64 bit processors and some newb question
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Thread: 64 bit processors and some newb question

  1. #1
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    64 bit processors and some newb question

    Ok, I'm not sure if this should go in newbies or here but I'll go ahead. Just starting to learn C and I got a couple questions.

    1) I have an AMD Athlon 64 bit processor. I only have a 32 bit version of windows. From what I understand I will not be able to utilize my 64-bit architecture until windows releases x64, is this true ? (on a side note, will linux be able to utilized my 64 bit processor ?)

    2) Any good references on programming with a 64 bit architecture ?

    3) From my understanding, x86 processors use little endian byte ordering. Does the AMD, and will this effect writing effeciant 64 bit programs ?

    One more question: On a linux command Line, how do I get a programm to accept command line parameters ? like:
    #myprog param1 param2

    Anyways, I will probably become a regular subscriber to this specific forum, since I am sure I will have more questions
    The fool doth think he is wise, but the wiseman knows himself to be a fool - Good Ole Bill Shakespeare

  2. #2
    T̙͓̞̣̯ͦͭͅͅȂͧͭͧ̏̈͏̖̖Z̿ ͆̎̄
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    This might answer question number two...

    http://www.experts-exchange.com/Prog...ing_Platforms/ Intel_Programming/Intel_64Bit_Architecture/ - 47k - 9 Feb 2005

    and here's the link to the page I found it on...

    http://www.google.ca/search?client=f...=Google+Search
    Google Search: programming with a 64 bit architecture

    it might provide more resources.

    Eg

  3. #3
    T̙͓̞̣̯ͦͭͅͅȂͧͭͧ̏̈͏̖̖Z̿ ͆̎̄
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    For easy reference to a variety of programs...


    http://directory.google.com/Top/Comp...ing/Languages/

    I think this has a strong list.

  4. #4
    AO French Antique News Whore
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    Windows need Windows XP x64 to use the 64 bits architecture. For Linux, there is 64 bits distructions out there.

    I'm not a programmer so I cannot answer the other question!
    -Simon \"SDK\"

  5. #5
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    Hi

    You need an OS supporting 64bit, if you develop code, you also need a
    compiler suitable for 64bit.


    64bit processors and OS

    Although I mainly work on AMDs Opteron, I made good experience with
    the Red Hat Enterprise Linux, which supports most 64bit architectures.
    We have it installed on AMD Opteron(tm) Processor 244, AMD Athlon(tm) 64,
    Intel(R) Itanium 2 and Intel(R) Xeon(TM) MP(64bit)

    There is also a free version of Windows XP Professional x64 Edition[1] available.



    64bit processors and compilers

    gcc[2] by default creates 64bit code on AMD64-machines. You could generate 32bit
    by an -m32 flag. The intel compiler icc[3] usually generates more performant
    code on an intel-based machine. You might have to pay for it, but check the licensing
    conditions for details.


    64bit processor programming

    Usually, the correct compiler already produces 64bit code - quite nicely optimised.
    You do not have to think about little/big-endian ordering in general.

    You can go further in optimisation, but for this you need quite an in-depth
    understanding. Check the intel.com[4] and amd.com[5] - pages - an example for
    optimisation[6], an example for SSE3[7].


    And as per you last question about command line parameter:
    Code:
    ...
    int main(int argc, char *argv[]){
    	int i;
    
    	for (i=0;i<argc;i++) printf("%s\n",argv[i]);
    }
    ...
    does the job


    Cheers


    [1] https://microsoft.order-9.com/winxp6...winxp64&id=dl#
    [2] http://gcc.gnu.org
    [3] http://www.intel.com/software/products/compilers/
    [4] http://www.intel.com/cd/ids/develope.../eng/index.htm
    [5] https://devcenter.amd.com/
    http://devforums.amd.com/index.php?act=idx
    [6] http://www.amd.com/us-en/assets/cont...docs/25112.PDF
    [7] http://www.intel.com/cd/ids/develope.../eng/66717.htm
    If the only tool you have is a hammer, you tend to see every problem as a nail.
    (Abraham Maslow, Psychologist, 1908-70)

  6. #6
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    whoa! Hey guys, thanks.
    Extra thanks to sec. Thanks a ton man. If I had enought antipoints to assign...
    The fool doth think he is wise, but the wiseman knows himself to be a fool - Good Ole Bill Shakespeare

  7. #7
    Senior Member
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    Ok, I know it is bad form to post twice in a row, but I couldn't edit my previous post, so here goes...
    After my code has accepted the command line parameters, how do I parse the different parameters into seperate char variables ? What I mean is this;

    ./myprogram param1 param2

    now after I accept from argc and argv how do I assign like this;

    char param1, param2

    char param1()
    ...code this or that...

    char param2()
    ...code this or that...

    ...or....

    int main(int argc, char *argv[]){
    int i;

    for (i=0;i<argc;i++) printf("%s\n",argv[i]);
    }

    after this, to take the integer i and assign the different parameters into different variables

    Also, A couple more questions, what are argv and argc ? Why do you assign them into different types of variables ? (char, int)

    What does the line:
    for (i=0;i<argc;i++) printf("%s\n",argv[i]);
    do ?

    what does the %s do ?

    Sorry for all the questions, it is kinda hard to turn up a (helpful) google.
    The fool doth think he is wise, but the wiseman knows himself to be a fool - Good Ole Bill Shakespeare

  8. #8
    Senior Member
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    Hi

    Maybe you should start reading some basic c tutorials. Two decent ones have been
    written by white_scorpion[1]. In the beginner tutorial, you learn about printf,
    in the intermediate one %s is explained.

    The line
    Code:
    for (i=0;i<argc;i++) printf("%s\n",argv[i]);
    simply prints the program arguments on the console.

    I would not try to achieve too much at once. First, learn to understand
    how that little program is doing what it is doing.
    char *argv[] are somewhat "advanced" data types (pointers and arrays).

    But if you want to convert the first parameter to an integer, try an
    Code:
      i = atoi(argv[1])
    If you want to check the second parameter char by char, try an
    Code:
    for (i=0;i<strlen(argv[2]);i++)
          printf("%c",argv[2][i]);
    Cheers

    [1] http://www.antionline.com/search.php...orumchoice=678
    If the only tool you have is a hammer, you tend to see every problem as a nail.
    (Abraham Maslow, Psychologist, 1908-70)

  9. #9
    Senior Member
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    hey thanks
    I am starting to get this, but I am having some problems (with the different syntaxes I think)

    this is what I have:
    Code:
    #include <stdio.h>
    
    int main(void)
    {
    	char name[15];
    	printf("Please enter your name:\n");
    	scanf("%s",name);
    	if(name == "myname")
    	{
    		printf("\n%s rocks",name);
    	}
    	else
    	{
    		printf("\nHello %s how are you?",name);
    	}
    	return 0;
    }
    but if I enter myname it still says "hello myname how are you" not "myname rocks" I think it has something to do with the if statement. coulda anyone tell me where I am going wrong ?
    The fool doth think he is wise, but the wiseman knows himself to be a fool - Good Ole Bill Shakespeare

  10. #10
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    Hi dmorgan

    The string comparison usually does not work in this way (with exceptions, eg fortran).
    I would use
    Code:
    #include<string.h>
    (...)
    if(strcmp(name,"myname")==0)
    (...)
    Cheers.
    If the only tool you have is a hammer, you tend to see every problem as a nail.
    (Abraham Maslow, Psychologist, 1908-70)

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