From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 57200 invoked by alias); 14 Nov 2015 08:50:12 -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 57188 invoked by uid 89); 14 Nov 2015 08:50:12 -0000 Authentication-Results: sourceware.org; auth=none X-Virus-Found: No X-Spam-SWARE-Status: No, score=-1.8 required=5.0 tests=AWL,BAYES_00,RP_MATCHES_RCVD,SPF_PASS autolearn=ham version=3.3.2 X-HELO: eusmtp01.atmel.com Received: from eusmtp01.atmel.com (HELO eusmtp01.atmel.com) (212.144.249.242) by sourceware.org (qpsmtpd/0.93/v0.84-503-g423c35a) with (AES128-SHA encrypted) ESMTPS; Sat, 14 Nov 2015 08:50:11 +0000 Received: from HNOCHT02.corp.atmel.com (10.161.30.162) by eusmtp01.atmel.com (10.161.101.30) with Microsoft SMTP Server (TLS) id 14.3.235.1; Sat, 14 Nov 2015 09:49:47 +0100 Received: from jaguar.atmel.com (10.161.30.18) by HNOCHT02.corp.atmel.com (10.161.30.162) with Microsoft SMTP Server (TLS) id 14.3.235.1; Sat, 14 Nov 2015 09:49:53 +0100 Date: Sat, 14 Nov 2015 08:50:00 -0000 From: Senthil Kumar Selvaraj To: CC: , Subject: Re: [Patch, vrp] Allow VRP type conversion folding only for widenings upto word mode Message-ID: <20151114084928.GA749@jaguar.atmel.com> References: <20151114071148.GA16647@jaguar.atmel.com> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.24 (2015-08-30) X-IsSubscribed: yes X-SW-Source: 2015-11/txt/msg01809.txt.bz2 On Sat, Nov 14, 2015 at 09:13:41AM +0100, Marc Glisse wrote: > On Sat, 14 Nov 2015, Senthil Kumar Selvaraj wrote: > > >This patch came out of a discussion held in the gcc mailing list > >(https://gcc.gnu.org/ml/gcc/2015-11/msg00067.html). > > > >The patch restricts folding of conditional exprs with lhs previously > >set by a type conversion to occur only if the source of the type > >conversion's mode is word mode or smaller. > > > >Bootstrapped and reg tested on x86_64 (with --enable-languages=c,c++). > > > >If ok, could you commit please? I don't have commit access. > > > >Regards > >Senthil > > > >gcc/ChangeLog > > > >2015-11-11 Senthil Kumar Selvaraj > > > > * tree-vrp.c (simplify_cond_using_ranges): Fold only > > if innerop's mode is word_mode or smaller. > > > > > >diff --git gcc/tree-vrp.c gcc/tree-vrp.c > >index e2393e4..c139bc6 100644 > >--- gcc/tree-vrp.c > >+++ gcc/tree-vrp.c > >@@ -9467,6 +9467,8 @@ simplify_cond_using_ranges (gcond *stmt) > > innerop = gimple_assign_rhs1 (def_stmt); > > > > if (TREE_CODE (innerop) == SSA_NAME > >+ && (GET_MODE_SIZE(TYPE_MODE(TREE_TYPE(innerop))) > >+ <= GET_MODE_SIZE(word_mode)) > > && !POINTER_TYPE_P (TREE_TYPE (innerop))) > > { > > value_range *vr = get_value_range (innerop); > > I thought the result of the discussion was that the transformation is ok if > either it is narrowing or it widens but to something no bigger than > word_mode. So you should have 2 comparisons, or 1 with a max. Hmm, I came to the opposite conclusion - I thought Richard only okayed "widening upto word-mode", not the narrowing. Richard? Regards Senthil > > -- > Marc Glisse