1 files changed, 54 insertions, 0 deletions
diff --git a/roms/edk2/MdePkg/Library/BaseMemoryLibMmx/X64/SetMem.nasm b/roms/edk2/MdePkg/Library/BaseMemoryLibMmx/X64/SetMem.nasm
new file mode 100644
index 000000000..450113ba8
--- /dev/null
+++ b/roms/edk2/MdePkg/Library/BaseMemoryLibMmx/X64/SetMem.nasm
@@ -0,0 +1,54 @@
+;------------------------------------------------------------------------------
+;
+; Copyright (c) 2006, Intel Corporation. All rights reserved.<BR>
+; SPDX-License-Identifier: BSD-2-Clause-Patent
+;
+; Module Name:
+;
+;   SetMem.nasm
+;
+; Abstract:
+;
+;   SetMem function
+;
+; Notes:
+;
+;------------------------------------------------------------------------------
+
+    DEFAULT REL
+    SECTION .text
+
+;------------------------------------------------------------------------------
+; VOID *
+; EFIAPI
+; InternalMemSetMem (
+;   OUT     VOID                      *Buffer,
+;   IN      UINTN                     Length,
+;   IN      UINT8                     Value
+;   );
+;------------------------------------------------------------------------------
+global ASM_PFX(InternalMemSetMem)
+ASM_PFX(InternalMemSetMem):
+    push    rdi
+    mov     rax, r8
+    mov     ah, al
+    DB      0x48, 0xf, 0x6e, 0xc0         ; movd mm0, rax
+    mov     r8, rcx
+    mov     rdi, r8                     ; rdi <- Buffer
+    mov     rcx, rdx
+    and     edx, 7
+    shr     rcx, 3
+    jz      @SetBytes
+    DB      0xf, 0x70, 0xC0, 0x0         ; pshufw mm0, mm0, 0h
+.0:
+    DB      0xf, 0xe7, 0x7              ; movntq [rdi], mm0
+    add     rdi, 8
+    loop    .0
+    mfence
+@SetBytes:
+    mov     ecx, edx
+    rep     stosb
+    mov     rax, r8
+    pop     rdi
+    ret
+