diff --git a/include/swift/AST/Attr.h b/include/swift/AST/Attr.h
index 63152ff76a5ec..47b013e4140ce 100644
--- a/include/swift/AST/Attr.h
+++ b/include/swift/AST/Attr.h
@@ -2962,7 +2962,7 @@ class AllowFeatureSuppressionAttr final
 
   ArrayRef<Identifier> getSuppressedFeatures() const {
     return {getTrailingObjects<Identifier>(),
-            Bits.AllowFeatureSuppressionAttr.NumFeatures};
+            static_cast<size_t>(Bits.AllowFeatureSuppressionAttr.NumFeatures)};
   }
 
   static bool classof(const DeclAttribute *DA) {
diff --git a/include/swift/AST/Decl.h b/include/swift/AST/Decl.h
index 10121e8071e12..980be00680074 100644
--- a/include/swift/AST/Decl.h
+++ b/include/swift/AST/Decl.h
@@ -8672,7 +8672,7 @@ class EnumCaseDecl final : public Decl,
   /// Get the list of elements declared in this case.
   ArrayRef<EnumElementDecl *> getElements() const {
     return {getTrailingObjects<EnumElementDecl *>(),
-            Bits.EnumCaseDecl.NumElements};
+            static_cast<size_t>(Bits.EnumCaseDecl.NumElements)};
   }
   SourceRange getSourceRange() const;
 
diff --git a/include/swift/AST/Expr.h b/include/swift/AST/Expr.h
index f34ffc15db38e..6de922e90d634 100644
--- a/include/swift/AST/Expr.h
+++ b/include/swift/AST/Expr.h
@@ -2453,10 +2453,10 @@ class CollectionExpr : public Expr {
 
   /// Retrieve the elements stored in the collection.
   ArrayRef<Expr *> getElements() const {
-    return {getTrailingObjectsPointer(), Bits.CollectionExpr.NumSubExprs};
+    return {getTrailingObjectsPointer(), static_cast<size_t>(Bits.CollectionExpr.NumSubExprs)};
   }
   MutableArrayRef<Expr *> getElements() {
-    return {getTrailingObjectsPointer(), Bits.CollectionExpr.NumSubExprs};
+    return {getTrailingObjectsPointer(), static_cast<size_t>(Bits.CollectionExpr.NumSubExprs)};
   }
   Expr *getElement(unsigned i) const { return getElements()[i]; }
   void setElement(unsigned i, Expr *E) { getElements()[i] = E; }
@@ -3517,7 +3517,7 @@ class ErasureExpr final : public ImplicitConversionExpr,
   /// that corresponding protocol).
   ArrayRef<ProtocolConformanceRef> getConformances() const {
     return {getTrailingObjects<ProtocolConformanceRef>(),
-            Bits.ErasureExpr.NumConformances };
+            static_cast<size_t>(Bits.ErasureExpr.NumConformances) };
   }
 
   /// Retrieve the conversion expressions mapping requirements from any
@@ -3719,7 +3719,7 @@ class UnresolvedSpecializeExpr final : public Expr,
   /// been bound to archetypes of the entity to be specialized.
   ArrayRef<TypeRepr *> getUnresolvedParams() const {
     return {getTrailingObjects<TypeRepr *>(),
-            Bits.UnresolvedSpecializeExpr.NumUnresolvedParams};
+            static_cast<size_t>(Bits.UnresolvedSpecializeExpr.NumUnresolvedParams)};
   }
   
   SourceLoc getLoc() const { return LAngleLoc; }
@@ -3989,11 +3989,11 @@ class SequenceExpr final : public Expr,
   unsigned getNumElements() const { return Bits.SequenceExpr.NumElements; }
 
   MutableArrayRef<Expr*> getElements() {
-    return {getTrailingObjects<Expr*>(), Bits.SequenceExpr.NumElements};
+    return {getTrailingObjects<Expr*>(), static_cast<size_t>(Bits.SequenceExpr.NumElements)};
   }
 
   ArrayRef<Expr*> getElements() const {
-    return {getTrailingObjects<Expr*>(), Bits.SequenceExpr.NumElements};
+    return {getTrailingObjects<Expr*>(), static_cast<size_t>(Bits.SequenceExpr.NumElements)};
   }
 
   Expr *getElement(unsigned i) const {
@@ -4592,7 +4592,7 @@ class CaptureListExpr final : public Expr,
 
   ArrayRef<CaptureListEntry> getCaptureList() {
     return {getTrailingObjects<CaptureListEntry>(),
-            Bits.CaptureListExpr.NumCaptures};
+            static_cast<size_t>(Bits.CaptureListExpr.NumCaptures)};
   }
   AbstractClosureExpr *getClosureBody() { return closureBody; }
   const AbstractClosureExpr *getClosureBody() const { return closureBody; }
diff --git a/include/swift/AST/Stmt.h b/include/swift/AST/Stmt.h
index dc394216e08ee..d27bb5ea695e4 100644
--- a/include/swift/AST/Stmt.h
+++ b/include/swift/AST/Stmt.h
@@ -212,12 +212,12 @@ class BraceStmt final : public Stmt,
 
   /// The elements contained within the BraceStmt.
   MutableArrayRef<ASTNode> getElements() {
-    return {getTrailingObjects<ASTNode>(), Bits.BraceStmt.NumElements};
+    return {getTrailingObjects<ASTNode>(), static_cast<size_t>(Bits.BraceStmt.NumElements)};
   }
 
   /// The elements contained within the BraceStmt (const version).
   ArrayRef<ASTNode> getElements() const {
-    return {getTrailingObjects<ASTNode>(), Bits.BraceStmt.NumElements};
+    return {getTrailingObjects<ASTNode>(), static_cast<size_t>(Bits.BraceStmt.NumElements)};
   }
 
   ASTNode findAsyncNode();
@@ -330,10 +330,10 @@ class YieldStmt final
   SourceLoc getEndLoc() const;
 
   ArrayRef<Expr*> getYields() const {
-    return {getTrailingObjects<Expr*>(), Bits.YieldStmt.NumYields};
+    return {getTrailingObjects<Expr*>(), static_cast<size_t>(Bits.YieldStmt.NumYields)};
   }
   MutableArrayRef<Expr*> getMutableYields() {
-    return {getTrailingObjects<Expr*>(), Bits.YieldStmt.NumYields};
+    return {getTrailingObjects<Expr*>(), static_cast<size_t>(Bits.YieldStmt.NumYields)};
   }
   
   static bool classof(const Stmt *S) { return S->getKind() == StmtKind::Yield; }
@@ -1259,11 +1259,11 @@ class CaseStmt final
   }
 
   ArrayRef<CaseLabelItem> getCaseLabelItems() const {
-    return {getTrailingObjects<CaseLabelItem>(), Bits.CaseStmt.NumPatterns};
+    return {getTrailingObjects<CaseLabelItem>(), static_cast<size_t>(Bits.CaseStmt.NumPatterns)};
   }
 
   MutableArrayRef<CaseLabelItem> getMutableCaseLabelItems() {
-    return {getTrailingObjects<CaseLabelItem>(), Bits.CaseStmt.NumPatterns};
+    return {getTrailingObjects<CaseLabelItem>(), static_cast<size_t>(Bits.CaseStmt.NumPatterns)};
   }
 
   unsigned getNumCaseLabelItems() const { return Bits.CaseStmt.NumPatterns; }
@@ -1448,7 +1448,7 @@ class SwitchStmt final : public LabeledStmt,
   void setSubjectExpr(Expr *e) { SubjectExpr = e; }
 
   ArrayRef<ASTNode> getRawCases() const {
-    return {getTrailingObjects<ASTNode>(), Bits.SwitchStmt.CaseCount};
+    return {getTrailingObjects<ASTNode>(), static_cast<size_t>(Bits.SwitchStmt.CaseCount)};
   }
 
 private:
@@ -1541,10 +1541,10 @@ class DoCatchStmt final
   void setBody(Stmt *s) { Body = s; }
 
   ArrayRef<CaseStmt *> getCatches() const {
-    return {getTrailingObjects<CaseStmt *>(), Bits.DoCatchStmt.NumCatches};
+    return {getTrailingObjects<CaseStmt *>(), static_cast<size_t>(Bits.DoCatchStmt.NumCatches)};
   }
   MutableArrayRef<CaseStmt *> getMutableCatches() {
-    return {getTrailingObjects<CaseStmt *>(), Bits.DoCatchStmt.NumCatches};
+    return {getTrailingObjects<CaseStmt *>(), static_cast<size_t>(Bits.DoCatchStmt.NumCatches)};
   }
 
   /// Retrieve the complete set of branches for this do-catch statement.
diff --git a/include/swift/AST/TypeRepr.h b/include/swift/AST/TypeRepr.h
index e6082dc295d2c..d18c62a544a96 100644
--- a/include/swift/AST/TypeRepr.h
+++ b/include/swift/AST/TypeRepr.h
@@ -917,7 +917,7 @@ class TupleTypeRepr final : public TypeRepr,
 
   ArrayRef<TupleTypeReprElement> getElements() const {
     return { getTrailingObjects<TupleTypeReprElement>(),
-             Bits.TupleTypeRepr.NumElements };
+             static_cast<size_t>(Bits.TupleTypeRepr.NumElements) };
   }
 
   void getElementTypes(SmallVectorImpl<TypeRepr *> &Types) const {
@@ -1003,7 +1003,7 @@ class CompositionTypeRepr final : public TypeRepr,
 
 public:
   ArrayRef<TypeRepr *> getTypes() const {
-    return {getTrailingObjects<TypeRepr*>(), Bits.CompositionTypeRepr.NumTypes};
+    return {getTrailingObjects<TypeRepr*>(), static_cast<size_t>(Bits.CompositionTypeRepr.NumTypes)};
   }
   SourceLoc getSourceLoc() const { return FirstTypeLoc; }
   SourceRange getCompositionRange() const { return CompositionRange; }
@@ -1494,7 +1494,7 @@ class SILBoxTypeRepr final : public TypeRepr,
   
   ArrayRef<Field> getFields() const {
     return {getTrailingObjects<Field>(),
-            Bits.SILBoxTypeRepr.NumFields};
+            static_cast<size_t>(Bits.SILBoxTypeRepr.NumFields)};
   }
   ArrayRef<TypeRepr *> getGenericArguments() const {
     return {getTrailingObjects<TypeRepr*>(),
diff --git a/include/swift/AST/Types.h b/include/swift/AST/Types.h
index 14195f16ed191..7ae6766315793 100644
--- a/include/swift/AST/Types.h
+++ b/include/swift/AST/Types.h
@@ -2824,7 +2824,7 @@ class BoundGenericType : public NominalOrBoundGenericNominalType,
 
   /// Retrieve the set of generic arguments provided at this level.
   ArrayRef<Type> getGenericArgs() const {
-    return {getTrailingObjectsPointer(), Bits.BoundGenericType.GenericArgCount};
+    return {getTrailingObjectsPointer(), static_cast<size_t>(Bits.BoundGenericType.GenericArgCount)};
   }
 
   SmallVector<Type, 2> getExpandedGenericArgs();
@@ -6365,7 +6365,7 @@ class ProtocolCompositionType final : public TypeBase,
   /// a protocol composition type; you also have to look at
   /// hasExplicitAnyObject().
   ArrayRef<Type> getMembers() const {
-    return {getTrailingObjects<Type>(), Bits.ProtocolCompositionType.Count};
+    return {getTrailingObjects<Type>(), static_cast<size_t>(Bits.ProtocolCompositionType.Count)};
   }
 
   InvertibleProtocolSet getInverses() const { return Inverses; }
@@ -6463,7 +6463,7 @@ class ParameterizedProtocolType final : public TypeBase,
 
   ArrayRef<Type> getArgs() const {
     return {getTrailingObjects<Type>(),
-            Bits.ParameterizedProtocolType.ArgCount};
+            static_cast<size_t>(Bits.ParameterizedProtocolType.ArgCount)};
   }
 
   bool requiresClass() const {
@@ -7513,7 +7513,7 @@ class ErrorUnionType final
   static Type get(const ASTContext &ctx, ArrayRef<Type> terms);
 
   ArrayRef<Type> getTerms() const {
-    return { getTrailingObjects<Type>(), Bits.ErrorUnionType.NumTerms };
+    return { getTrailingObjects<Type>(), static_cast<size_t>(Bits.ErrorUnionType.NumTerms) };
   };
 
   // Support for FoldingSet.
diff --git a/lib/AST/Stmt.cpp b/lib/AST/Stmt.cpp
index 2d5cbbe154f42..2de0f3b1e1204 100644
--- a/lib/AST/Stmt.cpp
+++ b/lib/AST/Stmt.cpp
@@ -771,7 +771,7 @@ CaseStmt::CaseStmt(CaseParentKind parentKind, SourceLoc itemIntroducerLoc,
   }
 
   MutableArrayRef<CaseLabelItem> items{getTrailingObjects<CaseLabelItem>(),
-                                       Bits.CaseStmt.NumPatterns};
+                                       static_cast<size_t>(Bits.CaseStmt.NumPatterns)};
 
   // At the beginning mark all of our var decls as being owned by this
   // statement. In the typechecker we wireup the case stmt var decl list since