Sometimes one wants to know...

Results in seconds for 100000000 (1e8) operations on Intel Core2 CPU (E6700), 2.66 GHz, code (see below) was compiled with g++ -static -O2 -Wall -ffast-math -o fptime.cpp, GCC 4.2.4

erf 1.900
erfc 2.120
gamma 6.020
tgamma 12.120
log 2.360
exp 5.290
pow 12.090
sqrt 2.550
cos 3.390
tan 4.840
atan 5.330
mul 0.103
div 1.400
add 0.105
floor 0.792
fabs 0.097

#include <cmath>
#include <cstdio>
#include <ctime>
#include <cstdlib>

using namespace std;

int main() {
    volatile double a;
    volatile double b = 0.8234234;
    volatile double c = 1.43234;
    clock_t t;

    const int N = 100000000;

    t = clock();
    for (int i=0; i < N; i++)
        a = erf(b);
    printf("erf %.3f\n", (clock()-t) / (float) CLOCKS_PER_SEC);    

    t = clock();
    for (int i=0; i < N; i++)
        a = erfc(b);
    printf("erfc %.3f\n", (clock()-t) / (float) CLOCKS_PER_SEC);    

    t = clock();
    for (int i=0; i < N; i++)
        a = gamma(b);
    printf("gamma %.3f\n", (clock()-t) / (float) CLOCKS_PER_SEC);    

    t = clock();
    for (int i=0; i < N; i++)
        a = tgamma(b);
    printf("tgamma %.3f\n", (clock()-t) / (float) CLOCKS_PER_SEC);     

    t = clock();
    for (int i=0; i < N; i++)
        a = log(b);
    printf("log %.3f\n", (clock()-t) / (float) CLOCKS_PER_SEC);      

    t = clock();
    for (int i=0; i < N; i++)
        a = exp(b);
    printf("exp %.3f\n", (clock()-t) / (float) CLOCKS_PER_SEC);     

    t = clock();
    for (int i=0; i < N; i++)
        a = pow(b, c);
    printf("pow %.3f\n", (clock()-t) / (float) CLOCKS_PER_SEC);     

    t = clock();
    for (int i=0; i < N; i++)
        a = sqrt(b);
    printf("sqrt %.3f\n", (clock()-t) / (float) CLOCKS_PER_SEC);     

    t = clock();
    for (int i=0; i < N; i++)
        a = cos(b);
    printf("cos %.3f\n", (clock()-t) / (float) CLOCKS_PER_SEC);     

    t = clock();
    for (int i=0; i < N; i++)
        a = tan(b);
    printf("tan %.3f\n", (clock()-t) / (float) CLOCKS_PER_SEC);     

    t = clock();
    for (int i=0; i < N; i++)
        a = atan(b);
    printf("atan %.3f\n", (clock()-t) / (float) CLOCKS_PER_SEC);     

        
    t = clock();
    for (int i=0; i < 10*N; i++)
        a = b*c;
    printf("mul %.3f\n", (clock()-t) / 10 / (float) CLOCKS_PER_SEC);    

    t = clock();
    for (int i=0; i < N; i++)
        a = b/c;
    printf("div %.3f\n", (clock()-t) / (float) CLOCKS_PER_SEC);  

    t = clock();
    for (int i=0; i < 10*N; i++)
        a = b+c;
    printf("add %.3f\n", (clock()-t) / 10 / (float) CLOCKS_PER_SEC);  

    t = clock();
    for (int i=0; i < 10*N; i++)
        a = floor(b);
    printf("floor %.3f\n", (clock()-t) / 10 / (float) CLOCKS_PER_SEC);  

    t = clock();
    for (int i=0; i < 10*N; i++)
        a = fabs(b);
    printf("fabs %.3f\n", (clock()-t) / 10 / (float) CLOCKS_PER_SEC);  

    return EXIT_SUCCESS;
}

posted at: 19:55 | path: /programming | permanent link