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Diffstat (limited to 'device/lib/_divsint.c')
| -rw-r--r-- | device/lib/_divsint.c | 218 |
1 files changed, 218 insertions, 0 deletions
diff --git a/device/lib/_divsint.c b/device/lib/_divsint.c new file mode 100644 index 0000000..cacfe93 --- /dev/null +++ b/device/lib/_divsint.c @@ -0,0 +1,218 @@ +/*------------------------------------------------------------------------- + _divsint.c :- routine for signed int (16 bit) division. just calls + routine for unsigned division after sign adjustment + + 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 _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 +{ + __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 = (unsigned int)(x < 0 ? -x : x) / (unsigned int)(y < 0 ? -y : y); + if ((x < 0) ^ (y < 0)) + return -r; + else + return r; +} + +#endif // _DIVSINT_ASM_ |