[Bug target/80640] Missing memory side effect with __atomic_thread_fence (2)

["amonakov at gcc dot gnu.org" <gcc-bugzilla at gcc dot gnu dot org>]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=80640

--- Comment #8 from Alexander Monakov <amonakov at gcc dot gnu.org> ---
Author: amonakov
Date: Mon Aug 28 10:58:45 2017
New Revision: 251377

URL: https://gcc.gnu.org/viewcvs?rev=251377&root=gcc&view=rev
Log:
optabs: ensure mem_thread_fence is a compiler barrier

        PR target/80640
        * doc/md.texi (mem_thread_fence): Remove mention of mode.  Rewrite.
        * optabs.c (expand_mem_thread_fence): Emit a compiler barrier when
        using targetm.gen_mem_thread_fence.
testsuite/
        * gcc.dg/atomic/pr80640.c: New testcase.


Added:
    trunk/gcc/testsuite/gcc.dg/atomic/pr80640.c
Modified:
    trunk/gcc/ChangeLog
    trunk/gcc/doc/md.texi
    trunk/gcc/optabs.c
    trunk/gcc/testsuite/ChangeLog