From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-yw1-x1129.google.com (mail-yw1-x1129.google.com [IPv6:2607:f8b0:4864:20::1129]) by sourceware.org (Postfix) with ESMTPS id DA8AF385736B for ; Tue, 17 May 2022 08:54:14 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.4.1 sourceware.org DA8AF385736B Received: by mail-yw1-x1129.google.com with SMTP id 00721157ae682-2ebf4b91212so179714387b3.8 for ; Tue, 17 May 2022 01:54:14 -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:content-transfer-encoding; bh=RVZjZslEjR7hf1hr5cAAIa4xdQ+xcY1Ky+OWIFAdjqg=; b=oDieVPXsQkCjDtw10d0o2+N0Arc2gbtIzz1k1ER+KR0OP48GQoDWMWNgSiyso532JM IQwDWXv0cRLMeGe+NTPTRjeI6Yn/VG2EId3UuxIKl9Sb7UvsdgdW4zKBIYKJeqbVmWRO tt5OjHaeoEYgFBGq7zf0UG8B7byItJlN0GNNY8qkwJ0ICXtG8SgaveSxdOV96+6GVmZC qkBHO6r+F+HOup2I+JAxTaC45Y2ZWDtCuJAYlAHbH+OVsxrUDR1xhhP2YZYgnF00x6cj vRY5jSiDVcCt/HZkZT0dh9NQXwDkxeBf1FkngEAH6+XQHLci5CfoiUStggxirOvAu+CA EpJw== X-Gm-Message-State: AOAM531UIh0oB46b2c4fsIANgc5P1z3ZpiVj8yLVp8HKMeYY1fjegmNy kh1kTzHKBgwATTyW5i2XHZ0Onpde84TwjcrHinwx4YEg X-Google-Smtp-Source: ABdhPJyNGyVY0du9chiCvuWDPLKcMLaDgLJ7k9+Xx4iic5AD5l/KxQwzIUMI0qD/ishKPT5Oyl5JBRSr8se04pZCgtc= X-Received: by 2002:a0d:c8c3:0:b0:2fe:e9eb:664 with SMTP id k186-20020a0dc8c3000000b002fee9eb0664mr12065719ywd.301.1652777654275; Tue, 17 May 2022 01:54:14 -0700 (PDT) MIME-Version: 1.0 References: <062812e4-e912-4eaf-876c-91006a6c47a6@gmx.net> In-Reply-To: <062812e4-e912-4eaf-876c-91006a6c47a6@gmx.net> From: Stefan Ring Date: Tue, 17 May 2022 10:54:03 +0200 Message-ID: Subject: Re: gcc optimization options and lto (detailed info) To: gcc-help Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable X-Spam-Status: No, score=-0.1 required=5.0 tests=BAYES_00, DKIM_SIGNED, DKIM_VALID, DKIM_VALID_AU, DKIM_VALID_EF, FREEMAIL_FROM, RCVD_IN_DNSWL_NONE, 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-help@gcc.gnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Gcc-help mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 17 May 2022 08:54:16 -0000 On Tue, May 17, 2022 at 8:56 AM muzungu--- via Gcc-help wrote: > > * does every -f have a -fno-? I think that=E2=80=99s the idea. > * would I be able able to disable single optimizations activated via -O using -fno- after -O? Yes. > * When LTO is enabled, are the optimizations only effective at link time = and not during the compilation into IR (GIMPLE)? I would expect them to be recorded in the intermediate object file and becoming effective during code generation, but I am not sure about that. > * Since there is a rather long list of optimization options which would v= ery likely exceed the command line length, what is the solution to activate= a custom set of optimzations? I could not find a --configfile option or si= milar to replace the command line. What do you think is your maximum command line length? This should not be a problem on any sane OS.