From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 98252 invoked by alias); 12 Jul 2018 16:03:17 -0000 Mailing-List: contact gcc-help@gcc.gnu.org; run by ezmlm Precedence: bulk List-Id: List-Archive: List-Post: List-Help: Sender: gcc-owner@gcc.gnu.org Received: (qmail 98235 invoked by uid 89); 12 Jul 2018 16:03:16 -0000 Authentication-Results: sourceware.org; auth=none X-Spam-SWARE-Status: No, score=-2.7 required=5.0 tests=AWL,BAYES_00,RCVD_IN_DNSWL_NONE,SPF_HELO_PASS,SPF_PASS autolearn=ham version=3.3.2 spammy=code,we, gcc81, softfloat, mhard-float X-HELO: EUR01-VE1-obe.outbound.protection.outlook.com Received: from mail-ve1eur01on0077.outbound.protection.outlook.com (HELO EUR01-VE1-obe.outbound.protection.outlook.com) (104.47.1.77) by sourceware.org (qpsmtpd/0.93/v0.84-503-g423c35a) with ESMTP; Thu, 12 Jul 2018 16:03:14 +0000 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=armh.onmicrosoft.com; s=selector1-arm-com; h=From:Date:Subject:Message-ID:Content-Type:MIME-Version:X-MS-Exchange-SenderADCheck; bh=8vMjJVE79muz8OtPS+uH+XJ5VUnPsEAitqTklVdj6YU=; b=lecwcC0PA+2OPMSHJYxVPFbyIQTVOHmM/AU19hG+v7zdFeub7gvBBtIgUT2Gni/8LliDw4bVz+SyXQI3BiARoMJz5NVrdskZJOzCa5S5EeiJwY/PdJnogChV0gJ9HuhsIffLS6fMXS/ciit4d/TWqSKtasyP59VK+yApboWRYyc= Authentication-Results: spf=none (sender IP is ) smtp.mailfrom=Szabolcs.Nagy@arm.com; Received: from [10.2.206.57] (217.140.96.140) by AM0PR08MB3284.eurprd08.prod.outlook.com (2603:10a6:208:5e::29) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.952.18; Thu, 12 Jul 2018 16:03:11 +0000 Cc: nd@arm.com Subject: Re: Subnormal float support in armv7(with -msoft-float) for intrinsics To: Umesh Kalappa , gcc@gcc.gnu.org References: From: Szabolcs Nagy Message-ID: <61ff7d39-fc33-3a69-4b49-504862c350e5@arm.com> Date: Thu, 12 Jul 2018 16:03:00 -0000 User-Agent: Mozilla/5.0 (X11; Linux aarch64; rv:52.0) Gecko/20100101 Thunderbird/52.7.0 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 7bit Return-Path: szabolcs.nagy@arm.com Received-SPF: None (protection.outlook.com: arm.com does not designate permitted sender hosts) X-IsSubscribed: yes X-SW-Source: 2018-07/txt/msg00192.txt.bz2 On 12/07/18 16:20, Umesh Kalappa wrote: > Hi everyone, > > we have our source base ,that was compiled for armv7 on gcc8.1 with > soft-float and for following input > > a=0x0010000000000000 > b=0x0000000000000001 > > result = a - b ; > > we are getting the result as "0x000ffffffffffffe" and with > -mhard-float (disabled the flush to zero mode ) we are getting the > result as ""0x000fffffffffffff" as expected. > please submit it as a bug report to bugzilla > while debugging the soft-float code,we see that ,the compiler calls > the intrinsic "__aeabi_dsub" with arm calling conventions i.e passing > "a" in r0 and r1 registers and respectively for "b". > > we are investigating the routine "__aeabi_dsub" that comes from libgcc > for incorrect result and meanwhile we would like to know that > > a)do libgcc routines/intrinsic for float operations support or > consider the subnormal values ? ,if so how we can enable the same. > > Thank you > ~Umesh >