Re: STL Slow - VS2005

Here is the file that was tested with vs2005 stl and vs2005 w/stlport 5.0

// string_compare.cpp : Defines the entry point for the console application.
//
#include <cstdio>
#include <string>

// This DEFINE is needed for VC6.
// IN VC8 namespace std is used
#ifdef USE_STLPORT
    #pragma message ("USING STLPORT")
    using namespace stlport;
#else
    using namespace std;
#endif

string func(string par )
{
    string tmp(par);
    return tmp ;
}

string func2(string& par )
{
    string tmp(par);
    return tmp ;
}

int main ( int , char* const* )
{
    HighResPerformanceMeasurement usecTimer;

    {
        usecTimer.Start();
        string s ;
        for ( int i = 0 ; i < 100000000; ++ i ) {
            s += " " ;
        }
        usecTimer.End();
        double msecs =
double((usecTimer.GetDifference()*1000)/usecTimer.GetFrequency());
        printf("Append one character to empty string 100 million times: %.0f
ms\n", msecs);
    }

    {
        usecTimer.Start();
        string s("qyweyuewunfkHBUKGYUGL ,wehbYGUW^( @T@H!BALWD:h^&@#*@(#:
JKHWJ:CND");
        for (int i = 0 ; i < 10000000; ++i) {
            s.find( "unfkHBUKGY" ) ;
            s.find( "W^( @T@H!B" ) ;
            s.find( "J:CND" ) ;
        }
        usecTimer.End();
        double msecs =
double((usecTimer.GetDifference()*1000)/usecTimer.GetFrequency());
        printf("Search long string for 3 different substrings 10 million times:
%.0f ms\n", msecs);
    }

    {
        usecTimer.Start();
        string s("qyweyuewunfkHBUKGYUGL ,wehbYGUW^( @T@H!BALWD:h^&@#*@(#:
JKHWJ:CND");
        string::size_type p ;
        string ss1( "unfkHBUKGY");
        string ss2 ( "123456" ) ;
        string sx ;
        for ( int i = 0 ; i < 10000000; ++ i ) {
            sx = s ;
            p = sx.find ( ss1 ) ;
            sx.replace ( p , ss1.size() , ss2 ) ;
            sx += s ;
        }
        usecTimer.End();
        double msecs =
double((usecTimer.GetDifference()*1000)/usecTimer.GetFrequency());
        printf("Assignment, search, replace 10 million times: %.0f ms\n", msecs);
    }

    {
        usecTimer.Start();
        string s("qyweyuewunfkHBUKGYUGL ,wehbYGUW^( @T@H!BALWD:h^&@#*@(#:
JKHWJ:CND");
        for( int i = 0 ; i < 10000000; ++ i ) {
            string sx = func( s );
        }
        usecTimer.End();
        double msecs =
double((usecTimer.GetDifference()*1000)/usecTimer.GetFrequency());
        printf("Pass and return by value function called 10 million times: %.0f
ms\n", msecs);
    }

    {
        usecTimer.Start();
        string s("qyweyuewunfkHBUKGYUGL ,wehbYGUW^( @T@H!BALWD:h^&@#*@(#:
JKHWJ:CND");
        for( int i = 0 ; i < 10000000; ++ i ) {
            string sx = func2( s );
        }
        usecTimer.End();
        double msecs =
double((usecTimer.GetDifference()*1000)/usecTimer.GetFrequency());
        printf("Pass by reference return by value function called 10 million
times: %.0f ms\n", msecs);
    }

    {
        usecTimer.Start();
        string s("1234567890");
        for( int i = 0 ; i < 10000000; ++ i ) {
            string sx = func( s );
        }
        usecTimer.End();
        double msecs =
double((usecTimer.GetDifference()*1000)/usecTimer.GetFrequency());
        printf("Short String - Pass and return by value function called 10 million
times: %.0f ms\n", msecs);
    }

    return 0 ;
}

"Carl Daniel [VC++ MVP]" wrote: