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User forums => Using Code::Blocks => Topic started by: biotech54 on September 22, 2017, 04:33:41 am

Title: OpenMP
Post by: biotech54 on September 22, 2017, 04:33:41 am

I'm trying to get OpenMP programs to compile using CB. I read previous OpenMP discussions on this forum, written about 7 years ago. However, I did not understand what they were talking about, and i'm sure CB has changed since 2010. Does anyone know what i need to click, what settings i need to change, so that my OpenMP programs will compile? I get error messages when i try to compile simple five line programs. Thanks,
Edward

Title: Re: OpenMP
Post by: stahta01 on September 22, 2017, 05:10:02 am

http://forums.codeblocks.org/index.php?topic=22123.0 (http://forums.codeblocks.org/index.php?topic=22123.0)

Title: Re: OpenMP
Post by: biotech54 on September 22, 2017, 05:38:00 am

Thanks, but just too complicated for me.

Title: Re: OpenMP
Post by: stahta01 on September 22, 2017, 05:41:41 am

Quote from: biotech54 on September 22, 2017, 05:38:00 am

Thanks, but just too complicated for me.

If using a project and posting a build log is too complex for you.
Then, using OpenMP is likely too complex for you, at least till you can do both of those items.

Tim S.

Title: Re: OpenMP
Post by: biotech54 on September 22, 2017, 05:57:29 am

oh sorry, i didn't know you wanted to see the build log. Here is the program, and build log. I'm using Windows 7.

#include <stdio.h>
#include <stdlib.h>
#include <omp.h>

void hello();

int main()
{
int threadCount = 4
#pragma omp parallel num_threads(threadCount)
hello();

return 0;
}

void hello(){

int myRank = omp_get_thread_num();
int threadCount = omp_get_num_threads();
printf("thread %d of %d\n", myRank, threadCount);
}

-------------- Build: Debug in OpenMPTest (compiler: GNU GCC Compiler)---------------

mingw32-gcc.exe -Wall -g -c C:\MyHomeComputer\MyCppProjects\OpenMPTest\main.c -o obj\Debug\main.o
C:\MyHomeComputer\MyCppProjects\OpenMPTest\main.c: In function 'main':
C:\MyHomeComputer\MyCppProjects\OpenMPTest\main.c:11:0: warning: ignoring #pragma omp parallel [-Wunknown-pragmas]
#pragma omp parallel num_threads(threadCount)
^
C:\MyHomeComputer\MyCppProjects\OpenMPTest\main.c:12:4: error: expected ',' or ';' before 'hello'
hello();
^
C:\MyHomeComputer\MyCppProjects\OpenMPTest\main.c:10:8: warning: unused variable 'threadCount' [-Wunused-variable]
int threadCount = 4
^
Process terminated with status 1 (0 minute(s), 0 second(s))
1 error(s), 2 warning(s) (0 minute(s), 0 second(s))

Title: Re: OpenMP
Post by: biotech54 on September 22, 2017, 05:59:07 am

sorry, i had a typo, i missed a semicolon, here is the build log.

-------------- Build: Debug in OpenMPTest (compiler: GNU GCC Compiler)---------------

mingw32-gcc.exe -Wall -g -c C:\MyHomeComputer\MyCppProjects\OpenMPTest\main.c -o obj\Debug\main.o
C:\MyHomeComputer\MyCppProjects\OpenMPTest\main.c: In function 'main':
C:\MyHomeComputer\MyCppProjects\OpenMPTest\main.c:10:0: warning: ignoring #pragma omp parallel [-Wunknown-pragmas]
#pragma omp parallel num_threads(threadCount)
^
C:\MyHomeComputer\MyCppProjects\OpenMPTest\main.c:9:8: warning: unused variable 'threadCount' [-Wunused-variable]
int threadCount = 4;
^
mingw32-g++.exe -o bin\Debug\OpenMPTest.exe obj\Debug\main.o
obj\Debug\main.o: In function `hello':
C:/MyHomeComputer/MyCppProjects/OpenMPTest/main.c:18: undefined reference to `omp_get_thread_num'
C:/MyHomeComputer/MyCppProjects/OpenMPTest/main.c:19: undefined reference to `omp_get_num_threads'
collect2.exe: error: ld returned 1 exit status
Process terminated with status 1 (0 minute(s), 0 second(s))
3 error(s), 2 warning(s) (0 minute(s), 0 second(s))

Title: Re: OpenMP
Post by: stahta01 on September 22, 2017, 03:35:21 pm

link to the library gomp if I recall correctly.

Tim S.

Title: Re: OpenMP
Post by: BlueHazzard on September 22, 2017, 04:22:09 pm

https://gcc.gnu.org/onlinedocs/libgomp/Enabling-OpenMP.html

You can add compiler commands in
Project->Build options->Select your project on the left side->Compiler settings->other compiler options

As stahta01 noted you probably will also need to link against a openmp library. You can google for it. The additional libraries can be added into
Project->Build options->Select your project on the left side->Linker settings->Link linraries

Title: Re: OpenMP
Post by: biotech54 on September 25, 2017, 02:40:35 am

I checked both openmp website and gcc websites, unable to find the omp library, so I couldn't get the second step done

Title: Re: OpenMP
Post by: stahta01 on September 25, 2017, 03:36:20 am

Quote from: biotech54 on September 25, 2017, 02:40:35 am

I checked both openmp website and gcc websites, unable to find the omp library, so I couldn't get the second step done

Did you try linking to the gomp library before going on a search for the omp library?

Note: This is my last attempt to help you!

Tim S.

Title: Re: OpenMP
Post by: BlueHazzard on September 25, 2017, 09:45:38 am

Ok, i tried it on my system with different compiler. The result:

\|	Compiler version	\|	result	\|
\|	TDM-GCC-4.9	\|	Ok	\|
\|	TDM-GCC-5.X	\|	libgomp.spec not found, missing in the installation direcotry	\|
\|	TDM-GCC-6	\|	Ok	\|

so this is dependent of your compiler. You need TDM-GCC-6 or TDM-GCC-4. TDM-GCC-5 wont work because of missing libgomp.spec

My project used the compiler options

Code

-fopenmp

and the library

Code

gomp

in the linker->library settings

Title: Re: OpenMP
Post by: Miguel Gimenez on September 25, 2017, 11:56:35 am

BlueHazzard, where did you find TDM-GCC-6?. The project seems abandoned after 5.1...

Title: Re: OpenMP
Post by: BlueHazzard on September 25, 2017, 12:28:54 pm

Quote from: Miguel Gimenez on September 25, 2017, 11:56:35 am

BlueHazzard, where did you find TDM-GCC-6?. The project seems abandoned after 5.1...

it is a "kind of TDM-GCC": http://forums.codeblocks.org/index.php/topic,22103.0.html

Title: Re: OpenMP
Post by: Misa on June 20, 2021, 06:17:11 pm

Quote from: biotech54 on September 22, 2017, 04:33:41 am

I'm trying to get OpenMP programs to compile using CB. I read previous OpenMP discussions on this forum, written about 7 years ago. However, I did not understand what they were talking about, and i'm sure CB has changed since 2010. Does anyone know what i need to click, what settings i need to change, so that my OpenMP programs will compile? I get error messages when i try to compile simple five line programs. Thanks,
Edward

Step 1: Setup a new GCC compiler in Settings->Compiler by simply cloning the 'GNU GCC compiler', let's say it's 'OpenMP GNU GCC compiler'

Step 2: Configure as in attached pictures

Code::Blocks Forums

User forums => Using Code::Blocks => Topic started by: biotech54 on September 22, 2017, 04:33:41 am