tree daed0d926e5e8740a3f5a003b2afe749581fac3d
parent 71e4cd670f794fc08493cd25995a8ce85e81b914
author Vaughn Iverson <vsivsi@yahoo.com> 1611276589 -0800
committer Martin Möhrmann <moehrmann@google.com> 1620027464 +0000

cpu: fix AVX512 support detection on Darwin

Summary: On darwin/amd64, it is not adequate to use OSXSAVE
bits to determine AVX512 availabilty. The reason is involved.
See github issue for details.

The fix consists of implementing Apple's recommended approach
using the process commpage cpu_capabilities bits to determine
availability of AVX512.

Fixes golang/go#43089

Change-Id: I1ba89965498863d268fbf2e427dbfd6429c7409f
Reviewed-on: https://go-review.googlesource.com/c/sys/+/285572
Trust: Tobias Klauser <tobias.klauser@gmail.com>
Run-TryBot: Tobias Klauser <tobias.klauser@gmail.com>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Martin Möhrmann <moehrmann@google.com>