https://gcc.gnu.org/bugzilla/show_bug.cgi?id=100182
--- Comment #13 from Uroš Bizjak <ubizjak at gmail dot com> --- (In reply to Jakub Jelinek from comment #12) > They do. Though, in the combined patch I'm still a little bit worried about > the first 4 modified peephole2s, the last 4 look good to me. > The last 4 are where the original insn did a normal DFmode store and your > patch restores those DFmode stores. > But the first 4 had an atomic store followed by a DFmode read, shouldn't > those > preserve an atomic store instead of the DFmode store? A non-atomic DFmode > read is one thing, but it could be followed later by atomic loads, both into > DFmode and ones into DImode that would check the whole bit pattern. DFmode loads and stores *are* atomic, this is what the optimization is based on.
