Messages in this thread | | | From | Len Brown <> | Date | Thu, 20 May 2021 17:22:58 -0400 | Subject | Re: Candidate Linux ABI for Intel AMX and hypothetical new related features |
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On Thu, May 20, 2021 at 4:54 PM Thomas Gleixner <tglx@linutronix.de> wrote:
Thomas,
> > AMX is analogous to the multiplier used by AVX-512. > > The architectural state must exist on every CPU, including HT siblings. > > Today, the HT siblings share the same execution unit, > > and I have no reason to expect that will change. > > I'm well aware that HT siblings share the same execution unit for > AVX. > > Though AMX is if I remember the discussions two years ago correctly > shared by more than the HT siblings which makes things worse.
I regret that we were unable to get together in the last year to have an updated discussion. I think if we had, then we would have saved a lot of mis-understanding and a lot of email!
So let me emphasize here:
There is one TMUL execution unit per core. It is shared by the HT siblings within that core.
So the comparison to the AVX-512 multiplier is a good one.
Len Brown, Intel Open Source Technology Center
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