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Re: Speed Test for Comparison

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"Mel Smith" <med_cutout_syntel@aol.com> wrote in message
news:9khmneF4udU1@mid.individual.net...

> for i := 1 to 1000000
>   str( i / 1000 )     // no assignment of the return value
> next

You want to compare C code that does this *directly*, or C code that
implements some arbitrary virtual machine that does the same job?

In either case, the timings will be dominated by the time needed to convert
floating point numbers to strings, and, if the implementation does proper
string handling, by the overheads of creating and discarding a million short
strings.

Any comparison is anyway likely to be meaningless because you are testing
one arbitrary implementation against another.

FWIW, a simple sprintf() loop in C took about 1 second on my machine. Your 
str(i/1000) loop in one of my scripting languages, with proper string 
handling, took 2 seconds to execute a million times. This language is 
usually much slower than C. So the actual task, rather than language 
overheads, seems to be dominating execution time.

However, given the complicated-looking C code that your language generates, 
I'm surprised it isn't much slower. Your first step might be to simply find 
out how long the task itself might be expected to take, but I'm not sure why 
you can't do this for yourself:

#include <stdio.h>

int main(void) {
int i;
char str[100];

for (i=0; i<1000000; ++i) {
 sprintf(str,"%f",i/1000.0);
}
}

-- 
Bartc 

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Speed Test for Comparison "Mel Smith" <med_cutout_syntel@aol.com> - 2011-12-08 10:09 -0700
  Re: Speed Test for Comparison Richard Sanders <lnr729@gmail.com> - 2011-12-08 11:19 -0800
    Re: Speed Test for Comparison "Mel Smith" <med_cutout_syntel@aol.com> - 2011-12-08 13:13 -0700
      Re: Speed Test for Comparison "Mel Smith" <med_cutout_syntel@aol.com> - 2011-12-08 13:18 -0700
        Re: Speed Test for Comparison Seebs <usenet-nospam@seebs.net> - 2011-12-08 20:41 +0000
          Re: Speed Test for Comparison Ben Pfaff <blp@cs.stanford.edu> - 2011-12-08 12:49 -0800
            Re: Speed Test for Comparison Seebs <usenet-nospam@seebs.net> - 2011-12-08 21:53 +0000
      Re: Speed Test for Comparison Seebs <usenet-nospam@seebs.net> - 2011-12-08 20:41 +0000
  Re: Speed Test for Comparison "BartC" <bc@freeuk.com> - 2011-12-08 21:43 +0000
  Re: Speed Test for Comparison ImpalerCore <jadill33@gmail.com> - 2011-12-08 13:58 -0800
  Re: Speed Test for Comparison Keith Thompson <kst-u@mib.org> - 2011-12-08 14:58 -0800
    Re: Speed Test for Comparison "Mel Smith" <med_cutout_syntel@aol.com> - 2011-12-10 11:28 -0700
      Re: Speed Test for Comparison "BartC" <bc@freeuk.com> - 2011-12-10 21:40 +0000
        Re: Speed Test for Comparison "Mel Smith" <med_cutout_syntel@aol.com> - 2011-12-10 19:26 -0700
      Re: Speed Test for Comparison Keith Thompson <kst-u@mib.org> - 2011-12-10 13:49 -0800

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