By: -.- (blarg.delete@this.mailinator.com), September 20, 2021 4:44 pm
Room: Moderated Discussions
dmcq (dmcq.delete@this.fano.co.uk) on September 20, 2021 2:19 am wrote:
> It'd be interesting to see how Supercomputer Fugaku fares thst way as they said they were doing special work
> accessing two cache lines at once to deal with their 512 bit reads and writes being split in two like that.
Side note, but worth pointing out that SVE allows vectors to have non power-of-2 widths.
I'm not sure what ARM's intentions are with alignment on a machine with say, 384-bit vectors, but it would seem like the best you could hope for is that a portion of accesses align.
For Fugaku, coders probably specifically target the uArch, so not likely an issue, but if you're following SVE's "write once, run on any vector width" mantra, it seems like attaining alignment might be more trouble than it's worth.
> It'd be interesting to see how Supercomputer Fugaku fares thst way as they said they were doing special work
> accessing two cache lines at once to deal with their 512 bit reads and writes being split in two like that.
Side note, but worth pointing out that SVE allows vectors to have non power-of-2 widths.
I'm not sure what ARM's intentions are with alignment on a machine with say, 384-bit vectors, but it would seem like the best you could hope for is that a portion of accesses align.
For Fugaku, coders probably specifically target the uArch, so not likely an issue, but if you're following SVE's "write once, run on any vector width" mantra, it seems like attaining alignment might be more trouble than it's worth.
