1 files changed, 65 insertions, 0 deletions
diff --git a/roms/edk2/MdePkg/Library/BaseMemoryLibSse2/X64/SetMem.nasm b/roms/edk2/MdePkg/Library/BaseMemoryLibSse2/X64/SetMem.nasm
new file mode 100644
index 000000000..5bd1c2262
--- /dev/null
+++ b/roms/edk2/MdePkg/Library/BaseMemoryLibSse2/X64/SetMem.nasm
@@ -0,0 +1,65 @@
+;------------------------------------------------------------------------------
+;
+; 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 *
+;  InternalMemSetMem (
+;    IN VOID   *Buffer,
+;    IN UINTN  Count,
+;    IN UINT8  Value
+;    )
+;------------------------------------------------------------------------------
+global ASM_PFX(InternalMemSetMem)
+ASM_PFX(InternalMemSetMem):
+    push    rdi
+    mov     rdi, rcx                    ; rdi <- Buffer
+    mov     al, r8b                     ; al <- Value
+    mov     r9, rdi                     ; r9 <- Buffer as return value
+    xor     rcx, rcx
+    sub     rcx, rdi
+    and     rcx, 15                     ; rcx + rdi aligns on 16-byte boundary
+    jz      .0
+    cmp     rcx, rdx
+    cmova   rcx, rdx
+    sub     rdx, rcx
+    rep     stosb
+.0:
+    mov     rcx, rdx
+    and     rdx, 15
+    shr     rcx, 4
+    jz      @SetBytes
+    mov     ah, al                      ; ax <- Value repeats twice
+    movdqa  [rsp + 0x10], xmm0           ; save xmm0
+    movd    xmm0, eax                   ; xmm0[0..16] <- Value repeats twice
+    pshuflw xmm0, xmm0, 0               ; xmm0[0..63] <- Value repeats 8 times
+    movlhps xmm0, xmm0                  ; xmm0 <- Value repeats 16 times
+.1:
+    movntdq [rdi], xmm0                 ; rdi should be 16-byte aligned
+    add     rdi, 16
+    loop    .1
+    mfence
+    movdqa  xmm0, [rsp + 0x10]           ; restore xmm0
+@SetBytes:
+    mov     ecx, edx                    ; high 32 bits of rcx are always zero
+    rep     stosb
+    mov     rax, r9                     ; rax <- Return value
+    pop     rdi
+    ret
+