/*-------------------------------------------------------------------------
-
_modsint.c :- routine for signed int (16 bit) modulus
Written By - Sandeep Dutta . sandeep.dutta@usa.net (1999)
under the terms of the GNU Library 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 Library General Public License for more details.
-
+
You should have received a copy of the GNU Library General Public License
along with this program; if not, write to the Free Software
Foundation, 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
-
+
In other words, you are welcome to use, share and improve this program.
You are forbidden to forbid anyone else to use, share and improve
- what you give them. Help stamp out software-hoarding!
+ what you give them. Help stamp out software-hoarding!
-------------------------------------------------------------------------*/
+
+#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 = _moduint((a < 0 ? -a : a),
(b < 0 ? -b : b));
- if ( (a < 0) ^ (b < 0))
+ if (a < 0)
return -r;
else
return r;
}
+
+#endif // _MODSINT_ASM_
projects / fw / sdcc / blobdiff