From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-ua1-x935.google.com (mail-ua1-x935.google.com [IPv6:2607:f8b0:4864:20::935]) by sourceware.org (Postfix) with ESMTPS id 1EA603858D39 for ; Mon, 3 Apr 2023 19:55:16 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.4.2 sourceware.org 1EA603858D39 Authentication-Results: sourceware.org; dmarc=pass (p=none dis=none) header.from=gmail.com Authentication-Results: sourceware.org; spf=pass smtp.mailfrom=gmail.com Received: by mail-ua1-x935.google.com with SMTP id ay14so21714433uab.13 for ; Mon, 03 Apr 2023 12:55:16 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; t=1680551715; h=to:subject:message-id:date:from:in-reply-to:references:mime-version :from:to:cc:subject:date:message-id:reply-to; bh=vKeuhtzroVTYmp0thHOZz5O+ljekfDCuSH2FYadQS5E=; b=QpEViN8EMqUmNLWLCncRCtFDRBB4/ri6nWf/Fw8gttnhchWodNrd5fE6cnwYH7KuIb 15XnXCqOtVgQ4AanzcgbDT1FFphuFusuGNyI2swD9ktzQXunWcEP5Tv+0+FlISDFAAaV NqR02kP6OwsE8H3pYNl9cLbuNLsKIrGPIg4i5XI+heT9WEIovT2Geeo2uKOcOSJCveNz JXZsU5Ah91C729jqgH86LOwJdIWgOAg+9LJmU5QklwNhCUtpPur4ufIhPFApw5bfdEYc iBIu1AKrk6iNzumuq1XGEQjTvPjCzQQcP6/I+69kskV1y26WxmU6EBxDxKDaHgtHUBhH sezQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; t=1680551715; h=to:subject:message-id:date:from:in-reply-to:references:mime-version :x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=vKeuhtzroVTYmp0thHOZz5O+ljekfDCuSH2FYadQS5E=; b=yF+hJ7E2if9lV9Z3qN2eiIOkZm83F/Ib9EAoaTdKUec5FFxC8vVZPRmvcX2Ijj9r6R ABUcTv9aaVNXELlZm6QkMPEXigtRSsvIg//uIh95qAbwmA7DNQnAgj04cuXSLVL0IKjF +k9mI1WY5oAIg92oszz9bvSn8fP1NdiHDl8IEUo7VGTqM86uYmIQ7DjAkPlNRgszsXD5 rNilaikECOwBM4u3z4J3UyiHgv2mduoHjWmwxe69es7oQl1osGJele+XVIgVNi/ZPF7a EdPQmgCq0ITfA8He5b9CKptETb3FiExaAd5nSyFjA6+rL9aqXBWKhr4+/zqhZp2vUbzZ ZXPg== X-Gm-Message-State: AAQBX9epwiaE8fA8sYVtWdoVUqTEPV5GoCbungI6pLcgZmaDsRvp8FMN MYWItFDFz9s6hd9WBcQJCP0Gi+M65B1z2XYfjAWnBKXf8zyY2Q== X-Google-Smtp-Source: AKy350aVC27NQHX5bczQjBHQdhISbUokXk/dKJ+0BVzn+Ap4kJ2mNUj3wBKhWzfl6SrRfZa80qjEf6pq2mp/AtYLv7w= X-Received: by 2002:a1f:aac3:0:b0:43c:6ef1:7200 with SMTP id t186-20020a1faac3000000b0043c6ef17200mr436083vke.3.1680551715097; Mon, 03 Apr 2023 12:55:15 -0700 (PDT) MIME-Version: 1.0 References: In-Reply-To: From: Rishi Raj Date: Tue, 4 Apr 2023 01:25:03 +0530 Message-ID: Subject: Re: [GSOC] few question about Bypass assembler when generating LTO object files To: gcc@gcc.gnu.org, mjambor@suse.cz, hubicka@ucw.cz Content-Type: multipart/alternative; boundary="0000000000000151f605f873f019" X-Spam-Status: No, score=-0.2 required=5.0 tests=BAYES_00,DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF,FREEMAIL_ENVFROM_END_DIGIT,FREEMAIL_FROM,HTML_MESSAGE,RCVD_IN_DNSWL_NONE,SPF_HELO_NONE,SPF_PASS,TXREP autolearn=ham autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on server2.sourceware.org List-Id: --0000000000000151f605f873f019 Content-Type: text/plain; charset="UTF-8" While going through the patch and simple-object.c I understood that the file simple-object.c is used to handle the object file format. However, this file does not contain all the architecture information required for LTO object files, so the workaround used in the patch is to read the crtbegin.o file and merge the missing attributes. While this workaround is functional, it is not optimal, and the ideal solution would be to extend simple-object.c to include the missing information. Regarding the phrase "Support in the driver to properly execute *1 binary", it is not entirely clear what it refers to. My interpretation is that the compiler driver (the program that coordinates the compilation process) needs to be modified to correctly output LTO object files instead of assembler files (the current approach involves passing the -S and -o .o options) and also skip the assembler option while using -fbypass-asm option but I am not sure. Can Jan or Martin please shed some light on this? Thanks & Regards Rishi Raj On Sun, 2 Apr 2023 at 03:05, Rishi Raj wrote: > Hii Everyone, > I had already expressed my interest in the " Bypass assembler when > generating LTO object files" project and making a proposal for the same. I > know I should have done it earlier but I was admitted to the hospital for > past few days :(. > I have a few doubts. > 1) > > "One problem is that the object files produced by libiberty/simple-object.c > (which is the low-level API used by the LTO code) > are missing some information (such as the architecture info and symbol > table) and API of the simple object will need to be extended to handle > that" I found this in the previous mailing list discussion. So who output this information currently in the object file, is it assembler? > > Also in the current patch for this project by Jan Hubica, from where are we getting these information from? Is it from crtbegin.o? > > 2) > "Support in driver to properly execute *1 binary." I found this on Jan original patch's email. what does it mean > > exactly? > > Regards > > Rishi Raj > > > > --0000000000000151f605f873f019--