How to run cilk plus fibonacci example ?

[amina-jarraya]

Hello,

I am trying to compile and run my first example of fibbonacci with cilk plus langage :

#include
#include

int fib(int n)
{
int x, y;

if (n < 2)
return n;

x = cilk_spawn fib(n-1);
y = fib(n-2);
cilk_sync;
return x+y;
}

int main(int argc, char **argv)
{
int n = 30;
printf("fib(%d): %d\\n", n, fib(n));
return 0;
}

I compile this example as the following :

amina@amina-laptop:~/projet/cilkplus-install/examples/fibonacci$ gcc -ldl -lcilkrts fibonacci.cpp

I have the a.out file as a result :

amina@amina-laptop:~/projet/cilkplus-install/examples/fibonacci$ ls
a.out fibonacci.cpp

Now, how to run it ??

is it as the following :

amina@amina-laptop:~/projet/cilkplus-install/examples/fibonacci$ ./a.out
./a.out: error while loading shared libraries: libcilkrts.so.5: cannot open shared object file: No such file or directory

Thank you for your help,

[amina-jarraya]

Hello everybody,

The problem is that we have to add libraries LIBRARY_PATH and LD_LIBRARY_PATH in path :

amina@amina-laptop:~/projet/cilkplus-install/bin$ export LD_LIBRARY_PATH=/home/amina/projet/cilkplus-install/lib
amina@amina-laptop:~/projet/cilkplus-install/bin$ echo $LD_LIBRARY_PATH
/home/amina/projet/cilkplus-install/lib
amina@amina-laptop:~/projet/cilkplus-install/bin$ export LIBRARY_PATH=/home/amina/projet/cilkplus-install/lib
amina@amina-laptop:~/projet/cilkplus-install/bin$ echo $LIBRARY_PATH
/home/amina/projet/cilkplus-install/lib

it runs ok :

amina@amina-laptop:~/projet/cilkplus-install/examples/fibonacci$ gcc -pthread -o fib fibonacci.cpp -lcilkrts -ldlamina@amina-laptop:~/projet/cilkplus-install/examples/fibonacci$ ls
a.out fib fibonacci.cpp fibonacci_old.cpp
amina@amina-laptop:~/projet/cilkplus-install/examples/fibonacci$ ./fib
fib(30): 832040

But, i have added the libraries after installing the cilkplus branch of gcc, why the librairies are deleted ??

i have to add the librairies each time to run an example ??

[amina-jarraya]

I have another question please :

I want to use the cilkwiew, i add the following lines to fibonnaci example :

int main(int argc, char *argv[])
{
cilkview_data_t d;
int n = atoi(argv[1]);
__cilkview_query(d);
int result = fib(n);
printf("Fibonacci of %d is %d.\n", n, result);
__cilkview_report(d, NULL, "Fib-result", CV_REPORT_WRITE_TO_RESULTS);

return 0;
}

when compiling i have errors :

root@amina-laptop:/home/amina/projet/cilkplus-install/examples/fibonacci# gcc -pthread -o fib2 fibonacci_old.cpp -lcilkrts -ldl
In file included from fibonacci_old.cpp:33:0:
/home/amina/projet/cilkplus-install/include/cilktools/cilkview.h: In function void __cilkview_do_report(cilkview_data_t*, cilkview_data_t*, char*, unsigned int):
/home/amina/projet/cilkplus-install/include/cilktools/cilkview.h:198:52: erreur: void __cilkview_do_report(cilkview_data_t*, cilkview_data_t*, char*, unsigned int) was declared extern and later static [-fpermissive]
/home/amina/projet/cilkplus-install/include/cilktools/cilkview.h:106:6: erreur: previous declaration of void __cilkview_do_report(cilkview_data_t*, cilkview_data_t*, char*, unsigned int) [-fpermissive]
/home/amina/projet/cilkplus-install/include/cilktools/cilkview.h: In function void __cilkview_do_report(cilkview_data_t*, cilkview_data_t*, char*, unsigned int):
/home/amina/projet/cilkplus-install/include/cilktools/cilkview.h:241:19: attention : deprecated conversion from string constant to char* [-Wwrite-strings]
fibonacci_old.cpp: In function int main(int, char**):
fibonacci_old.cpp:57:3: erreur: cannot convert cilkview_data_t to cilkview_data_t* for argument 1 to void __cilkview_do_report(cilkview_data_t*, cilkview_data_t*, char*, unsigned int)


Have you an idea for this problem ??

Thank you in advance.

[Balaji_I_Intel]

Your LD_LIBRARY_PATH and LIBRARY_PATH are both wrong.

Please set your LD_LIBRARY_PATH and LIBRARY_PATH to ~/project/cilkplus-install/lib (or make sure it points to the lib directory of wherever you have installed the gcc compiler).

Thanks,

Balaji V. Iyer.

[Balaji_I_Intel]

We do not yet implemented Cilkview and Cilkscreen support into the Cilkplus GCC.

Thanks,

Balaji V. Iyer.

[amina-jarraya]

Hello Balaji,

Thank you for your reply,

So, can i use the ctime librairy to compute the time of execution ? :

#include
...

int main(int argc, char *argv[])
{

int n = atoi(argv[1]);
clock_t debut,fin;

debut = clock();

int result = fib(n);
printf("Fibonacci of %d is %d.\n", n, result);

fin = clock();
cout<<"Time of execution : "<<(double)(fin-debut) / (double) CLOCKS_PER_SEC<<" secondes \n";

return 0;
}

The result :

amina@amina-laptop:~/projet/cilkplus-install/examples/fibonacci$ gcc -pthread -o fib2 fibonacci_old.cpp -lcilkrts
amina@amina-laptop:~/projet/cilkplus-install/examples/fibonacci$ ./fib2 30 CILK_NWORKERS=4
Fibonacci of 30 is 832040.
Time of execution : 0.19 secondes
amina@amina-laptop:~/projet/cilkplus-install/examples/fibonacci$

is it correct to know the time of execution on multicore architecture ?