include/asm-parisc/div64.h

   1 #ifndef __ASM_PARISC_DIV64
   2 #define __ASM_PARISC_DIV64
   3
   4 #ifdef __LP64__
   5
   6 /*
   7  * Copyright (C) 1999 Hewlett-Packard Co
   8  * Copyright (C) 1999 David Mosberger-Tang <davidm@hpl.hp.com>
   9  *
  10  * vsprintf uses this to divide a 64-bit integer N by a small integer BASE.
  11  * This is incredibly hard on IA-64 and HPPA
  12  */
  13
  14 #define do_div(n,base)                                          \
  15 ({                                                              \
  16         int _res;                                               \
  17         _res = ((unsigned long) (n)) % (unsigned) (base);       \
  18         (n) = ((unsigned long) (n)) / (unsigned) (base);        \
  19         _res;                                                   \
  20 })
  21
  22 #else
  23 /*
  24  * unsigned long long division.  Yuck Yuck!  What is Linux coming to?
  25  * This is 100% disgusting
  26  */
  27 #define do_div(n,base)                                                  \
  28 ({                                                                      \
  29         unsigned long __low, __low2, __high, __rem;                     \
  30         __low  = (n) & 0xffffffff;                                      \
  31         __high = (n) >> 32;                                             \
  32         if (__high) {                                                   \
  33                 __rem   = __high % (unsigned long)base;                 \
  34                 __high  = __high / (unsigned long)base;                 \
  35                 __low2  = __low >> 16;                                  \
  36                 __low2 += __rem << 16;                                  \
  37                 __rem   = __low2 % (unsigned long)base;                 \
  38                 __low2  = __low2 / (unsigned long)base;                 \
  39                 __low   = __low & 0xffff;                               \
  40                 __low  += __rem << 16;                                  \
  41                 __rem   = __low  % (unsigned long)base;                 \
  42                 __low   = __low  / (unsigned long)base;                 \
  43                 n = __low  + ((long long)__low2 << 16) +                \
  44                         ((long long) __high << 32);                     \
  45         } else {                                                        \
  46                 __rem = __low % (unsigned long)base;                    \
  47                 n = (__low / (unsigned long)base);                      \
  48         }                                                               \
  49         __rem;                                                          \
  50 })
  51 #endif
  52
  53 #endif
  54