source: bootcd/isolinux/syslinux-6.03/gpxe/src/libgcc/__udivmoddi4.c

#include "libgcc.h"

__libgcc uint64_t __udivmoddi4(uint64_t num, uint64_t den, uint64_t *rem_p)
{
  uint64_t quot = 0, qbit = 1;

  if ( den == 0 ) {
    return 1/((unsigned)den); /* Intentional divide by zero, without
                                 triggering a compiler warning which
                                 would abort the build */
  }

  /* Left-justify denominator and count shift */
  while ( (int64_t)den >= 0 ) {
    den <<= 1;
    qbit <<= 1;
  }

  while ( qbit ) {
    if ( den <= num ) {
      num -= den;
      quot += qbit;
    }
    den >>= 1;
    qbit >>= 1;
  }

  if ( rem_p )
    *rem_p = num;

  return quot;
}