Index: lib/Target/WebAssembly/WebAssemblyRuntimeLibcallSignatures.cpp
===================================================================
--- lib/Target/WebAssembly/WebAssemblyRuntimeLibcallSignatures.cpp
+++ lib/Target/WebAssembly/WebAssemblyRuntimeLibcallSignatures.cpp
@@ -394,12 +394,11 @@
 /* MEMMOVE */ iPTR_func_iPTR_iPTR_iPTR,
 
 // ELEMENT-WISE ATOMIC MEMORY
-/* MEMCPY_ELEMENT_ATOMIC_1 */ iPTR_func_iPTR_iPTR_iPTR,
-/* MEMCPY_ELEMENT_ATOMIC_2 */ iPTR_func_iPTR_iPTR_iPTR,
-/* MEMCPY_ELEMENT_ATOMIC_4 */ iPTR_func_iPTR_iPTR_iPTR,
-/* MEMCPY_ELEMENT_ATOMIC_8 */ iPTR_func_iPTR_iPTR_iPTR,
-/* MEMCPY_ELEMENT_ATOMIC_16 */ iPTR_func_iPTR_iPTR_iPTR,
-
+/* MEMCPY_ELEMENT_UNORDERED_ATOMIC_1 */ unsupported,
+/* MEMCPY_ELEMENT_UNORDERED_ATOMIC_2 */ unsupported,
+/* MEMCPY_ELEMENT_UNORDERED_ATOMIC_4 */ unsupported,
+/* MEMCPY_ELEMENT_UNORDERED_ATOMIC_8 */ unsupported,
+/* MEMCPY_ELEMENT_UNORDERED_ATOMIC_16 */ unsupported,
 /* MEMMOVE_ELEMENT_UNORDERED_ATOMIC_1 */ unsupported,
 /* MEMMOVE_ELEMENT_UNORDERED_ATOMIC_2 */ unsupported,
 /* MEMMOVE_ELEMENT_UNORDERED_ATOMIC_4 */ unsupported,
@@ -845,11 +844,11 @@
 /* MEMCPY */ "memcpy",
 /* MEMMOVE */ "memset",
 /* MEMSET */ "memmove",
-/* MEMCPY_ELEMENT_ATOMIC_1 */ "MEMCPY_ELEMENT_ATOMIC_1",
-/* MEMCPY_ELEMENT_ATOMIC_2 */ "MEMCPY_ELEMENT_ATOMIC_2",
-/* MEMCPY_ELEMENT_ATOMIC_4 */ "MEMCPY_ELEMENT_ATOMIC_4",
-/* MEMCPY_ELEMENT_ATOMIC_8 */ "MEMCPY_ELEMENT_ATOMIC_8",
-/* MEMCPY_ELEMENT_ATOMIC_16 */ "MEMCPY_ELEMENT_ATOMIC_16",
+/* MEMCPY_ELEMENT_UNORDERED_ATOMIC_1 */ nullptr,
+/* MEMCPY_ELEMENT_UNORDERED_ATOMIC_2 */ nullptr,
+/* MEMCPY_ELEMENT_UNORDERED_ATOMIC_4 */ nullptr,
+/* MEMCPY_ELEMENT_UNORDERED_ATOMIC_8 */ nullptr,
+/* MEMCPY_ELEMENT_UNORDERED_ATOMIC_16 */ nullptr,
 /* MEMMOVE_ELEMENT_UNORDERED_ATOMIC_1 */ nullptr,
 /* MEMMOVE_ELEMENT_UNORDERED_ATOMIC_2 */ nullptr,
 /* MEMMOVE_ELEMENT_UNORDERED_ATOMIC_4 */ nullptr,