builtin-fls.h 412 B

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  1. /* SPDX-License-Identifier: GPL-2.0 */
  2. #ifndef _ASM_GENERIC_BITOPS_BUILTIN_FLS_H_
  3. #define _ASM_GENERIC_BITOPS_BUILTIN_FLS_H_
  4. /**
  5. * fls - find last (most-significant) bit set
  6. * @x: the word to search
  7. *
  8. * This is defined the same way as ffs.
  9. * Note fls(0) = 0, fls(1) = 1, fls(0x80000000) = 32.
  10. */
  11. static __always_inline int fls(unsigned int x)
  12. {
  13. return x ? sizeof(x) * 8 - __builtin_clz(x) : 0;
  14. }
  15. #endif