def into a set by evaluating one of its fields. 
+struct FieldExpander : public SetTheory::Expander { 
+  StringRef FieldName; 
+ 
+  FieldExpander(StringRef fn) : FieldName(fn) {} 
+ 
+  void expand(SetTheory &ST, Record *Def, RecSet &Elts) override { 
+    ST.evaluate(Def->getValueInit(FieldName), Elts, Def->getLoc()); 
+  } 
+}; 
+ 
+} // end anonymous namespace 
+ 
+// Pin the vtables to this file. 
+void SetTheory::Operator::anchor() {} 
+void SetTheory::Expander::anchor() {} 
+ 
+SetTheory::SetTheory() { 
+  addOperator("add", std::make_unique<AddOp>()); 
+  addOperator("sub", std::make_unique<SubOp>()); 
+  addOperator("and", std::make_unique<AndOp>()); 
+  addOperator("shl", std::make_unique<ShlOp>()); 
+  addOperator("trunc", std::make_unique<TruncOp>()); 
+  addOperator("rotl", std::make_unique<RotOp>(false)); 
+  addOperator("rotr", std::make_unique<RotOp>(true)); 
+  addOperator("decimate", std::make_unique<DecimateOp>()); 
+  addOperator("interleave", std::make_unique<InterleaveOp>()); 
+  addOperator("sequence", std::make_unique<SequenceOp>()); 
+} 
+ 
+void SetTheory::addOperator(StringRef Name, std::unique_ptr<Operator> Op) { 
+  Operators[Name] = std::move(Op); 
+} 
+ 
+void SetTheory::addExpander(StringRef ClassName, std::unique_ptr<Expander> E) { 
+  Expanders[ClassName] = std::move(E); 
+} 
+ 
+void SetTheory::addFieldExpander(StringRef ClassName, StringRef FieldName) { 
+  addExpander(ClassName, std::make_unique<FieldExpander>(FieldName)); 
+} 
+ 
+void SetTheory::evaluate(Init *Expr, RecSet &Elts, ArrayRef<SMLoc> Loc) { 
+  // A def in a list can be a just an element, or it may expand. 
+  if (DefInit *Def = dyn_cast<DefInit>(Expr)) { 
+    if (const RecVec *Result = expand(Def->getDef())) 
+      return Elts.insert(Result->begin(), Result->end()); 
+    Elts.insert(Def->getDef()); 
+    return; 
+  } 
+ 
+  // Lists simply expand. 
+  if (ListInit *LI = dyn_cast<ListInit>(Expr)) 
+    return evaluate(LI->begin(), LI->end(), Elts, Loc); 
+ 
+  // Anything else must be a DAG. 
+  DagInit *DagExpr = dyn_cast<DagInit>(Expr); 
+  if (!DagExpr) 
+    PrintFatalError(Loc, "Invalid set element: " + Expr->getAsString()); 
+  DefInit *OpInit = dyn_cast<DefInit>(DagExpr->getOperator()); 
+  if (!OpInit) 
+    PrintFatalError(Loc, "Bad set expression: " + Expr->getAsString()); 
+  auto I = Operators.find(OpInit->getDef()->getName()); 
+  if (I == Operators.end()) 
+    PrintFatalError(Loc, "Unknown set operator: " + Expr->getAsString()); 
+  I->second->apply(*this, DagExpr, Elts, Loc); 
+} 
+ 
+const RecVec *SetTheory::expand(Record *Set) { 
+  // Check existing entries for Set and return early. 
+  ExpandMap::iterator I = Expansions.find(Set); 
+  if (I != Expansions.end()) 
+    return &I->second; 
+ 
+  // This is the first time we see Set. Find a suitable expander. 
+  ArrayRef<std::pair<Record *, SMRange>> SC = Set->getSuperClasses(); 
+  for (const auto &SCPair : SC) { 
+    // Skip unnamed superclasses. 
+    if (!isa<StringInit>(SCPair.first->getNameInit())) 
+      continue; 
+    auto I = Expanders.find(SCPair.first->getName()); 
+    if (I != Expanders.end()) { 
+      // This breaks recursive definitions. 
+      RecVec &EltVec = Expansions[Set]; 
+      RecSet Elts; 
+      I->second->expand(*this, Set, Elts); 
+      EltVec.assign(Elts.begin(), Elts.end()); 
+      return &EltVec; 
+    } 
+  } 
+ 
+  // Set is not expandable. 
+  return nullptr; 
+}