/*-------------------------------------------------------------------------
_modsint.c - routine for signed int (16 bit) modulus
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 _moduint (unsigned a, unsigned b);
#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 _MODSINT_ASM_SMALL_AUTO
# else
# define _MODSINT_ASM_SMALL
# endif
# endif
# endif
#endif
#if defined _MODSINT_ASM_SMALL
static void
_modsint_dummy (void) __naked
{
__asm
#define a0 dpl
#define a1 dph
.globl __modsint
#if defined(__SDCC_PARMS_IN_BANK1)
#define b0 (b1_0)
#define b1 (b1_1)
#else
// _modsint_PARM_2 shares the same memory with _moduint_PARM_2
// and is defined in _moduint.c
#define b0 (__modsint_PARM_2)
#define b1 (__modsint_PARM_2 + 1)
#endif
__modsint:
; a1 in dph
; b1 in (__modsint_PARM_2 + 1)
clr F0 ; Flag 0 in PSW
; available to user for general purpose
mov a,a1
jnb acc.7,a_not_negative
setb F0
clr a
clr c
subb a,a0
mov a0,a
clr a
subb a,a1
mov a1,a
a_not_negative:
mov a,b1
jnb acc.7,b_not_negative
clr a
clr c
subb a,b0
mov b0,a
clr a
subb a,b1
mov b1,a
b_not_negative:
lcall __moduint
jnb F0,not_negative
clr a
clr c
subb a,a0
mov a0,a
clr a
subb a,a1
mov a1,a
not_negative:
ret
__endasm;
}
#elif defined _MODSINT_ASM_SMALL_AUTO
static void
_modsint_dummy (void) __naked
{
__asm
#define a0 dpl
#define a1 dph
ar0 = 0 ; BUG register set is not considered
ar1 = 1
.globl __modsint
__modsint:
clr F0 ; Flag 0 in PSW
; available to user for general purpose
mov a,a1
jnb acc.7,a_not_negative
setb F0
clr a
clr c
subb a,a0
mov a0,a
clr a
subb a,a1
mov a1,a
a_not_negative:
mov a,sp
add a,#-2 ; 2 bytes return address
mov r0,a ; r0 points to b1
mov a,@r0 ; b1
jnb acc.7,b_not_negative
dec r0
clr a
clr c
subb a,@r0 ; b0
mov @r0,a
clr a
inc r0
subb a,@r0 ; b1
mov @r0,a
b_not_negative:
mov ar1,@r0 ; b1
dec r0
mov ar0,@r0 ; b0
lcall __modint
jnb F0,not_negative
clr a
clr c
subb a,a0
mov a0,a
clr a
subb a,a1
mov a1,a
not_negative:
ret
__endasm;
}
#else // _MODSINT_ASM_
int _modsint (int a, int b)
{
register int r;
r = (unsigned)(a < 0 ? -a : a) % (unsigned)(b < 0 ? -b : b);
if (a < 0)
return -r;
else
return r;
}
#endif // _MODSINT_ASM_