On Sun, 13 Nov 2022 21:08:53 GMT, Claes Redestad <redes...@openjdk.org> wrote:
> How far off is this ...? Back then it looked way too constrained (tight constraints on code shapes). But I considered it as a generally applicable optimization. > ... do you think it'll be able to match the efficiency we see here with a > memoized coefficient table etc? Yes, it is able to build the constant table at runtime when folding multiplications of constant coefficients produced during loop unrolling and then packing scalars into a constant vector. Moreover, briefly looking at the code shape, the vectorizer would produce a more optimal loop shape (pre-loop would align vector accesses and would use 512-bit vectors when available; vector post-loop could help as well). ------------- PR: https://git.openjdk.org/jdk/pull/10847
