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 [63.128.21.124]) by sourceware.org (Postfix) with ESMTP id 28D9439450F1 for ; Fri, 28 Aug 2020 15:23:09 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.3.2 sourceware.org 28D9439450F1 Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-350-1V37hk3vMD-YKu1AvKSpew-1; Fri, 28 Aug 2020 11:23:07 -0400 X-MC-Unique: 1V37hk3vMD-YKu1AvKSpew-1 Received: from smtp.corp.redhat.com (int-mx06.intmail.prod.int.phx2.redhat.com [10.5.11.16]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 4D05A1074655 for ; Fri, 28 Aug 2020 15:23:06 +0000 (UTC) Received: from oldenburg2.str.redhat.com (ovpn-112-37.ams2.redhat.com [10.36.112.37]) by smtp.corp.redhat.com (Postfix) with ESMTPS id C7B685C1C2 for ; Fri, 28 Aug 2020 15:23:05 +0000 (UTC) From: Florian Weimer To: libc-help@sourceware.org Subject: isnan and exceptions Date: Fri, 28 Aug 2020 17:23:04 +0200 Message-ID: <87wo1ipzfr.fsf@oldenburg2.str.redhat.com> User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/26.3 (gnu/linux) MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.16 X-Mimecast-Spam-Score: 0.001 X-Mimecast-Originator: redhat.com Content-Type: text/plain X-Spam-Status: No, score=-7.2 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_H5, RCVD_IN_MSPIKE_WL, SPF_HELO_NONE, SPF_PASS, TXREP autolearn=ham autolearn_force=no version=3.4.2 X-Spam-Checker-Version: SpamAssassin 3.4.2 (2018-09-13) on server2.sourceware.org X-BeenThere: libc-help@sourceware.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Libc-help mailing list List-Unsubscribe: , List-Archive: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 28 Aug 2020 15:23:10 -0000 It seems that __builtin_isnanl raises Invalid Operation for sNaNs on x86-64, but glibc's isnanl implementation does not. Is this expected? Are both behaviors correct? The background of my question is that if I replace isnanl with this: int isnanl (long double x) { return __builtin_isnanl (x); } I get these test suite failures: testing long double (without inline functions) Failure: isnan (sNaN): Exception "Invalid operation" set Failure: isnan (-sNaN): Exception "Invalid operation" set Failure: isnan_downward (sNaN): Exception "Invalid operation" set Failure: isnan_downward (-sNaN): Exception "Invalid operation" set Failure: isnan_towardzero (sNaN): Exception "Invalid operation" set Failure: isnan_towardzero (-sNaN): Exception "Invalid operation" set Failure: isnan_upward (sNaN): Exception "Invalid operation" set Failure: isnan_upward (-sNaN): Exception "Invalid operation" set Thanks, Florian