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 [170.10.133.124]) by sourceware.org (Postfix) with ESMTPS id 2FA2D3858C20 for ; Tue, 16 Aug 2022 11:57:39 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.4.1 sourceware.org 2FA2D3858C20 Received: from mimecast-mx02.redhat.com (mimecast-mx02.redhat.com [66.187.233.88]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-186-IByZ7NDdOI-MLVEUX4W5vQ-1; Tue, 16 Aug 2022 07:57:34 -0400 X-MC-Unique: IByZ7NDdOI-MLVEUX4W5vQ-1 Received: from smtp.corp.redhat.com (int-mx10.intmail.prod.int.rdu2.redhat.com [10.11.54.10]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id 50BD985A581; Tue, 16 Aug 2022 11:57:34 +0000 (UTC) Received: from tucnak.zalov.cz (unknown [10.39.192.41]) by smtp.corp.redhat.com (Postfix) with ESMTPS id F0AA3492C3B; Tue, 16 Aug 2022 11:57:33 +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 27GBvUXc1272156 (version=TLSv1.3 cipher=TLS_AES_256_GCM_SHA384 bits=256 verify=NOT); Tue, 16 Aug 2022 13:57:31 +0200 Received: (from jakub@localhost) by tucnak.zalov.cz (8.17.1/8.17.1/Submit) id 27GBvT2I1272155; Tue, 16 Aug 2022 13:57:29 +0200 Date: Tue, 16 Aug 2022 13:57:29 +0200 From: Jakub Jelinek To: Richard Biener Cc: gcc-patches@gcc.gnu.org, FX , "Joseph S. Myers" Subject: Re: [PATCH] Implement __builtin_issignaling Message-ID: Reply-To: Jakub Jelinek References: MIME-Version: 1.0 In-Reply-To: X-Scanned-By: MIMEDefang 2.85 on 10.11.54.10 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=-3.6 required=5.0 tests=BAYES_00, DKIMWL_WL_HIGH, DKIM_SIGNED, DKIM_VALID, DKIM_VALID_AU, DKIM_VALID_EF, RCVD_IN_DNSWL_NONE, SPF_HELO_NONE, SPF_NONE, TXREP, T_SCC_BODY_TEXT_LINE autolearn=ham autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on server2.sourceware.org X-BeenThere: gcc-patches@gcc.gnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Gcc-patches mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 16 Aug 2022 11:57:40 -0000 On Tue, Aug 16, 2022 at 11:41:06AM +0000, Richard Biener wrote: > Can you also amend the extend.texi documentation? I think the > behavior will be special enough to worth mentioning it (I don't see > any of -ffinite-math-only effect on isnan/isinf mentioned though). Like this? --- gcc/doc/extend.texi.jj 2022-08-16 13:23:04.227103773 +0200 +++ gcc/doc/extend.texi 2022-08-16 13:56:01.250769807 +0200 @@ -13557,6 +13557,8 @@ In the same fashion, GCC provides @code{ @code{isinf_sign}, @code{isnormal} and @code{signbit} built-ins used with @code{__builtin_} prefixed. The @code{isinf} and @code{isnan} built-in functions appear both with and without the @code{__builtin_} prefix. +With @code{-ffinite-math-only} option the @code{isinf} and @code{isnan} +built-in functions will always return 0. GCC provides built-in versions of the ISO C99 floating-point rounding and exceptions handling functions @code{fegetround}, @code{feclearexcept} and @@ -14496,6 +14498,12 @@ Note while the parameter list is an ellipsis, this function only accepts exactly one floating-point argument. GCC treats this parameter as type-generic, which means it does not do default promotion from float to double. +This built-in function can work even without the non-default +@code{-fsignaling-nans} option, although if a signaling NaN is computed, +stored or passed as argument to some function other than this built-in +in the current translation unit, it is safer to use @code{-fsignaling-nans}. +With @code{-ffinite-math-only} option this built-in function will always +return 0. @end deftypefn @deftypefn {Built-in Function} int __builtin_ffs (int x) Jakub