muldi3.c
2.69 KB
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/*
* U-boot - muldi3.c contains routines for mult and div
*
* Copyright (c) 2005-2007 Analog Devices Inc.
*
* See file CREDITS for list of people who contributed to this
* project.
*
* 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 Free Software Foundation; either version 2 of
* the License, or (at your option) any later version.
*
* This program 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 program; if not, write to the Free Software
* Foundation, Inc., 51 Franklin St, Fifth Floor, Boston,
* MA 02110-1301 USA
*/
/* Generic function got from GNU gcc package, libgcc2.c */
#ifndef SI_TYPE_SIZE
#define SI_TYPE_SIZE 32
#endif
#define __ll_B (1L << (SI_TYPE_SIZE / 2))
#define __ll_lowpart(t) ((USItype) (t) % __ll_B)
#define __ll_highpart(t) ((USItype) (t) / __ll_B)
#define BITS_PER_UNIT 8
#if !defined (umul_ppmm)
#define umul_ppmm(w1, w0, u, v) \
do { \
USItype __x0, __x1, __x2, __x3; \
USItype __ul, __vl, __uh, __vh; \
\
__ul = __ll_lowpart (u); \
__uh = __ll_highpart (u); \
__vl = __ll_lowpart (v); \
__vh = __ll_highpart (v); \
\
__x0 = (USItype) __ul * __vl; \
__x1 = (USItype) __ul * __vh; \
__x2 = (USItype) __uh * __vl; \
__x3 = (USItype) __uh * __vh; \
\
__x1 += __ll_highpart (__x0);/* this can't give carry */ \
__x1 += __x2; /* but this indeed can */ \
if (__x1 < __x2) /* did we get it? */ \
__x3 += __ll_B; /* yes, add it in the proper pos. */ \
\
(w1) = __x3 + __ll_highpart (__x1); \
(w0) = __ll_lowpart (__x1) * __ll_B + __ll_lowpart (__x0); \
} while (0)
#endif
#if !defined (__umulsidi3)
#define __umulsidi3(u, v) \
({DIunion __w; \
umul_ppmm (__w.s.high, __w.s.low, u, v); \
__w.ll; })
#endif
typedef unsigned int USItype __attribute__ ((mode(SI)));
typedef int SItype __attribute__ ((mode(SI)));
typedef int DItype __attribute__ ((mode(DI)));
typedef int word_type __attribute__ ((mode(__word__)));
struct DIstruct {
SItype low, high;
};
typedef union {
struct DIstruct s;
DItype ll;
} DIunion;
DItype __muldi3(DItype u, DItype v)
{
DIunion w;
DIunion uu, vv;
uu.ll = u, vv.ll = v;
/* panic("kernel panic for __muldi3"); */
w.ll = __umulsidi3(uu.s.low, vv.s.low);
w.s.high += ((USItype) uu.s.low * (USItype) vv.s.high
+ (USItype) uu.s.high * (USItype) vv.s.low);
return w.ll;
}