;; @file
; IPRT - ASMAtomicBitTestAndToggle().
;

;
; Copyright (C) 2006-2007 Oracle Corporation
;
; 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 (GPL) 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.
;
; The contents of this file may alternatively be used under the terms
; of the Common Development and Distribution License Version 1.0
; (CDDL) only, as it comes in the "COPYING.CDDL" file of the
; VirtualBox OSE distribution, in which case the provisions of the
; CDDL are applicable instead of those of the GPL.
;
; You may elect to license modified versions of this file under the
; terms and conditions of either the GPL or the CDDL or both.
;


;*******************************************************************************
;* Header Files                                                                *
;*******************************************************************************
%include "iprt/asmdefs.mac"

BEGINCODE

;;
; Atomically tests and toggles a bit in a bitmap.
;
; @returns al(rax)      true if the bit was set.
; @returns al(rax)      false if the bit was clear.
; @param   rcx          pvBitmap    Pointer to the bitmap.
; @param   edx          iBit        The bit to test and toggle.
BEGINPROC_EXPORTED ASMAtomicBitTestAndToggle
        lock btc [rcx], edx
        sbb     eax, eax
        ret
ENDPROC ASMAtomicBitTestAndToggle