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/*-------------------------------------------------------------------------
_divslong.c - routine for division of 32 bit long
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 long _divulong (unsigned long x, unsigned long 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 _DIVSLONG_ASM_SMALL_AUTO
# else
# define _DIVSLONG_ASM_SMALL
# endif
# endif
# endif
#endif
#if defined _DIVSLONG_ASM_SMALL
static void
_divslong_dummy (void) __naked
{
__asm
#define x0 dpl
#define x1 dph
#define x2 b
#define x3 r3
.globl __divslong
// _divslong_PARM_2 shares the same memory with _divulong_PARM_2
// and is defined in _divulong.c
#if defined(__SDCC_PARMS_IN_BANK1)
#define y0 (b1_0)
#define y1 (b1_1)
#define y2 (b1_2)
#define y3 (b1_3)
#else
#define y0 (__divslong_PARM_2)
#define y1 (__divslong_PARM_2 + 1)
#define y2 (__divslong_PARM_2 + 2)
#define y3 (__divslong_PARM_2 + 3)
#endif
__divslong:
; x3 in acc
; y3 in (__divslong_PARM_2 + 3)
mov x3,a ; save x3
clr F0 ; Flag 0 in PSW
; available to user for general purpose
jnb acc.7,a_not_negative
setb F0
clr a
clr c
subb a,x0
mov x0,a
clr a
subb a,x1
mov x1,a
clr a
subb a,x2
mov x2,a
clr a
subb a,x3
mov x3,a
a_not_negative:
mov a,y3
jnb acc.7,b_not_negative
cpl F0
clr a
clr c
subb a,y0
mov y0,a
clr a
subb a,y1
mov y1,a
clr a
subb a,y2
mov y2,a
clr a
subb a,y3
mov y3,a
b_not_negative:
mov a,x3 ; restore x3 in acc
lcall __divulong
jnb F0,not_negative
mov x3,a ; save x3
clr a
clr c
subb a,x0
mov x0,a
clr a
subb a,x1
mov x1,a
clr a
subb a,x2
mov x2,a
clr a
subb a,x3 ; x3 ends in acc
not_negative:
ret
__endasm;
}
#elif defined _DIVSLONG_ASM_SMALL_AUTO
static void
_divslong_dummy (void) __naked
{
__asm
#define x0 dpl
#define x1 dph
#define x2 b
#define x3 r3
.globl __divslong
__divslong:
; x3 in acc
mov x3,a ; save x3
clr F0 ; Flag 0 in PSW
; available to user for general purpose
jnb acc.7,a_not_negative
setb F0
clr a
clr c
subb a,x0
mov x0,a
clr a
subb a,x1
mov x1,a
clr a
subb a,x2
mov x2,a
clr a
subb a,x3
mov x3,a
a_not_negative:
mov a,sp
add a,#-2 ; 2 bytes return address
mov r0,a ; r0 points to y3
mov a,@r0 ; y3
jnb acc.7,b_not_negative
cpl F0
dec r0
dec r0
dec r0
clr a
clr c
subb a,@r0 ; y0
mov @r0,a
clr a
inc r0
subb a,@r0 ; y1
mov @r0,a
clr a
inc r0
subb a,@r0 ; y2
mov @r0,a
clr a
inc r0
subb a,@r0 ; y3
mov @r0,a
b_not_negative:
dec r0
dec r0
dec r0 ; r0 points to y0
lcall __divlong
jnb F0,not_negative
mov x3,a ; save x3
clr a
clr c
subb a,x0
mov x0,a
clr a
subb a,x1
mov x1,a
clr a
subb a,x2
mov x2,a
clr a
subb a,x3 ; x3 ends in acc
not_negative:
ret
__endasm;
}
#else // _DIVSLONG_ASM
long
_divslong (long x, long y)
{
long r;
r = (unsigned long)(x < 0 ? -x : x) / (unsigned long)(y < 0 ? -y : y);
if ((x < 0) ^ (y < 0))
return -r;
else
return r;
}
#endif // _DIVSLONG_ASM