Re: kern/60426 (Signal handler corrupts AVX (YMM) registers)

[Robert Elz <kre%munnari.OZ.AU@localhost>]

    Date:        Thu, 9 Jul 2026 10:29:18 +0000
    From:        Taylor R Campbell <riastradh%NetBSD.org@localhost>
    Message-ID:  <20260709102920.640E184DAC%mail.netbsd.org@localhost>


  | The xmm registers, which have always been available on amd64 since the
  | beginning, are aliases for the low halves of the ymm registers.  Any
  | SSE2 instruction (again: available on amd64 since the beginning)
  | writing to xmmN will generally zero the high half of ymmN as a side
  | effect.

Ugh.   OK - I know zero about the architecture, I am still fuming that
IBM picked the 8080 when the NetSemi equiv (the identity of which I have
forgotten) was so much nicer.   Even the z80 was (slightly) better.
I assume that so few people wanted 8080s (in quantity) that they got
a good deal...

That however sounds like yet another horrid Intel design choice.

kre