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:

"WXS" <WXS@xxxxxxxxxxxxxxxxxxxxxxxxx> wrote in message
news:B3C45289-3843-4465-BC3B-BE287471DD4C@xxxxxxxxxxxxxxxx
VS2005
We compared the MS STL with stlport5.0 and found the results so
significantly slow as to make us question the implementation. Here is an
output of our tester compiled under vs2005 comparing vs2005's stl with
stlport 5.0's stl implementation.

Anyone else seeing the same or know how to improve performance? We tried
enabling small block allocation and setting the security checks define to
0
but no luck, performance got even worse.

Without knowing exactly how you built the code, and exactly what the code is
doing, it's impossible to comment beyond the superficial.

Can you post your test program for others to inspect and verify your
results?

-cd



.

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