/*-------------------------------------------------------------------------
-
_divsint.c :- routine for signed int (16 bit) division. just calls
routine for unsigned division after sign adjustment
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!
-------------------------------------------------------------------------*/
-int _divsint (int a, int b)
-#ifndef SDCC_STACK_AUTO
- critical
+
+
+#include <sdcc-lib.h>
+
+#if _SDCC_MANGLES_SUPPORT_FUNS
+unsigned unsigned _divuint (unsigned x, unsigned 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 _DIVSINT_ASM_SMALL_AUTO
+# else
+# define _DIVSINT_ASM_SMALL
+# endif
+# endif
+# endif
+#endif
+
+#if defined _DIVSINT_ASM_SMALL
+
+static void
+_divsint_dummy (void) __naked
+{
+ __asm
+
+ #define xl dpl
+ #define xh dph
+
+ .globl __divsint
+
+ // _divsint_PARM_2 shares the same memory with _divuint_PARM_2
+ // and is defined in _divuint.c
+#if defined(SDCC_PARMS_IN_BANK1)
+ #define yl (b1_0)
+ #define yh (b1_1)
+#else
+ #define yl (__divsint_PARM_2)
+ #define yh (__divsint_PARM_2 + 1)
+#endif
+__divsint:
+ ; xh in dph
+ ; yh in (__divsint_PARM_2 + 1)
+
+ clr F0 ; Flag 0 in PSW
+ ; available to user for general purpose
+ mov a,xh
+ jnb acc.7,a_not_negative
+
+ setb F0
+
+ clr a
+ clr c
+ subb a,xl
+ mov xl,a
+ clr a
+ subb a,xh
+ mov xh,a
+
+a_not_negative:
+
+ mov a,yh
+ jnb acc.7,b_not_negative
+
+ cpl F0
+
+ clr a
+ clr c
+ subb a,yl
+ mov yl,a
+ clr a
+ subb a,yh
+ mov yh,a
+
+b_not_negative:
+
+ lcall __divuint
+
+ jnb F0,not_negative
+
+ clr a
+ clr c
+ subb a,xl
+ mov xl,a
+ clr a
+ subb a,xh
+ mov xh,a
+
+not_negative:
+ ret
+
+ __endasm;
+}
+
+#elif defined _DIVSINT_ASM_SMALL_AUTO
+
+static void
+_divsint_dummy (void) __naked
{
- register int r;
-
- r = _divuint((a < 0 ? -a : a),
- (b < 0 ? -b : b));
- if ( (a < 0) ^ (b < 0)) {
-
- return -r;
- }
- else {
-
- return r;
- }
+ __asm
+
+ #define xl dpl
+ #define xh dph
+
+ .globl __divsint
+
+__divsint:
+
+ clr F0 ; Flag 0 in PSW
+ ; available to user for general purpose
+ mov a,xh
+ jnb acc.7,a_not_negative
+
+ setb F0
+
+ clr a
+ clr c
+ subb a,xl
+ mov xl,a
+ clr a
+ subb a,xh
+ mov xh,a
+
+a_not_negative:
+
+ mov a,sp
+ add a,#-2 ; 2 bytes return address
+ mov r0,a ; r0 points to yh
+ mov a,@r0 ; a = yh
+
+ jnb acc.7,b_not_negative
+
+ cpl F0
+
+ dec r0
+
+ clr a
+ clr c
+ subb a,@r0 ; yl
+ mov @r0,a
+ clr a
+ inc r0
+ subb a,@r0 ; a = yh
+
+b_not_negative:
+
+ mov r1,a ; yh
+ dec r0
+ mov a,@r0 ; yl
+ mov r0,a
+
+ lcall __divint
+
+ jnb F0,not_negative
+
+ clr a
+ clr c
+ subb a,xl
+ mov xl,a
+ clr a
+ subb a,xh
+ mov xh,a
+
+not_negative:
+ ret
+
+ __endasm;
}
+
+#else // _DIVSINT_ASM_
+
+int
+_divsint (int x, int y)
+{
+ register int r;
+
+ r = _divuint((x < 0 ? -x : x),
+ (y < 0 ? -y : y));
+ if ( (x < 0) ^ (y < 0))
+ return -r;
+ else
+ return r;
+}
+
+#endif // _DIVSINT_ASM_
projects / fw / sdcc / blobdiff