18c2ecf20Sopenharmony_ci/* SPDX-License-Identifier: GPL-2.0 */
28c2ecf20Sopenharmony_ci#ifndef _ASM_GENERIC_BITOPS_FLS_H_
38c2ecf20Sopenharmony_ci#define _ASM_GENERIC_BITOPS_FLS_H_
48c2ecf20Sopenharmony_ci
58c2ecf20Sopenharmony_ci/**
68c2ecf20Sopenharmony_ci * fls - find last (most-significant) bit set
78c2ecf20Sopenharmony_ci * @x: the word to search
88c2ecf20Sopenharmony_ci *
98c2ecf20Sopenharmony_ci * This is defined the same way as ffs.
108c2ecf20Sopenharmony_ci * Note fls(0) = 0, fls(1) = 1, fls(0x80000000) = 32.
118c2ecf20Sopenharmony_ci */
128c2ecf20Sopenharmony_ci
138c2ecf20Sopenharmony_cistatic __always_inline int fls(unsigned int x)
148c2ecf20Sopenharmony_ci{
158c2ecf20Sopenharmony_ci	int r = 32;
168c2ecf20Sopenharmony_ci
178c2ecf20Sopenharmony_ci	if (!x)
188c2ecf20Sopenharmony_ci		return 0;
198c2ecf20Sopenharmony_ci	if (!(x & 0xffff0000u)) {
208c2ecf20Sopenharmony_ci		x <<= 16;
218c2ecf20Sopenharmony_ci		r -= 16;
228c2ecf20Sopenharmony_ci	}
238c2ecf20Sopenharmony_ci	if (!(x & 0xff000000u)) {
248c2ecf20Sopenharmony_ci		x <<= 8;
258c2ecf20Sopenharmony_ci		r -= 8;
268c2ecf20Sopenharmony_ci	}
278c2ecf20Sopenharmony_ci	if (!(x & 0xf0000000u)) {
288c2ecf20Sopenharmony_ci		x <<= 4;
298c2ecf20Sopenharmony_ci		r -= 4;
308c2ecf20Sopenharmony_ci	}
318c2ecf20Sopenharmony_ci	if (!(x & 0xc0000000u)) {
328c2ecf20Sopenharmony_ci		x <<= 2;
338c2ecf20Sopenharmony_ci		r -= 2;
348c2ecf20Sopenharmony_ci	}
358c2ecf20Sopenharmony_ci	if (!(x & 0x80000000u)) {
368c2ecf20Sopenharmony_ci		x <<= 1;
378c2ecf20Sopenharmony_ci		r -= 1;
388c2ecf20Sopenharmony_ci	}
398c2ecf20Sopenharmony_ci	return r;
408c2ecf20Sopenharmony_ci}
418c2ecf20Sopenharmony_ci
428c2ecf20Sopenharmony_ci#endif /* _ASM_GENERIC_BITOPS_FLS_H_ */
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