diff options
| author | Uros Bizjak <ubizjak@gmail.com> | 2025-03-25 18:52:01 +0100 |
|---|---|---|
| committer | Ingo Molnar <mingo@kernel.org> | 2025-03-25 22:38:29 +0100 |
| commit | 0717b1392dc7e3f350e5a5d25ea794aa92210684 (patch) | |
| tree | c4f3a2e32f6f95f7edba6f9e15374a012e968c19 | |
| parent | 3d66af75b08609281cbd7b71d40bbb9829c88764 (diff) | |
x86/bitops: Use TZCNT mnemonic in <asm/bitops.h>
Current minimum required version of binutils is 2.25,
which supports TZCNT instruction mnemonic.
Replace "REP; BSF" in variable__{ffs,ffz}() function
with this proper mnemonic.
No functional change intended.
Signed-off-by: Uros Bizjak <ubizjak@gmail.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Link: https://lore.kernel.org/r/20250325175215.330659-1-ubizjak@gmail.com
| -rw-r--r-- | arch/x86/include/asm/bitops.h | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/arch/x86/include/asm/bitops.h b/arch/x86/include/asm/bitops.h index 100413aff640..bbaf75ea6703 100644 --- a/arch/x86/include/asm/bitops.h +++ b/arch/x86/include/asm/bitops.h @@ -248,7 +248,7 @@ arch_test_bit_acquire(unsigned long nr, const volatile unsigned long *addr) static __always_inline unsigned long variable__ffs(unsigned long word) { - asm("rep; bsf %1,%0" + asm("tzcnt %1,%0" : "=r" (word) : ASM_INPUT_RM (word)); return word; @@ -267,7 +267,7 @@ static __always_inline unsigned long variable__ffs(unsigned long word) static __always_inline unsigned long variable_ffz(unsigned long word) { - asm("rep; bsf %1,%0" + asm("tzcnt %1,%0" : "=r" (word) : "r" (~word)); return word; |