/* * Written by J.T. Conklin . * Public domain. * Adapted for NetBSD/x86_64 by Frank van der Linden */ #include ENTRY(ffs) RETGUARD_SETUP(ffs, r11) bsfl %edi,%eax jz L1 /* ZF is set if all bits are 0 */ incl %eax /* bits numbered from 1, not 0 */ jmp L2 _ALIGN_TRAPS L1: xorl %eax,%eax /* clear result */ L2: RETGUARD_CHECK(ffs, r11) ret