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 [170.10.129.124]) by sourceware.org (Postfix) with ESMTPS id EA5B63857407 for ; Fri, 21 Oct 2022 07:29:21 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.4.1 sourceware.org EA5B63857407 Authentication-Results: sourceware.org; dmarc=pass (p=none dis=none) header.from=redhat.com Authentication-Results: sourceware.org; spf=pass smtp.mailfrom=redhat.com DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1666337361; h=from:from:reply-to:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type; bh=WSuuTmcvlgB35aQgfzTIDi4FIeRAlIFJAs8h41W6c5c=; b=Dtcw6onwjYzwhTcUXxDJYDDHGrDugIDOEMeQazWy5OxTfi8Xwkt1KDXPyXYwqalJO4sm+s QcR/ZcZs/kckFaDefjSN5zi8jaGWSLV9nFDNkePpjFVLDWgAhp3wY5aLYKzdojweNvhF6I hvmLkNEDrrRfTkkWvbpt56A1enlVI1k= Received: from mimecast-mx02.redhat.com (mx3-rdu2.redhat.com [66.187.233.73]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-633-w6SILfM0Mh2etG-YPX4juw-1; Fri, 21 Oct 2022 03:29:19 -0400 X-MC-Unique: w6SILfM0Mh2etG-YPX4juw-1 Received: from smtp.corp.redhat.com (int-mx07.intmail.prod.int.rdu2.redhat.com [10.11.54.7]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id 7446C3C10147; Fri, 21 Oct 2022 07:29:19 +0000 (UTC) Received: from tucnak.zalov.cz (unknown [10.39.193.252]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 32B27141C68B; Fri, 21 Oct 2022 07:29:19 +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 29L7TFTW3484855 (version=TLSv1.3 cipher=TLS_AES_256_GCM_SHA384 bits=256 verify=NOT); Fri, 21 Oct 2022 09:29:16 +0200 Received: (from jakub@localhost) by tucnak.zalov.cz (8.17.1/8.17.1/Submit) id 29L7TFhH3484854; Fri, 21 Oct 2022 09:29:15 +0200 Date: Fri, 21 Oct 2022 09:29:14 +0200 From: Jakub Jelinek To: Jonathan Wakely Cc: gcc-patches@gcc.gnu.org, libstdc++@gcc.gnu.org Subject: [PATCH] libstdc++: Small extended float support tweaks Message-ID: Reply-To: Jakub Jelinek MIME-Version: 1.0 X-Scanned-By: MIMEDefang 3.1 on 10.11.54.7 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=-4.2 required=5.0 tests=BAYES_00,DKIMWL_WL_HIGH,DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF,KAM_SHORT,RCVD_IN_DNSWL_NONE,RCVD_IN_MSPIKE_H2,SPF_HELO_NONE,SPF_NONE,TXREP autolearn=ham autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on server2.sourceware.org List-Id: Hi! The following patch isn't for immediate commit, as it has several dependencies, in particular: https://gcc.gnu.org/pipermail/gcc-patches/2022-October/603665.html https://gcc.gnu.org/pipermail/gcc-patches/2022-October/604080.html https://gcc.gnu.org/pipermail/libstdc++/2022-October/054849.html On top of those, this patch 1) enables the std::float128_t overloads for x86 with glibc 2.26+ 2) makes std::nextafter(std::float16_t, std::float16_t) and std::nextafter(std::bfloat16_t, std::bfloat16_t) constexpr 3) adds (small) testsuite coverage for that Bootstrapped/regtested on x86_64-linux and i686-linux, ok for trunk if/when the above dependencies are in? 2022-10-21 Jakub Jelinek * config/os/gnu-linux/os_defines.h (_GLIBCXX_HAVE_FLOAT128_MATH): Uncomment. * include/c_global/cmath (nextafter(_Float16, _Float16)): Make it constexpr. If std::__is_constant_evaluated() call __builtin_nextafterf16. (nextafter(__gnu_cxx::__bfloat16_t, __gnu_cxx::__bfloat16_t): Similarly but call __builtin_nextafterf16b. * testsuite/26_numerics/headers/cmath/nextafter_c++23.cc (test): Add static assertions to test constexpr nextafter. --- libstdc++-v3/config/os/gnu-linux/os_defines.h.jj 2022-10-18 11:35:55.514865483 +0200 +++ libstdc++-v3/config/os/gnu-linux/os_defines.h 2022-10-20 16:57:59.715681664 +0200 @@ -57,7 +57,7 @@ || (defined(__powerpc__) && defined(_ARCH_PWR8) \ && defined(__LITTLE_ENDIAN__) && (_CALL_ELF == 2) \ && defined(__FLOAT128__))) -//# define _GLIBCXX_HAVE_FLOAT128_MATH 1 +# define _GLIBCXX_HAVE_FLOAT128_MATH 1 #endif #if __GLIBC_PREREQ(2, 27) --- libstdc++-v3/include/c_global/cmath.jj 2022-10-19 11:23:51.484488161 +0200 +++ libstdc++-v3/include/c_global/cmath 2022-10-20 17:03:56.760805581 +0200 @@ -2755,9 +2755,11 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION nearbyint(_Float16 __x) { return _Float16(__builtin_nearbyintf(__x)); } - inline _Float16 + constexpr _Float16 nextafter(_Float16 __x, _Float16 __y) { + if (std::__is_constant_evaluated()) + return __builtin_nextafterf16(__x, __y); #ifdef __INT16_TYPE__ using __float16_int_type = __INT16_TYPE__; #else @@ -3471,9 +3473,11 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION nearbyint(__gnu_cxx::__bfloat16_t __x) { return __gnu_cxx::__bfloat16_t(__builtin_nearbyintf(__x)); } - inline __gnu_cxx::__bfloat16_t + constexpr __gnu_cxx::__bfloat16_t nextafter(__gnu_cxx::__bfloat16_t __x, __gnu_cxx::__bfloat16_t __y) { + if (std::__is_constant_evaluated()) + return __builtin_nextafterf16b(__x, __y); #ifdef __INT16_TYPE__ using __bfloat16_int_type = __INT16_TYPE__; #else --- libstdc++-v3/testsuite/26_numerics/headers/cmath/nextafter_c++23.cc.jj 2022-10-20 16:57:29.940088318 +0200 +++ libstdc++-v3/testsuite/26_numerics/headers/cmath/nextafter_c++23.cc 2022-10-20 17:19:40.141923257 +0200 @@ -100,6 +100,8 @@ test () VERIFY( std::fpclassify(t36) == FP_NAN ); T t37 = std::nextafter(T(-0.0), T()); VERIFY( t37 == T() && !std::signbit(t37) ); + static_assert(std::nextafter(T(1.0), T(2.0)) > T(1.0)); + static_assert(std::nextafter(std::nextafter(T(1.0), T(5.0)), T(0.0)) == T(1.0)); } int Jakub