Magnus Fromreide <ma...@lysator.liu.se> writes: > I recently ended up in a discussion about the -pthread flag at work and > when looking at the documentation I noticed that it is defined onlt for > SPARC and RS/6000/PowerPC. > > Additionally -fopenmp and -ftree-parallelize-loops say they are only > supported on targets where -pthread are available. > > Now, on x86-linux it seems as if -pthread does something but there is no > documentation of it so I'd like to know > > * What does -pthread do on x86?
On x86 GNU/Linux -pthread defines _REENTRANT for the preprocessor and links against -lpthread. > * If I am to compile a threaded program am I then requiered to use > -pthread? On GNU/Linux, you need to use -pthread or -D_REENTRANT at compilation time, and you need to use -pthread or -lpthread at link time. I agree that this really ought to be documented. Ian
