From d00248980be23b5c889601cf749f5738a5dc8724 Mon Sep 17 00:00:00 2001
From: Russ Cox <rsc@golang.org>
Date: Mon, 2 Nov 2009 10:50:18 -0800
Subject: [PATCH] do not emit USED for global x when compiling "_ = x;"

R=ken@golang.org
CC=r
http://go/go-review/1018019
---
 src/cmd/gc/gen.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/cmd/gc/gen.c b/src/cmd/gc/gen.c
index bb1b19bfc97..475058fa28e 100644
--- a/src/cmd/gc/gen.c
+++ b/src/cmd/gc/gen.c
@@ -427,7 +427,7 @@ cgen_discard(Node *nr)
 
 	switch(nr->op) {
 	case ONAME:
-		if(!(nr->class & PHEAP))
+		if(!(nr->class & PHEAP) && nr->class != PEXTERN && nr->class != PFUNC)
 			gused(nr);
 		break;