audk/MdePkg/Library/BaseSynchronizationLib/Ia32/InterlockedDecrement.nasm

34 lines
888 B
NASM

;------------------------------------------------------------------------------
;
; Copyright (c) 2006 - 2018, Intel Corporation. All rights reserved.<BR>
; SPDX-License-Identifier: BSD-2-Clause-Patent
;
; Module Name:
;
; InterlockedDecrement.Asm
;
; Abstract:
;
; InterlockedDecrement function
;
; Notes:
;
;------------------------------------------------------------------------------
SECTION .text
;------------------------------------------------------------------------------
; UINT32
; EFIAPI
; InternalSyncDecrement (
; IN volatile UINT32 *Value
; );
;------------------------------------------------------------------------------
global ASM_PFX(InternalSyncDecrement)
ASM_PFX(InternalSyncDecrement):
mov ecx, [esp + 4]
mov eax, 0FFFFFFFFh
lock xadd dword [ecx], eax
dec eax
ret