From patchwork Wed Jun 27 22:16:12 2012 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Richard Henderson X-Patchwork-Id: 167754 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Received: from sourceware.org (server1.sourceware.org [209.132.180.131]) by ozlabs.org (Postfix) with SMTP id D047EB6FFC for ; Thu, 28 Jun 2012 08:16:38 +1000 (EST) Comment: DKIM? See http://www.dkim.org DKIM-Signature: v=1; a=rsa-sha1; c=relaxed/relaxed; d=gcc.gnu.org; s=default; x=1341440200; h=Comment: DomainKey-Signature:Received:Received:Received:Received:Received: Message-ID:Date:From:User-Agent:MIME-Version:To:CC:Subject: References:In-Reply-To:Content-Type:Mailing-List:Precedence: List-Id:List-Unsubscribe:List-Archive:List-Post:List-Help:Sender: Delivered-To; bh=iUjHQQZG1W+5BEw+2pjJYBnJJW8=; b=LbymqQI2m3VWG+0 Mv/aGEEDW0hc/bAXbgcvhQIVSp75xEPfPr/z2YBv3rAiUI5MJT+91OzZPpuK1Td/ 9sZKOZk46btJJoBK9tVuVOPWJzsbcHVqxZm9y6Rm7+m6Oli6URD8WyIVfrM5QWg3 pfIOAveIuinF9XM2Uqb6ol7Xp/DM= Comment: DomainKeys? See http://antispam.yahoo.com/domainkeys DomainKey-Signature: a=rsa-sha1; q=dns; c=nofws; s=default; d=gcc.gnu.org; h=Received:Received:X-SWARE-Spam-Status:X-Spam-Check-By:Received:Received:Received:Message-ID:Date:From:User-Agent:MIME-Version:To:CC:Subject:References:In-Reply-To:Content-Type:X-IsSubscribed:Mailing-List:Precedence:List-Id:List-Unsubscribe:List-Archive:List-Post:List-Help:Sender:Delivered-To; b=QFjRdbSsIybViz3sQ2Za1en6GF9IEbf/fgKuhb12Vd059YW5b0i6ICgtloPnDG bLW2TWKGoiwuF07sa9hzZNF/z/9e/CWCtkMNsfu+4EB4QcKx0DT2n32z7FmqgyPa GI2eIH7XJX7ArF8tHgW7hdaQxMn10bFjF1fw/zDoIvmMg=; Received: (qmail 4404 invoked by alias); 27 Jun 2012 22:16:36 -0000 Received: (qmail 4393 invoked by uid 22791); 27 Jun 2012 22:16:35 -0000 X-SWARE-Spam-Status: No, hits=-7.0 required=5.0 tests=AWL, BAYES_00, KHOP_RCVD_UNTRUST, KHOP_THREADED, RCVD_IN_DNSWL_HI, RCVD_IN_HOSTKARMA_W, SPF_HELO_PASS, T_RP_MATCHES_RCVD X-Spam-Check-By: sourceware.org Received: from mx1.redhat.com (HELO mx1.redhat.com) (209.132.183.28) by sourceware.org (qpsmtpd/0.43rc1) with ESMTP; Wed, 27 Jun 2012 22:16:13 +0000 Received: from int-mx02.intmail.prod.int.phx2.redhat.com (int-mx02.intmail.prod.int.phx2.redhat.com [10.5.11.12]) by mx1.redhat.com (8.14.4/8.14.4) with ESMTP id q5RMGD3d009667 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=OK); Wed, 27 Jun 2012 18:16:13 -0400 Received: from anchor.twiddle.home (vpn-234-208.phx2.redhat.com [10.3.234.208]) by int-mx02.intmail.prod.int.phx2.redhat.com (8.13.8/8.13.8) with ESMTP id q5RMGCXD007680; Wed, 27 Jun 2012 18:16:12 -0400 Message-ID: <4FEB862C.2050904@redhat.com> Date: Wed, 27 Jun 2012 15:16:12 -0700 From: Richard Henderson User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:13.0) Gecko/20120605 Thunderbird/13.0 MIME-Version: 1.0 To: Steven Bosscher CC: gcc-patches@gcc.gnu.org Subject: Re: [PATCH] Add MULT_HIGHPART_EXPR References: <1340833028-3712-1-git-send-email-rth@redhat.com> In-Reply-To: X-IsSubscribed: yes Mailing-List: contact gcc-patches-help@gcc.gnu.org; run by ezmlm Precedence: bulk List-Id: List-Unsubscribe: List-Archive: List-Post: List-Help: Sender: gcc-patches-owner@gcc.gnu.org Delivered-To: mailing list gcc-patches@gcc.gnu.org On 06/27/2012 02:42 PM, Steven Bosscher wrote: > Maybe also a bit in doc/generic.texi? Or is this not supposed to be > exposed to the front ends? I can't imagine it being terribly useful to front ends, but there's certainly nothing that ought to prevent it. How's this? r~ diff --git a/gcc/doc/generic.texi b/gcc/doc/generic.texi index e99366f..c48b663 100644 --- a/gcc/doc/generic.texi +++ b/gcc/doc/generic.texi @@ -1235,6 +1235,7 @@ the byte offset of the field, but should not be used directly; call @tindex PLUS_EXPR @tindex MINUS_EXPR @tindex MULT_EXPR +@tindex MULT_HIGHPART_EXPR @tindex RDIV_EXPR @tindex TRUNC_DIV_EXPR @tindex FLOOR_DIV_EXPR @@ -1433,6 +1434,11 @@ one operand is of floating type and the other is of integral type. The behavior of these operations on signed arithmetic overflow is controlled by the @code{flag_wrapv} and @code{flag_trapv} variables. +@item MULT_HIGHPART_EXPR +This node represents the ``high-part'' of a widening multiplication. +For an integral type with @var{b} bits of precision, the result is +the most significant @var{b} bits of the full @math{2@var{b}} product. + @item RDIV_EXPR This node represents a floating point division operation.