strcmp.asm revision e64031e20c39650a7bc902a3e1aba613b9415dee
; $Id$
;; @file
; IPRT - No-CRT strcmp - AMD64 & X86.
;
;
; 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.
;
%include "iprt/asmdefs.mac"
BEGINCODE
;;
; @param psz1 gcc: rdi msc: rcx x86:[esp+4]
; @param psz2 gcc: rsi msc: rdx x86:[esp+8]
RT_NOCRT_BEGINPROC strcmp
; input
%ifdef RT_ARCH_AMD64
%ifdef ASM_CALL64_MSC
%define psz1 rcx
%define psz2 rdx
%else
%define psz1 rdi
%define psz2 rsi
%endif
%else
mov ecx, [esp + 4]
mov edx, [esp + 8]
%define psz1 ecx
%define psz2 edx
%endif
;
; The loop.
;
.next:
mov al, [psz1]
mov ah, [psz2]
cmp al, ah
jne .not_equal
test al, al
jz .equal
mov al, [psz1 + 1]
mov ah, [psz2 + 1]
cmp al, ah
jne .not_equal
test al, al
jz .equal
mov al, [psz1 + 2]
mov ah, [psz2 + 2]
cmp al, ah
jne .not_equal
test al, al
jz .equal
mov al, [psz1 + 3]
mov ah, [psz2 + 3]
cmp al, ah
jne .not_equal
test al, al
jz .equal
add psz1, 4
add psz2, 4
jmp .next
.equal:
xor eax, eax
ret
.not_equal:
movzx ecx, ah
and eax, 0ffh
sub eax, ecx
ret
ENDPROC RT_NOCRT(strcmp)