linux/tools/include/asm-generic/bitops/fls.h
Namhyung Kim 99e4e1174a tools/include: Sync asm-generic/bitops/fls.h with the kernel sources
To pick up the changes from:

  cb4ede9261 ("riscv: Avoid code duplication with generic bitops implementation")

This should address these tools/perf build warnings:

  Warning: Kernel ABI header differences:
    diff -u tools/include/asm-generic/bitops/__fls.h include/asm-generic/bitops/__fls.h
    diff -u tools/include/asm-generic/bitops/fls.h include/asm-generic/bitops/fls.h

Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Palmer Dabbelt <palmer@rivosinc.com>
Cc: linux-arch@vger.kernel.org
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Link: https://lore.kernel.org/r/20240408185520.1550865-9-namhyung@kernel.org
2024-04-11 10:38:29 -07:00

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C

/* 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 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_ */