X-Git-Url: https://git.gag.com/?a=blobdiff_plain;f=device%2Flib%2F_modulong.c;h=97274c4c611658142eb9b315054c9c56ace4136d;hb=c77ed7bf2a718bfe2d6fb1167cd85dac0f514f89;hp=8b56a72606f9c9281f99ad11d714903961d4e212;hpb=b09af35f2f1cde7649d3ac4a6f5d2af6d97895a0;p=fw%2Fsdcc diff --git a/device/lib/_modulong.c b/device/lib/_modulong.c index 8b56a726..97274c4c 100644 --- a/device/lib/_modulong.c +++ b/device/lib/_modulong.c @@ -5,48 +5,358 @@ Bug fixes by Martijn van Balen, aed@iae.nl - This program is free software; you can redistribute it and/or modify it - under the terms of the GNU General Public License as published by the + This library is free software; you can redistribute it and/or modify it + 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 program is distributed in the hope that it will be useful, + + 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 + 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! -------------------------------------------------------------------------*/ -#define MSB_SET(x) ((x >> (8*sizeof(x)-1)) & 1) +/* 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 _MODULONG_ASM_SMALL_AUTO +# else +# define _MODULONG_ASM_SMALL +# endif +# endif +# endif +#endif + +#if defined _MODULONG_ASM_SMALL -unsigned long _modulong (unsigned long a ,unsigned long b) +static void +_modlong_dummy (void) __naked { - unsigned short count = 0; - - - while (!MSB_SET(b)) { - b <<= 1; - if (b > a) - { - b >>=1; - break; - } - count++; - } - - do { - if (b <= a) { - a -= b; - } - b >>= 1; - } while (count--); - - return a; + __asm + + .globl __modulong + + #define a0 dpl + #define a1 dph + #define a2 b + #define a3 r1 + #define count r0 + +__modulong: +#if defined(SDCC_PARMS_IN_BANK1) + #define b0 (b1_0) + #define b1 (b1_1) + #define b2 (b1_2) + #define b3 (b1_3) +#else +#if defined(SDCC_NOOVERLAY) + .area DSEG (DATA) +#else + .area OSEG (OVR,DATA) +#endif + + .globl __modulong_PARM_2 + .globl __modslong_PARM_2 + +__modulong_PARM_2: +__modslong_PARM_2: + .ds 4 + + .area CSEG (CODE) + + #define b0 (__modulong_PARM_2) + #define b1 (__modulong_PARM_2 + 1) + #define b2 (__modulong_PARM_2 + 2) + #define b3 (__modulong_PARM_2 + 3) +#endif + ; parameter a comes in a, b, dph, dpl + mov a3,a ; save parameter a3 + + mov a,b0 ; b == 0? avoid endless loop + orl a,b1 + orl a,b2 + orl a,b3 + jz div_by_0 + + mov count,#0 + clr c ; when loop1 jumps immediately to loop2 + +loop1: inc count + + mov a,b3 ; if (!MSB_SET(b)) + jb acc.7,loop2 + + mov a,b0 ; b <<= 1 + add a,acc + mov b0,a + mov a,b1 + rlc a + mov b1,a + mov a,b2 + rlc a + mov b2,a + mov a,b3 + rlc a + mov b3,a + + mov a,a0 ; a - b + subb a,b0 ; here carry is always clear + mov a,a1 + subb a,b1 + mov a,a2 + subb a,b2 + mov a,a3 + subb a,b3 + + jnc loop1 + + + clr c + mov a,b3 ; b >>= 1; + rrc a + mov b3,a + mov a,b2 + rrc a + mov b2,a + mov a,b1 + rrc a + mov b1,a + mov a,b0 + rrc a + mov b0,a + +loop2: ; clr c never set + mov a,a0 ; a - b + subb a,b0 + mov r4,a + mov a,a1 + subb a,b1 + mov r5,a + mov a,a2 + subb a,b2 + mov r6,a + mov a,a3 + subb a,b3 + + jc smaller ; a >= b? + + mov a3,a ; -> yes; a = a - b; + mov a2,r6 + mov a1,r5 + mov a0,r4 +smaller: ; -> no + clr c + mov a,b3 ; b >>= 1; + rrc a + mov b3,a + mov a,b2 + rrc a + mov b2,a + mov a,b1 + rrc a + mov b1,a + mov a,b0 + rrc a + mov b0,a + + djnz count,loop2 + + mov a,a3 ; prepare the return value +div_by_0: + ret + + __endasm; } + +#elif defined _MODULONG_ASM_SMALL_AUTO + +static void +_modlong_dummy (void) __naked +{ + __asm + + .globl __modulong + +__modulong: + + #define count r0 + + #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 __modlong ; entry point for __modslong + + ; parameter a comes in a, b, dph, dpl + mov a3,a ; save parameter a3 + + 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 ar5,@r0 ; b3 + +__modlong: ; entry point for __modslong + ; a in r1, b, dph, dpl + ; b in r5, r4, r3, r2 + + mov count,#0 + + mov a,b0 ; b == 0? avoid endless loop + orl a,b1 + orl a,b2 + orl a,b3 + jz div_by_0 + + mov count,#0 + clr c ; when loop1 jumps immediately to loop2 + +loop1: inc count + + mov a,b3 ; if (!MSB_SET(b)) + jb acc.7,loop2 + + mov a,b0 ; b <<= 1 + add a,acc + mov b0,a + mov a,b1 + rlc a + mov b1,a + mov a,b2 + rlc a + mov b2,a + mov a,b3 + rlc a + mov b3,a + + mov a,a0 ; a - b + subb a,b0 ; here carry is always clear + mov a,a1 + subb a,b1 + mov a,a2 + subb a,b2 + mov a,a3 + subb a,b3 + + jnc loop1 + + clr c + mov a,b3 ; b >>= 1; + rrc a + mov b3,a + mov a,b2 + rrc a + mov b2,a + mov a,b1 + rrc a + mov b1,a + mov a,b0 + rrc a + mov b0,a + +loop2: ; clr c never set + mov a,a0 ; a - b + subb a,b0 + mov a,a1 + subb a,b1 + mov r6,a ; d1 + mov a,a2 + subb a,b2 + mov r7,a ; d2 + mov a,a3 + subb a,b3 + + jc smaller ; a >= b? + + mov a3,a ; -> yes; a = a - b; + mov a2,r7 + mov a1,r6 + mov a,a0 + subb a,b0 + mov a0,a +smaller: ; -> no + clr c + mov a,b3 ; b >>= 1; + rrc a + mov b3,a + mov a,b2 + rrc a + mov b2,a + mov a,b1 + rrc a + mov b1,a + mov a,b0 + rrc a + mov b0,a + + djnz count,loop2 + + mov a,a3 ; prepare the return value +div_by_0: + ret + + __endasm; +} + +#else // _MODULONG_ASM + +#define MSB_SET(x) ((x >> (8*sizeof(x)-1)) & 1) + +unsigned long +_modulong (unsigned long a, unsigned long b) +{ + unsigned char count = 0; + + while (!MSB_SET(b)) + { + b <<= 1; + if (b > a) + { + b >>=1; + break; + } + count++; + } + do + { + if (a >= b) + a -= b; + b >>= 1; + } + while (count--); + + return a; +} + +#endif // _MODULONG_ASM