AST: Cache isNoncopyable() and isEscapable() bits inside TypeBase

Author: slavapestov

include/swift/AST/Types.h

@@ -413,15 +413,19 @@ class alignas(1 << TypeAlignInBits) TypeBase
   // clang-format off
   union { uint64_t OpaqueBits;
 
-  SWIFT_INLINE_BITFIELD_BASE(TypeBase, bitmax(NumTypeKindBits,8) +
-                             RecursiveTypeProperties::BitWidth + 1,
+  SWIFT_INLINE_BITFIELD_BASE(TypeBase, NumTypeKindBits +
+                             RecursiveTypeProperties::BitWidth + 1 + 3,
     /// Kind - The discriminator that indicates what subclass of type this is.
-    Kind : bitmax(NumTypeKindBits,8),
+    Kind : NumTypeKindBits,
 
     Properties : RecursiveTypeProperties::BitWidth,
 
     /// Whether this type is canonical or not.
-    IsCanonical : 1
+    IsCanonical : 1,
+
+    ComputedInvertibleConformances : 1,
+    IsCopyable : 1,
+    IsEscapable : 1
   );
 
   SWIFT_INLINE_BITFIELD(ErrorType, TypeBase, 1,
@@ -441,8 +445,7 @@ class alignas(1 << TypeAlignInBits) TypeBase
     HasClangTypeInfo : 1,
     HasThrownError : 1,
     HasLifetimeDependencies : 1,
-    : NumPadBits,
-    NumParams : 16
+    NumParams : 15
   );
 
   SWIFT_INLINE_BITFIELD_FULL(ArchetypeType, TypeBase, 1+1+16,
@@ -455,9 +458,8 @@ class alignas(1 << TypeAlignInBits) TypeBase
   SWIFT_INLINE_BITFIELD_FULL(TypeVariableType, TypeBase, 7+28,
     /// Type variable options.
     Options : 7,
-    : NumPadBits,
     /// The unique number assigned to this type variable.
-    ID : 28
+    ID : 27
   );
 
   SWIFT_INLINE_BITFIELD_FULL(ErrorUnionType, TypeBase, 32,
@@ -560,6 +562,11 @@ class alignas(1 << TypeAlignInBits) TypeBase
       Bits.TypeBase.IsCanonical = true;
       Context = CanTypeCtx;
     }
+
+    Bits.TypeBase.ComputedInvertibleConformances = false;
+    Bits.TypeBase.IsCopyable = false;
+    Bits.TypeBase.IsEscapable = false;
+
     setRecursiveProperties(properties);
   }
 
@@ -591,6 +598,8 @@ class alignas(1 << TypeAlignInBits) TypeBase
 private:
   CanType computeCanonicalType();
 
+  void computeInvertibleConformances();
+
 public:
   /// getCanonicalType - Return the canonical version of this type, which has
   /// sugar from all levels stripped off.

lib/AST/ConformanceLookup.cpp

@@ -897,68 +897,60 @@ bool TypeBase::isSendableType() {
 /// Copyable and Escapable checking utilities
 ///
 
-/// Preprocesses a type before querying whether it conforms to an invertible.
-static CanType preprocessTypeForInvertibleQuery(Type orig) {
-  Type type = orig;
-
-  // Strip off any StorageType wrapper.
-  type = type->getReferenceStorageReferent();
-
-  // Pack expansions such as `repeat T` themselves do not have conformances,
-  // so check its pattern type for conformance.
-  if (auto *pet = type->getAs<PackExpansionType>()) {
-    type = pet->getPatternType()->getCanonicalType();
-  }
-
-  // Strip @lvalue and canonicalize.
-  auto canType = type->getRValueType()->getCanonicalType();
-  return canType;
-}
-
 static bool conformsToInvertible(CanType type, InvertibleProtocolKind ip) {
-  auto &ctx = type->getASTContext();
-
-  auto *proto = ctx.getProtocol(getKnownProtocolKind(ip));
-  assert(proto && "missing Copyable/Escapable from stdlib!");
+  // FIXME: Remove these.
+  if (isa<SILPackType>(type))
+    return true;
 
-  // Must not have a type parameter!
-  assert(!type->hasTypeParameter() && "caller forgot to mapTypeIntoContext!");
+  if (isa<SILTokenType>(type))
+    return true;
 
-  assert(!type->hasUnboundGenericType() && "a UGT has no conformances!");
+  auto *proto = type->getASTContext().getProtocol(getKnownProtocolKind(ip));
+  ASSERT(proto);
 
-  assert(!type->is<PackExpansionType>());
+  return (bool) checkConformance(type, proto, /*allowMissing=*/false);
+}
 
-  // FIXME: lldb misbehaves by getting here with a SILPackType.
-  //  just pretend it it conforms.
-  if (type->is<SILPackType>())
-    return true;
+void TypeBase::computeInvertibleConformances() {
+  Bits.TypeBase.ComputedInvertibleConformances = true;
 
-  if (type->is<SILTokenType>()) {
-    return true;
-  }
-
-  // The SIL types in the AST do not have real conformances, and should have
-  // been handled in SILType instead.
-  assert(!(type->is<SILBoxType,
-                    SILMoveOnlyWrappedType,
-                    SILPackType,
-                    SILTokenType>()));
+  Type type(this);
 
-  const bool conforms =
-      (bool) checkConformance(type, proto, /*allowMissing=*/false);
+  // FIXME: Remove all of the below. Callers should be changed to perform any
+  // necessary unwrapping themselves.
 
-  return conforms;
+  // Pack expansions such as `repeat T` themselves do not have conformances,
+  // so check its pattern type for conformance.
+  if (auto *pet = type->getAs<PackExpansionType>())
+    type = pet->getPatternType();
+
+  auto canType = type->getReferenceStorageReferent()
+                     ->getWithoutSpecifierType()
+                     ->getCanonicalType();
+
+  assert(!canType->hasTypeParameter());
+  assert(!canType->hasUnboundGenericType());
+  assert(!isa<SILBoxType>(canType));
+  assert(!isa<SILMoveOnlyWrappedType>(canType));
+
+  Bits.TypeBase.IsCopyable = conformsToInvertible(
+      canType, InvertibleProtocolKind::Copyable);
+  Bits.TypeBase.IsEscapable = conformsToInvertible(
+      canType, InvertibleProtocolKind::Escapable);
 }
 
 /// \returns true iff this type lacks conformance to Copyable.
 bool TypeBase::isNoncopyable() {
-  auto canType = preprocessTypeForInvertibleQuery(this);
-  return !conformsToInvertible(canType, InvertibleProtocolKind::Copyable);
+  if (!Bits.TypeBase.ComputedInvertibleConformances)
+    computeInvertibleConformances();
+  return !Bits.TypeBase.IsCopyable;
 }
 
+/// \returns true iff this type conforms to Escaping.
 bool TypeBase::isEscapable() {
-  auto canType = preprocessTypeForInvertibleQuery(this);
-  return conformsToInvertible(canType, InvertibleProtocolKind::Escapable);
+  if (!Bits.TypeBase.ComputedInvertibleConformances)
+    computeInvertibleConformances();
+  return Bits.TypeBase.IsEscapable;
 }
 
 bool TypeBase::isEscapable(GenericSignature sig) {