/* $OpenBSD: ffs.S,v 1.3 2005/08/07 11:30:38 espie Exp $ */ /* * Written by J.T. Conklin <jtc@netbsd.org>. * Public domain. */ #include <machine/asm.h> ENTRY(ffs) bsfl 4(%esp),%eax jz L1 /* ZF is set if all bits are 0 */ incl %eax /* bits numbered from 1, not 0 */ ret .align 2 L1: xorl %eax,%eax /* clear result */ ret END(ffs)