]>
git.ipfire.org Git - people/ms/u-boot.git/blob - lib/div64.c
2 * Copyright (C) 2003 Bernardo Innocenti <bernie@develer.com>
4 * Based on former do_div() implementation from asm-parisc/div64.h:
5 * Copyright (C) 1999 Hewlett-Packard Co
6 * Copyright (C) 1999 David Mosberger-Tang <davidm@hpl.hp.com>
9 * Generic C version of 64bit/32bit division and modulo, with
10 * 64bit result and 32bit remainder.
12 * The fast case for (n>>32 == 0) is handled inline by do_div().
14 * Code generated for this function might be very inefficient
15 * for some CPUs. __div64_32() can be overridden by linking arch-specific
16 * assembly versions such as arch/powerpc/lib/div64.S and arch/sh/lib/div64.S.
19 #include <linux/types.h>
21 uint32_t __div64_32(uint64_t *n
, uint32_t base
)
26 uint32_t high
= rem
>> 32;
28 /* Reduce the thing a bit first */
32 res
= (uint64_t) high
<< 32;
33 rem
-= (uint64_t) (high
*base
) << 32;
36 while ((int64_t)b
> 0 && b
< rem
) {