[Bug c/68908] inefficient code for _Atomic operations

[mpolacek at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=68908

--- Comment #16 from Marek Polacek <mpolacek at gcc dot gnu.org> ---
Author: mpolacek
Date: Mon Jan  4 12:27:08 2016
New Revision: 232052

URL: https://gcc.gnu.org/viewcvs?rev=232052&root=gcc&view=rev
Log:
        PR c/68908
        * c-typeck.c (build_atomic_assign): Improve commentary.  Add
        optimization to use __atomic_fetch_* built-in if possible.

        * gcc.dg/atomic/c11-atomic-exec-6.c: New test.
        * gcc.dg/atomic/c11-atomic-exec-7.c: New test.
        * gcc.dg/atomic/stdatomic-op-5.c: New test.

Added:
    trunk/gcc/testsuite/gcc.dg/atomic/c11-atomic-exec-6.c
    trunk/gcc/testsuite/gcc.dg/atomic/c11-atomic-exec-7.c
    trunk/gcc/testsuite/gcc.dg/atomic/stdatomic-op-5.c
Modified:
    trunk/gcc/c/ChangeLog
    trunk/gcc/c/c-typeck.c
    trunk/gcc/testsuite/ChangeLog