$ gcc 12.c -fopenmp
12.c:9:9: fatal error: 'omp.h' file not found
1 error generated.
While compiling openMP programs I get the above error. I am using OS X Yosemite. I first tried by installing native gcc compiler by typing gcc in terminal and later downloaded Xcode too still I got the same error. Then I downloaded gcc through:
$ brew install gcc
Still I'm getting the same error. I did try changing the compiler path too still it shows:
$ which gcc
So how do I compile programs with gcc?
EDIT: As of 13 Aug 2017 the
--without-multilib option is no longer present in Homebrew and should not be used. The standard installation
brew install gcc
will provide a
gcc installation that can be used to compile OpenMP programs. As below it will be installed into
gcc-<version>. The current gcc version available from Homebrew (as of writing) will install as
gcc-8. You can compile programs with OpenMP support using it via
gcc-8 -fopenmp hello.c
Alternatively you could put an alias in your
and then compile using
gcc -fopenmp hello.c
Note: I'm leaving the original post here in case it is useful to somebody.
The standard gcc available on OS X through XCode and Clang doesn't support OpenMP. To install the Homebrew version of gcc with OpenMP support you need to install it with
brew install gcc --without-multilib
or as pointed out by @Mark Setchell
brew reinstall gcc --without-multilib
This will install it to the
/usr/local/bin directory. Homebrew will install it as
gcc-<version> so as not to clobber the gcc bundled with XCode.