From: Shenghou Ma <minux.ma@gmail.com>
Date: Thu, 24 May 2012 16:08:52 +0000 (+0800)
Subject: cmd/cc: fix uint right shift in constant evaluation
X-Git-Tag: go1.1rc2~3125
X-Git-Url: http://www.git.cypherpunks.su/?a=commitdiff_plain;h=34ad3995e06fb4a4e209adfbd11367cc3d22f8b8;p=gostls13.git

cmd/cc: fix uint right shift in constant evaluation
        Fixes #3664.

R=golang-dev, bradfitz, rsc
CC=golang-dev
https://golang.org/cl/6249048
---

diff --git a/src/cmd/cc/scon.c b/src/cmd/cc/scon.c
index 193331f774..f6031a5be7 100644
--- a/src/cmd/cc/scon.c
+++ b/src/cmd/cc/scon.c
@@ -175,7 +175,10 @@ evconst(Node *n)
 		break;
 
 	case OLSHR:
-		v = (uvlong)l->vconst >> r->vconst;
+		if(l->type->width != sizeof(uvlong))
+			v = ((uvlong)l->vconst & 0xffffffffULL) >> r->vconst;
+		else
+			v = (uvlong)l->vconst >> r->vconst;
 		break;
 
 	case OASHR: