From: Cherry Zhang <cherryyz@google.com>
Date: Fri, 30 Oct 2020 21:16:51 +0000 (-0400)
Subject: runtime: add a comment about thread pointer alignment on darwin/arm64
X-Git-Tag: go1.16beta1~375
X-Git-Url: http://www.git.cypherpunks.su/?a=commitdiff_plain;h=fd56942fe3725feaa53bed67daf7412742e4f2ab;p=gostls13.git

runtime: add a comment about thread pointer alignment on darwin/arm64

Address a review comment in CL 266373.

Change-Id: Ic21bd5c4f87fd0c7dc594155a10fe23602698187
Reviewed-on: https://go-review.googlesource.com/c/go/+/266777
Trust: Cherry Zhang <cherryyz@google.com>
Reviewed-by: Austin Clements <austin@google.com>
---

diff --git a/src/runtime/race_arm64.s b/src/runtime/race_arm64.s
index 59373a9f3f..5b1a1cb89a 100644
--- a/src/runtime/race_arm64.s
+++ b/src/runtime/race_arm64.s
@@ -25,12 +25,15 @@
 
 // The race ctx, ThreadState *thr below, is passed in R0 and loaded in racecalladdr.
 
+// Darwin may return unaligned thread pointer. Align it. (See tls_arm64.s)
+// No-op on other OSes.
 #ifdef TLS_darwin
 #define TP_ALIGN	AND	$~7, R0
 #else
 #define TP_ALIGN
 #endif
 
+// Load g from TLS. (See tls_arm64.s)
 #define load_g \
 	MRS_TPIDR_R0 \
 	TP_ALIGN \