From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 84267 invoked by alias); 14 Dec 2015 15:09:19 -0000 Mailing-List: contact gcc-patches-help@gcc.gnu.org; run by ezmlm Precedence: bulk List-Id: List-Archive: List-Post: List-Help: Sender: gcc-patches-owner@gcc.gnu.org Received: (qmail 84254 invoked by uid 89); 14 Dec 2015 15:09:18 -0000 Authentication-Results: sourceware.org; auth=none X-Virus-Found: No X-Spam-SWARE-Status: No, score=-2.0 required=5.0 tests=AWL,BAYES_00,SPF_PASS,T_RP_MATCHES_RCVD autolearn=ham version=3.3.2 X-HELO: e06smtp05.uk.ibm.com Received: from e06smtp05.uk.ibm.com (HELO e06smtp05.uk.ibm.com) (195.75.94.101) by sourceware.org (qpsmtpd/0.93/v0.84-503-g423c35a) with (CAMELLIA256-SHA encrypted) ESMTPS; Mon, 14 Dec 2015 15:09:09 +0000 Received: from localhost by e06smtp05.uk.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Mon, 14 Dec 2015 15:09:06 -0000 Received: from d06dlp01.portsmouth.uk.ibm.com (9.149.20.13) by e06smtp05.uk.ibm.com (192.168.101.135) with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted; Mon, 14 Dec 2015 15:09:05 -0000 X-IBM-Helo: d06dlp01.portsmouth.uk.ibm.com X-IBM-MailFrom: uweigand@de.ibm.com X-IBM-RcptTo: gcc-patches@gcc.gnu.org Received: from b06cxnps4075.portsmouth.uk.ibm.com (d06relay12.portsmouth.uk.ibm.com [9.149.109.197]) by d06dlp01.portsmouth.uk.ibm.com (Postfix) with ESMTP id 2327E17D8059 for ; Mon, 14 Dec 2015 15:09:39 +0000 (GMT) Received: from d06av03.portsmouth.uk.ibm.com (d06av03.portsmouth.uk.ibm.com [9.149.37.213]) by b06cxnps4075.portsmouth.uk.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id tBEF94Lv30998632 for ; Mon, 14 Dec 2015 15:09:04 GMT Received: from d06av03.portsmouth.uk.ibm.com (localhost [127.0.0.1]) by d06av03.portsmouth.uk.ibm.com (8.14.4/8.14.4/NCO v10.0 AVout) with ESMTP id tBEF93AH032318 for ; Mon, 14 Dec 2015 08:09:04 -0700 Received: from oc7340732750.ibm.com (dyn-9-152-213-173.boeblingen.de.ibm.com [9.152.213.173]) by d06av03.portsmouth.uk.ibm.com (8.14.4/8.14.4/NCO v10.0 AVin) with ESMTP id tBEF93au032282; Mon, 14 Dec 2015 08:09:03 -0700 Received: by oc7340732750.ibm.com (Postfix, from userid 500) id 1A4DACDB4; Mon, 14 Dec 2015 16:08:33 +0100 (CET) Subject: Re: [PATCH] S/390: Allow to use r1 to r4 as literal pool base. To: vogt@linux.vnet.ibm.com Date: Mon, 14 Dec 2015 15:09:00 -0000 From: "Ulrich Weigand" Cc: gcc-patches@gcc.gnu.org, krebbel@linux.vnet.ibm.com (Andreas Krebbel), Ulrich.Weigand@de.ibm.com (Ulrich Weigand) In-Reply-To: <20151211165048.GA23037@linux.vnet.ibm.com> from "Dominik Vogt" at Dec 11, 2015 05:50:48 PM MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Message-Id: <20151214150833.1A4DACDB4@oc7340732750.ibm.com> X-TM-AS-MML: disable X-Content-Scanned: Fidelis XPS MAILER x-cbid: 15121415-0021-0000-0000-00000529D0D8 X-SW-Source: 2015-12/txt/msg01405.txt.bz2 Dominik Vogt wrote: > The attached patch enables using r1 to r4 as the literal pool base pointer if > one of them is unused in a leaf function. The unpatched code supports only r5 > and r13. I don't think that r1 is actually safe here. Note that it may be used (unconditionally) as temp register in s390_emit_prologue in certain cases; the upcoming split-stack code will also need to use r1 in some cases. r2 through r4 should be fine. [ Not sure if there will be many (any?) cases where one of those is unused but r5 isn't, however. ] Bye, Ulrich -- Dr. Ulrich Weigand GNU/Linux compilers and toolchain Ulrich.Weigand@de.ibm.com