/*-------------------------------------------------------------------------
_divsint.c :- routine for signed int (16 bit) division. just calls
routine for unsigned division after sign adjustment
Copyright (C) 1999, Sandeep Dutta . sandeep.dutta@usa.net
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 <sdcc-lib.h>
#if _SDCC_MANGLES_SUPPORT_FUNS
unsigned unsigned _divuint (unsigned x, unsigned y);
#endif
/* Assembler-functions are provided for:
mcs51 small
mcs51 small stack-auto
*/
#if !defined(__SDCC_USE_XSTACK) && !defined(_SDCC_NO_ASM_LIB_FUNCS)
# if defined(__SDCC_mcs51)
# if defined(__SDCC_MODEL_SMALL)
# if defined(__SDCC_STACK_AUTO) && !defined(__SDCC_PARMS_IN_BANK1)
# define _DIVSINT_ASM_SMALL_AUTO
# else
# define _DIVSINT_ASM_SMALL
# endif
# endif
# endif
#endif
#if defined _DIVSINT_ASM_SMALL
static void
_divsint_dummy (void) __naked
{
__asm
#define xl dpl
#define xh dph
.globl __divsint
// _divsint_PARM_2 shares the same memory with _divuint_PARM_2
// and is defined in _divuint.c
#if defined(__SDCC_PARMS_IN_BANK1)
#define yl (b1_0)
#define yh (b1_1)
#else
#define yl (__divsint_PARM_2)
#define yh (__divsint_PARM_2 + 1)
#endif
__divsint:
; xh in dph
; yh in (__divsint_PARM_2 + 1)
clr F0 ; Flag 0 in PSW
; available to user for general purpose
mov a,xh
jnb acc.7,a_not_negative
setb F0
clr a
clr c
subb a,xl
mov xl,a
clr a
subb a,xh
mov xh,a
a_not_negative:
mov a,yh
jnb acc.7,b_not_negative
cpl F0
clr a
clr c
subb a,yl
mov yl,a
clr a
subb a,yh
mov yh,a
b_not_negative:
lcall __divuint
jnb F0,not_negative
clr a
clr c
subb a,xl
mov xl,a
clr a
subb a,xh
mov xh,a
not_negative:
ret
__endasm;
}
#elif defined _DIVSINT_ASM_SMALL_AUTO
static void
_divsint_dummy (void) __naked
{
__asm
#define xl dpl
#define xh dph
.globl __divsint
__divsint:
clr F0 ; Flag 0 in PSW
; available to user for general purpose
mov a,xh
jnb acc.7,a_not_negative
setb F0
clr a
clr c
subb a,xl
mov xl,a
clr a
subb a,xh
mov xh,a
a_not_negative:
mov a,sp
add a,#-2 ; 2 bytes return address
mov r0,a ; r0 points to yh
mov a,@r0 ; a = yh
jnb acc.7,b_not_negative
cpl F0
dec r0
clr a
clr c
subb a,@r0 ; yl
mov @r0,a
clr a
inc r0
subb a,@r0 ; a = yh
b_not_negative:
mov r1,a ; yh
dec r0
mov a,@r0 ; yl
mov r0,a
lcall __divint
jnb F0,not_negative
clr a
clr c
subb a,xl
mov xl,a
clr a
subb a,xh
mov xh,a
not_negative:
ret
__endasm;
}
#else // _DIVSINT_ASM_
int
_divsint (int x, int y)
{
register int r;
r = (unsigned int)(x < 0 ? -x : x) / (unsigned int)(y < 0 ? -y : y);
if ((x < 0) ^ (y < 0))
return -r;
else
return r;
}
#endif // _DIVSINT_ASM_