https://gcc.gnu.org/bugzilla/show_bug.cgi?id=120347
Richard Earnshaw <rearnsha at gcc dot gnu.org> changed: What |Removed |Added ---------------------------------------------------------------------------- See Also| |https://gcc.gnu.org/bugzill | |a/show_bug.cgi?id=20972 CC|richard.earnshaw at arm dot com |rearnsha at gcc dot gnu.org --- Comment #1 from Richard Earnshaw <rearnsha at gcc dot gnu.org> --- This is somewhat of a heisenbug. The instruction is unpredictable because the increment may take place before the value to be stored is read. Unfortunately, there's currently no way in the machine description (that I'm aware of) to describe this restriction - I don't think you can early-clobber a mem.