From: guenther <guenther@openbsd.org>
Date: Tue, 24 Jul 2018 14:49:44 +0000 (+0000)
Subject: Fix previous commit: the RSB refill bits change %rcx so it needed to be
X-Git-Url: http://artulab.com/gitweb/?a=commitdiff_plain;h=9d94673f525e999bfff1d3a30db7acbe8ae9ea3b;p=openbsd

Fix previous commit: the RSB refill bits change %rcx so it needed to be
given an input/output ASM constraint...but I made it output-only, so the
compiler deleted the initialization.

reported by many, starting with Edd Barrett (edd(at)theunixzoo.co.uk)
---

diff --git a/sys/arch/amd64/include/cpufunc.h b/sys/arch/amd64/include/cpufunc.h
index 9c6cc12f097..395250c3ba5 100644
--- a/sys/arch/amd64/include/cpufunc.h
+++ b/sys/arch/amd64/include/cpufunc.h
@@ -1,4 +1,4 @@
-/*	$OpenBSD: cpufunc.h,v 1.28 2018/07/24 02:42:25 guenther Exp $	*/
+/*	$OpenBSD: cpufunc.h,v 1.29 2018/07/24 14:49:44 guenther Exp $	*/
 /*	$NetBSD: cpufunc.h,v 1.3 2003/05/08 10:27:43 fvdl Exp $	*/
 
 /*-
@@ -305,7 +305,7 @@ mwait(u_long extensions, u_int hints)
 		"	.align	16,0xcc		;"
 		"7:	loop	3b		;"
 		"	add	$(16*8),%%rsp"
-	    : "=c" (extensions) : "a" (hints));
+	    : "+c" (extensions) : "a" (hints));
 }
 
 static __inline void