From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-ej1-x629.google.com (mail-ej1-x629.google.com [IPv6:2a00:1450:4864:20::629]) by sourceware.org (Postfix) with ESMTPS id 9620A3858D28 for ; Tue, 12 Apr 2022 09:59:02 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.4.1 sourceware.org 9620A3858D28 Received: by mail-ej1-x629.google.com with SMTP id p15so36237623ejc.7 for ; Tue, 12 Apr 2022 02:59:02 -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=+/q8hecUrfp9NlEDd9kGkOjSIdBF5Hd01TpCCXwnOLk=; b=6ILKOeCHamYg6rIZL9kp3lvztXOgQ6OU/x0SmOnLhQoleJIUBs/szGun3TaLdoIyiD 4cKZRpJs6ebp5TWahb5QNfEpXXsGKQIATZn8zYXrioaDUbEU8JRl1zipoHX9ksZp0HGA MwJHwvKknJ1ppYUjdGjB8CuVTiA/59o2DDpr7kqTjbiNFLuAhn5tKcja1acslzELHNQo iXqsH1kYcf0s47tiZliy7FcPanJQfJdD0stXKHk+VKeC0V1cMvToBaJx9sl95Lb/R8aU UHUYsm8u1dUCLeVraNaujCG1xuuPLPFvrrW1TPb00Cir8boi7e/hxds3KnfxG1c+0nFY ZD3g== X-Gm-Message-State: AOAM5335HqDJ5XnarzX0bY/IH2pJUqmG7qHGD/CJs9insBDIkfoIY7qq 58Q8k1Q/V5tQ7pH1zYyfXK0psRgeF48PuYwT/DU= X-Google-Smtp-Source: ABdhPJyFsUdT0r3+OA7SlYfgnUoc7w3QT782iAlQ3N/RICp8MAohI7x4VboW25kYiqRadUHfBQ+wTuqvXnZHLxz0Q3g= X-Received: by 2002:a17:907:3e17:b0:6e8:bda7:e397 with SMTP id hp23-20020a1709073e1700b006e8bda7e397mr132112ejc.657.1649757541214; Tue, 12 Apr 2022 02:59:01 -0700 (PDT) MIME-Version: 1.0 References: <7B167841-0CDA-4084-A160-62C625B85486@gmail.com> In-Reply-To: From: Richard Biener Date: Tue, 12 Apr 2022 11:58:50 +0200 Message-ID: Subject: Re: [GSoC]Bypass assembler when generating LTO object files To: Jan Hubicka Cc: Ankur Saini , GCC Development , =?UTF-8?Q?Martin_Li=C5=A1ka?= Content-Type: text/plain; charset="UTF-8" X-Spam-Status: No, score=-2.2 required=5.0 tests=BAYES_00, DKIM_SIGNED, DKIM_VALID, DKIM_VALID_AU, DKIM_VALID_EF, FREEMAIL_FROM, KAM_SHORT, RCVD_IN_DNSWL_NONE, SPF_HELO_NONE, SPF_PASS, TXREP, T_SCC_BODY_TEXT_LINE, WEIRD_PORT autolearn=ham autolearn_force=no version=3.4.4 X-Spam-Checker-Version: SpamAssassin 3.4.4 (2020-01-24) on server2.sourceware.org X-BeenThere: gcc@gcc.gnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Gcc mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 12 Apr 2022 09:59:04 -0000 On Tue, Apr 12, 2022 at 11:20 AM Jan Hubicka via Gcc wrote: > > Hi, > > > > > > > On 08-Apr-2022, at 6:32 PM, Jan Hubicka wrote: > > > > > > Ankur, > > >> I was browsing the list of submitted GSoC projects this year and the > > >> project regarding bypassing assembler when generating LTO object files > > >> caught my eye. > > > I apologize for late reply. I would be very happy to mentor this > > > project. > > > > Thanks for the reply, but unfortunately, due to some reasons, I would not > > be able to take part in GSoC this year. > > But the project seems interesting and would be amazing opportunity to > > learn a lot more things for me, so would it be okay if I try to give it a > > go outside GSoC if no-one else picks it as their GSoC project this year ? > > I would be still very happy to help with that! However it would be also > pity to not take part of GSoC, so if there is something I can help with > on that let me know. > > > > >> > > >> I already have a gcc built from source (sync-ed with trunk/master) and > > >> launched the test-suite on it. > > >> > > >> I am currently in process of understanding the primilary patch > > >> (https://gcc.gnu.org/legacy-ml/gcc/2014-09/msg00340.html), and > > >> experimenting with it. > > >> > > >> are there any other things I should be aware of (useful Doc/blog or a > > >> bug tracking the project) before proceeding further ? > > > > > > I think it is pretty much all that exists. Basically we will need to > > > implement everything that is necessary to stream out valid object file > > > directly from GCC rather than going through gas. The experimental > > > prototype sort of worked but it was lacking few things. > > > > When I try to apply that patch on my local branch ( branched from trunk ), > > it seem to be incompatible with the current working tree. Is there a > > specific branch that I have to apply it to ? or is it due to the recent > > file rename patch ( changing extensions from .c to .cc ) ? > > > > ``` > > $ git apply --check bypass_asm_patch > > > > error: patch failed: Makefile.in:1300 > > error: Makefile.in: patch does not apply > > error: common.opt: No such file or directory > > error: langhooks.c: No such file or directory > > error: lto/Make-lang.in: No such file or directory > > error: lto/lto-object.c: No such file or directory > > error: lto/lto.c: No such file or directory > > error: lto/lto.h: No such file or directory > > error: lto-streamer.h: No such file or directory > > error: toplev.c: No such file or directory > > ``` > > I can try to update the patch, or it probably should apply to trunk > checked out around the date I sent the patch. Indeed we need to change > c to cc but there are likely more changes since then - most importnatly > the early debug info. > At I will see how easy/hard is to make the patch build with current > trunk. We do have ideas for the early debug with the asm-out abstraction to also solve a different issue (missing simple-object support for mingw/darwin). Namely assemble the early debug in a different file and include the resulting native object in binary form in the compile output - not needing to write assembly .data for that would be a good way to make this more viable. You might want to talk to Martin Liska for this who I think had some prototype on this? Richard. > Honza > > > > Thanks > > - Ankur > >