http://gcc.gnu.org/bugzilla/show_bug.cgi?id=42616
Charles Wilson <gcc.20.cwilson at spamgourmet dot com> changed: What |Removed |Added ---------------------------------------------------------------------------- CC| |gcc.20.cwilson at | |spamgourmet dot com --- Comment #11 from Charles Wilson <gcc.20.cwilson at spamgourmet dot com> 2011-05-04 17:48:14 UTC --- FWIW, using mingw.org's gcc-4.5.2 release, the test passes: $ g++ -fopenmp omp_test.c -o omp_test -lpthread $ ./omp_test.exe OMP : All looks good Relevant installation data: gcc-core-4.5.2-1-mingw32-bin gcc-c++-4.5.2-1-mingw32-bin libgcc-4.5.2-1-mingw32-dll-1 libstdc++-4.5.2-1-mingw32-dll-6 libgomp-4.5.2-1-mingw32-dll-1 mingwrt-3.18-mingw32-dll mingwrt-3.18-mingw32-dev w32api-3.17-2-mingw32-dev pthreads-w32-2.8.0-3-mingw32-dev libpthread-2.8.0-3-mingw32-dll-2 I believe this is because TLS support was added to the mingw(32) runtime in late Jan 2010, thanks to Kai's work: http://thread.gmane.org/gmane.comp.gnu.mingw.devel/3550 (Although a full compiler suite, and mingw runtime, with TLS support was not officially released until March 2010)