From: Bill O'Farrell <billo@ca.ibm.com>
Date: Fri, 27 Oct 2017 18:40:59 +0000 (-0400)
Subject: runtime: remove unnecessary sync from publicationBarrier on s390x
X-Git-Tag: go1.10beta1~526
X-Git-Url: http://www.git.cypherpunks.su/?a=commitdiff_plain;h=7fff1db0605739fee20673475cbc1813fdf7008e;p=gostls13.git

runtime: remove unnecessary sync from publicationBarrier on s390x

Memory accesses on z are at least as ordered as they are on AMD64.

Change-Id: Ia515430e571ebd07e9314de05c54dc992ab76b95
Reviewed-on: https://go-review.googlesource.com/74010
Run-TryBot: Michael Munday <mike.munday@ibm.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Michael Munday <mike.munday@ibm.com>
---

diff --git a/src/runtime/asm_s390x.s b/src/runtime/asm_s390x.s
index 42b9326607..487ed62306 100644
--- a/src/runtime/asm_s390x.s
+++ b/src/runtime/asm_s390x.s
@@ -915,7 +915,8 @@ TEXT runtime·sigreturn(SB),NOSPLIT,$0-0
 	RET
 
 TEXT ·publicationBarrier(SB),NOSPLIT|NOFRAME,$0-0
-	SYNC
+        // Stores are already ordered on s390x, so this is just a
+        // compile barrier.
 	RET
 
 TEXT runtime·cmpstring(SB),NOSPLIT|NOFRAME,$0-40