Swift SIL: add some instruction classes and APIs

* add `UnownedRetainInst` and `UnownedReleaseInst`
* add `var value` to `RetainValueInst` and `ReleaseValueInst`
* make the protocol `UnaryInstruction` be an `Instruction`
* add `var Type.isValueTypeWithDeinit`
* add `var Type.isUnownedStorageType`
* add `var OperandArray.values`

Author: eeckstein

SwiftCompilerSources/Sources/SIL/ApplySite.swift

@@ -80,7 +80,7 @@ extension ApplySite {
   ///
   /// This does not include the callee function operand.
   public var arguments: LazyMapSequence<OperandArray, Value> {
-    argumentOperands.lazy.map { $0.value }
+    argumentOperands.values
   }
 
   public var substitutionMap: SubstitutionMap {

SwiftCompilerSources/Sources/SIL/Builder.swift

@@ -136,6 +136,18 @@ public struct Builder {
     return notifyNew(release.getAs(StrongReleaseInst.self))
   }
 
+  @discardableResult
+  public func createUnownedRetain(operand: Value) -> UnownedRetainInst {
+    let retain = bridged.createUnownedRetain(operand.bridged)
+    return notifyNew(retain.getAs(UnownedRetainInst.self))
+  }
+
+  @discardableResult
+  public func createUnownedRelease(operand: Value) -> UnownedReleaseInst {
+    let release = bridged.createUnownedRelease(operand.bridged)
+    return notifyNew(release.getAs(UnownedReleaseInst.self))
+  }
+
   public func createFunctionRef(_ function: Function) -> FunctionRefInst {
     let functionRef = bridged.createFunctionRef(function.bridged)
     return notifyNew(functionRef.getAs(FunctionRefInst.self))

SwiftCompilerSources/Sources/SIL/Instruction.swift

@@ -197,7 +197,7 @@ public class MultipleValueInstruction : Instruction {
 }
 
 /// Instructions, which have a single operand.
-public protocol UnaryInstruction : AnyObject {
+public protocol UnaryInstruction : Instruction {
   var operands: OperandArray { get }
   var operand: Operand { get }
 }
@@ -306,14 +306,24 @@ final public class StrongRetainInst : RefCountingInst {
   public var instance: Value { operand.value }
 }
 
+final public class UnownedRetainInst : RefCountingInst {
+  public var instance: Value { operand.value }
+}
+
 final public class RetainValueInst : RefCountingInst {
+  public var value: Value { return operand.value }
 }
 
 final public class StrongReleaseInst : RefCountingInst {
   public var instance: Value { operand.value }
 }
 
+final public class UnownedReleaseInst : RefCountingInst {
+  public var instance: Value { operand.value }
+}
+
 final public class ReleaseValueInst : RefCountingInst {
+  public var value: Value { return operand.value }
 }
 
 final public class DestroyValueInst : Instruction, UnaryInstruction {

SwiftCompilerSources/Sources/SIL/Operand.swift

@@ -76,6 +76,10 @@ public struct OperandArray : RandomAccessCollection, CustomReflectable {
       base: OptionalBridgedOperand(op: base.advancedBy(bounds.lowerBound).op),
       count: bounds.upperBound - bounds.lowerBound)
   }
+
+  public var values: LazyMapSequence<LazySequence<OperandArray>.Elements, Value> {
+    self.lazy.map { $0.value }
+  }
 }
 
 public struct UseList : CollectionLikeSequence {

SwiftCompilerSources/Sources/SIL/Registration.swift

@@ -54,8 +54,10 @@ public func registerSILClasses() {
   register(EndApplyInst.self)
   register(AbortApplyInst.self)
   register(StrongRetainInst.self)
+  register(UnownedRetainInst.self)
   register(RetainValueInst.self)
   register(StrongReleaseInst.self)
+  register(UnownedReleaseInst.self)
   register(ReleaseValueInst.self)
   register(DestroyValueInst.self)
   register(DestroyAddrInst.self)

SwiftCompilerSources/Sources/SIL/Type.swift

@@ -31,6 +31,10 @@ public struct Type : CustomStringConvertible, NoReflectionChildren {
     return !bridged.isNonTrivialOrContainsRawPointer(function.bridged.getFunction())
   }
 
+  /// True if this type is a value type (struct/enum) that requires deinitialization beyond
+  /// destruction of its members.
+  public var isValueTypeWithDeinit: Bool { bridged.isValueTypeWithDeinit() }
+
   public func isLoadable(in function: Function) -> Bool {
     return bridged.isLoadable(function.bridged.getFunction())
   }
@@ -39,6 +43,10 @@ public struct Type : CustomStringConvertible, NoReflectionChildren {
     return bridged.isReferenceCounted(function.bridged.getFunction())
   }
 
+  public var isUnownedStorageType: Bool {
+    return bridged.isUnownedStorageType()
+  }
+
   public var hasArchetype: Bool { bridged.hasArchetype() }
 
   public var isNominal: Bool { bridged.getNominalOrBoundGenericNominal() != nil }

include/swift/SIL/SILBridging.h

@@ -1105,6 +1105,18 @@ struct BridgedBuilder{
     return {b.createStrongRelease(regularLoc(), op.getSILValue(), b.getDefaultAtomicity())};
   }
 
+  SWIFT_IMPORT_UNSAFE
+  BridgedInstruction createUnownedRetain(BridgedValue op) const {
+    auto b = builder();
+    return {b.createUnownedRetain(regularLoc(), op.getSILValue(), b.getDefaultAtomicity())};
+  }
+
+  SWIFT_IMPORT_UNSAFE
+  BridgedInstruction createUnownedRelease(BridgedValue op) const {
+    auto b = builder();
+    return {b.createUnownedRelease(regularLoc(), op.getSILValue(), b.getDefaultAtomicity())};
+  }
+
   SWIFT_IMPORT_UNSAFE
   BridgedInstruction createFunctionRef(BridgedFunction function) const {
     return {builder().createFunctionRef(regularLoc(), function.getFunction())};

include/swift/SIL/SILType.h

@@ -394,6 +394,8 @@ class SILType {
 
   bool isReferenceCounted(SILFunction *f) const;
 
+  bool isUnownedStorageType() const { return is<UnownedStorageType>(); }
+
   /// Returns true if the referenced type is a function type that never
   /// returns.
   bool isNoReturnFunction(SILModule &M, TypeExpansionContext context) const;
@@ -745,6 +747,10 @@ class SILType {
   /// for a move only wrapped type.
   bool isPureMoveOnly() const;
 
+  /// Return true if this is a value type (struct/enum) that requires
+  /// deinitialization beyond destruction of its members.
+  bool isValueTypeWithDeinit() const;
+
   /// Returns true if and only if this type is a first class move only
   /// type. NOTE: Returns false if the type is a move only wrapped type.
   bool isMoveOnlyNominalType() const;

lib/SIL/IR/SILType.cpp

@@ -1048,6 +1048,15 @@ bool SILType::isPureMoveOnly() const {
   return false;
 }
 
+bool SILType::isValueTypeWithDeinit() const {
+  // Do not look inside an aggregate type that has a user-deinit, for which
+  // memberwise-destruction is not equivalent to aggregate destruction.
+  if (auto *nominal = getNominalOrBoundGenericNominal()) {
+    return nominal->getValueTypeDestructor() != nullptr;
+  }
+  return false;
+}
+
 SILType SILType::getInstanceTypeOfMetatype(SILFunction *function) const {
   auto metaType = castTo<MetatypeType>();
   CanType instanceTy = metaType.getInstanceType();