From ad055099309d0faeb2725764ec441b1ee847ecbf Mon Sep 17 00:00:00 2001
From: Andrew Kelley <andrew@ziglang.org>
Date: Thu, 17 Dec 2020 22:40:53 -0700
Subject: [PATCH] std: align(16) main_thread_tls_buffer

Before this change, thread local variables were landmines if LLVM
decided to optimize any writes to them using vector instructions.
---
 lib/std/os/linux/tls.zig | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/lib/std/os/linux/tls.zig b/lib/std/os/linux/tls.zig
index f6c339bc2c..d78a14c311 100644
--- a/lib/std/os/linux/tls.zig
+++ b/lib/std/os/linux/tls.zig
@@ -327,7 +327,7 @@ pub fn prepareTLS(area: []u8) usize {
         if (tls_tp_points_past_tcb) tls_image.data_offset else tls_image.tcb_offset;
 }
 
-var main_thread_tls_buffer: [256]u8 = undefined;
+var main_thread_tls_buffer: [256]u8 align(16) = undefined;
 
 pub fn initStaticTLS() void {
     initTLS();