diff --git a/stdlib/public/runtime/HeapObject.cpp b/stdlib/public/runtime/HeapObject.cpp
index 65f52fbaecb..1a07eb4abac 100644
--- a/stdlib/public/runtime/HeapObject.cpp
+++ b/stdlib/public/runtime/HeapObject.cpp
@@ -72,12 +72,6 @@ static inline bool isValidPointerForNativeRetain(const void *p) {
 #endif
 }
 
-HeapObject *swift::swift_allocObject(HeapMetadata const *metadata,
-                                     size_t requiredSize,
-                                     size_t requiredAlignmentMask) {
-  return _swift_allocObject(metadata, requiredSize, requiredAlignmentMask);
-}
-
 static HeapObject *_swift_allocObject_(HeapMetadata const *metadata,
                                        size_t requiredSize,
                                        size_t requiredAlignmentMask) {
@@ -98,7 +92,18 @@ static HeapObject *_swift_allocObject_(HeapMetadata const *metadata,
   return object;
 }
 
-auto swift::_swift_allocObject = _swift_allocObject_;
+HeapObject *swift::swift_allocObject(HeapMetadata const *metadata,
+                                     size_t requiredSize,
+                                     size_t requiredAlignmentMask) {
+  if (SWIFT_UNLIKELY(_swift_allocObject))
+    return _swift_allocObject(metadata, requiredSize, requiredAlignmentMask);
+  else
+    return _swift_allocObject_(metadata, requiredSize, requiredAlignmentMask);
+}
+
+HeapObject *(*swift::_swift_allocObject)(HeapMetadata const *metadata,
+                                         size_t requiredSize,
+                                         size_t requiredAlignmentMask);
 
 HeapObject *
 swift::swift_initStackObject(HeapMetadata const *metadata,
@@ -292,10 +297,6 @@ HeapObject *swift::swift_allocEmptyBox() {
 extern "C" LLVM_LIBRARY_VISIBILITY LLVM_ATTRIBUTE_NOINLINE LLVM_ATTRIBUTE_USED 
 void _swift_release_dealloc(HeapObject *object);
 
-HeapObject *swift::swift_retain(HeapObject *object) {
-  return _swift_retain(object);
-}
-
 static HeapObject *_swift_retain_(HeapObject *object) {
   SWIFT_RT_TRACK_INVOCATION(object, swift_retain);
   if (isValidPointerForNativeRetain(object))
@@ -303,7 +304,14 @@ static HeapObject *_swift_retain_(HeapObject *object) {
   return object;
 }
 
-auto swift::_swift_retain = _swift_retain_;
+HeapObject *swift::swift_retain(HeapObject *object) {
+  if (SWIFT_UNLIKELY(_swift_retain))
+    return _swift_retain(object);
+  else
+    return _swift_retain_(object);
+}
+
+HeapObject *(*swift::_swift_retain)(HeapObject *object);
 
 HeapObject *swift::swift_nonatomic_retain(HeapObject *object) {
   SWIFT_RT_TRACK_INVOCATION(object, swift_nonatomic_retain);
@@ -312,10 +320,6 @@ HeapObject *swift::swift_nonatomic_retain(HeapObject *object) {
   return object;
 }
 
-HeapObject *swift::swift_retain_n(HeapObject *object, uint32_t n) {
-  return _swift_retain_n(object, n);
-}
-
 static HeapObject *_swift_retain_n_(HeapObject *object, uint32_t n) {
   SWIFT_RT_TRACK_INVOCATION(object, swift_retain_n);
   if (isValidPointerForNativeRetain(object))
@@ -323,7 +327,14 @@ static HeapObject *_swift_retain_n_(HeapObject *object, uint32_t n) {
   return object;
 }
 
-auto swift::_swift_retain_n = _swift_retain_n_;
+HeapObject *swift::swift_retain_n(HeapObject *object, uint32_t n) {
+  if (SWIFT_UNLIKELY(_swift_retain_n))
+    return _swift_retain_n(object, n);
+  else
+    return _swift_retain_n_(object, n);
+}
+
+HeapObject *(*swift::_swift_retain_n)(HeapObject *object, uint32_t n);
 
 HeapObject *swift::swift_nonatomic_retain_n(HeapObject *object, uint32_t n) {
   SWIFT_RT_TRACK_INVOCATION(object, swift_nonatomic_retain_n);
@@ -332,17 +343,20 @@ HeapObject *swift::swift_nonatomic_retain_n(HeapObject *object, uint32_t n) {
   return object;
 }
 
-void swift::swift_release(HeapObject *object) {
-  _swift_release(object);
-}
-
 static void _swift_release_(HeapObject *object) {
   SWIFT_RT_TRACK_INVOCATION(object, swift_release);
   if (isValidPointerForNativeRetain(object))
     object->refCounts.decrementAndMaybeDeinit(1);
 }
 
-auto swift::_swift_release = _swift_release_;
+void swift::swift_release(HeapObject *object) {
+  if (SWIFT_UNLIKELY(_swift_release))
+    _swift_release(object);
+  else
+    _swift_release_(object);
+}
+
+void (*swift::_swift_release)(HeapObject *object);
 
 void swift::swift_nonatomic_release(HeapObject *object) {
   SWIFT_RT_TRACK_INVOCATION(object, swift_nonatomic_release);
@@ -350,17 +364,20 @@ void swift::swift_nonatomic_release(HeapObject *object) {
     object->refCounts.decrementAndMaybeDeinitNonAtomic(1);
 }
 
-void swift::swift_release_n(HeapObject *object, uint32_t n) {
-  return _swift_release_n(object, n);
-}
-
 static void _swift_release_n_(HeapObject *object, uint32_t n) {
   SWIFT_RT_TRACK_INVOCATION(object, swift_release_n);
   if (isValidPointerForNativeRetain(object))
     object->refCounts.decrementAndMaybeDeinit(n);
 }
 
-auto swift::_swift_release_n = _swift_release_n_;
+void swift::swift_release_n(HeapObject *object, uint32_t n) {
+  if (SWIFT_UNLIKELY(_swift_release_n))
+    return _swift_release_n(object, n);
+  else
+    return _swift_release_n_(object, n);
+}
+
+void (*swift::_swift_release_n)(HeapObject *object, uint32_t n);
 
 void swift::swift_nonatomic_release_n(HeapObject *object, uint32_t n) {
   SWIFT_RT_TRACK_INVOCATION(object, swift_nonatomic_release_n);
@@ -484,10 +501,6 @@ void swift::swift_nonatomic_unownedRelease_n(HeapObject *object, int n) {
   }
 }
 
-HeapObject *swift::swift_tryRetain(HeapObject *object) {
-  return _swift_tryRetain(object);
-}
-
 static HeapObject *_swift_tryRetain_(HeapObject *object) {
   SWIFT_RT_TRACK_INVOCATION(object, swift_tryRetain);
   if (!isValidPointerForNativeRetain(object))
@@ -497,7 +510,14 @@ static HeapObject *_swift_tryRetain_(HeapObject *object) {
   else return nullptr;
 }
 
-auto swift::_swift_tryRetain = _swift_tryRetain_;
+HeapObject *swift::swift_tryRetain(HeapObject *object) {
+  if (SWIFT_UNLIKELY(_swift_tryRetain))
+    return _swift_tryRetain(object);
+  else
+    return _swift_tryRetain_(object);
+}
+
+HeapObject *(*swift::_swift_tryRetain)(HeapObject *object);
 
 bool swift::swift_isDeallocating(HeapObject *object) {
   if (!isValidPointerForNativeRetain(object))