From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 109027 invoked by alias); 28 Jan 2019 17:34:01 -0000 Mailing-List: contact gcc-help@gcc.gnu.org; run by ezmlm Precedence: bulk List-Id: List-Archive: List-Post: List-Help: Sender: gcc-owner@gcc.gnu.org Received: (qmail 108547 invoked by uid 89); 28 Jan 2019 17:34:01 -0000 Authentication-Results: sourceware.org; auth=none X-Spam-SWARE-Status: No, score=-1.9 required=5.0 tests=BAYES_00,KAM_SHORT,SPF_PASS autolearn=ham version=3.3.2 spammy=attracts, apologize, distributions, saved X-HELO: mx1.suse.de Received: from mx2.suse.de (HELO mx1.suse.de) (195.135.220.15) by sourceware.org (qpsmtpd/0.93/v0.84-503-g423c35a) with ESMTP; Mon, 28 Jan 2019 17:33:59 +0000 Received: from relay2.suse.de (unknown [195.135.220.254]) by mx1.suse.de (Postfix) with ESMTP id DD18FACA8; Mon, 28 Jan 2019 17:33:56 +0000 (UTC) From: Martin Jambor To: Siddhartha Sen Cc: GCC Mailing List Subject: Re: [GSOC] variations in testsuite results In-Reply-To: References: User-Agent: Notmuch/0.26 (https://notmuchmail.org) Emacs/26.1 (x86_64-suse-linux-gnu) Date: Mon, 28 Jan 2019 17:34:00 -0000 Message-ID: MIME-Version: 1.0 Content-Type: text/plain X-IsSubscribed: yes X-SW-Source: 2019-01/txt/msg00239.txt.bz2 Hello Siddhartha, first and foremost, I'd like to apologize for replying so late. I have accidently marked your messages as only needing attention when the new GSoC year is about to start. On Sat, Dec 01 2018, Siddhartha Sen wrote: > Hi Martin, > > Firstly,I use an x86_64(Ubuntu 18.04) since you asked,although I am not > sure whether that was a big factor or not. Anyways, I checked out the > source code. I checked on the internet to find that a few missing libraries > were required to compile gcc. Initially I was going to install them by hand > but then I realised it woud be a long process, considering I had to get > each one of those as well as check each of their versions,etc. On Ubuntu and other Debian-based distributions it should be enough to just install libgmp-dev, libmpfr-dev and libmpc-dev through apt or aptitude. > So I used > the script that has been bundled with the source about which,to be > honest, That works too. > I was unaware of until very recently. Then, I initially unset everything > and then enabled 'langages' and 'gold' and disabled 'libquadmath'(the quad > math library),werror' and 'bootstrap'. Being able to bootstrap the compiler is essential so that you can test your changes (they have to pass bootstrap). For development, you definitely want to have bootstrap disabled. > (A quick question:Did I also need to > disable the support for quadmath as well?). I personally don't care about it and it gets automatically enabled. > I thought of using the default > ld linker instead of the gold linker, but then I read somewhere gold linker > worked faster for c++ projects. Unless you have specific need for one or the other, I don't think it matters which one you choose (it might make a difference in LTO projects but because of bugs of one or the other rather than anything else). > Finally I compiled it(which took a bit longer than it should have) That is most certainly because of enable bootstrap. > and installed it for usage.I was actually > experimenting a bit and went a bit further and added it as an environment > variable through the export command. And that was all. Good, it looks like you are all set up. I'm not sure I understand the bit about the environment variable though. > Please let me know what you thought and tell me what to do next. I'm not sure I understand this question well either. But I'd suggest looking at https://gcc.gnu.org/wiki/GettingStarted and especially at https://gcc.gnu.org/wiki/DebuggingGCC and https://gcc.gnu.org/onlinedocs/gcc/Developer-Options.html. Compile a simple but non-trivial program with -O3 -S -fdump-tree-all -fdump-ipa-all -fdump-rtl-all and look through the generated files. Look at the the source code, especially in the `gcc` subdirectory and try to set a breakpoint somewhere and hit it. Then look around in gdb. And then it is really up to you what you want to focus on, it depends on what attracts you most, what you are most interested in. As far as GSoC is concerned, we are in the process of finalizing an "official" list of project ideas for this year at https://gcc.gnu.org/wiki/GettingStarted but it will not be finished for at least a few more days, possibly even a week. If you have any further specific questions, please feel free to ask, I'll make my best to be more diligent with replying. Martin > Thank You. > > On Wed, Nov 28, 2018 at 10:46 PM Martin Jambor wrote: > >> Hi Siddhartha, >> >> On Tue, Nov 27 2018, Siddhartha Sen wrote: >> > I am Siddhartha Sen,currently pursuing my B.Tech degree in Information >> > Science and Engineering,2nd year. I have taken a keen interest in your >> > projects and have some ideas of my own as well. I am really interested in >> > working with you in G-SOC 2019. >> >> We are delighted. >> >> > I am proficient in C and C++ and am eager >> > to work on brushing my skills in whichever field required. I have already >> > checked out the GCC trunk source-code and am being able to build GCC from >> > it.I have run the testsuite and saved the results. >> >> Great, those are all the essential first steps, it seems like you are >> ready to work on your first patch. >> >> > However, upon building >> > it and saving it again, the results don't match. I apologise for my lack >> of >> > knowledge but any help on your part would be great. >> >> How did you compare the test results and which tests behaved >> differently? How did you configure GCC? Was it on an x86_64? >> >> Unfortunately, this sometimes happens. As far as I can tell, the libgo >> testsuite is very flaky and I basically ignore its results. In the >> past, I believe that also some guality tests sometimes passed and >> sometimes did not, but I have not heard such reports recently. These >> tests however also depend on the GDB (version) you have installed on >> your system. >> >> Martin >>