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 0747A3858418 for ; Thu, 23 Dec 2021 12:44:08 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.4.1 sourceware.org 0747A3858418 Received: from mail-yb1-f199.google.com (mail-yb1-f199.google.com [209.85.219.199]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-488-anoZIuUHPJ65PheLgBxwVA-1; Thu, 23 Dec 2021 07:44:06 -0500 X-MC-Unique: anoZIuUHPJ65PheLgBxwVA-1 Received: by mail-yb1-f199.google.com with SMTP id e131-20020a25d389000000b005fb5e6eb757so9669620ybf.22 for ; Thu, 23 Dec 2021 04:44:06 -0800 (PST) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=7mbGb7sGNiN+H3HWWnbX8eiBsHiUuq+s8GBQpO6uAuc=; b=b+OXxGTZ85s5feNejApdEKh0yELqtfPzHnJ3//Uqgw6Wzfm7BfNDsCb9RxFTtDM4U+ QxmW+BuAh7rwuv1jK3m+HVkLfaqzUFu5p5XNt5Q9BRHgDT3Xyzjv/CbPgKHVNfevWJZI OOw+ZayNxj7GV0+s2vDNh8tULir9SpJGgELB+XrK7kDyunXxHu/b6MyzRw0CXriWDaQr geIXQNWuTiMRRxrD5R/gSG/xVkM8h896lJUj7EOvHlWstwKnDlpxXKRZX41t6+SNEqu7 VJtQGp6DBWHNndApT0MMGwXErLg2LPZ9WFiLbVBZCGjJGHBNMM8lkY5iQf5osw3fY3CF 8u/A== X-Gm-Message-State: AOAM530wn9j9W46b0Lg5vfVkc01w5vIC606jv9w9LxdgyVVhXy0e7mSE N7cRH3LiwpwAPa81KXNZkcm7zkrAh3Z5MC/dFcS6cak90j5ocTjsPonB/ppKUwp0FcX1TKCCZgy ulJEpGxyxmddcc6MXSK5aXX3se013NXo= X-Received: by 2002:a25:4788:: with SMTP id u130mr3011187yba.66.1640263444644; Thu, 23 Dec 2021 04:44:04 -0800 (PST) X-Google-Smtp-Source: ABdhPJw9sW62ZzMLSp/RgOGpKHYfiSDZcjaIJvZ1APLv440XHBi2qog5H/ATW4bSpxAawZS+htqTMlxYSczETonqSuY= X-Received: by 2002:a25:4788:: with SMTP id u130mr3011173yba.66.1640263444455; Thu, 23 Dec 2021 04:44:04 -0800 (PST) MIME-Version: 1.0 References: <88d3aa39-2146-3ea5-8bb2-a4d9b70accbd@gmail.com> <20200717125809.GC2827066@redhat.com> <0a5b6bcb-6475-2674-adfb-23f6793bfefc@gmail.com> <1491e266-fb74-dd9c-9955-8a7dd0334bb4@gmail.com> <73be2079-5046-c06f-f144-1af85052fc50@gmail.com> <22461d18-d2a0-d906-4b20-6b95cf036bde@gmail.com> In-Reply-To: <22461d18-d2a0-d906-4b20-6b95cf036bde@gmail.com> From: Jonathan Wakely Date: Thu, 23 Dec 2021 12:43:53 +0000 Message-ID: Subject: Re: [PATCH][Hashtable 6/6] PR 68303 small size optimization To: =?UTF-8?Q?Fran=C3=A7ois_Dumont?= Cc: =?UTF-8?Q?Daniel_Kr=C3=BCgler?= , "libstdc++@gcc.gnu.org" , gcc-patches X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com X-Spam-Status: No, score=-6.9 required=5.0 tests=BAYES_00, DKIMWL_WL_HIGH, DKIM_SIGNED, DKIM_VALID, DKIM_VALID_AU, DKIM_VALID_EF, HTML_MESSAGE, RCVD_IN_DNSWL_LOW, RCVD_IN_MSPIKE_H3, RCVD_IN_MSPIKE_WL, SPF_HELO_NONE, SPF_NONE, TXREP autolearn=unavailable autolearn_force=no version=3.4.4 X-Spam-Checker-Version: SpamAssassin 3.4.4 (2020-01-24) on server2.sourceware.org Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable X-Content-Filtered-By: Mailman/MimeDel 2.1.29 X-BeenThere: libstdc++@gcc.gnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Libstdc++ mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 23 Dec 2021 12:44:09 -0000 On Tue, 21 Dec 2021 at 17:56, Fran=C3=A7ois Dumont via Libstdc++ < libstdc++@gcc.gnu.org> wrote: > On 21/12/21 7:28 am, Daniel Kr=C3=BCgler wrote: > > Am Di., 21. Dez. 2021 um 07:08 Uhr schrieb Fran=C3=A7ois Dumont via > > Libstdc++ : > >> Hi > >> > >> Is there a chance for this patch to be integrated for next gcc > >> release ? > >> > >> Fran=C3=A7ois > >> > > No counterargument for the acceptance, but: Shouldn't > > __small_size_threshold() be a noexcept function? > > > > - Daniel > > Could it enhance code generation ? I could make it depends on > _Hashtable_hash_traits<>::__small_size_threshold() noexcept > qualification if so. But I was hoping that the compiler to detect all > that itself. > > Otherwise no, it do not have to be noexcept as it is used to avoid > hasher invocation in some situations and hasher is not noexcept > constraint. At least I do not need to static_assert this. > > But why not make it noexcept? It just returns a constant integer. It can be noexcept.