/*-------------------------------------------------------------------------
_strlen.c - part of string library functions
Copyright (C) 1999, Sandeep Dutta . sandeep.dutta@usa.net
mcs51 assembler by Frieder Ferlemann (2007)
This library 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, or (at your option) any
later version.
This library 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 library; see the file COPYING. If not, write to the
Free Software Foundation, 51 Franklin Street, Fifth Floor, Boston,
MA 02110-1301, USA.
As a special exception, if you link this library with other files,
some of which are compiled with SDCC, to produce an executable,
this library does not by itself cause the resulting executable to
be covered by the GNU General Public License. This exception does
not however invalidate any other reasons why the executable file
might be covered by the GNU General Public License.
-------------------------------------------------------------------------*/
#include <string.h>
#if (!defined (__SDCC_mcs51))
/* Generic routine first */
size_t strlen ( const char * str
) {
register int i = 0 ;
while (*str++)
i++ ;
return i;
}
#else
#if defined(__SDCC)
#include <sdcc-lib.h>
#endif
/* Assembler version for mcs51 */
size_t strlen ( const char * str
) __naked
{
str; /* hush the compiler */
__asm
; dptr holds pointer
; b holds pointer memspace
;
; char *ptr = str:
mov r2,dpl
mov r3,dph
;
; while ( *ptr ) ptr++;
L00101$:
lcall __gptrget
jz L00102$
inc dptr
sjmp L00101$
;
L00102$:
; return ptr - str;
clr c
mov a,dpl
subb a,r2
mov dpl,a
;
mov a,dph
subb a,r3
mov dph,a
;
_RETURN
__endasm;
}
#endif