100 byte bf compiler in asm

;non-compliant (dialect) version, non-commands are not ignored, only 100 bytes

[bits 16]
[org 0x100]
; assume bp=091e used
; assume di=fffe
; assume si=0100
; assume dx=cs (see here)
; assume cx=00ff
; assume bx=0000
; assume ax=0000 used (ah)
; assume sp=fffe
start:
        mov al, code_left - start
code_start:
        mov ch, 0x7f ; allow bigger programs
        mov bx, cx
        mov di, cx
        rep stosb
        mov bp, find_right + start - code_start ;cache loop head for smaller compiled programs
        jmp code_start_end
find_right:
        pop si
        dec si
        dec si ;point to loop head
        cmp [bx], cl
        jne loop_right_end
loop_right:
        lodsb
        cmp al, 0xD5 ; the "bp" part of "call bp" (because 0xFF is not unique, watch for additional '[')
        jne loop_left
        inc cx
loop_left:
        cmp al, 0xC3 ; ret (watch for ']')
        jne loop_right
        loop loop_right ;all brackets matched when cx==0
        db 0x3c ;cmp al, xx (mask push)
loop_right_end:
        push si
        lodsw ; skip "call" or dummy "dec" instruction, depending on context
        push si
code_sqright:
        ret
code_dec:
        dec byte [bx]
code_start_end:
        db '$' ;end DOS string, also "and al, xx"
code_inc:
        inc byte [bx]
        db '$'
code_right:
        inc bx ;al -> 2
        db '$'
code_left:
        dec bx
        db '$'
code_sqleft:
        call bp
        db '$'
; create lookup table
real_start:
        sub byte [bx+'>'], al ;point to code_right
        add byte [bx+'['], al ;point to code_sqleft
        mov byte [bx+']'], code_sqright - start
        lea sp, [bx+45+2] ;'+' + 4 (2b='+', 2c=',', 2d='-', 2e='.')
        push (code_dec - start) + (code_dot - start) * 256
        push (code_inc - start) + (code_comma - start) * 256
pre_write:
        mov ah, code_start >> 8
        xchg dx, ax
; write
        mov ah, 9
        int 0x21
; read
code_comma:
        mov dl, 0xff
        db 0x3d ; cmp ax, xxxx (mask mov)
code_dot:
        mov dl, [bx]
        mov ah, 6
        int 0x21
        mov [bx], al
        db '$'
        db 0xff ; parameter for '$', doubles as test for zero
; switch
        xlatb
        jne pre_write
  ; next two lines can also be removed
  ; if the program ends with extra ']'
  ; and then we are at 96 bytes... :-)
the_end:
        mov dl, 0xC3
        int 0x21
        int 0x20