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; $Id: ASMAtomicReadU64.asm $
;; @file
; IPRT - ASMAtomicReadU64().
;
;
; Copyright (C) 2006-2009 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 reads 64-bit value.
;
; @param pu64 x86:ebp+8
;
; @returns The current value. (x86:eax+edx)
;
;
BEGINPROC_EXPORTED ASMAtomicReadU64
%ifdef RT_ARCH_AMD64
mfence ; ASSUME its present.
%ifdef ASM_CALL64_MSC
mov rax, [rcx]
%else
mov rax, [rdi]
%endif
ret
%endif
%ifdef RT_ARCH_X86
push ebp
mov ebp, esp
push ebx
push edi
xor eax, eax
xor edx, edx
mov edi, [ebp+08h]
xor ecx, ecx
xor ebx, ebx
lock cmpxchg8b [edi]
pop edi
pop ebx
leave
ret
%endif
ENDPROC ASMAtomicReadU64
|
