Jeremy Sanders <[EMAIL PROTECTED]> wrote:
> It must be the debugging, the compiler or a poor STL implementation. With
> gcc 4 it runs instantly on my computer (using -O2), even with 10x the
> number of values.
$ gcc --version
i686-apple-darwin8-gcc-4.0.1 (GCC) 4.0.1 (Apple Computer, Inc. build
5363)
I adapted original poster's code and made a function that did not create
strings each time. The NoisyString is a class we can use to actually
track copying.
In fact Python here is faster. Suppose it has a really optimized set
class...
Here some results (I know that the fpoint optimizations are useless...
it's is my "prebuilt" full optimization macro :) ):
$ g++ -O3 -pipe -O2 -march=pentium-m -msse3 -fomit-frame-pointer
-mfpmath=sse -o set_impl set_impl.cpp
$ ./set_impl
What do you know?
chicken crosses road
fool
so long...
What do you know?
chicken crosses road
fool
so long...
Elapsed 5.8
Elapsed 1.71
$ g++ -Os -pipe -O2 -march=pentium-m -msse3 -fomit-frame-pointer
-mfpmath=sse -o set_impl set_impl.cpp
$ ./set_impl
What do you know?
chicken crosses road
fool
so long...
What do you know?
chicken crosses road
fool
so long...
Elapsed 5.8
Elapsed 1.71
$ g++ -O3 -o set_impl set_impl.cpp
$ ./set_impl
What do you know?
chicken crosses road
fool
so long...
What do you know?
chicken crosses road
fool
so long...
Elapsed 0.47
Elapsed 0.18
$ g++ -o set_impl set_impl.cpp
$ ./set_impl
What do you know?
chicken crosses road
fool
so long...
What do you know?
chicken crosses road
fool
so long...
Elapsed 0.63
Elapsed 0.33
$ python -O set_impl.py
so long...
What do you know
fool
chicken crosses road
so long...
What do you know
fool
chicken crosses road
Elapsed: 1.370000 seconds
Elapsed: 3.810000 seconds
------------------- PYTHON CODE ---------------------------------
#python
global size
size = 1000000
def f():
a = []
for i in range(size):
a.append('What do you know')
a.append('so long...')
a.append('chicken crosses road')
a.append('fool')
b = set(a)
for s in b:
print s
def slow_f():
a = []
for i in range(size):
a.append('%s' % 'What do you know')
a.append('%s' % 'so long...')
a.append('%s' % 'chicken crosses road')
a.append('%s' % 'fool')
b = set(a)
for s in b:
print s
import time
from time import clock
f_start = clock()
f()
f_end = clock()
slow_f_start = clock()
slow_f()
slow_f_end = clock()
print "Elapsed: %f seconds" % (f_end - f_start)
print "Elapsed: %f seconds" % (slow_f_end - slow_f_start)
------------------------------------------------------------------
----------------- CPP CODE -------------------------------------
#include <iostream>
#include <ostream>
#include <iterator>
#include <string>
#include <vector>
#include <set>
#include <algorithm>
#include <ctime>
using namespace std;
#define SIZE 1000000
class NoisyString : public std::string {
public:
NoisyString(const string& cp)
: string(cp)
{
cout << "Fuck I got copied!" << endl;
}
NoisyString(const char* s ) : string(s) {
}
};
void f(){
vector<string> a;
for (long int i=0; i<SIZE ; ++i){
a.push_back("What do you know?");
a.push_back("so long...");
a.push_back("chicken crosses road");
a.push_back("fool");
}
set<string> b(a.begin(), a.end());
copy(b.begin(), b.end(), ostream_iterator<string>(cout, "\n"));
}
void fast_f(){
vector<string> a;
string s1 = "What do you know?" ;
string s2 = "so long..." ;
string s3 = "chicken crosses road";
string s4 = "fool" ;
for (long int i=0; i<SIZE ; ++i){
a.push_back(s1);
a.push_back(s2);
a.push_back(s3);
a.push_back(s4);
}
set<string> b(a.begin(), a.end());
copy(b.begin(), b.end(), ostream_iterator<string>(cout, "\n"));
}
int main(){
clock_t f_start,
f_end,
faster_f_start,
faster_f_end,
fast_f_start,
fast_f_end;
f_start = clock();
f();
f_end = clock();
fast_f_start = clock();
fast_f();
fast_f_end = clock();
cout << "Elapsed " << (f_end - f_start) / double(CLOCKS_PER_SEC) <<
endl;
cout << "Elapsed " << (fast_f_end - fast_f_start) /
double(CLOCKS_PER_SEC) << endl;
}
-----------------------------------------------------------------------
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