/*
 * Written by J.T. Conklin <jtc@netbsd.org>.
 * Public domain.
 * Adapted for NetBSD/x86_64 by Frank van der Linden <fvdl@wasabisystems.com>
 */

#include <machine/asm.h>

ENTRY(ffs)
	RETGUARD_SETUP(ffs, r11)
	bsfl	%edi,%eax
	jz	1f	 		/* ZF is set if all bits are 0 */
	incl	%eax			/* bits numbered from 1, not 0 */
	jmp	2f

	_ALIGN_TRAPS
1:	xorl	%eax,%eax		/* clear result */
2:	RETGUARD_CHECK(ffs, r11)
	ret
	lfence
END(ffs)