Re: [Mingw-users] libstdc++ vs stlport

[Paul G. <pga...@at...>]

> Hi all
> 
> Take this little program:
> 
> #include <iostream>
> #include <string>
> #include <windows.h>
> using namespace std;
> 
> int main()
> {
>     string str = "0123456789abc";
> 
>     unsigned long start = GetTickCount();
>     for (int i = 0; i < 10000000; ++i)
>     {
>         str.find("abc");
>     }
>     unsigned long stop = GetTickCount();
>     cout << (stop - start) / 1000.0 << endl;
> }
> 
> I've compiled it with gcc 3.2's libstdc++ and with stlport 5.0
> both with -O3 switch, and here the results:
> libstdc++:
> 5.75s, 5.75s, 5.75s
> stlport:
> 0.843s, 0.859s, 0.844s
> 
> With: strstr(str.c_str(), "abc")  took only:
> 0.484s, 0.469s, 0.484s
> 
> I don't know why the libstdc++ find is 6.8 times slower than
> stlport find!

	At a guess, I think it may be due to the fact that libstdc++ does a much more 
detailed search based on the string in question, whereas stlport does a much more generic 
search of the string in question.

	Take a look at the actual stlport version of strstr vs. the actual libstdc++ version of 
strstr as it may be something that can give you a better idea of the functionality differences 
between the two methods.

	Paul G.