1*ae3cb403Sguenther/* $OpenBSD: ffs.S,v 1.7 2018/01/18 08:23:44 guenther Exp $ */ 2df930be7Sderaadt/* 3df930be7Sderaadt * Written by J.T. Conklin <jtc@netbsd.org>. 4df930be7Sderaadt * Public domain. 5df930be7Sderaadt */ 6df930be7Sderaadt 7ea6088e7Sguenther#include "DEFS.h" 8df930be7Sderaadt 9df930be7SderaadtENTRY(ffs) 10df930be7Sderaadt bsfl 4(%esp),%eax 11df930be7Sderaadt jz L1 /* ZF is set if all bits are 0 */ 12df930be7Sderaadt incl %eax /* bits numbered from 1, not 0 */ 13df930be7Sderaadt ret 14df930be7Sderaadt 153308d86bSderaadt .align 2,0xcc 16df930be7SderaadtL1: xorl %eax,%eax /* clear result */ 17df930be7Sderaadt ret 18*ae3cb403SguentherEND(ffs) 19*ae3cb403Sguenther.protected ffs 20