LXR linux/include/linux/calc64.h

   1#ifndef _LINUX_CALC64_H
   2#define _LINUX_CALC64_H
   3
   4#include <linux/types.h>
   5#include <asm/div64.h>
   6
   7/*
   8 * This is a generic macro which is used when the architecture
   9 * specific div64.h does not provide a optimized one.
  10 *
  11 * The 64bit dividend is divided by the divisor (data type long), the
  12 * result is returned and the remainder stored in the variable
  13 * referenced by remainder (data type long *). In contrast to the
  14 * do_div macro the dividend is kept intact.
  15 */
  16#ifndef div_long_long_rem
  17#define div_long_long_rem(dividend, divisor, remainder) \
  18        do_div_llr((dividend), divisor, remainder)
  19
  20static inline unsigned long do_div_llr(const long long dividend,
  21                                       const long divisor, long *remainder)
  22{
  23        u64 result = dividend;
  24
  25        *(remainder) = do_div(result, divisor);
  26        return (unsigned long) result;
  27}
  28#endif
  29
  30/*
  31 * Sign aware variation of the above. On some architectures a
  32 * negative dividend leads to an divide overflow exception, which
  33 * is avoided by the sign check.
  34 */
  35static inline long div_long_long_rem_signed(const long long dividend,
  36                                            const long divisor, long *remainder)
  37{
  38        long res;
  39
  40        if (unlikely(dividend < 0)) {
  41                res = -div_long_long_rem(-dividend, divisor, remainder);
  42                *remainder = -(*remainder);
  43        } else
  44                res = div_long_long_rem(dividend, divisor, remainder);
  45
  46        return res;
  47}
  48
  49#endif
  50