[Bug target/66224] PowerPC _GLIBCXX_READ_MEM_BARRIER too weak

[dje at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=66224

--- Comment #4 from David Edelsohn <dje at gcc dot gnu.org> ---
Author: dje
Date: Fri May 22 13:02:34 2015
New Revision: 223564

URL: https://gcc.gnu.org/viewcvs?rev=223564&root=gcc&view=rev
Log:
        PR target/66224
        * config/cpu/powerpc/atomic_word.h (_GLIBCXX_READ_MEM_BARRIER):
        Don't use isync. Use lwsync if available.

Modified:
    branches/gcc-4_9-branch/libstdc++-v3/ChangeLog
    branches/gcc-4_9-branch/libstdc++-v3/config/cpu/powerpc/atomic_word.h