From d373079f3544b3e36fab38e3ccc3df6ca3fb004f Mon Sep 17 00:00:00 2001
From: Luke Champine <luke.champine@gmail.com>
Date: Wed, 13 Jan 2021 12:11:26 -0500
Subject: [PATCH] Prevent panic in darwin AVX512 detection

---
 cpu_darwin.go | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/cpu_darwin.go b/cpu_darwin.go
index e2c48d6..5af5635 100644
--- a/cpu_darwin.go
+++ b/cpu_darwin.go
@@ -17,6 +17,6 @@ func init() {
 	if !haveAVX512 {
 		// On some Macs, AVX512 detection is buggy, so fallback to sysctl
 		b, _ := syscall.Sysctl("hw.optional.avx512f")
-		haveAVX512 = b[0] == 1
+		haveAVX512 = len(b) > 0 && b[0] == 1
 	}
 }