SIL: Let SubstitutionMap.replacementTypes return AST types rather than optional SIL types.

This is what the C++ SubstitutionMap does. One has to use `Type.loweredType` to get from the AST type to the SIL type.

Author: eeckstein

SwiftCompilerSources/Sources/AST/SubstitutionMap.swift

@@ -56,4 +56,14 @@ public struct SubstitutionMap: CustomStringConvertible {
       return Conformance(bridged: bridgedSubs.getConformance(index))
     }
   }
+
+  public var replacementTypes: TypeArray {
+    TypeArray(bridged: bridged.getReplacementTypes())
+  }
+
+  /// The single replacement type if it's guarnateed that the substitution map has a single replacement type.
+  public var replacementType: Type {
+    assert(replacementTypes.count == 1)
+    return replacementTypes[0]
+  }
 }

SwiftCompilerSources/Sources/AST/Type.swift

@@ -64,3 +64,23 @@ public struct CanonicalType: CustomStringConvertible, NoReflectionChildren {
     return type.subst(with: substitutionMap).canonical
   }
 }
+
+public struct TypeArray : RandomAccessCollection, CustomReflectable {
+  public let bridged: BridgedASTTypeArray
+
+  public var startIndex: Int { return 0 }
+  public var endIndex: Int { return bridged.getCount() }
+
+  public init(bridged: BridgedASTTypeArray) {
+    self.bridged = bridged
+  }
+
+  public subscript(_ index: Int) -> Type {
+    Type(bridged: bridged.getAt(index))
+  }
+
+  public var customMirror: Mirror {
+    let c: [Mirror.Child] = map { (label: nil, value: $0) }
+    return Mirror(self, children: c)
+  }
+}

SwiftCompilerSources/Sources/Optimizer/FunctionPasses/AllocVectorLowering.swift

@@ -224,9 +224,10 @@ private func createOutlinedGlobal(
     return
   }
 
-  let elementType = allocVectorBuiltin.substitutionMap.replacementTypes[0]!
+  let function = allocVectorBuiltin.parentFunction
+  let elementType = allocVectorBuiltin.substitutionMap.replacementTypes[0].loweredType(in: function)
   let outlinedGlobal = context.createGlobalVariable(
-        name: context.mangleOutlinedVariable(from: allocVectorBuiltin.parentFunction),
+        name: context.mangleOutlinedVariable(from: function),
         type: elementType, linkage: .private, isLet: false)
 
   let globalBuilder = Builder(staticInitializerOf: outlinedGlobal, context)
@@ -259,7 +260,8 @@ private func createStackAllocatedVector(
   _ context: FunctionPassContext
 ) {
   let builder = Builder(before: allocVectorBuiltin, context)
-  let elementType = allocVectorBuiltin.substitutionMap.replacementTypes[0]!
+  let function = allocVectorBuiltin.parentFunction
+  let elementType = allocVectorBuiltin.substitutionMap.replacementTypes[0].loweredType(in: function)
   let allocVec = builder.createAllocVector(capacity: allocVectorBuiltin.operands[1].value, elementType: elementType)
   let rawVectorPointer = builder.createAddressToPointer(address: allocVec, pointerType: allocVectorBuiltin.type,
                                                         needStackProtection: true)

SwiftCompilerSources/Sources/Optimizer/InstructionSimplification/SimplifyBuiltin.swift

@@ -33,7 +33,7 @@ extension BuiltinInst : OnoneSimplifyable {
            .Alignof:
         optimizeTargetTypeConst(context)
       case .DestroyArray:
-        if let elementType = substitutionMap.replacementTypes[0],
+        if let elementType = substitutionMap.replacementTypes[0].canonical.silType,
            elementType.isTrivial(in: parentFunction)
         {
           context.erase(instruction: self)
@@ -129,7 +129,7 @@ private extension BuiltinInst {
   }
 
   func optimizeCanBeClass(_ context: SimplifyContext) {
-    guard let ty = substitutionMap.replacementTypes[0] else {
+    guard let ty = substitutionMap.replacementTypes[0].canonical.silType else {
       return
     }
     let literal: IntegerLiteralInst
@@ -167,7 +167,7 @@ private extension BuiltinInst {
   }
 
   func optimizeTargetTypeConst(_ context: SimplifyContext) {
-    guard let ty = substitutionMap.replacementTypes[0] else {
+    guard let ty = substitutionMap.replacementTypes[0].canonical.silType else {
       return
     }
 

SwiftCompilerSources/Sources/SIL/ASTExtensions.swift

@@ -58,9 +58,4 @@ extension SubstitutionMap {
   public func getMethodSubstitutions(for method: Function) -> SubstitutionMap {
     return SubstitutionMap(bridged: method.bridged.getMethodSubstitutions(bridged))
   }
-
-  public var replacementTypes: OptionalTypeArray {
-    let types = BridgedTypeArray.fromReplacementTypes(bridged)
-    return OptionalTypeArray(bridged: types)
-  }
 }

SwiftCompilerSources/Sources/SIL/Type.swift

@@ -243,26 +243,6 @@ public struct TypeArray : RandomAccessCollection, CustomReflectable {
   }
 }
 
-public struct OptionalTypeArray : RandomAccessCollection, CustomReflectable {
-  private let bridged: BridgedTypeArray
-
-  public var startIndex: Int { return 0 }
-  public var endIndex: Int { return bridged.getCount() }
-
-  public init(bridged: BridgedTypeArray) {
-    self.bridged = bridged
-  }
-
-  public subscript(_ index: Int) -> Type? {
-    bridged.getAt(index).typeOrNil
-  }
-
-  public var customMirror: Mirror {
-    let c: [Mirror.Child] = map { (label: nil, value: $0 ?? "<invalid>") }
-    return Mirror(self, children: c)
-  }
-}
-
 public struct NominalFieldsArray : RandomAccessCollection, FormattedLikeArray {
   fileprivate let type: Type
   fileprivate let function: Function

include/swift/AST/ASTBridging.h

@@ -2293,6 +2293,15 @@ class BridgedCanType {
   SWIFT_IMPORT_UNSAFE BRIDGED_INLINE BridgedASTType getType() const;
 };
 
+struct BridgedASTTypeArray {
+  BridgedArrayRef typeArray;
+
+  SwiftInt getCount() const { return SwiftInt(typeArray.Length); }
+
+  SWIFT_IMPORT_UNSAFE BRIDGED_INLINE
+  BridgedASTType getAt(SwiftInt index) const;
+};
+
 struct BridgedConformance {
   void * _Nullable opaqueValue;
 
@@ -2330,6 +2339,7 @@ struct BridgedSubstitutionMap {
   BRIDGED_INLINE bool hasAnySubstitutableParams() const;
   BRIDGED_INLINE SwiftInt getNumConformances() const;
   SWIFT_IMPORT_UNSAFE BRIDGED_INLINE BridgedConformance getConformance(SwiftInt index) const;
+  SWIFT_IMPORT_UNSAFE BRIDGED_INLINE BridgedASTTypeArray getReplacementTypes() const;
 };
 
 struct BridgedFingerprint {

include/swift/AST/ASTBridgingImpl.h

@@ -338,6 +338,15 @@ BridgedASTType BridgedCanType::getType() const {
   return {type};
 }
 
+//===----------------------------------------------------------------------===//
+// MARK: BridgedASTTypeArray
+//===----------------------------------------------------------------------===//
+
+BridgedASTType BridgedASTTypeArray::getAt(SwiftInt index) const {
+  return {typeArray.unbridged<swift::Type>()[index].getPointer()};
+}
+
+
 //===----------------------------------------------------------------------===//
 // MARK: BridgedConformance
 //===----------------------------------------------------------------------===//
@@ -462,6 +471,10 @@ BridgedConformance BridgedSubstitutionMap::getConformance(SwiftInt index) const
   return unbridged().getConformances()[index];
 }
 
+BridgedASTTypeArray BridgedSubstitutionMap::getReplacementTypes() const {
+  return {unbridged().getReplacementTypes()};
+}
+
 //===----------------------------------------------------------------------===//
 // MARK: BridgedFingerprint
 //===----------------------------------------------------------------------===//

include/swift/SIL/SILBridging.h

@@ -614,18 +614,6 @@ struct BridgedMultiValueResult {
   BRIDGED_INLINE SwiftInt getIndex() const;
 };
 
-struct BridgedTypeArray {
-  BridgedArrayRef typeArray;
-
-  SWIFT_IMPORT_UNSAFE BRIDGED_INLINE
-  static BridgedTypeArray fromReplacementTypes(BridgedSubstitutionMap substMap);
-
-  SwiftInt getCount() const { return SwiftInt(typeArray.Length); }
-
-  SWIFT_IMPORT_UNSAFE BRIDGED_INLINE
-  BridgedType getAt(SwiftInt index) const;
-};
-
 struct BridgedSILTypeArray {
   BridgedArrayRef typeArray;
 

include/swift/SIL/SILBridgingImpl.h

@@ -988,24 +988,7 @@ SwiftInt BridgedMultiValueResult::getIndex() const {
 }
 
 //===----------------------------------------------------------------------===//
-//                                BridgedTypeArray
-//===----------------------------------------------------------------------===//
-
-BridgedTypeArray 
-BridgedTypeArray::fromReplacementTypes(BridgedSubstitutionMap substMap) {
-  return {substMap.unbridged().getReplacementTypes()};
-}
-
-BridgedType BridgedTypeArray::getAt(SwiftInt index) const {
-  swift::Type origTy = typeArray.unbridged<swift::Type>()[index];
-  auto ty = origTy->getCanonicalType();
-  if (ty->isLegalSILType())
-    return swift::SILType::getPrimitiveObjectType(ty);
-  return swift::SILType();
-}
-
-//===----------------------------------------------------------------------===//
-//                                BridgedTypeArray
+//                              BridgedSILTypeArray
 //===----------------------------------------------------------------------===//
 
 BridgedType BridgedSILTypeArray::getAt(SwiftInt index) const {