From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-yb1-xb30.google.com (mail-yb1-xb30.google.com [IPv6:2607:f8b0:4864:20::b30]) by sourceware.org (Postfix) with ESMTPS id E5B7D385803E for ; Thu, 14 Apr 2022 22:44:50 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.4.1 sourceware.org E5B7D385803E Received: by mail-yb1-xb30.google.com with SMTP id f38so11964659ybi.3 for ; Thu, 14 Apr 2022 15:44:50 -0700 (PDT) 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=ia8Hepnv9ul+u94y8U/YjrpyzHvISigU8/1X5Iy/RxA=; b=Wk63P2hbFKILWACZ+Bew+GQyfJNSTKkZsp36ym0VAd9yNxEclLF5RJsRzZLvIkwkS9 Wmrx9IUNnLcuw4A/+rRkbe0IaHoTVwFyi2xEj2jCcdR4WBmpjy7jq5L0c9FnXXipnjja dntgblZblh8v794Vu72IzJB1+HsPsKyDJdwfb32kqdbRo+aLd5tcFbCcE8KW160CZa0C qek3Z+r7bQrqTC2DtpzsVTqfJiwLXb5hk6zEGusyb8yFM7/PAmvrnLxLs69LeiDDrb/9 wkPwhMHHSHN9jj64v/7dEgIlyi7y/iL17byFxWK+068ZK7dIUiTqCfVOVTWpkOF8xBz1 S5mA== X-Gm-Message-State: AOAM530oaLKvaV9N737oS9pBCY7AyErTzzHP+dHZrnrdWikR+c6U5y43 zRY+iicinSmPsFPYV/zDf2QKlT24orypL2IUKIgpJiP3 X-Google-Smtp-Source: ABdhPJw6vUXSaXVzuBgENG47pmSvLHLKb2NtLtYXOmMt+V+tE51qHWrzG11rp+SR5GUWGoTlPqjU2Ng5UQOCpsQ5UJU= X-Received: by 2002:a25:7544:0:b0:629:33a2:b142 with SMTP id q65-20020a257544000000b0062933a2b142mr3477908ybc.136.1649976290373; Thu, 14 Apr 2022 15:44:50 -0700 (PDT) MIME-Version: 1.0 References: <20220411010913.1061799-1-goldstein.w.n@gmail.com> <20220411010913.1061799-2-goldstein.w.n@gmail.com> In-Reply-To: From: Noah Goldstein Date: Thu, 14 Apr 2022 17:44:39 -0500 Message-ID: Subject: Re: [PATCH v1 2/2] x86_64: Add {u}int_fast defs ideal for x86_64 To: Joseph Myers Cc: GNU C Library Content-Type: text/plain; charset="UTF-8" X-Spam-Status: No, score=-2.1 required=5.0 tests=BAYES_00, DKIM_SIGNED, DKIM_VALID, DKIM_VALID_AU, DKIM_VALID_EF, FREEMAIL_FROM, KAM_NUMSUBJECT, RCVD_IN_DNSWL_NONE, SPF_HELO_NONE, SPF_PASS, TXREP, T_SCC_BODY_TEXT_LINE autolearn=no autolearn_force=no version=3.4.4 X-Spam-Checker-Version: SpamAssassin 3.4.4 (2020-01-24) on server2.sourceware.org X-BeenThere: libc-alpha@sourceware.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Libc-alpha mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 14 Apr 2022 22:44:52 -0000 On Thu, Apr 14, 2022 at 5:24 PM Joseph Myers wrote: > > On Sun, 10 Apr 2022, Noah Goldstein via Libc-alpha wrote: > > > {u}int_fast{16|32} should never use 64-bit types. 64-bit instructions > > often use more code size (REX prefix) and a variety of instructions are > > slower on many implementations (div, bswap, etc...). > > Apart from the other issues discussed with this patch, installed headers > should not be specific to either x86_64 or 32-bit x86; such headers, where > architecture-specific, should go in an x86/ sysdeps directory and contain > appropriate conditionals within the header, so a single set of installed > headers works with a multilibbed compiler. > > > +# include > > And an installed header can't do that sort of thing, because only a single > version of any such header gets installed. If you want to include a > generic file it has to have a different name, with both being installed > (cf. bits/mman-*.h, for example). Good info to have but the patches have been drop for the ABI concerns. > > -- > Joseph S. Myers > joseph@codesourcery.com