Cregit: Linux 6.18: fls.h

Contributors: 6
Author	Tokens	Token Proportion	Commits	Commit Proportion
Akinobu Mita	128	87.67%	1	14.29%
Xiao Wang	14	9.59%	2	28.57%
Matthew Wilcox	1	0.68%	1	14.29%
Kees Cook	1	0.68%	1	14.29%
Greg Kroah-Hartman	1	0.68%	1	14.29%
Andi Kleen	1	0.68%	1	14.29%
Total	146		7

/* SPDX-License-Identifier: GPL-2.0 */
#ifndef _ASM_GENERIC_BITOPS_FLS_H_
#define _ASM_GENERIC_BITOPS_FLS_H_

/**
 * generic_fls - find last (most-significant) bit set
 * @x: the word to search
 *
 * This is defined the same way as ffs.
 * Note fls(0) = 0, fls(1) = 1, fls(0x80000000) = 32.
 */

static __always_inline __attribute_const__ int generic_fls(unsigned int x)
{
	int r = 32;

	if (!x)
		return 0;
	if (!(x & 0xffff0000u)) {
		x <<= 16;
		r -= 16;
	}
	if (!(x & 0xff000000u)) {
		x <<= 8;
		r -= 8;
	}
	if (!(x & 0xf0000000u)) {
		x <<= 4;
		r -= 4;
	}
	if (!(x & 0xc0000000u)) {
		x <<= 2;
		r -= 2;
	}
	if (!(x & 0x80000000u)) {
		x <<= 1;
		r -= 1;
	}
	return r;
}

#ifndef __HAVE_ARCH_FLS
#define fls(x) generic_fls(x)
#endif

#endif /* _ASM_GENERIC_BITOPS_FLS_H_ */