[Bug libstdc++/65033] C++11 atomics: is_lock_free result does not always match the real lock-free property

jason at gcc dot gnu.org gcc-bugzilla@gcc.gnu.org
Thu Feb 12 17:16:00 GMT 2015


https://gcc.gnu.org/bugzilla/show_bug.cgi?id=65033

Jason Merrill <jason at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
           Keywords|                            |wrong-code
             Status|UNCONFIRMED                 |NEW
   Last reconfirmed|                            |2015-02-12
                 CC|                            |jason at gcc dot gnu.org,
                   |                            |rth at gcc dot gnu.org
     Ever confirmed|0                           |1

--- Comment #3 from Jason Merrill <jason at gcc dot gnu.org> ---
(In reply to Bin Fan from comment #0)
> 2. g++ tries to make lock-free property per-type, but the libatomic.so
> implementation does not match.

This.  We always pass a null pointer to libatomic and do not pass any
information about the alignment of the type.  rth suggested that we might try
passing a fake, minimally-aligned pointer instead of null as a way of
communicating the alignment without adding a new entry point.



More information about the Gcc-bugs mailing list