usr/src/lib/libc/mips/string/ffs.s

/*-
 * Copyright (c) 1991, 1993
 *      The Regents of the University of California.  All rights reserved.
 *
 * This code is derived from software contributed to Berkeley by
 * Ralph Campbell.
 *
 * %sccs.include.redist.c%
 */

#include <machine/machAsmDefs.h>

#if defined(LIBC_SCCS) && !defined(lint)
        ASMSTR("@(#)ffs.s       8.1 (Berkeley) %G%")
#endif /* LIBC_SCCS and not lint */

/* bit = ffs(value) */

LEAF(ffs)
        move    v0, zero
        beq     a0, zero, done
1:
        and     v1, a0, 1               # bit set?
        addu    v0, v0, 1
        srl     a0, a0, 1
        beq     v1, zero, 1b            # no, continue
done:
        j       ra
END(ffs)