forked from KolibriOS/kolibrios
93 lines
2.3 KiB
PHP
93 lines
2.3 KiB
PHP
; string2dword - a useless string to double word conversion routine
|
|
;
|
|
; Copyright (c) 2003 Thomas Mathys
|
|
; killer@vantage.ch
|
|
;
|
|
; This program 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; either version 2 of the License, or
|
|
; (at your option) any later version.
|
|
;
|
|
; This program is distributed in the hope that it will be useful,
|
|
; but WITHOUT ANY WARRANTY; without even the implied warranty of
|
|
; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
|
; GNU General Public License for more details.
|
|
;
|
|
; You should have received a copy of the GNU General Public License
|
|
; along with this program; if not, write to the Free Software
|
|
; Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
|
|
;
|
|
|
|
|
|
;********************************************************************
|
|
; converts an asciiz string into an unsigned doubleword.
|
|
; (base 10 is assumed)
|
|
;
|
|
; - first, leading whitespaces are skipped
|
|
; - then the function converts the string, until it
|
|
; finds the terminating zero, another character it
|
|
; cannot convert or the number becomes too large.
|
|
;
|
|
; input : esi = pointer to string
|
|
; output : eax = unsigned doubleword
|
|
; the function tries to convert as
|
|
; many digits as possible, before it
|
|
; stops. if the value of the dword
|
|
; becomes too large, 0xffffffff is
|
|
; returned.
|
|
; destroys : nothing
|
|
;********************************************************************
|
|
string2dword:
|
|
push ebx
|
|
push ecx
|
|
push edx
|
|
push esi
|
|
pushfd
|
|
|
|
xor ebx,ebx ; ebx : dword
|
|
|
|
; skip leading whitespaces
|
|
.skipspaces:
|
|
lodsb
|
|
cmp al,32 ; space
|
|
je .skipspaces
|
|
cmp al,12 ; ff
|
|
je .skipspaces
|
|
cmp al,10 ; lf
|
|
je .skipspaces
|
|
cmp al,13 ; cr
|
|
je .skipspaces
|
|
cmp al,9 ; ht
|
|
je .skipspaces
|
|
cmp al,11 ; vt
|
|
je .skipspaces
|
|
|
|
; convert string
|
|
dec esi ; esi -> 1st non-whitespace
|
|
.convert:
|
|
xor eax,eax ; get character
|
|
lodsb
|
|
sub al,'0' ; convert to digit
|
|
cmp al,9 ; is digit in range [0,9] ?
|
|
ja .done ; nope -> stop conversion
|
|
mov ecx,eax ; save new digit
|
|
mov eax,10 ; dword = dword * 10
|
|
mul ebx
|
|
jc .overflow
|
|
add eax,ecx ; + new digit
|
|
jc .overflow
|
|
mov ebx,eax
|
|
jmp .convert
|
|
|
|
.overflow:
|
|
mov ebx,0xffffffff
|
|
.done:
|
|
mov eax,ebx
|
|
popfd
|
|
pop esi
|
|
pop edx
|
|
pop ecx
|
|
pop ebx
|
|
ret
|
|
|