From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.129.124]) by sourceware.org (Postfix) with ESMTPS id 11BF5385828E for ; Thu, 10 Nov 2022 15:40:10 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.4.1 sourceware.org 11BF5385828E Authentication-Results: sourceware.org; dmarc=pass (p=none dis=none) header.from=redhat.com Authentication-Results: sourceware.org; spf=pass smtp.mailfrom=redhat.com DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1668094809; h=from:from:reply-to:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type:in-reply-to:in-reply-to: references:references; bh=3F5Mdh44Pbo47JYWedGXBw1ZyEd0i8vLK+rKkUKbaUY=; b=ADcsfKoKhyWaNQXj88aKbBgbj2INJuvF77j9FoD5itOUPLjb487G+GuyeGOWabLXGVpagB 7wns1g/X2VxeYMmNcoIT4e0OgwY+BEujmkcRoYBU8PDL1T1udfKsWhy0V3dQp1AXCoHD9a WLvEB5Y6gYQdGbu6XRS8a0evbqwtWkU= Received: from mimecast-mx02.redhat.com (mx3-rdu2.redhat.com [66.187.233.73]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-613-DMlcIsRMOL6X9T-ow1cuoQ-1; Thu, 10 Nov 2022 10:40:08 -0500 X-MC-Unique: DMlcIsRMOL6X9T-ow1cuoQ-1 Received: from smtp.corp.redhat.com (int-mx01.intmail.prod.int.rdu2.redhat.com [10.11.54.1]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id 4CA871C09B63 for ; Thu, 10 Nov 2022 15:40:08 +0000 (UTC) Received: from tucnak.zalov.cz (unknown [10.39.192.38]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 02E1840C83DD; Thu, 10 Nov 2022 15:40:07 +0000 (UTC) Received: from tucnak.zalov.cz (localhost [127.0.0.1]) by tucnak.zalov.cz (8.17.1/8.17.1) with ESMTPS id 2AAFe52Y1373133 (version=TLSv1.3 cipher=TLS_AES_256_GCM_SHA384 bits=256 verify=NOT); Thu, 10 Nov 2022 16:40:05 +0100 Received: (from jakub@localhost) by tucnak.zalov.cz (8.17.1/8.17.1/Submit) id 2AAFe4xV1373132; Thu, 10 Nov 2022 16:40:04 +0100 Date: Thu, 10 Nov 2022 16:40:04 +0100 From: Jakub Jelinek To: Aldy Hernandez Cc: GCC patches , Andrew MacLeod Subject: Re: [PATCH] Do not specify NAN sign in frange::set_nonnegative. Message-ID: Reply-To: Jakub Jelinek References: <20221110150345.157116-1-aldyh@redhat.com> MIME-Version: 1.0 In-Reply-To: <20221110150345.157116-1-aldyh@redhat.com> X-Scanned-By: MIMEDefang 3.1 on 10.11.54.1 X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Type: text/plain; charset=us-ascii Content-Disposition: inline X-Spam-Status: No, score=-3.9 required=5.0 tests=BAYES_00,DKIMWL_WL_HIGH,DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF,RCVD_IN_DNSWL_NONE,RCVD_IN_MSPIKE_H2,SPF_HELO_NONE,SPF_NONE,TXREP autolearn=ham autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on server2.sourceware.org List-Id: On Thu, Nov 10, 2022 at 04:03:46PM +0100, Aldy Hernandez wrote: > [Jakub, how's this? Do you agree?] > > After further reading of the IEEE 754 standard, it has become clear > that there are no guarantees with regards to the sign of a NAN when it > comes to any operation other than copy, copysign, abs, and negate. > > Currently, set_nonnegative() is only used in one place in ranger > applicable to floating point values, when expanding unknown calls. > Since we already specially handle copy, copysign, abs, and negate, all > the calls to set_nonnegative() must be NAN-sign agnostic. > > The cleanest solution is to leave the sign unspecificied in > frange::set_nonnegative(). Any special case, must be handled by the > caller. > > gcc/ChangeLog: > > * value-range.cc (frange::set_nonnegative): Remove NAN sign handling. > (range_tests_signed_zeros): Adjust test. LGTM, thanks. Jakub