Signed numbers, calculator, fasm code

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edemko

Joined: 18 Jul 2009
Posts: 549

edemko 24 Nov 2010, 08:32

0.
Hi the board.

1.
Working over a routine or making some calculations i use fasm's calc in some cases to recheck myself.
It's boring much that it does not support unsigned qword operations(division, e.g.).
A "sign" & "unsign" directives could have solved the problem.
That way fasm, to my mind, would have to inform user about sign mode changes through "display" directive.
So that user avoided lot of cry.

2.
Tomasz, set calc's font to ASMEDIT's, please.

3.
Tomasz, open "exprcalc.inc", line ~930, optimize-able for size.
Partial snippet given only.

Code:

        xor     ebx,ebx              ;)
        cmp     dword [edi],0        ;here
        jne     divider_ok
        cmp     dword [edi+4],0      ;here
        jne     divider_ok
        cmp     [next_pass_needed],0 ;here
        je      value_out_of_range
        jmp     div_done
      divider_ok:
        bt      dword [esi+4],31     ;here    cmp dword[esi+4],ebx
        jnc     div_first_sign_ok    ;        js
        not     dword [esi]
        not     dword [esi+4]
        add     dword [esi],1
        adc     dword [esi+4],0      ;here
        ...                          ;there

24 Nov 2010, 08:32

edemko

Joined: 18 Jul 2009
Posts: 549

edemko 24 Nov 2010, 08:45

Code:

        not     dword [esi] 
        not     dword [esi+4] 
        add     dword [esi],1 
        adc     dword [esi+4],0

equals

Code:

        not     dword[esi+4]
        neg     dword[esi]
        adc     dword[esi+4],0 ;ebx

24 Nov 2010, 08:45

ouadji

Joined: 24 Dec 2008
Posts: 1081
Location: Belgium

ouadji 24 Nov 2010, 11:27

hi edemko,

I've also seen a lot of little things like that !
But I think Tomasz does not favor the size,
but rather to maintain readability.
It is more difficult to change a optimized code ...
and less easy to understand it after a while!
I like much to optimize my code to the maximum,
but sometimes i waste a lot of time to understand it again after a long time.

_________________
I am not young enough to know everything (Oscar Wilde)-

24 Nov 2010, 11:27

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