Execute HQ9+: Difference between revisions

=={{header|x86 Assembly}}==

<lang X86 Assembly>

;ds:si: pointer to asciiz string containing HQ9++ source code

ExecuteHQ9:

push ax

push dx

push si

push di

push es

push bx

mov bx, si

.interpret:

lodsb

cmp al, 'H'

je .doHelloWorld

cmp al, 'Q'

je .doPrintCode

cmp al, '9'

je .doDrinkBeer

cmp al, '+'

je .doCounter

pop bx

pop es

pop di

pop si

pop dx

pop ax

ret

.doHelloWorld:

push ds

mov ax, cs

mov ds, ax

push si

mov si, .dataHelloWorld

call .printString

pop si

pop ds

jmp .interpret

.doPrintCode:

push si

mov si, bx

call .printString

pop si

jmp .interpret

.doDrinkBeer:

push ds

push si

push ax

mov ax, cs

mov ds, ax

mov ax, 99

.beer_loop:

call .printHexNumber

mov si, .dataBeerSong1

call .printString

call .printHexNumber

mov si, .dataBeerSong2

call .printString

dec ax

call .printHexNumber

mov si, .dataBeerSong3

call .printString

test ax, ax

jnz .beer_loop

pop ax

pop si

pop ds

jmp .interpret

.doCounter:

push ax

inc ax

pop ax

jmp .interpret

.printString:

push ax

push si

.looping:

lodsb

test al, al

jz .done

mov ah, 0Eh

int 10h

jmp .looping

.done:

pop si

pop ax

ret

.printHexNumber:

pusha

push ds

mov ax, cs

mov ds, ax

push word 0

mov bx, ax

xor dx, dx

mov cx, 4r

.convert_loop:

mov ax, bx

and ax, 0Fh

cmp ax, 9

ja .greater_than_9

add ax, '0'

jmp .converted

.greater_than_9:

add ax, 'A'-0Ah

.converted:

push ax

shr bx, 4

dec cx

jnz .convert_loop

.popoff:

pop ax

cmp ax, 0

je .done

mov ah, 0Eh

int 10h

jmp .popoff

.done:

pop ds

popa

ret

.dataHelloWorld: db "Hello World!", 0

.dataBeerSong1: db " bottles of beer on the wall ", 0

.dataBeerSong2: db " bottles of beer", 13, 10, "Take one down, pass it around "

.dataBeerSong3: db 0, " bottles of beer on the wall", 0

</lang>