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Index > Compiler Internals > EXPRPARS.INC/optimization

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ouadji



Joined: 24 Dec 2008
Posts: 1081
Location: Belgium
ouadji

I don't change anything to the behavior of Fasm,
I just removed unnecessary code.
Results in memory are exactly the same as the original code (syser debugger)
Fasm works perfectly with this change.
Code:
fp_get:             lods    byte[esi]
           .....
;              call    fp_optimize             ;[-] useless (only to do "mov "dword[edi+8],8000h)
                mov     dword[edi+8],8000h      ;[+]
                mov     [fp_format],0
fp_before_dot:     lods    byte[esi]
           .....
;              mov     [edi+7],al              ;[-]
;               mov     dl,7                    ;[-]
;               mov     dword [edi+8],edx       ;[-]
                call    fp_optimize
         .....

;-----------------------------------------------------

;fp_optimize:    mov     eax,[edi]               ;[-] "OLD" fp_optimize
;           mov     ebp,[edi+4]
;                or      ebp,[edi]
;          or      ebp,[edi+12]
;               jz      fp_zero
;.loop:          test    byte [edi+7],80h
;           jnz     .done
;              shld    [edi+4],eax,1
;              mov     ebp,[edi+12]
;               shld    eax,ebp,1
;          mov     [edi],eax
;          shl     dword [edi+12],1
;           dec     dword [edi+8]
;              jmp     .loop
;.done:            ret
;fp_zero:    mov     dword [edi+8],8000h
;                ret

fp_optimize:     or      al,al                   ;[+] "NEW" fp_optimize
            jz      fp_zero
             mov     [edi+7],al
          mov     dword[edi+8],7
.loop:            dec     dword[edi+8]
                shl     dword[edi+4],1
              jns     .loop
               ret
fp_zero:     mov     dword[edi+8],8000h
          ret
    


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Last edited by ouadji on 02 Nov 2011, 01:46; edited 2 times in total
Post 01 Nov 2011, 09:49
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ouadji



Joined: 24 Dec 2008
Posts: 1081
Location: Belgium
ouadji

Make fasm more compact, faster, optimize the code,
remove unnecessary instructions ...
all this does not interest you Tomasz ?
Don't you want any more to evolve/change the code of your compiler ?
or maybe do you prefer to have no changes from "outside" ?
What is the reason for your silence when someone suggests a code change?

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I am not young enough to know everything (Oscar Wilde)- Image
Post 02 Nov 2011, 01:40
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revolution
When all else fails, read the source


Joined: 24 Aug 2004
Posts: 17716
Location: In your JS exploiting you and your system
revolution
Have patience young padawan. It hasn't even been one day yet.
Post 02 Nov 2011, 01:45
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ouadji



Joined: 24 Dec 2008
Posts: 1081
Location: Belgium
ouadji

"padawan", yes Very Happy

but "jong" ... Crying or Very sad

(ok, sorry, you are right)

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Post 02 Nov 2011, 01:55
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