Although you probably overestimate a bit the impact of uarch diff between haswell and zen, there is some truth in theory in what you said. In practice, zen is quite close to Skylake in terms of general uarch principles and main figures, and zenv2 even more so (or even better). IIRC for ZenV1 AVX2 should yield no gain compared to AVX, though.
glibc is not Intel's project and is expected to have a minimum amount of neutrality in own it is maintained -- that also includes how patches are accepted or modifications are asked before they are integrated.
The dispatching is probably to implement things like memset & memcpy etc, which are easy to benchmark, and it is probable that the haswell version will at least be better than whatever is used right now with an amd zen (and even more probable for zenv2). Optimizing further can come later, if anybody wants to do it.
Therefore, I think this ticket is justified (but I also think that this is not a drama that is has not be taken care of sooner)
glibc is not Intel's project and is expected to have a minimum amount of neutrality in own it is maintained -- that also includes how patches are accepted or modifications are asked before they are integrated.
The dispatching is probably to implement things like memset & memcpy etc, which are easy to benchmark, and it is probable that the haswell version will at least be better than whatever is used right now with an amd zen (and even more probable for zenv2). Optimizing further can come later, if anybody wants to do it.
Therefore, I think this ticket is justified (but I also think that this is not a drama that is has not be taken care of sooner)