Re: [boost] BOOST_FOREACH slow?

Subject: Re: [boost] BOOST_FOREACH slow?
From: Hansi (hansipet_at_[hidden])
Date: 2008-11-17 12:36:01

Sorry, I have forgotten to write that I use VS2005 and i compile with 
the macro _SECURE_SCL=0 defined..

Best regards
Hansjörg

Hansi schrieb:
> Hello,
> 
> I have made a few tests with the performance of BOOST_FOREACH. The 
> results are for me unexpected slow...may be one has an idea if I make 
> something wrong...
> 
> vector[int]: index:0.00167619
> vector[int]: iterator:0.00167619
> vector[int]: BOOST_FOREACH:9.40036
> 
> list[int]: iterator:239.669
> list[int]: BOOST_FOREACH:233.219
> 
> vector[TestData]: index:0.00167619
> vector[TestData]: iterator:0.00167619
> vector[TestData]: BOOST_FOREACH:9.40008
> 
> list[TestData]: iterator:233.827
> list[TestData]: BOOST_FOREACH:238.513
> 
> testArray[int]: index:0.00167619
> testArray[int]: BOOST_FOREACH:9.40008
> 
> Best regards
> Hansjörg
> 
> 
> 
> the test program was:
> 
> // ForEach.cpp : Defines the entry point for the console application.
> //
> 
> #include "stdafx.h"
> #include "..\include\PerformanceCounter.h"
> #include <vector>
> #include <boost\foreach.hpp>
> #include <iostream>
> #include <list>
> 
> using namespace std;
> using namespace Microtec;
> 
> class TestData
> {
> public:
>     TestData(int val1, int val2, int 
> val3):var1(val1),var2(val2),var3(val3){}
>     int var1;
>     int var2;
>     int var3;
> };
> 
> int testArray[10000000];
> 
> int _tmain(int argc, _TCHAR* argv[])
> {
>     vector<int> data;
>     list<int> lstData;
>     vector<TestData> vectorTestData;
>     list<TestData> lstTestData;
> 
>     for(int i = 0; i < 10000000;i++)
>     {
>         data.push_back(i);
>         lstData.push_back(i);
>         vectorTestData.push_back(TestData(i,i,i));
>         lstTestData.push_back(TestData(i,i,i));
>     }
> 
>     int res = 0;
> 
>     const int actSize = (int)data.size();
>     for(int i = 0; i < actSize; i++)
>     {
>         res += data[i];
>     }
>     //takes 0.0017 ms
>     
>     res = 0;
>     for(vector<int>::iterator it = data.begin(); it != data.end(); it++)
>     {
>         res += *it;
>     }
>     //takes 0.0017 ms
> 
>     res = 0;
>     BOOST_FOREACH(int val,data)
>     {
>         res += val;
>     }
>     //takes 9.400 ms
> 
> 
>     //list
>     res = 0;
>     for(list<int>::iterator it = lstData.begin(); it != lstData.end(); 
> it++)
>     {
>         res += *it;
>     }
>     //takes 239.669 ms
> 
>     res = 0;
>     BOOST_FOREACH(int val,lstData)
>     {
>         res += val;
>     }
>     //takes 233.219 ms
> 
> 
>     //vector TestData
>     for(int i = 0; i < actSize; i++)
>     {
>         res += vectorTestData[i].var1;
>     }
>     //takes 0.0017 ms
>     
>     res = 0;
>     for(vector<TestData>::iterator it = vectorTestData.begin(); it != 
> vectorTestData.end(); it++)
>     {
>         res += it->var1;
>     }
>     //takes 0.0017 ms
> 
>     res = 0;
>     BOOST_FOREACH(TestData& val,vectorTestData)
>     {
>         res += val.var1;
>     }
>     //takes 9.400 ms
> 
> 
>     //list
>     res = 0;
>     for(list<TestData>::iterator it = lstTestData.begin(); it != 
> lstTestData.end(); it++)
>     {
>         res += it->var1;
>     }
>     //takes 233.827 ms
> 
>     res = 0;
>     BOOST_FOREACH(TestData& val,lstTestData)
>     {
>         res += val.var1;
>     }
>     //takes 238.827 ms
> 
>     for(int i = 0; i < actSize; i++)
>     {
>         res += testArray[i];
>     }
>     //takes 0.0017 ms
>     
>     res = 0;
>     BOOST_FOREACH(int val,testArray)
>     {
>         res += val;
>     }
>     //takes 9.400 ms
> 
> 
>     return 0;
> }
> 
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