On 19 Jan 2012, at 18:09, Ed Schouten wrote: > In the very nearby future (after I switch SPARC64 and MIPS to > libcompiler_rt), it should be possible to safely use C11's <stdatomic.h> > on all supported architectures. The C11 interface allows any operation > to be combined with any type of barrier. > > Maybe we should simply migrate this code to use <stdatomic.h> then?
Currently, that will give worse code if we use gcc 4.2.1, but (I hope!) better code if we use clang. With GCC, we are implementing atomic_thread_fence() as __sync_synchronize(), which is a full barrier, and ignoring its argument. It would probably be worth postponing any such migration until: 1) Clang is the default compiler, and 2) The bugs in LLVM that cause the back end to fatal error on any nontrivial code using atomics are fixed. David_______________________________________________ svn-src-head@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/svn-src-head To unsubscribe, send any mail to "svn-src-head-unsubscr...@freebsd.org"
