Hello, i need help in porting this code from asm to delphi ( i have tried inlining it but it does not produce the right result)

@Test_00452510:
        movsx eax,byte ptr [esi+$050e858]  // =======> $050e858 is pointing to an address in memory  

        lea edx,[eax+esi+1]

        imul edx,ebx

        add ecx,edx

        mov eax,$07ccbfadf

        imul ecx

        sub edx,ecx

        sar edx,9

        mov eax,edx

        shr eax,$01f

        add eax,edx

        imul eax,eax,$03e7

        inc esi

        add ecx,eax

        cmp esi,edi

        jl @Test_00452510

the above code was ripped with code ripper plugin in olly.

Inline asm will work fine - after you fix some of your bugs.

 

1) initial EBX value is unknown;

2) initial ECX value is unknown;

3) initial ESI and EDI values are unknown;

4) and don't forget to save/restore all important registers. I prefer to wrap inline asm in pushad/popad, just to be sure.

5) result of your ripped ASM code is in ECX, Delphi by default will ignore that. Make sure you store it in some variable.

 

EDIT: added #5.

Edited November 19, 201410 yr by kao

thanks Kao for your suggestions but I have spent the better part of today trying to fix the bug ridden asm code but no success that is why I decided to port it in Delphi. well I will keep on trying and keep you updated on my progress. thanks once again.

To port that code to Delphi, you still need to answer my first 3 points about initial register values. If you'd give me few test inputs and expected results, I could try to make the appropriate Delphi code.

After some good night rest and a Cup of Coffee this morning, I have finally ported the code to work properly (still used inline asm).
the problem was the variable i set the result from the asm code was not set to zero on initialization so that caused it to have junk values in memory.

Thanks Kao for your help and suggestions, i really appreciate it.