gdtr value

[Anuz Pratap Singh Tomar]

On Mon, Feb 18, 2013 at 3:05 PM, Anuz Pratap Singh Tomar <
chambilkethakur at gmail.com> wrote:

>
>
> On Mon, Feb 18, 2013 at 5:07 AM, horseriver <horserivers at gmail.com> wrote:
>
>> hi:)
>>
>>   I have compiled a .S file ,using command gcc -c x.S -o x.
>>   Then I use objdump to look up its asm code, even find that some code is
>> not the
>>   same as that .S file , more important is , some code in origin  .S file
>> has disappear .
>>
>>   what is about the reason ? If it is due to version , why some code
>> chould get lost after compile?
>>
>> Couple of things
> 1. Please don't piggy back questions over the unrelated topic, that is
> totally misdirecting the discussion.
> 2. You ask a lot of question related to compilation and stuff, which are
> off-topic here, why not READ a little bit more or consult relevant
> documentation?
> 3. You seem to do no homework before asking viz googling or reading basic
> books on relevant topic for example in this case reading a book on assembly
> language programming.
>
> When you write any assembly code(or for that matter any code) your code is
> written to be read by HUMANS and not machines. For machines a lot of that
> code is redundant and has no use so machine code will be generated in such
> a form that it is most optimized for the execution. For example take any
> *.c code and do
>
> #gcc -S *.c
> you will see an equivalent assembly code. It may not exactly be similar to
> the code which you will write in assembly for same logic. There are some
> rules according to which compilers generate code, please read some book on
> compilers and lex and yacc.
>
>
> Some more info about objdump and assembly code  and why they are
different.
http://stackoverflow.com/questions/4309771/disassembling-modifying-and-then-reassembling-a-linux-executable
And bit of correction:
s/it is most optimized for the execution/it is optimized for compilation if
there are no optimization flags used/


>
>> thanks!
>>
>
>
>
> --
> Thank you
> Warm Regards
> Anuz
>



-- 
Thank you
Warm Regards
Anuz
-------------- next part --------------
An HTML attachment was scrubbed...
URL: http://lists.kernelnewbies.org/pipermail/kernelnewbies/attachments/20130218/77e62717/attachment.html