/*-------------------------------------------------------------------------
- _divslong.c - routine for division of 32 bit signed long
+ _divslong.c - routine for division of 32 bit long
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 long _divulong (unsigned long a, unsigned long b);
#endif
-long _divslong (long a, long b)
+/* 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)
+# 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
{
- long r;
-
- r = _divulong((a < 0 ? -a : a),
- (b < 0 ? -b : b));
- if ( (a < 0) ^ (b < 0))
- return -r;
- else
- return r;
-}
+ _asm
+
+ #define a0 dpl
+ #define a1 dph
+ #define a2 b
+ #define a3 r3
+
+ .globl __divslong
+
+ // _divslong_PARM_2 shares the same memory with _divulong_PARM_2
+ // and is defined in _divulong.c
+ #define b0 (__divslong_PARM_2)
+ #define b1 (__divslong_PARM_2 + 1)
+ #define b2 (__divslong_PARM_2 + 2)
+ #define b3 (__divslong_PARM_2 + 3)
+
+ __divslong:
+ ; a3 in acc
+ ; b3 in (__divslong_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
+ 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
+
+ cpl F0
+
+ clr a
+ 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 __divulong
+
+ jnb F0,not_negative
+
+ mov a3,a ; save a3
+
+ 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
+ mov a3,a
+
+ not_negative:
+ ret
+
+ _endasm ;
+}
+
+#elif defined _DIVSLONG_ASM_SMALL_AUTO
+
+static void
+_divslong_dummy (void) _naked
+{
+ _asm
+
+ #define a0 dpl
+ #define a1 dph
+ #define a2 b
+ #define a3 r3
+
+ .globl __divslong
+
+ __divslong:
+
+ ; a3 in acc
+ 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
+ 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 ; 2 bytes return address
+ mov r0,a ; r0 points to b3
+ mov a,@r0 ; b3
+
+ jnb acc.7,b_not_negative
+
+ cpl F0
+
+ dec r0
+ dec r0
+ dec r0
+
+ clr a
+ clr c
+ subb a,@r0 ; b0
+ mov @r0,a
+ clr a
+ inc r0
+ subb a,@r0 ; b1
+ mov @r0,a
+ clr a
+ inc r0
+ subb a,@r0 ; b2
+ mov @r0,a
+ clr a
+ inc r0
+ subb a,@r0 ; b3
+ mov @r0,a
+
+ b_not_negative:
+ dec r0
+ dec r0
+ dec r0 ; r0 points to b0
+
+ lcall __divlong
+
+ jnb F0,not_negative
+
+ mov a3,a ; save a3
+
+ 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
+ mov a3,a
+
+ not_negative:
+ ret
+
+ _endasm ;
+}
+
+#else // _DIVSLONG_ASM
+
+long
+_divslong (long a, long b)
+{
+ long r;
+
+ r = _divulong((a < 0 ? -a : a),
+ (b < 0 ? -b : b));
+ if ( (a < 0) ^ (b < 0))
+ return -r;
+ else
+ return r;
+}
+
+#endif // _DIVSLONG_ASM
projects / fw / sdcc / blobdiff