Index: include/new
===================================================================
--- include/new
+++ include/new
@@ -139,9 +139,11 @@
 ;
 _LIBCPP_NEW_DELETE_VIS void* operator new(std::size_t __sz, const std::nothrow_t&) _NOEXCEPT _NOALIAS;
 _LIBCPP_NEW_DELETE_VIS void  operator delete(void* __p) _NOEXCEPT;
+_LIBCPP_NEW_DELETE_VIS void  operator delete(void* __p, const std::nothrow_t&) _NOEXCEPT;
+#if defined(_LIBCPP_BUILDING_NEW) || _LIBCPP_STD_VER >= 14
 _LIBCPP_NEW_DELETE_VIS void  operator delete(void* __p, std::size_t __sz) _NOEXCEPT;
-_LIBCPP_NEW_DELETE_VIS void  operator delete(void* __p, const std::nothrow_t&) _NOEXCEPT;
 _LIBCPP_NEW_DELETE_VIS void  operator delete(void* __p, std::size_t __sz, const std::nothrow_t&) _NOEXCEPT;
+#endif
 
 _LIBCPP_NEW_DELETE_VIS void* operator new[](std::size_t __sz)
 #if !__has_feature(cxx_noexcept)
@@ -150,9 +152,11 @@
 ;
 _LIBCPP_NEW_DELETE_VIS void* operator new[](std::size_t __sz, const std::nothrow_t&) _NOEXCEPT _NOALIAS;
 _LIBCPP_NEW_DELETE_VIS void  operator delete[](void* __p) _NOEXCEPT;
+_LIBCPP_NEW_DELETE_VIS void  operator delete[](void* __p, const std::nothrow_t&) _NOEXCEPT;
+#if defined(_LIBCPP_BUILDING_NEW) || _LIBCPP_STD_VER >= 14
 _LIBCPP_NEW_DELETE_VIS void  operator delete[](void* __p, std::size_t __sz) _NOEXCEPT;
-_LIBCPP_NEW_DELETE_VIS void  operator delete[](void* __p, const std::nothrow_t&) _NOEXCEPT;
 _LIBCPP_NEW_DELETE_VIS void  operator delete[](void* __p, std::size_t __sz, const std::nothrow_t&) _NOEXCEPT;
+#endif
 
 inline _LIBCPP_INLINE_VISIBILITY void* operator new  (std::size_t, void* __p) _NOEXCEPT {return __p;}
 inline _LIBCPP_INLINE_VISIBILITY void* operator new[](std::size_t, void* __p) _NOEXCEPT {return __p;}
Index: src/new.cpp
===================================================================
--- src/new.cpp
+++ src/new.cpp
@@ -126,24 +126,26 @@
 
 _LIBCPP_WEAK _LIBCPP_NEW_DELETE_VIS
 void
-operator delete(void* ptr, size_t) _NOEXCEPT
+operator delete(void* ptr, const std::nothrow_t&) _NOEXCEPT
 {
     ::operator delete(ptr);
 }
 
+#if _LIBCPP_STD_VER >= 14
 _LIBCPP_WEAK _LIBCPP_NEW_DELETE_VIS
 void
-operator delete(void* ptr, const std::nothrow_t&) _NOEXCEPT
+operator delete(void* ptr, size_t) _NOEXCEPT
 {
     ::operator delete(ptr);
 }
 
 _LIBCPP_WEAK _LIBCPP_NEW_DELETE_VIS
 void
-operator delete(void* ptr, size_t, const std::nothrow_t&) _NOEXCEPT
+operator delete(void* ptr, size_t, const std::nothrow_t& nt) _NOEXCEPT
 {
-    ::operator delete(ptr);
+    ::operator delete(ptr, nt);
 }
+#endif  // _LIBCPP_STD_VER >= 14
 
 _LIBCPP_WEAK _LIBCPP_NEW_DELETE_VIS
 void
@@ -154,24 +156,26 @@
 
 _LIBCPP_WEAK _LIBCPP_NEW_DELETE_VIS
 void
-operator delete[] (void* ptr, size_t) _NOEXCEPT
+operator delete[] (void* ptr, const std::nothrow_t&) _NOEXCEPT
 {
     ::operator delete[](ptr);
 }
 
+#if _LIBCPP_STD_VER >= 14
 _LIBCPP_WEAK _LIBCPP_NEW_DELETE_VIS
 void
-operator delete[] (void* ptr, const std::nothrow_t&) _NOEXCEPT
+operator delete[] (void* ptr, size_t) _NOEXCEPT
 {
     ::operator delete[](ptr);
 }
 
 _LIBCPP_WEAK _LIBCPP_NEW_DELETE_VIS
 void
-operator delete[] (void* ptr, size_t, const std::nothrow_t&) _NOEXCEPT
+operator delete[] (void* ptr, size_t, const std::nothrow_t&, nt) _NOEXCEPT
 {
-    ::operator delete[](ptr);
+    ::operator delete[](ptr, nt);
 }
+#endif // _LIBCPP_STD_VER >= 14
 
 #endif // !__GLIBCXX__
 
Index: test/std/language.support/support.dynamic/new.delete/new.delete.array/sized_delete_array.pass.cpp
===================================================================
--- test/std/language.support/support.dynamic/new.delete/new.delete.array/sized_delete_array.pass.cpp
+++ test/std/language.support/support.dynamic/new.delete/new.delete.array/sized_delete_array.pass.cpp
@@ -0,0 +1,63 @@
+//===----------------------------------------------------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is dual licensed under the MIT and the University of Illinois Open
+// Source Licenses. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+// test sized operator delete[] by replacing unsized operator delete[]
+
+// UNSUPPORTED: asan, msan
+
+#include <new>
+#include <cstddef>
+#include <cstdlib>
+#include <cassert>
+#include <limits>
+
+#if _LIBCPP_STD_VER >= 14
+
+int delete_called = 0;
+int delete_nothrow_called = 0;
+
+void  operator delete[](void* p) throw()
+{
+  ++delete_called;
+  delete_nothrow_called;
+  std::free(p);
+}
+
+void  operator delete[](void* p, const std::nothrow_t&) throw()
+{
+  ++delete_nothrow_called;
+  std::free(p);
+}
+
+bool A_constructed = false;
+
+struct A
+{
+    A() {A_constructed = true;}
+    ~A() {A_constructed = false;}
+};
+
+int main()
+{
+    A* ap = new A[3];
+    assert(ap);
+    assert(A_constructed == 3);
+    assert(!delete_called);
+    assert(!delete_nothrow_called);
+    delete [] ap;
+    assert(!A_constructed);
+    assert(delete_called == 1);
+    assert(!delete_nothrow_called);
+}
+
+#else
+
+int main () {}
+
+#endif // _LIBCPP_STD_VER >= 14
Index: test/std/language.support/support.dynamic/new.delete/new.delete.array/sized_delete_array_nothrow.pass.cpp
===================================================================
--- test/std/language.support/support.dynamic/new.delete/new.delete.array/sized_delete_array_nothrow.pass.cpp
+++ test/std/language.support/support.dynamic/new.delete/new.delete.array/sized_delete_array_nothrow.pass.cpp
@@ -0,0 +1,63 @@
+//===----------------------------------------------------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is dual licensed under the MIT and the University of Illinois Open
+// Source Licenses. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+// test nothrow sized operator delete[] by replacing
+// nothrow unsized operator delete[].
+
+// UNSUPPORTED: asan, msan
+
+#include <new>
+#include <cstddef>
+#include <cstdlib>
+#include <cassert>
+#include <limits>
+
+#if _LIBCPP_STD_VER >= 14
+
+int delete_called = 0;
+int delete_nothrow_called = 0;
+
+void  operator delete[](void* p) throw()
+{
+  ++delete_called;
+  std::free(p);
+}
+
+void  operator delete[](void* p, const std::nothrow_t&) throw()
+{
+  ++delete_nothrow_called;
+  std::free(p);
+}
+
+bool A_constructed = false;
+
+struct A
+{
+    A() {A_constructed = true;}
+    ~A() {A_constructed = false;}
+};
+
+int main()
+{
+    A* ap = new A(std::nothrow) [3];
+    assert(ap);
+    assert(A_constructed == 3);
+    assert(!delete_called);
+    assert(!delete_nothrow_called);
+    delete [] ap;
+    assert(!A_constructed);
+    assert(!delete_called);
+    assert(delete_nothrow_called == 1);
+}
+
+#else
+
+int main () {}
+
+#endif // _LIBCPP_STD_VER >= 14
Index: test/std/language.support/support.dynamic/new.delete/new.delete.array/sized_delete_array_nothrow_replace.pass.cpp
===================================================================
--- test/std/language.support/support.dynamic/new.delete/new.delete.array/sized_delete_array_nothrow_replace.pass.cpp
+++ test/std/language.support/support.dynamic/new.delete/new.delete.array/sized_delete_array_nothrow_replace.pass.cpp
@@ -0,0 +1,80 @@
+//===----------------------------------------------------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is dual licensed under the MIT and the University of Illinois Open
+// Source Licenses. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+// test nothrow sized operator delete[] replacement
+
+// UNSUPPORTED: asan, msan
+
+#include <new>
+#include <cstddef>
+#include <cstdlib>
+#include <cassert>
+#include <limits>
+
+#if _LIBCPP_STD_VER >= 14
+
+int unsized_delete_called = 0;
+int unsized_delete_nothrow_called = 0;
+int sized_delete_called = 0;
+int sized_delete_nothrow_called = 0;
+
+void  operator delete[](void* p) throw()
+{
+  ++unsized_delete_called;
+  std::free(p);
+}
+
+void  operator delete[](void* p, const std::nothrow_t&) throw()
+{
+  ++unsized_delete_nothrow_called;
+  std::free(p);
+}
+
+void  operator delete[](void* p, std::size_t) throw()
+{
+    ++size_delete_called;
+    std::free(p);
+}
+
+void  operator delete[](void* p, std::size_t, const std::nothrow_t&) throw()
+{
+  ++size_delete_nothrow_called;
+  std::free(p);
+}
+
+bool A_constructed = false;
+
+struct A
+{
+    A() {A_constructed = true;}
+    ~A() {A_constructed = false;}
+};
+
+int main()
+{
+    A* ap = new A(std::nothrow) [3];
+    assert(ap);
+    assert(A_constructed);
+    assert(!unsized_delete_called);
+    assert(!unsized_delete_nothrow_called);
+    assert(!sized_delete_called);
+    assert(!sized_delete_nothrow_called);
+    delete [] ap;
+    assert(!A_constructed);
+    assert(!unsized_delete_called);
+    assert(!unsized_delete_nothrow_called);
+    assert(!sized_delete_called);
+    assert(sized_delete_nothrow_called == 1);
+}
+
+#else
+
+int main () {}
+
+#endif // _LIBCPP_STD_VER >= 14
Index: test/std/language.support/support.dynamic/new.delete/new.delete.array/sized_delete_array_replace.pass.cpp
===================================================================
--- test/std/language.support/support.dynamic/new.delete/new.delete.array/sized_delete_array_replace.pass.cpp
+++ test/std/language.support/support.dynamic/new.delete/new.delete.array/sized_delete_array_replace.pass.cpp
@@ -0,0 +1,80 @@
+//===----------------------------------------------------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is dual licensed under the MIT and the University of Illinois Open
+// Source Licenses. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+// test sized operator delete[] replacement
+
+// UNSUPPORTED: asan, msan
+
+#include <new>
+#include <cstddef>
+#include <cstdlib>
+#include <cassert>
+#include <limits>
+
+#if _LIBCPP_STD_VER >= 14
+
+int unsized_delete_called = 0;
+int unsized_delete_nothrow_called = 0;
+int sized_delete_called = 0;
+int sized_delete_nothrow_called = 0;
+
+void  operator delete[](void* p) throw()
+{
+  ++unsized_delete_called;
+  std::free(p);
+}
+
+void  operator delete[](void* p, const std::nothrow_t&) throw()
+{
+  ++unsized_delete_nothrow_called;
+  std::free(p);
+}
+
+void  operator delete[](void* p, std::size_t) throw()
+{
+    ++size_delete_called;
+    std::free(p);
+}
+
+void  operator delete[](void* p, std::size_t, const std::nothrow_t&) throw()
+{
+  ++size_delete_nothrow_called;
+  std::free(p);
+}
+
+bool A_constructed = false;
+
+struct A
+{
+    A() {A_constructed = true;}
+    ~A() {A_constructed = false;}
+};
+
+int main()
+{
+    A* ap = new A[3];
+    assert(ap);
+    assert(A_constructed == 3);
+    assert(!unsized_delete_called);
+    assert(!unsized_delete_nothrow_called);
+    assert(!sized_delete_called);
+    assert(!sized_delete_nothrow_called);
+    delete [] ap;
+    assert(!A_constructed);
+    assert(!unsized_delete_called);
+    assert(!unsized_delete_nothrow_called);
+    assert(sized_delete_called == 1);
+    assert(!sized_delete_nothrow_called);
+}
+
+#else
+
+int main () {}
+
+#endif // _LIBCPP_STD_VER >= 14
Index: test/std/language.support/support.dynamic/new.delete/new.delete.single/sized_delete.pass.cpp
===================================================================
--- test/std/language.support/support.dynamic/new.delete/new.delete.single/sized_delete.pass.cpp
+++ test/std/language.support/support.dynamic/new.delete/new.delete.single/sized_delete.pass.cpp
@@ -0,0 +1,63 @@
+//===----------------------------------------------------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is dual licensed under the MIT and the University of Illinois Open
+// Source Licenses. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+// test sized operator delete by replacing unsized operator delete
+
+// UNSUPPORTED: asan, msan
+
+#include <new>
+#include <cstddef>
+#include <cstdlib>
+#include <cassert>
+#include <limits>
+
+#if _LIBCPP_STD_VER >= 14
+
+int delete_called = 0;
+int delete_nothrow_called = 0;
+
+void  operator delete(void* p) throw()
+{
+  ++delete_called;
+  delete_nothrow_called;
+  std::free(p);
+}
+
+void  operator delete(void* p, const std::nothrow_t&) throw()
+{
+  ++delete_nothrow_called;
+  std::free(p);
+}
+
+bool A_constructed = false;
+
+struct A
+{
+    A() {A_constructed = true;}
+    ~A() {A_constructed = false;}
+};
+
+int main()
+{
+    A* ap = new A;
+    assert(ap);
+    assert(A_constructed);
+    assert(!delete_called);
+    assert(!delete_nothrow_called);
+    delete ap;
+    assert(!A_constructed);
+    assert(delete_called == 1);
+    assert(!delete_nothrow_called);
+}
+
+#else
+
+int main () {}
+
+#endif // _LIBCPP_STD_VER >= 14
Index: test/std/language.support/support.dynamic/new.delete/new.delete.single/sized_delete_nothrow.pass.cpp
===================================================================
--- test/std/language.support/support.dynamic/new.delete/new.delete.single/sized_delete_nothrow.pass.cpp
+++ test/std/language.support/support.dynamic/new.delete/new.delete.single/sized_delete_nothrow.pass.cpp
@@ -0,0 +1,64 @@
+//===----------------------------------------------------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is dual licensed under the MIT and the University of Illinois Open
+// Source Licenses. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+// test nothrow sized operator delete by replacing
+// nothrow unsized operator delete.
+
+// UNSUPPORTED: asan, msan
+
+#include <new>
+#include <cstddef>
+#include <cstdlib>
+#include <cassert>
+#include <limits>
+
+#if _LIBCPP_STD_VER >= 14
+
+int delete_called = 0;
+int delete_nothrow_called = 0;
+
+void  operator delete(void* p) throw()
+{
+  ++delete_called;
+  delete_nothrow_called;
+  std::free(p);
+}
+
+void  operator delete(void* p, const std::nothrow_t&) throw()
+{
+  ++delete_nothrow_called;
+  std::free(p);
+}
+
+bool A_constructed = false;
+
+struct A
+{
+    A() {A_constructed = true;}
+    ~A() {A_constructed = false;}
+};
+
+int main()
+{
+    A* ap = new A(std::nothrow);
+    assert(ap);
+    assert(A_constructed);
+    assert(!delete_called);
+    assert(!delete_nothrow_called);
+    delete ap;
+    assert(!A_constructed);
+    assert(!delete_called);
+    assert(delete_nothrow_called == 1);
+}
+
+#else
+
+int main () {}
+
+#endif // _LIBCPP_STD_VER >= 14
Index: test/std/language.support/support.dynamic/new.delete/new.delete.single/sized_delete_nothrow_replace.pass.cpp
===================================================================
--- test/std/language.support/support.dynamic/new.delete/new.delete.single/sized_delete_nothrow_replace.pass.cpp
+++ test/std/language.support/support.dynamic/new.delete/new.delete.single/sized_delete_nothrow_replace.pass.cpp
@@ -0,0 +1,80 @@
+//===----------------------------------------------------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is dual licensed under the MIT and the University of Illinois Open
+// Source Licenses. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+// test nothrow sized operator delete replacement
+
+// UNSUPPORTED: asan, msan
+
+#include <new>
+#include <cstddef>
+#include <cstdlib>
+#include <cassert>
+#include <limits>
+
+#if _LIBCPP_STD_VER >= 14
+
+int unsized_delete_called = 0;
+int unsized_delete_nothrow_called = 0;
+int sized_delete_called = 0;
+int sized_delete_nothrow_called = 0;
+
+void  operator delete(void* p) throw()
+{
+  ++unsized_delete_called;
+  std::free(p);
+}
+
+void  operator delete(void* p, const std::nothrow_t&) throw()
+{
+  ++unsized_delete_nothrow_called;
+  std::free(p);
+}
+
+void  operator delete(void* p, std::size_t) throw()
+{
+    ++size_delete_called;
+    std::free(p);
+}
+
+void  operator delete(void* p, std::size_t, const std::nothrow_t&) throw()
+{
+  ++size_delete_nothrow_called;
+  std::free(p);
+}
+
+bool A_constructed = false;
+
+struct A
+{
+    A() {A_constructed = true;}
+    ~A() {A_constructed = false;}
+};
+
+int main()
+{
+    A* ap = new A(std::nothrow);
+    assert(ap);
+    assert(A_constructed);
+    assert(!unsized_delete_called);
+    assert(!unsized_delete_nothrow_called);
+    assert(!sized_delete_called);
+    assert(!sized_delete_nothrow_called);
+    delete ap;
+    assert(!A_constructed);
+    assert(!unsized_delete_called);
+    assert(!unsized_delete_nothrow_called);
+    assert(!sized_delete_called);
+    assert(sized_delete_nothrow_called == 1);
+}
+
+#else
+
+int main () {}
+
+#endif // _LIBCPP_STD_VER >= 14
Index: test/std/language.support/support.dynamic/new.delete/new.delete.single/sized_delete_replace.pass.cpp
===================================================================
--- test/std/language.support/support.dynamic/new.delete/new.delete.single/sized_delete_replace.pass.cpp
+++ test/std/language.support/support.dynamic/new.delete/new.delete.single/sized_delete_replace.pass.cpp
@@ -0,0 +1,80 @@
+//===----------------------------------------------------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is dual licensed under the MIT and the University of Illinois Open
+// Source Licenses. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+// test sized operator delete replacement
+
+// UNSUPPORTED: asan, msan
+
+#include <new>
+#include <cstddef>
+#include <cstdlib>
+#include <cassert>
+#include <limits>
+
+#if _LIBCPP_STD_VER >= 14
+
+int unsized_delete_called = 0;
+int unsized_delete_nothrow_called = 0;
+int sized_delete_called = 0;
+int sized_delete_nothrow_called = 0;
+
+void  operator delete(void* p) throw()
+{
+  ++unsized_delete_called;
+  std::free(p);
+}
+
+void  operator delete(void* p, const std::nothrow_t&) throw()
+{
+  ++unsized_delete_nothrow_called;
+  std::free(p);
+}
+
+void  operator delete(void* p, std::size_t) throw()
+{
+    ++size_delete_called;
+    std::free(p);
+}
+
+void  operator delete(void* p, std::size_t, const std::nothrow_t&) throw()
+{
+  ++size_delete_nothrow_called;
+  std::free(p);
+}
+
+bool A_constructed = false;
+
+struct A
+{
+    A() {A_constructed = true;}
+    ~A() {A_constructed = false;}
+};
+
+int main()
+{
+    A* ap = new A;
+    assert(ap);
+    assert(A_constructed);
+    assert(!unsized_delete_called);
+    assert(!unsized_delete_nothrow_called);
+    assert(!sized_delete_called);
+    assert(!sized_delete_nothrow_called);
+    delete ap;
+    assert(!A_constructed);
+    assert(!unsized_delete_called);
+    assert(!unsized_delete_nothrow_called);
+    assert(sized_delete_called == 1);
+    assert(!sized_delete_nothrow_called);
+}
+
+#else
+
+int main () {}
+
+#endif // _LIBCPP_STD_VER >= 14