MaskRay

7 ms·

1. 31.▲
   by MaskRay 2y ago

   I almost use rr every day, along with a gdb frontend: cgdb. rr record /tmp/Debug/bin/llvm-mc a.s && rr replay -d cgdb I've have success story with some bugs only reproducible with LTO. Without rr it would be
2. 32.▲
   by MaskRay 2y ago

   tl;dr - Mapping symbols describe data in code and instruction sets transition (e.g. A32<=>T32). - Pending LLVM integrated assembler patch that will eliminate almost all mapping symbols without breaking disassemblers https:/&#x2F
3. 33.▲
   Mapping Symbols: Rethinking for Efficiency(maskray.me)

   16 points by MaskRay 2y ago|1 comments
4. 34.▲
   polyfill-glibc(github.com)

   1 points by MaskRay 2y ago|0 comments
5. 35.▲
   by MaskRay 2y ago

   Big thanks for the recent performance changes! The "many small inefficiencies" point resonates – it definitely shows how performance is hurt in many small areas. (I aim to write blog posts every 2-3 weeks, but this latest one was
6. 36.▲
   by MaskRay 2y ago

   Thanks!
7. 37.▲
   by MaskRay 2y ago

   https://mirrors.edge.kernel.org/pub/tools/llvm/ provides a PGO-optimized LLVM toolchain. It is likely much faster than Distro provided Clang. You might also want to replace the malloc with mimalloc/snmal
8. 38.▲
   by MaskRay 2y ago

   Thx. Fixed
9. 39.▲
   Integrated assembler improvements in LLVM 19(maskray.me)

   104 points by MaskRay 2y ago|27 comments
10. 40.▲
    by MaskRay 2y ago

    For people who prefer rebase and force push, https://getcord.github.io/spr/ is a great tool resembling Phabricator's `arc diff`. https://github.com/orgs/community/discussions/3478 (
11. 41.▲
    by MaskRay 2y ago

    https://www.sco.com/developers/gabi/latest/revision.html specifies > Second draft published May 3, 1999. > ... > New dynamic section tags DT_RUNPATH and DT_FLAGS added. Dynamic section tag DT_RPATH m
12. 42.▲
    by MaskRay 2y ago

    Nice! In llvm-project, obj2yaml pretty prints an object file in YAML and yaml2obj can convert the output back to an object file. The test cases are a good way to explore the functionality: https://github.com/llvm/llvm-p
13. 43.▲
    by MaskRay 2y ago

    Linkers and Loaders I have analyzed a few object file formats in another blog post https://maskray.me/blog/2024-01-14-exploring-object-file-for... (HN discussion: https://news.ycombinator.com/item?id=38
14. 44.▲
    by MaskRay 2y ago

    Yes! I immediately thought about APE when I read The 86open Project's FAQ. However, I feel that APE is less related to the blog post so decide not to add the link to the post.
15. 45.▲
    by MaskRay 2y ago

    - 2003-2010 The SCO Group - 2011- Xinous, but Xinous has stopped updating https://www.sco.com/developers/gabi/latest/contents.html . It seems that Xinous has moved on from System V based OpenServer/UnixW
16. 46.▲
    by MaskRay 2y ago

    Decker builds on the legacy of HyperCard and MacPaint, and utilizes an interesting little language ( https://beyondloom.com/decker/lil.html 2022 HN discussion: https://news.ycombinator.com/item?id=333932
17. 47.▲
    Another Year with Decker(beyondloom.com)

    1 points by MaskRay 2y ago|1 comments
18. 48.▲
    by MaskRay 2y ago

    I feel that The SCO Group's role in the evolution of the System V ABI seems to have been more of a curator/editor than an innovator, inheriting the System V ABI from previous entities. Given that the Tool Interface Standard (TIS)
19. 49.▲
    by MaskRay 2y ago

    Thank you! This will be very useful. Yes, for C/C++ one needs: * ISA manual * ELF (generic ABI, psABI (e.g. x86-64-psABI), OSABI) * DWARF * Floating-point * Language standards * Itanium C++ ABI and probably a few other stuff. > it s
20. 50.▲
    by MaskRay 2y ago

    A few folks have asked me the generic ABI status (unmaintained?) and the availability of an up-to-date specification (no). I compiled “History” and “Evolution of the generic ABI” in the blog post. I have two specific questions: - Key featur
21. 51.▲
    Evolution of the ELF object file format(maskray.me)

    148 points by MaskRay 2y ago|51 comments
22. 52.▲
    by MaskRay 2y ago

    Interesting. Traditionally, Clang's -O1 and higher optimizations have been considered less debuggable than GCC's. Sony developers have proposed changes to improve the debugging experience and some work has been done, e.g. https:&
23. 53.▲
    by MaskRay 2y ago

    Thanks for mentioning nasm. Both GNU assembler and LLVM integrate assembler parse and match instructions only once. hey then store an internal representation in memory and perform fixed-point iteration. The section/fragment representat
24. 54.▲
    by MaskRay 2y ago

    There is ongoing work to improve debuggability for optimized code. https://discourse.llvm.org/t/rfc-redefine-og-o1-and-add-a-ne... ``` Mode | Execution Time | Debuggability | Compile Time O0 | 1.0000 |
25. 55.▲
    by MaskRay 2y ago

    Thanks for posting:)
26. 56.▲
    Reflections on LLVM's switch to GitHub pull requests(maskray.me)

    6 points by MaskRay 3y ago|0 comments
27. 57.▲
    by MaskRay 3y ago

    I added this sentence to the article, hopefully making it clearer: > If h is in the range [0x0fffff01,0x0fffffff] in the previous iteration, shifting it by 4 and adding *name may make h larger than UINT32_MAX.
28. 58.▲
    Relocatable linking(maskray.me)

    52 points by MaskRay 4y ago|3 comments
29. 59.▲
    _FORTIFY_SOURCE(maskray.me)

    3 points by MaskRay 4y ago|0 comments
30. 60.▲
    by MaskRay 4y ago

    The subject should be "glibc and DT_GNU_HASH" :) Hope this gives some background information for "Easy Anti-Cheat" users.