From unknown Sat Jun 14 19:25:05 2025 X-Loop: help-debbugs@gnu.org Subject: bug#41665: python-numpy: incorrect results on i686-linux Resent-From: Diego Nicola Barbato Original-Sender: "Debbugs-submit" Resent-CC: bug-guix@gnu.org Resent-Date: Tue, 02 Jun 2020 16:17:01 +0000 Resent-Message-ID: Resent-Sender: help-debbugs@gnu.org X-GNU-PR-Message: report 41665 X-GNU-PR-Package: guix X-GNU-PR-Keywords: To: 41665@debbugs.gnu.org X-Debbugs-Original-To: bug-guix@gnu.org Received: via spool by submit@debbugs.gnu.org id=B.15911146064794 (code B ref -1); Tue, 02 Jun 2020 16:17:01 +0000 Received: (at submit) by debbugs.gnu.org; 2 Jun 2020 16:16:46 +0000 Received: from localhost ([127.0.0.1]:40732 helo=debbugs.gnu.org) by debbugs.gnu.org with esmtp (Exim 4.84_2) (envelope-from ) id 1jg9aa-0001F2-5p for submit@debbugs.gnu.org; Tue, 02 Jun 2020 12:16:45 -0400 Received: from lists.gnu.org ([209.51.188.17]:45108) by debbugs.gnu.org with esmtp (Exim 4.84_2) (envelope-from ) id 1jg9aY-0001Ev-Nc for submit@debbugs.gnu.org; Tue, 02 Jun 2020 12:16:31 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:33414) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1jg9aY-0002Qu-9v for bug-guix@gnu.org; Tue, 02 Jun 2020 12:16:30 -0400 Received: from mout02.posteo.de ([185.67.36.66]:45957) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1jg9aW-0006Zr-Gh for bug-guix@gnu.org; Tue, 02 Jun 2020 12:16:29 -0400 Received: from submission (posteo.de [89.146.220.130]) by mout02.posteo.de (Postfix) with ESMTPS id 383D82400FE for ; Tue, 2 Jun 2020 18:16:25 +0200 (CEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=posteo.de; s=2017; t=1591114585; bh=0aABnfTpDLX4CToMVkUx8WLZRk42qMQBI1YOUYS88PA=; h=From:To:Subject:Date:From; b=D+zbGwwTeocwE0aE1kbSbqMvrZfghuLEOKiWaCZL+af6P0N9eg2GwgnHDYN3AIh3T KzPaRJDgdI7UqJbhrKKvOoFkOzXDCOAlARkhZUyIYUuFxm2HTiQQsPJ53Owb60G4++ 44i3sLQzlJGYVcaIpI7ug51V4MO3gKXOQQ4ZEoX8pQolYoUdiqZFmBRrphAaSBm6n5 wDU4nLamzl2TxMCH35MtpWyVO26D9ra4cUX5VRW5LX8JYlSKD9hK4oFRYjzge/m1rQ znGeVf9HD76sXYENDycUXkq6ytRbeNo4nhKgdrJufepnpNezrnl3lT8qXYER6YVuhB mJWNSASD1G1Wg== Received: from customer (localhost [127.0.0.1]) by submission (posteo.de) with ESMTPSA id 49bxxN5TSSz9rxG for ; Tue, 2 Jun 2020 18:16:24 +0200 (CEST) From: Diego Nicola Barbato Date: Tue, 02 Jun 2020 18:16:24 +0200 Message-ID: <87a71la1ev.fsf@GlaDOS.home> User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/26.3 (gnu/linux) MIME-Version: 1.0 Content-Type: text/plain Received-SPF: pass client-ip=185.67.36.66; envelope-from=dnbarbato@posteo.de; helo=mout02.posteo.de X-detected-operating-system: by eggs.gnu.org: First seen = 2020/06/02 12:16:25 X-ACL-Warn: Detected OS = Linux 3.11 and newer X-Spam_score_int: -43 X-Spam_score: -4.4 X-Spam_bar: ---- X-Spam_report: (-4.4 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_MED=0.001, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_MED=-2.3, RCVD_IN_MSPIKE_H4=0.001, RCVD_IN_MSPIKE_WL=0.001, SPF_PASS=-0.001, URIBL_BLOCKED=0.001 autolearn=_AUTOLEARN X-Spam_action: no action X-Spam-Score: -1.3 (-) X-BeenThere: debbugs-submit@debbugs.gnu.org X-Mailman-Version: 2.1.18 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: debbugs-submit-bounces@debbugs.gnu.org Sender: "Debbugs-submit" X-Spam-Score: -0.0 (/) Hi Guix, On i686-linux Numpy produces incorrect results for some matrix products. This minimal reproducer ... --8<---------------cut here---------------start------------->8--- python3 <8--- ... should return: --8<---------------cut here---------------start------------->8--- [0. 0. 1.] [0. 0. 1.] --8<---------------cut here---------------end--------------->8--- On x86_64-linux, armhf-linux, and aarch64-linux I get the correct result. On i686-linux I get this instead: --8<---------------cut here---------------start------------->8--- [ 0.00000000e+00 -5.55111512e-17 1.00000000e+00] [0. 0. 1.] --8<---------------cut here---------------end--------------->8--- I came across this bug while looking into https://debbugs.gnu.org/40406, for which it seems to be the underlying cause. I'm surprised this wasn't caught by Numpy's test suite. Regards, Diego