On Tue, Jun 15, 2021 at 9:55 PM Neal Gompa <ngompa13(a)gmail.com> wrote:
Yeah, I think that proposal was not workable because of AVX2. The
x86_64-v2 subarch adds SSSE3, SSE4.2, POPCNT, and CMPXCHG16B to the
current x86_64 baseline. All of these instructions were present in the
first Intel Macs launched in 2007, as I recall.
I believe the earliest 64-bit capable Intel Macs were using
core 2 processors, and they would not include a couple of
those instructions (which happened with nehalem).