1 files changed, 53 insertions, 0 deletions
diff --git a/MdePkg/Library/BaseMemoryLibOptPei/X64/ScanMem64.asm b/MdePkg/Library/BaseMemoryLibOptPei/X64/ScanMem64.asm
new file mode 100644
index 0000000000..71f85a1ab7
--- /dev/null
+++ b/MdePkg/Library/BaseMemoryLibOptPei/X64/ScanMem64.asm
@@ -0,0 +1,53 @@
+;------------------------------------------------------------------------------
+;
+; Copyright (c) 2006, Intel Corporation
+; All rights reserved. This program and the accompanying materials
+; are licensed and made available under the terms and conditions of the BSD License
+; which accompanies this distribution.  The full text of the license may be found at
+; http://opensource.org/licenses/bsd-license.php
+;
+; THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
+; WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
+;
+; Module Name:
+;
+;   ScanMem64.Asm
+;
+; Abstract:
+;
+;   ScanMem64 function
+;
+; Notes:
+;
+;   The following BaseMemoryLib instances contain the same copy of this file:
+;
+;       BaseMemoryLibRepStr
+;       BaseMemoryLibMmx
+;       BaseMemoryLibSse2
+;       BaseMemoryLibOptDxe
+;       BaseMemoryLibOptPei
+;
+;------------------------------------------------------------------------------
+
+    .code
+
+;------------------------------------------------------------------------------
+; CONST VOID *
+; EFIAPI
+; InternalMemScanMem64 (
+;   IN      CONST VOID                *Buffer,
+;   IN      UINTN                     Length,
+;   IN      UINT64                    Value
+;   );
+;------------------------------------------------------------------------------
+InternalMemScanMem64    PROC    USES    rdi
+    mov     rdi, rcx
+    mov     rax, r8
+    mov     rcx, rdx
+    repne   scasq
+    lea     rax, [rdi - 8]
+    cmovnz  rax, rcx
+    ret
+InternalMemScanMem64    ENDP
+
+    END