;; @file ; innotek Portable Runtime - ASMAtomicXchgU8(). ; ; ; Copyright (C) 2006-2007 innotek GmbH ; ; This file is part of VirtualBox Open Source Edition (OSE), as ; available from http://www.virtualbox.org. This file is free software; ; you can redistribute it and/or modify it under the terms of the GNU ; General Public License as published by the Free Software Foundation, ; in version 2 as it comes in the "COPYING" file of the VirtualBox OSE ; distribution. VirtualBox OSE is distributed in the hope that it will ; be useful, but WITHOUT ANY WARRANTY of any kind. ; ; If you received this file as part of a commercial VirtualBox ; distribution, then only the terms of your commercial VirtualBox ; license agreement apply instead of the previous paragraph. ; ;******************************************************************************* ;* Header Files * ;******************************************************************************* %include "iprt/asmdefs.mac" BEGINCODE ;; ; @returns al Current *pu8 value ; @param rcx pu8 Pointer to the 8-bit variable to update. ; @param dl u8 The 8-bit value to assign to *pu8. BEGINPROC_EXPORTED ASMAtomicXchgU8 xchg [rcx], dl movzx eax, dl ret ENDPROC ASMAtomicXchgU8