LXR linux/include/asm-generic/bitops/builtin-_

   1#ifndef _ASM_GENERIC_BITOPS_BUILTIN___FLS_H_
   2#define _ASM_GENERIC_BITOPS_BUILTIN___FLS_H_
   3
   4/**
   5 * __fls - find last (most-significant) set bit in a long word
   6 * @word: the word to search
   7 *
   8 * Undefined if no set bit exists, so code should check against 0 first.
   9 */
  10static __always_inline unsigned long __fls(unsigned long word)
  11{
  12        return (sizeof(word) * 8) - 1 - __builtin_clzl(word);
  13}
  14
  15#endif
  16