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GSoC 2025 Introduction & Interest in GCC Rust Front-End
Dear GCC Developers, I am Ansh Jaiswar , a second-year Computer Science student interested in compilers and systems programming. I have experience with C/C++ and basic knowledge of Rust. I am applying for GSoC 2025 and am particularly interested in the "Rewrite Rust Lints" project under GCC. I have gone through the gccrs GitHub repository and understand that this project involves implementing lints at the HIR level instead of relying on GCC’s existing infrastructure. I believe this will improve the flexibility and maintainability of Rust linting in GCC. To prepare, I am currently exploring the Rust-GCC frontend and its HIR structure. I would appreciate any pointers on how to get started, particularly regarding the existing linting mechanism and the visitor pattern approach. Additionally, I would like to know if there are any beginner-friendly tasks I could work on before GSoC officially starts. Looking forward to your guidance! Best regards, Ansh Jaiswar https://github.com/ANSHJAISWAR https://www.linkedin.com/in/ansh-jaiswar-638334300/
Re: GCC used to store pointers in FP registers on aarch64
Hey folks, My colleague Nicolas Savoire created a compiler reproducer[0] for the effect -- you can see a side-by-side comparison of code compiled with GCC 8.x and 9.x where 8.x emits fmov instructions and 9.x does not. He further used this example as a git bisect criteria and eventually found the relevant-looking commit[1] that changed the register allocator to no longer recruit FP registers for pointer storage. Mostly posting this as additional information for anyone that might stumble across this in the future, no questions at the moment :-) Attila. -- [0]: https://godbolt.org/z/fbqdjarYx [1]: https://github.com/gcc-mirror/gcc/commit/2eb2847ec54a3262f303f47697c5e5cbe3cc089d On Mon, Feb 24, 2025 at 9:48 AM Attila Szegedi wrote: > On Mon, Feb 24, 2025 at 1:21 PM Florian Weimer wrote: > >> * Attila Szegedi: >> >> >> That seems … quite unlikely. GCC 8 has seen extensive use on >> >> AArch64, on a variety of implementations, and I don't recall >> >> problems in this area. I don't follow AArch64 *that* closely, >> >> admittedly, but I expect it would have caused quite a ruckus. >> >> >> > >> > Yeah. The lack of discussion also led me to believe that even if this >> is an >> > issue, it's definitely not a widely encountered one. (It's also possible >> > that it's a red herring, although, well, as I said, forcing general regs >> > only did fix it.) >> >> Is it non-deterministic? It might be a context switching issue in the >> kernel/hypervisor/firmware. I usually don't notice fixes for those >> because they do not lead to questions whether it's necessary to >> rebuild the whole distribution. These bugs do happen from time to time: >> >> [PATCH v3 0/8] KVM: arm64: FPSIMD/SVE/SME fixes >> < >> https://lore.kernel.org/linux-arm-kernel/20250210195226.1215254-1-mark.rutl...@arm.com/ >> > >> > > Huh. That is interesting. Yes, it is non-deterministic. And it does occur > solely in containerized environments, so it's eminently possible it's a > hypervisor issue. > > (Still, a bit amusing that nothing came up with regard to how I don't see > GCC 12 schedule pointers onto aarch64 FP registers anymore :-). I > understood from Kyrylo's post that it's probably because no such explicit > decision was made.) > > Attila. >
gcc-13-20250328 is now available
Snapshot gcc-13-20250328 is now available on https://gcc.gnu.org/pub/gcc/snapshots/13-20250328/ and on various mirrors, see https://gcc.gnu.org/mirrors.html for details. This snapshot has been generated from the GCC 13 git branch with the following options: git://gcc.gnu.org/git/gcc.git branch releases/gcc-13 revision 4ef7948056030b9a44d185c9fac2467b8cce3daa You'll find: gcc-13-20250328.tar.xz Complete GCC SHA256=78de0f0e1a716bd682bec5ca2220f20c05729af109f9ab4288f066c82e155af8 SHA1=b238b83550dbab76f63203d90caa63f5f4753b85 Diffs from 13-20250321 are available in the diffs/ subdirectory. When a particular snapshot is ready for public consumption the LATEST-13 link is updated and a message is sent to the gcc list. Please do not use a snapshot before it has been announced that way.
Re: Sourceware Survey 2025
On Fri, 2025-03-14 at 01:29 +0100, Mark Wielaard wrote: > The Sourceware Project Leadership Committee would like to know who our > users are, which hosted projects they feel part of, what services they > rely on and what the priorities should be for new initiatives. > > https://nextcloud.sfconservancy.org/apps/forms/s/xmGgmJFzSb2FZNd58cXMtAZp Just 4 more days till the Sourceware Survey 2025 ends (Monday 31 March). We already received 85 replies. Thanks! Please do fill out the survey if you haven't yet and have some time this weekend: https://sourceware.org/survey-2025 > The survey will run till the end of March and contains 20 quick > questions (none of the questions are mandatory, please feel free to > skip any you find not relevant, but any answer you give is helpful.) > > The overview page (where we will also publish the summary/results) is > here https://sourceware.org/survey-2025 the direct link to the form is > https://nextcloud.sfconservancy.org/apps/forms/s/xmGgmJFzSb2FZNd58cXMtAZp > > Also if you like to discuss this survey or give feedback another way > there is the Sourceware Open Office this Friday 14 March at 16:00 UTC > in #overseers on irc.libera.chat. To get the right time in your local > timezone: $ date -d "Fri Mar 14 16:00 UTC 2025" > > Thanks, > > Frank Ch. Eigler, Christopher Faylor, Ian Kelling, Ian Lance Taylor, > Tom Tromey, Jon Turney, Mark J. Wielaard, Elena Zannoni
