Linking OpenMP

Mash · 03-07-2007, 05:31 PM

Hi there,

I am trying to write a program using openMP but i am getting the following message when compiling:

/tmp/ccpvkTQn.o: In function `main':
parallel.c

.text+0x12): undefined reference to `omp_get_thread_num'
parallel.c

.text+0x33): undefined reference to `omp_get_num_threads'
collect2: ld returned 1 exit status

I am guessing that I am failing to link to the openMP libraries. How exactly do I do this?
Should it be something like:

gcc -lomp prog.c -o prog

Any help would be awesome!

Thanx

Mash

KenJackson · 03-09-2007, 05:53 AM

I don't know what 'openMP' is, but your own suggestion looks pretty good.

Using -lomp means you are linking to library files named libomp.so and libomp.la (or libomp.a for static), probably in /usr/lib. If you can't find those files, then either you have the wrong name or openMP isn't installed.

Note that many packages have a separate package for development. So a package named package would have package-devel which must be installed separately in order to do development.

Brun007 · 07-28-2007, 02:44 PM

Quote:

Originally Posted by Mash

Hi there,

I am trying to write a program using openMP but i am getting the following message when compiling:

/tmp/ccpvkTQn.o: In function `main':
parallel.c

.text+0x12): undefined reference to `omp_get_thread_num'
parallel.c

.text+0x33): undefined reference to `omp_get_num_threads'
collect2: ld returned 1 exit status

I am guessing that I am failing to link to the openMP libraries. How exactly do I do this?
Should it be something like:

gcc -lomp prog.c -o prog

Any help would be awesome!

Thanx

Mash

Hi Mash,
I was having the same problem too, 'til I found that the right library to use is libgomp.so.1. So, in order to compile it you have to use, e.g: "gcc -lgomp helloworld.c -o helloworld"

[]s