Dear Alexander, thanks a lot for the reply! > Yes. Note that _m256d is declared with 'may_alias' attribute, so in general > it should weaken optimizations by disabling type-based alias analysis, > but in this case replacing _m256d with __v4df does not help. > > The following version should be easier to optimize, but still is not handled > well (at -O2 -mfma). I'd suggest to present it in the PR in addition to your > reduced version. I have opened PR c++/99728 for this in the meantime and will add your test case! Thanks again, Martin
