[Bug target/50123] cmpxchg generated for atomic and with zero/or with -1

[glisse at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=50123

--- Comment #3 from Marc Glisse <glisse at gcc dot gnu.org> ---
Is this fixed or do we want a tree-level optimization replacing one builtin
with a simpler one?