1 files changed, 35 insertions, 0 deletions
diff --git a/roms/edk2/MdePkg/Library/BaseSynchronizationLib/X64/InterlockedCompareExchange64.nasm b/roms/edk2/MdePkg/Library/BaseSynchronizationLib/X64/InterlockedCompareExchange64.nasm
new file mode 100644
index 000000000..4bee1e485
--- /dev/null
+++ b/roms/edk2/MdePkg/Library/BaseSynchronizationLib/X64/InterlockedCompareExchange64.nasm
@@ -0,0 +1,35 @@
+;------------------------------------------------------------------------------
+;
+; Copyright (c) 2006 - 2016, Intel Corporation. All rights reserved.<BR>
+; SPDX-License-Identifier: BSD-2-Clause-Patent
+;
+; Module Name:
+;
+;   InterlockedCompareExchange64.Asm
+;
+; Abstract:
+;
+;   InterlockedCompareExchange64 function
+;
+; Notes:
+;
+;------------------------------------------------------------------------------
+
+    DEFAULT REL
+    SECTION .text
+
+;------------------------------------------------------------------------------
+; UINT64
+; EFIAPI
+; InternalSyncCompareExchange64 (
+;   IN      volatile UINT64           *Value,
+;   IN      UINT64                    CompareValue,
+;   IN      UINT64                    ExchangeValue
+;   );
+;------------------------------------------------------------------------------
+global ASM_PFX(InternalSyncCompareExchange64)
+ASM_PFX(InternalSyncCompareExchange64):
+    mov     rax, rdx
+    lock    cmpxchg [rcx], r8
+    ret
+