From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from smtp-out2.suse.de (smtp-out2.suse.de [IPv6:2001:67c:2178:6::1d]) by sourceware.org (Postfix) with ESMTPS id DFCE43858C20 for ; Tue, 16 Aug 2022 12:04:54 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.4.1 sourceware.org DFCE43858C20 Received: from relay2.suse.de (relay2.suse.de [149.44.160.134]) by smtp-out2.suse.de (Postfix) with ESMTP id D0B511FB19; Tue, 16 Aug 2022 12:04:53 +0000 (UTC) Received: from wotan.suse.de (wotan.suse.de [10.160.0.1]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by relay2.suse.de (Postfix) with ESMTPS id 886C22C149; Tue, 16 Aug 2022 12:04:53 +0000 (UTC) Date: Tue, 16 Aug 2022 12:04:53 +0000 (UTC) From: Richard Biener To: Jakub Jelinek cc: gcc-patches@gcc.gnu.org, FX , "Joseph S. Myers" Subject: Re: [PATCH] Implement __builtin_issignaling In-Reply-To: Message-ID: References: User-Agent: Alpine 2.22 (LSU 394 2020-01-19) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII X-Spam-Status: No, score=-5.0 required=5.0 tests=BAYES_00, DKIM_SIGNED, DKIM_VALID, DKIM_VALID_AU, DKIM_VALID_EF, SPF_HELO_NONE, SPF_PASS, 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 12:04:56 -0000 On Tue, 16 Aug 2022, Jakub Jelinek wrote: > 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? Yes. Thanks, Richard. > --- 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 > > -- Richard Biener SUSE Software Solutions Germany GmbH, Frankenstrasse 146, 90461 Nuernberg, Germany; GF: Ivo Totev, Andrew Myers, Andrew McDonald, Boudien Moerman; HRB 36809 (AG Nuernberg)