What is wrong in this EXE code? (get cpu type)

Could someone suggest me what's wrong in the following code:

Code:


format MZ
;
getcpu: mov     bx,sp
        mov     ax,sp
        and     sp,not 3
        mov     cl,20h
        shr     ax,cl
        jz      getcp5   ;8086/8088
        push    sp
        pop     ax
        test    al,2
        mov     al,1
        jnz     getcp5  ;80186
        inc     ax
        sgdt    fword ptr gdtadr
        cmp     byte  ptr gdtadr+5,0ffh
        jz      getcp5    ;80286
        pushfd
        pushfd
        pop     eax
        or      eax,240000h
        push    eax
        popfd
        pushfd
        pop     eax
        shr     eax,10h
        and     al,24h
        jz      getcp3  ;80386
        cmp     al,4
        jz      getcp4  ;80486
        mov     ax,1
        cpuid
        mov     al,ah
        and     al,0fh
        jmp     getcp4
getcp3: mov     al,3
getcp4: popfd
getcp5: mov     sp,bx
        ret

gdtadr  dw      0ffffh
        times   3       dw      0
gigadsc dw      0ffffh
        dw      0
        db      0
        db      92h
        dw      8fh

Thanks for any help.