From owner-svn-src-head@freebsd.org  Sun Aug  9 10:00:14 2015
Return-Path: <owner-svn-src-head@freebsd.org>
Delivered-To: svn-src-head@mailman.ysv.freebsd.org
Received: from mx1.freebsd.org (mx1.freebsd.org
 [IPv6:2001:1900:2254:206a::19:1])
 by mailman.ysv.freebsd.org (Postfix) with ESMTP id DCAE39982AE;
 Sun,  9 Aug 2015 10:00:14 +0000 (UTC) (envelope-from dim@FreeBSD.org)
Received: from repo.freebsd.org (repo.freebsd.org
 [IPv6:2001:1900:2254:2068::e6a:0])
 (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits))
 (Client did not present a certificate)
 by mx1.freebsd.org (Postfix) with ESMTPS id CCA229EC;
 Sun,  9 Aug 2015 10:00:14 +0000 (UTC) (envelope-from dim@FreeBSD.org)
Received: from repo.freebsd.org ([127.0.1.70])
 by repo.freebsd.org (8.15.2/8.15.2) with ESMTP id t79A0ES1049443;
 Sun, 9 Aug 2015 10:00:14 GMT (envelope-from dim@FreeBSD.org)
Received: (from dim@localhost)
 by repo.freebsd.org (8.15.2/8.15.2/Submit) id t79A0E4S049442;
 Sun, 9 Aug 2015 10:00:14 GMT (envelope-from dim@FreeBSD.org)
Message-Id: <201508091000.t79A0E4S049442@repo.freebsd.org>
X-Authentication-Warning: repo.freebsd.org: dim set sender to dim@FreeBSD.org
 using -f
From: Dimitry Andric <dim@FreeBSD.org>
Date: Sun, 9 Aug 2015 10:00:14 +0000 (UTC)
To: src-committers@freebsd.org, svn-src-all@freebsd.org,
 svn-src-head@freebsd.org
Subject: svn commit: r286515 - head/lib/msun/src
X-SVN-Group: head
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit
X-BeenThere: svn-src-head@freebsd.org
X-Mailman-Version: 2.1.20
Precedence: list
List-Id: SVN commit messages for the src tree for head/-current
 <svn-src-head.freebsd.org>
List-Unsubscribe: <http://lists.freebsd.org/mailman/options/svn-src-head>,
 <mailto:svn-src-head-request@freebsd.org?subject=unsubscribe>
List-Archive: <http://lists.freebsd.org/pipermail/svn-src-head/>
List-Post: <mailto:svn-src-head@freebsd.org>
List-Help: <mailto:svn-src-head-request@freebsd.org?subject=help>
List-Subscribe: <http://lists.freebsd.org/mailman/listinfo/svn-src-head>,
 <mailto:svn-src-head-request@freebsd.org?subject=subscribe>
X-List-Received-Date: Sun, 09 Aug 2015 10:00:15 -0000

Author: dim
Date: Sun Aug  9 10:00:13 2015
New Revision: 286515
URL: https://svnweb.freebsd.org/changeset/base/286515

Log:
  In libm's exp2(3), avoid left-shifting a negative integer, which is
  undefined.  Replace it with the intended value, in a defined way.
  
  Reviewed by:	bde
  MFC after:	3 days

Modified:
  head/lib/msun/src/s_exp2.c

Modified: head/lib/msun/src/s_exp2.c
==============================================================================
--- head/lib/msun/src/s_exp2.c	Sun Aug  9 09:54:29 2015	(r286514)
+++ head/lib/msun/src/s_exp2.c	Sun Aug  9 10:00:13 2015	(r286515)
@@ -376,14 +376,14 @@ exp2(double x)
 	/* Compute r = exp2(y) = exp2t[i0] * p(z - eps[i]). */
 	t = tbl[i0];		/* exp2t[i0] */
 	z -= tbl[i0 + 1];	/* eps[i0]   */
-	if (k >= -1021 << 20)
+	if (k >= -(1021 << 20))
 		INSERT_WORDS(twopk, 0x3ff00000 + k, 0);
 	else
 		INSERT_WORDS(twopkp1000, 0x3ff00000 + k + (1000 << 20), 0);
 	r = t + t * z * (P1 + z * (P2 + z * (P3 + z * (P4 + z * P5))));
 
 	/* Scale by 2**(k>>20). */
-	if(k >= -1021 << 20) {
+	if(k >= -(1021 << 20)) {
 		if (k == 1024 << 20)
 			return (r * 2.0 * 0x1p1023);
 		return (r * twopk);