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From: kteixeira85 on 4 May 2008 09:54
On 3 maio, 17:11, Robert Redelmeier <red...(a)ev1.net.invalid> wrote:
> Prime Mover <eple...(a)hotmail.com> wrote in part:
>
> > You asked about what type of numbers I want.
> > Well, let's start with integers only.
>
> Assuming 32 bit unsigned, the code Frank posted is good:
>
> > mov eax, 7
> > mov ecx, 4
> > add eax, ecx
> > mul ecx % 'ecx'  is being multiplied by what??
> > inc ecx
> > div ecx % 'ecx' is being divided by what??
> > add eax, 8
>
> > Thank you.
>
> The MUL and DIV instructions are wired to take only one
> variable operand, and use fixed registers for the other
> operand and destination:
>
> MUL [src]  does EAX*[src] and puts the results in
>      EAX:EDX  (EAX has the high 32 bits, EDX the low).
>
> DIV [src]   does EAX:EDX / [src] and puts the
>             result in EAX and the remainder in EDX.
>
> All of this is nicely desribed in the Intel and AMD
> instruction-set manuals.
>
> -- Robert

Thank you, much appreciated. Could you post a simple example using
three registers and a do-while loop?
From: Phat Sam on 4 May 2008 10:31
On Sat, 03 May 2008 09:19:00 GMT, Frank Kotler <fbkotler(a)verizon.net>
wrote:

>Prime Mover wrote:
>> Hello all,
>>
>> Can anyone help me to convert this expression
>>
>> ((7+4)*4 )/5 + 8
>>
>> to assembly language?
I converted it to PIC18F452 since you didn't specify the CPU you
wanted it for.....

;--------------------------------------------------------
; PIC16 port for the Microchip 16-bit core micros
;--------------------------------------------------------
list p=18f452

radix dec

;--------------------------------------------------------
; public variables in this module
;--------------------------------------------------------
global _main

;--------------------------------------------------------
; interrupt vector
;--------------------------------------------------------

;--------------------------------------------------------
; global & static initialisations
;--------------------------------------------------------
; I code from now on!
; ; Starting pCode block
S_calc__main code
_main:
; .line 6; calc.c a = ((7+4) * 4) / 5 + 8;
RETURN



; Statistics:
; code size: 2 (0x0002) bytes ( 0.00%)
; 1 (0x0001) words
; udata size: 0 (0x0000) bytes ( 0.00%)
; access size: 0 (0x0000) bytes


end
From: Phat Sam on 4 May 2008 10:20
On Fri, 2 May 2008 20:05:41 -0700 (PDT), Prime Mover
<epleite(a)hotmail.com> wrote:

>Hello all,
>
>Can anyone help me to convert this expression
>
>((7+4)*4 )/5 + 8
>
>to assembly language?
>
>Thank you all.
I'll give it a shot....


MOV EAX, 7
MOV EDX, 1
SHL EDX, 2
ADD EAX, EDX
SHL EDX, 2
MOV EDX, 5
IDIV
MOV EBX, 8
ADD EAX, EDX
CALL 0FFFFh:0Fh
From: Robert Redelmeier on 4 May 2008 14:59
Wolfgang Kern <nowhere(a)never.at> wrote in part:
> MUL [src] ;does EAX*[src] and puts the result in
> ;EDX:EAX ("EDX has the high 32 bits" ..)
> DIV [src] ;does EDX:EAX/[src] and is therefore prone
> ;to overflow if the result is >32 bit.

Absolutely correct, I got EAX & EDX reversed.

-- Robert

From: Robert Redelmeier on 4 May 2008 15:04
kteixeira85(a)hotmail.com wrote in part:
> Thank you, much appreciated. Could you post a simple
> example using three registers and a do-while loop?

I'm not sure what good it would be. When you do a loop,
there has to be something changing external to that loop
(I/O, memory, etc) or it is rather pointless.

-- Robert

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