From fcbe22c59c2a7aa462a0f51e148b6afb90bbe7d9 Mon Sep 17 00:00:00 2001
From: George Steed <george.steed@arm.com>
Date: Tue, 11 Jun 2024 16:12:52 +0100
Subject: [PATCH] [AArch64] Enable SME feature detection on Apple Silicon

Check for availability of SME and SME2 by looking for the
hw.optional.arm.FEAT_SME2 feature string in sysctlbyname. Non-streaming
SVE is not supported but for our purposes the features can be treated as
orthogonal since our SME code will only ever run in streaming mode.

Change-Id: I7e9d242e0f581217b625d74c7c3b0c76a0fe03da
Reviewed-on: https://chromium-review.googlesource.com/c/libyuv/libyuv/+/5683128
Reviewed-by: Frank Barchard <fbarchard@chromium.org>
---
 source/cpu_id.cc | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/source/cpu_id.cc b/source/cpu_id.cc
index a31e89cd6..e34a3a905 100644
--- a/source/cpu_id.cc
+++ b/source/cpu_id.cc
@@ -256,6 +256,9 @@ LIBYUV_API SAFEBUFFERS int AArch64CpuCaps() {
     features |= kCpuHasNeonDotProd;
     if (have_feature("hw.optional.arm.FEAT_I8MM")) {
       features |= kCpuHasNeonI8MM;
+      if (have_feature("hw.optional.arm.FEAT_SME2")) {
+        features |= kCpuHasSME;
+      }
     }
   }
   // No SVE feature detection available here at time of writing.