c++ - What's more efficient ???

jim p (8/8) Oct 05 2003 I'm trying to find some information on the order of what operations exec...

Walter (10/17) Oct 05 2003 This usually depends on the CPU you're using. Check out the Intel CPU

jim p (7/24) Oct 05 2003 OK, Thanks Walter

Alex Vinokur (30/37) Oct 06 2003 [snip]

jim p (15/64) Oct 07 2003 That's just what I'm looking for.

Alex Vinokur (12/16) Oct 07 2003 I haven't try to do that. I am not working with Visual C++.

"jim p" <x y.com> writes:

I'm trying to find some information on the order of what operations execute
the fastest, eg. Transcendental  Functions, Square Root, Divide, multiply,
add/subtract, etc etc.



Also, for things like, is a for loop more efficient than a while loop?



I've been trying all day.

Can't seen to find anything.



Can anyone point me in the right direction.





Jim

Oct 05 2003

"Walter" <walter digitalmars.com> writes:

"jim p" <x y.com> wrote in message news:blpnb5$1hl2$1 digitaldaemon.com...
 I'm trying to find some information on the order of what operations

execute
 the fastest, eg. Transcendental  Functions, Square Root, Divide, multiply,
 add/subtract, etc etc.

This usually depends on the CPU you're using. Check out the Intel CPU
manuals for the various processors, they give the approximate times for each
instruction. It also depends on the context, for that you'll need to do some
benchmarking.

 Also, for things like, is a for loop more efficient than a while loop?

Neither. They generate the same code.

 I've been trying all day.
 Can't seen to find anything.
 Can anyone point me in the right direction.

Most of these kinds of questions are frequently very dependent on the
compiler/CPU you're using. So the best way to answer them is to obj2asm the
output of the compiler, or prepare a benchmark and time the results.

Oct 05 2003

"jim p" <x y.com> writes:

OK, Thanks Walter


"Walter" <walter digitalmars.com> wrote in message
news:blpogn$1j4t$1 digitaldaemon.com...
 "jim p" <x y.com> wrote in message news:blpnb5$1hl2$1 digitaldaemon.com...
 I'm trying to find some information on the order of what operations

 execute
 the fastest, eg. Transcendental  Functions, Square Root, Divide,


multiply,
 add/subtract, etc etc.

 This usually depends on the CPU you're using. Check out the Intel CPU
 manuals for the various processors, they give the approximate times for

each
 instruction. It also depends on the context, for that you'll need to do

some
 benchmarking.

 Also, for things like, is a for loop more efficient than a while loop?

 Neither. They generate the same code.

 I've been trying all day.
 Can't seen to find anything.
 Can anyone point me in the right direction.

 Most of these kinds of questions are frequently very dependent on the
 compiler/CPU you're using. So the best way to answer them is to obj2asm

the
 output of the compiler, or prepare a benchmark and time the results.

Oct 05 2003

"Alex Vinokur" <alexvn connect.to> writes:

"jim p" <x y.com> wrote in message news:blpnb5$1hl2$1 digitaldaemon.com...
 I'm trying to find some information on the order of what operations execute
 the fastest, eg. Transcendental  Functions, Square Root, Divide, multiply,
 add/subtract, etc etc.



 Also, for things like, is a for loop more efficient than a while loop?



 I've been trying all day.

 Can't seen to find anything.



 Can anyone point me in the right direction.

[snip]


Try to use C/C++ Program Perfometer.
The perfometer enables to get performance of C/C++ program and separated pieces
of code for any metrics
    (for instance : clocks, uclocks, rusage-metrics, metrics defined by user
etc.).

The perfometer has been compiled with GNU g++ compiler.

I also tried to compile it with Digital Mars C++ compiler.
Unfortunately the compilation failed.

 -----------------------------------

        * http://alexvn.freeservers.com/s1/perfometer.html


    -----------------------------------

        * http://sourceforge.net/projects/cpp-perfometer
        * http://alexvn.freeservers.com/s1/perfometer.zip
          (via http://alexvn.freeservers.com/s1/perfometer.html)


    -----------------------------------

        * Web Page :
http://lists.sourceforge.net/lists/listinfo/cpp-perfometer-users
        * Posting  : mailto:cpp-perfometer-users lists.sourceforge.net
        * Archives :
http://sourceforge.net/mailarchive/forum.php?forum=cpp-perfometer-users


        * Gmane Group : news://news.gmane.org/gmane.comp.lang.c++.perfometer
        * Archives         :
http://news.gmane.org/gmane.comp.lang.c%2B%2B.perfometer



Regards,

   =====================================
   Alex Vinokur
     mailto:alexvn connect.to
     http://mathforum.org/library/view/10978.html
   =====================================

Oct 06 2003

"jim p" <x y.com> writes:

That's just what I'm looking for.

You say you couldn't get it to compile under DM.
That's a pity.
What about Visual C++, have you tried it.

James


"Alex Vinokur" <alexvn connect.to> wrote in message
news:bls72l$256b$1 digitaldaemon.com...
 "jim p" <x y.com> wrote in message news:blpnb5$1hl2$1 digitaldaemon.com...
 I'm trying to find some information on the order of what operations


execute
 the fastest, eg. Transcendental  Functions, Square Root, Divide,


multiply,
 add/subtract, etc etc.



 Also, for things like, is a for loop more efficient than a while loop?



 I've been trying all day.

 Can't seen to find anything.



 Can anyone point me in the right direction.

 [snip]


 Try to use C/C++ Program Perfometer.
 The perfometer enables to get performance of C/C++ program and separated

pieces of code for any metrics
     (for instance : clocks, uclocks, rusage-metrics, metrics defined by

user etc.).
 The perfometer has been compiled with GNU g++ compiler.

 I also tried to compile it with Digital Mars C++ compiler.
 Unfortunately the compilation failed.

  -----------------------------------

         * http://alexvn.freeservers.com/s1/perfometer.html


     -----------------------------------

         * http://sourceforge.net/projects/cpp-perfometer
         * http://alexvn.freeservers.com/s1/perfometer.zip
           (via http://alexvn.freeservers.com/s1/perfometer.html)


     -----------------------------------

         * Web Page :

http://lists.sourceforge.net/lists/listinfo/cpp-perfometer-users
         * Posting  : mailto:cpp-perfometer-users lists.sourceforge.net
         * Archives :

http://sourceforge.net/mailarchive/forum.php?forum=cpp-perfometer-users

         * Gmane Group :

news://news.gmane.org/gmane.comp.lang.c++.perfometer
         * Archives         :

http://news.gmane.org/gmane.comp.lang.c%2B%2B.perfometer
 Regards,

    =====================================
    Alex Vinokur
      mailto:alexvn connect.to
      http://mathforum.org/library/view/10978.html
    =====================================

Oct 07 2003

"Alex Vinokur" <alexvn connect.to> writes:

"jim p" <x y.com> wrote in message news:blvo8s$21m4$1 digitaldaemon.com...
 That's just what I'm looking for.

 You say you couldn't get it to compile under DM.
 That's a pity.
 What about Visual C++, have you tried it.

I haven't try to do that. I am not working with Visual C++.

You could try it. If you have any question you can ask them at :

Mailing List  : http://lists.sourceforge.net/lists/listinfo/cpp-perfometer-users
Newsgroup : news://news.gmane.org/gmane.comp.lang.c++.perfometer

Those are discussed C/C++ Program Perfometer issues.

[snip]

   =====================================
   Alex Vinokur
     mailto:alexvn connect.to
     http://mathforum.org/library/view/10978.html
   =====================================

Oct 07 2003

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c++ - What's more efficient ???