/*-------------------------------------------------------------------------
_modslong.c - routine for modulus of 32 bit signed 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 _modulong (unsigned long a, unsigned long 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 _MODSLONG_ASM_SMALL_AUTO
# else
# define _MODSLONG_ASM_SMALL
# endif
# endif
# endif
#endif
#if defined _MODSLONG_ASM_SMALL
static void
_modslong_dummy (void) __naked
{
__asm
#define a0 dpl
#define a1 dph
#define a2 b
#define a3 r1
.globl __modslong
#if defined(__SDCC_PARMS_IN_BANK1)
#define b0 (b1_0)
#define b1 (b1_1)
#define b2 (b1_2)
#define b3 (b1_3)
#else
// _modslong_PARM_2 shares the same memory with _modulong_PARM_2
// and is defined in _modulong.c
#define b0 (__modslong_PARM_2)
#define b1 (__modslong_PARM_2 + 1)
#define b2 (__modslong_PARM_2 + 2)
#define b3 (__modslong_PARM_2 + 3)
#endif
__modslong:
; a3 in acc
; b3 in (__modslong_PARM_2 + 3)
mov a3,a ; save a3
clr F0 ; Flag 0 in PSW
; available to user for general purpose
jnb acc.7,a_not_negative
setb F0
clr a ; a = -a;
clr c
subb a,a0
mov a0,a
clr a
subb a,a1
mov a1,a
clr a
subb a,a2
mov a2,a
clr a
subb a,a3
mov a3,a
a_not_negative:
mov a,b3
jnb acc.7,b_not_negative
clr a ; b = -b;
clr c
subb a,b0
mov b0,a
clr a
subb a,b1
mov b1,a
clr a
subb a,b2
mov b2,a
clr a
subb a,b3
mov b3,a
b_not_negative:
mov a,a3 ; restore a3 in acc
lcall __modulong
jnb F0,not_negative
; result in (a == r1), b, dph, dpl
clr a
clr c
subb a,a0
mov a0,a
clr a
subb a,a1
mov a1,a
clr a
subb a,a2
mov a2,a
clr a
subb a,a3
; result in a, b, dph, dpl
not_negative:
ret
__endasm;
}
#elif defined _MODSLONG_ASM_SMALL_AUTO
static void
_modslong_dummy (void) __naked
{
__asm
#define a0 dpl
#define a1 dph
#define a2 b
#define a3 r1
#define b0 r2
#define b1 r3
#define b2 r4
#define b3 r5
ar2 = 2 ; BUG register set is not considered
ar3 = 3
ar4 = 4
ar5 = 5
.globl __modslong
__modslong:
; a3 in acc
mov a3,a ; save a3
clr F0 ; F0 (Flag 0)
; available to user for general purpose
jnb acc.7,a_not_negative
setb F0
clr a ; a = -a;
clr c
subb a,a0
mov a0,a
clr a
subb a,a1
mov a1,a
clr a
subb a,a2
mov a2,a
clr a
subb a,a3
mov a3,a
a_not_negative:
mov a,sp
add a,#-2-3 ; 2 bytes return address, 3 bytes param b
mov r0,a ; r1 points to b0
mov ar2,@r0 ; load b0
inc r0 ; r0 points to b1
mov ar3,@r0 ; b1
inc r0
mov ar4,@r0 ; b2
inc r0
mov a,@r0 ; b3
mov b3,a
jnb acc.7,b_not_negative
clr a ; b = -b;
clr c
subb a,b0
mov b0,a
clr a
subb a,b1
mov b1,a
clr a
subb a,b2
mov b2,a
clr a
subb a,b3
mov b3,a
b_not_negative:
lcall __modlong
jnb F0,not_negative
; result in (a == r1), b, dph, dpl
clr a
clr c
subb a,a0
mov a0,a
clr a
subb a,a1
mov a1,a
clr a
subb a,a2
mov a2,a
clr a
subb a,a3 ; result in a, b, dph, dpl
not_negative:
ret
__endasm;
}
#else // _MODSLONG_ASM
long
_modslong (long a, long b)
{
long r;
r = (unsigned long)(a < 0 ? -a : a) % (unsigned long)(b < 0 ? -b : b);
if (a < 0)
return -r;
else
return r;
}
#endif // _MODSLONG_ASM