source: trunk/minix/lib/i386/string/strrchr.s@ 10

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

! char *strrchr(const char *s, int c)
!       Look for the last occurrence a character in a string.
!
.sect .text
.define _strrchr
        .align  16
_strrchr:
        push    ebp
        mov     ebp, esp
        push    edi
        mov     edi, 8(ebp)     ! edi = string
        mov     ecx, -1
        xorb    al, al
        cld
        repne
        scasb                   ! Look for the end of the string
        not     ecx             ! -1 - ecx = Length of the string + null
        dec     edi             ! Put edi back on the zero byte
        movb    al, 12(ebp)     ! The character to look for
        std                     ! Downwards search
        repne
        scasb
        cld                     ! Direction bit back to default
        jne     failure
        lea     eax, 1(edi)     ! Found it
        pop     edi
        pop     ebp
        ret
failure:xor     eax, eax        ! Not there
        pop     edi
        pop     ebp
        ret