Re: why so slow? gcc vs vc6

[Georg Steffers <georg at steffers dot org>]

As far as I understand profiling you must not read the time results as  
the values you got without profiling. Profiling is there to find  
inefficiencies in your code, such as unneccessary loops etc. and thus  
the times are only to compare the different calls. Additionally it is  
very likely that gprof called you app several times, to get a better  
comparison. (That is only how i understand profiling, dont beat me if i  
am wrong)

You can see that your program spend the most time for the logarithmic  
calculation, followed by the power caculation.

In my opinion your problem is that you did not use fast-math, as far as  
i know vc uses a math lib with similar optimizations by default.

so as Ishwar Rattan mentioned, if speed is important and vc6 is faster  
that use vc6.

greets Georg

Am 21.04.2005 08:17:12 schrieb(en) CyberSnoopy:
> I've tried gprof
> this is the result
> Flat profile:
>
> Each sample counts as 0.01 seconds.(what does this mean?)
>   %   cumulative   self              self     total
>  time   seconds   seconds    calls   s/call   s/call  name
>  32.23      7.56     7.56                             __ieee754_log
--snip--
>   0.02     23.45     0.01
--snip--
> I'm wondering is the total time as much as 23.46 seconds? I'm
> comfused...

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