Thread: C vs ASM

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    Registered User CompiledMonkey's Avatar
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    C vs ASM

    I'm curious to know if C can do as much as assembler can. Can I access memory and do other really low level items with C like you can in ASM? I kinda want to learn some low level programming for fun, and I'm trying to decide between ASM and C. Any input is appreciated.

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    ... kermit's Avatar
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    Its been my understanding that you can do anything in assembly that you can in C. It is also my understanding that it is a lot more work to write in assembly, and usually the only advantage to using it is if you have a part of your code that is uber slow, and could use some tweaking.

    kermit

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    Registered User CompiledMonkey's Avatar
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    So I can write directly to memory in C, and do other tasks I can't in Java?

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    Registered User kinghajj's Avatar
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    Well...

    Some things can ONLY be done in ASM - like bootloaders. But, for the most part, C can do anything that you want.

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    ... kermit's Avatar
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    I guess I should have answered your question properly.. - You asked if 'C can do as much as assembler,' to which I answered you can do anything in assembly that you can in C - so I was not really answering your question like you wanted - and notice the word order - I was not saying that you can do everything with C that you can with assembly.

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    Some things can ONLY be done in ASM - like bootloaders
    Why is that?

    Why isnt there a compiler option to let you pick where it goes in memory? Cant you make a absolute binary with gcc(i have no idea whats its really called, i mean when it requires nothing to run on its own)?

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    Just because ygfperson's Avatar
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    Originally posted by mart_man00
    Why is that?
    A bootloader has specific requirements for where bytes go. (For instance, the bootloader needs to end with 7c 00 (or something like that.)) There's also the fact that some things in writing operating systems (like going into protected mode) need specific things done in a specific order, or else it will foul up for no apparent reason. You don't have this level of control with assembly.

    Why isnt there a compiler option to let you pick where it goes in memory? Cant you make a absolute binary with gcc(i have no idea whats its really called, i mean when it requires nothing to run on its own)?
    There is, and you can

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    There is, and you can
    So doesnt that mean its possible?

    Do you really have to go that low level for a bootloader(besides from memory)? I mean isnt its sole purpose to load another program? So you woulnt have to go into protective mode(isnt that what compilcates things?)?

    Im assuming that Lilo is like 2 sperate programs with this.


    Ive been wondering this for a while, thanks.

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    C++ Developer XSquared's Avatar
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    >>You don't have this level of control with assembly.
    I'm assuming you mean C, not assembly.
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    Re: C vs ASM

    Originally posted by CompiledMonkey
    I'm curious to know if C can do as much as assembler can. Can I access memory and do other really low level items with C like you can in ASM? I kinda want to learn some low level programming for fun, and I'm trying to decide between ASM and C. Any input is appreciated.
    In my best knowledge, you have a lot more control on a lower level over everything in assambler. You can control anything from hardware level to any given variable level.
    The gratest disadvantage is that it is a lot more dificult to write code.
    But the program you have to do will work faster and with less resources needed.

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    Its not rocket science vasanth's Avatar
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    Re: Re: C vs ASM

    Originally posted by molie666
    In my best knowledge, you have a lot more control on a lower level over everything in assambler. You can control anything from hardware level to any given variable level.
    The gratest disadvantage is that it is a lot more dificult to write code.
    But the program you have to do will work faster and with less resources needed.
    well then let me see you convert a 10000 line C++/C program to ASM and let me see how effeciently it will run.. obviously you can not convert all that in an optimized manner..

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    Re: Re: Re: C vs ASM

    Originally posted by vasanth
    well then let me see you convert a 10000 line C++/C program to ASM and let me see how effeciently it will run.. obviously you can not convert all that in an optimized manner..
    Just as I said it is a lot more dificult to write code in assembler, but, if done properly, you can build more reliable programs.

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    >>>well then let me see you convert a 10000 line C++/C program to ASM and let me see how effeciently it will run.. obviously you can not convert all that in an optimized manner..


    He never said that. and that was never the question. The question was if C can do "everything" that can be done using assembler. I do not know assembly language, heck I dont even know C so well, but I would think, C cant do everything that assembler does.

    Anoop.

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    Originally posted by anoopks
    >>>well then let me see you convert a 10000 line C++/C program to ASM and let me see how effeciently it will run.. obviously you can not convert all that in an optimized manner..


    He never said that. and that was never the question. The question was if C can do "everything" that can be done using assembler. I do not know assembly language, heck I dont even know C so well, but I would think, C cant do everything that assembler does.

    Anoop.
    Yes it can.
    If you have the apropriate .h files, that is.

  15. #15
    Its not rocket science vasanth's Avatar
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    Originally posted by anoopks
    >>>well then let me see you convert a 10000 line C++/C program to ASM and let me see how effeciently it will run.. obviously you can not convert all that in an optimized manner..


    He never said that. and that was never the question. The question was if C can do "everything" that can be done using assembler. I do not know assembly language, heck I dont even know C so well, but I would think, C cant do everything that assembler does.

    Anoop.
    hi anoop.. looks like u r from India.. me tooo

    ok let me put it this way...

    Using Assembler to do big stuff is like using a pen torch cell to power up a building.. instead i would use a generator which is C/C++ May be you can get thousands of cells to power up but not viable...

    There are things like small circuits, etc etc which need to be programmed.. assembler is very usefull hee since there is not much of overhead.. Even it is used to optimize some parts of code in a C/C++ program( you can use inline assembly)..

    Knowing Asm is a good thing since you will be familiar with the structure of the PC archite..... And can make you a better programmer..( atleast thats what i think).

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