From patchwork Tue Jun 6 15:59:31 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jonathan Wakely X-Patchwork-Id: 1791286 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@legolas.ozlabs.org Authentication-Results: legolas.ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=gcc.gnu.org (client-ip=8.43.85.97; helo=sourceware.org; envelope-from=gcc-patches-bounces+incoming=patchwork.ozlabs.org@gcc.gnu.org; receiver=) Authentication-Results: legolas.ozlabs.org; dkim=pass (1024-bit key; unprotected) header.d=gcc.gnu.org header.i=@gcc.gnu.org header.a=rsa-sha256 header.s=default header.b=sNAnj584; dkim-atps=neutral Received: from sourceware.org (server2.sourceware.org [8.43.85.97]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (P-384) server-digest SHA384) (No client certificate requested) by legolas.ozlabs.org (Postfix) with ESMTPS id 4QbFYD21fhz20WK for ; Wed, 7 Jun 2023 02:00:00 +1000 (AEST) Received: from server2.sourceware.org (localhost [IPv6:::1]) by sourceware.org (Postfix) with ESMTP id 4A9DA3856DDA for ; Tue, 6 Jun 2023 15:59:58 +0000 (GMT) DKIM-Filter: OpenDKIM Filter v2.11.0 sourceware.org 4A9DA3856DDA DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gcc.gnu.org; s=default; t=1686067198; bh=DQjHvMhfvnnXRt1gFv7cujOfkNtdMIdjqsyG0C3jL/w=; h=To:Cc:Subject:Date:List-Id:List-Unsubscribe:List-Archive: List-Post:List-Help:List-Subscribe:From:Reply-To:From; b=sNAnj584BiEaQVi+ZtEZReCWos8NVHOm1EXRbLel8WFCwEyF97LgxiljP0Q0ueBYR I6w4Lyf1E9BxL/ICKAZjSUcrn8ma1n9fLDv2QhDbfpXyS7kSKP/8loQuDCr3td/0yD KQPgWDHhtfAxPKNowtdFvMDbVyZcFFXDUM508FzU= X-Original-To: gcc-patches@gcc.gnu.org Delivered-To: gcc-patches@gcc.gnu.org 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 E44D83857711 for ; Tue, 6 Jun 2023 15:59:37 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.4.2 sourceware.org E44D83857711 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-246-Pa8SD3VgMByxfzc32YcHCw-1; Tue, 06 Jun 2023 11:59:34 -0400 X-MC-Unique: Pa8SD3VgMByxfzc32YcHCw-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 4F5E53C11A26; Tue, 6 Jun 2023 15:59:34 +0000 (UTC) Received: from localhost (unknown [10.42.28.30]) by smtp.corp.redhat.com (Postfix) with ESMTP id C3B424A927E; Tue, 6 Jun 2023 15:59:33 +0000 (UTC) To: libstdc++@gcc.gnu.org, gcc-patches@gcc.gnu.org Cc: Jakub Jelinek Subject: [committed] libstdc++: Make std::numeric_limits<__float128> more portable [PR104772] Date: Tue, 6 Jun 2023 16:59:31 +0100 Message-Id: <20230606155931.1241991-1-jwakely@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 3.1 on 10.11.54.10 X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com X-Spam-Status: No, score=-12.1 required=5.0 tests=BAYES_00, DKIMWL_WL_HIGH, DKIM_SIGNED, DKIM_VALID, DKIM_VALID_AU, DKIM_VALID_EF, GIT_PATCH_0, RCVD_IN_DNSWL_NONE, SPF_HELO_NONE, SPF_NONE, TXREP, T_SCC_BODY_TEXT_LINE autolearn=unavailable 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-Patchwork-Original-From: Jonathan Wakely via Gcc-patches From: Jonathan Wakely Reply-To: Jonathan Wakely Errors-To: gcc-patches-bounces+incoming=patchwork.ozlabs.org@gcc.gnu.org Sender: "Gcc-patches" Tested x86_64-linux and powerpc64le-linux. Pushed to trunk. -- >8 -- This redefines std::numeric_limits<__float128> so that it works with non-GCC compilers. The previous definition didn't work with Clang, due to it not supporting __builtin_high_valq, __builtin_nanq, and __builtin_nansq. It also didn't work in strict modes, due to using Q literal suffixes. The new definition uses the Q suffixes when supported, or calculates the correct values using __float128 arithmetic from double values. Ideally the values would be defined as hexadecimal-floating-point-literals, but that won't work for C++14 and older. The only member that can't be defined this way is signaling_NaN() which still requires a built-in. If __builtin_nansq is not supported, try to use __builtin_nansf128 (with a possibly-redundant bit_cast) and if that isn't supported, return a quiet NaN and define has_signaling_NaN and is_iec754 to be false. libstdc++-v3/ChangeLog: PR libstdc++/104772 * include/std/limits: (numeric_limits<__float128>): Define for __STRICT_ANSI__ as well. * testsuite/18_support/numeric_limits/128bit.cc: Remove check for __STRICT_ANSI__. Co-authored-by: Jakub Jelinek --- libstdc++-v3/include/std/limits | 95 +++++++++++++++---- .../18_support/numeric_limits/128bit.cc | 2 +- 2 files changed, 80 insertions(+), 17 deletions(-) diff --git a/libstdc++-v3/include/std/limits b/libstdc++-v3/include/std/limits index 5f341e63b93..52b19ef8264 100644 --- a/libstdc++-v3/include/std/limits +++ b/libstdc++-v3/include/std/limits @@ -2071,9 +2071,11 @@ __glibcxx_float_n(128) }; #endif -#endif +#endif // C++23 -#if defined(_GLIBCXX_USE_FLOAT128) && !defined(__STRICT_ANSI__) +#if defined(_GLIBCXX_USE_FLOAT128) +// We either need Q literal suffixes, or IEEE double. +#if ! defined(__STRICT_ANSI__) || defined(_GLIBCXX_DOUBLE_IS_IEEE_BINARY64) __extension__ template<> struct numeric_limits<__float128> @@ -2082,11 +2084,28 @@ __glibcxx_float_n(128) static _GLIBCXX_CONSTEXPR __float128 min() _GLIBCXX_USE_NOEXCEPT - { return __extension__ 3.36210314311209350626267781732175260e-4932Q; } + { +#ifdef __STRICT_ANSI__ + // 0x1.0p-30 * 0x1.0p-16352 + return double(9.3132257461547852e-10) * _S_1pm16352(); +#else + return __extension__ 0x1.0p-16382Q; +#endif + } static _GLIBCXX_CONSTEXPR __float128 max() _GLIBCXX_USE_NOEXCEPT - { return __extension__ 1.18973149535723176508575932662800702e+4932Q; } + { +#ifdef __STRICT_ANSI__ + // (0x1.fffffffffffffp+127 + 0x0.fffffffffffffp+75 + 0x0.ffp+23) + // * 0x1.0p16256 + return (__float128(double(3.4028236692093843e+38)) + + double(3.7778931862957153e+22) + double(8.35584e+6)) + * _S_1p16256(); +#else + return __extension__ 0x1.ffffffffffffffffffffffffffffp+16383Q; +#endif + } static _GLIBCXX_CONSTEXPR __float128 lowest() _GLIBCXX_USE_NOEXCEPT @@ -2094,8 +2113,9 @@ __glibcxx_float_n(128) static _GLIBCXX_USE_CONSTEXPR int digits = 113; static _GLIBCXX_USE_CONSTEXPR int digits10 = 33; - static _GLIBCXX_USE_CONSTEXPR int max_digits10 - = __glibcxx_max_digits10 (112); +#if __cplusplus >= 201103L + static constexpr int max_digits10 = 35; +#endif static _GLIBCXX_USE_CONSTEXPR bool is_signed = true; static _GLIBCXX_USE_CONSTEXPR bool is_integer = false; static _GLIBCXX_USE_CONSTEXPR bool is_exact = false; @@ -2103,10 +2123,10 @@ __glibcxx_float_n(128) static _GLIBCXX_CONSTEXPR __float128 epsilon() _GLIBCXX_USE_NOEXCEPT - { return __extension__ 1.92592994438723585305597794258492732e-34Q; } + { return double(1.9259299443872359e-34); } static _GLIBCXX_CONSTEXPR __float128 - round_error() _GLIBCXX_USE_NOEXCEPT { return __extension__ 0.5Q; } + round_error() _GLIBCXX_USE_NOEXCEPT { return 0.5; } static _GLIBCXX_USE_CONSTEXPR int min_exponent = -16381; static _GLIBCXX_USE_CONSTEXPR int min_exponent10 = -4931; @@ -2115,29 +2135,48 @@ __glibcxx_float_n(128) static _GLIBCXX_USE_CONSTEXPR bool has_infinity = 1; static _GLIBCXX_USE_CONSTEXPR bool has_quiet_NaN = 1; - static _GLIBCXX_USE_CONSTEXPR bool has_signaling_NaN = has_quiet_NaN; +#if __has_builtin(__builtin_nansq) \ + || (__has_builtin(__builtin_bit_cast) && __has_builtin(__builtin_nansf128)) + static _GLIBCXX_USE_CONSTEXPR bool has_signaling_NaN = true; +#else + static _GLIBCXX_USE_CONSTEXPR bool has_signaling_NaN = false; +#endif static _GLIBCXX_USE_CONSTEXPR float_denorm_style has_denorm = denorm_present; static _GLIBCXX_USE_CONSTEXPR bool has_denorm_loss = false; static _GLIBCXX_CONSTEXPR __float128 infinity() _GLIBCXX_USE_NOEXCEPT - { return __builtin_huge_valq(); } + { return __builtin_huge_val(); } static _GLIBCXX_CONSTEXPR __float128 quiet_NaN() _GLIBCXX_USE_NOEXCEPT - { return __builtin_nanq(""); } + { return __builtin_nan(""); } static _GLIBCXX_CONSTEXPR __float128 signaling_NaN() _GLIBCXX_USE_NOEXCEPT - { return __builtin_nansq(""); } + { +#if __has_builtin(__builtin_nansq) + return __builtin_nansq(""); +#elif __has_builtin(__builtin_bit_cast) && __has_builtin(__builtin_nansf128) + return __builtin_bit_cast(__float128, __builtin_nansf128("")); +#else + return quiet_NaN(); +#endif + } static _GLIBCXX_CONSTEXPR __float128 denorm_min() _GLIBCXX_USE_NOEXCEPT - { return __extension__ 6.47517511943802511092443895822764655e-4966Q; } + { +#if defined(__STRICT_ANSI__) || defined(__INTEL_COMPILER) + // 0x1.0p-142 * 0x1.0p-16352 + return double(1.7936620343357659e-43) * _S_1pm16352(); +#else + return __extension__ 0x1.0p-16494Q; +#endif + } - static _GLIBCXX_USE_CONSTEXPR bool is_iec559 - = has_infinity && has_quiet_NaN && has_denorm == denorm_present; + static _GLIBCXX_USE_CONSTEXPR bool is_iec559 = has_signaling_NaN; static _GLIBCXX_USE_CONSTEXPR bool is_bounded = true; static _GLIBCXX_USE_CONSTEXPR bool is_modulo = false; @@ -2145,8 +2184,32 @@ __glibcxx_float_n(128) static _GLIBCXX_USE_CONSTEXPR bool tinyness_before = false; static _GLIBCXX_USE_CONSTEXPR float_round_style round_style = round_to_nearest; + +#if defined(__STRICT_ANSI__) || defined(__INTEL_COMPILER) + private: + static _GLIBCXX_CONSTEXPR __float128 + _S_4p(__float128 __v) _GLIBCXX_USE_NOEXCEPT + { return __v * __v * __v * __v; } + + static _GLIBCXX_CONSTEXPR __float128 + _S_1pm4088() _GLIBCXX_USE_NOEXCEPT + { return _S_4p(/* 0x1.0p-1022 */ double(2.2250738585072014e-308)); } + + static _GLIBCXX_CONSTEXPR __float128 + _S_1pm16352() _GLIBCXX_USE_NOEXCEPT + { return _S_4p(_S_1pm4088()); } + + static _GLIBCXX_CONSTEXPR __float128 + _S_1p4064() _GLIBCXX_USE_NOEXCEPT + { return _S_4p(/* 0x1.0p+1016 */ double(7.0222388080559215e+305)); } + + static _GLIBCXX_CONSTEXPR __float128 + _S_1p16256() _GLIBCXX_USE_NOEXCEPT + { return _S_4p(_S_1p4064()); } +#endif }; -#endif // _GLIBCXX_USE_FLOAT128 && ! __STRICT_ANSI__ +#endif // !__STRICT_ANSI__ || DOUBLE_IS_IEEE_BINARY64 +#endif // _GLIBCXX_USE_FLOAT128 _GLIBCXX_END_NAMESPACE_VERSION } // namespace diff --git a/libstdc++-v3/testsuite/18_support/numeric_limits/128bit.cc b/libstdc++-v3/testsuite/18_support/numeric_limits/128bit.cc index e8ea568df94..b13d83776ba 100644 --- a/libstdc++-v3/testsuite/18_support/numeric_limits/128bit.cc +++ b/libstdc++-v3/testsuite/18_support/numeric_limits/128bit.cc @@ -2,7 +2,7 @@ #include -#if __SIZEOF_FLOAT128__ && !defined __STRICT_ANSI__ +#if __SIZEOF_FLOAT128__ __extension__ template class std::numeric_limits<__float128>; #endif