source: trunk/minix/lib/i86/string/bcmp.s@ 9

!       bcmp()                                          Author: Kees J. Bot
!                                                               27 Jan 1994
.sect .text; .sect .rom; .sect .data; .sect .bss

! int bcmp(const void *s1, const void *s2, size_t n)
!       Compare two chunks of memory.
!       This is a BSD routine that escaped from the kernel.  Don't use.
!       (Alas it is not without some use, it reports the number of bytes
!       after the bytes that are equal.  So it can't be simply replaced.)
!
.sect .text
.define _bcmp
_bcmp:
        push    bp
        mov     bp, sp
        push    8(bp)
        push    6(bp)
        push    4(bp)
        call    _memcmp         ! Let memcmp do the work
        mov     sp, bp
        test    ax, ax
        jz      equal
        sub     dx, 4(bp)       ! Memcmp was nice enough to leave "si" in dx
        dec     dx              ! Number of bytes that are equal
        mov     ax, 8(bp)
        sub     ax, dx          ! Number of bytes that are unequal
equal:  pop     bp
        ret