strncpy.asm revision 897afdda769ec9fd3dbe35b57a3a041cfde0d6a7
; $Id$
;; @file
; IPRT - No-CRT strncpy - AMD64 & X86.
;
;
; Copyright (C) 2006-2012 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 pszDst gcc: rdi msc: rcx x86:[esp+4]
; @param pszSrc gcc: rsi msc: rdx x86:[esp+8]
; @param cbMax gcc: rdx msc: r8 x86:[esp+12]
RT_NOCRT_BEGINPROC strcpy
; input
%ifdef RT_ARCH_AMD64
%ifdef ASM_CALL64_MSC
%define pszDst rcx
%define pszSrc rdx
%define cbMax r8
%else
%define pszDst rdi
%define pszSrc rsi
%define cbMax rdx
%endif
mov r9, pszDst
%else
mov ecx, [esp + 4]
mov edx, [esp + 8]
push ebx
mov ebx, [esp + 12 + 4]
%define pszDst ecx
%define pszSrc edx
%define cbMax ebx
push pszDst
%endif
;
; The rolled out loop.
;
.next:
cmp cbMax, 4
jb .simple_intro
mov al, [pszSrc]
mov [pszDst], al
test al, al
jz .done
mov al, [pszSrc + 1]
mov [pszDst + 1], al
test al, al
jz .done
mov al, [pszSrc + 2]
mov [pszDst + 2], al
test al, al
jz .done
mov al, [pszSrc + 3]
mov [pszDst + 3], al
test al, al
jz .done
add pszDst, 4
add pszSrc, 4
sub cbMax, 4
jmp .next
;
; Char by char.
;
.simple_intro:
test cbMax, cbMax
jz .done
.simple_next:
mov al, [pszSrc]
mov [pszDst], al
test al, al
jz .done
dec cbMax
jz .done
inc pszSrc
inc pszDst
jmp .simple_next
.done:
%ifdef RT_ARCH_AMD64
mov rax, r9
%else
pop ebx
pop eax
%endif
ret
ENDPROC RT_NOCRT(strcpy)