llvm/llvm-project on Hacker News

To answer my own question, it appears the Oryon CPUs do not according to this LLVM patch: https://github.com/llvm/llvm-project/blob/8aebe46d7fdd15f02a... There's a pretty good interpretation of it here:…

comment by 201984 · 2024-05-23 · in Introducing Copilot+ PCs

…it to enable partial and runtime unrolling for in-order models. I've left a review comment https://github.com/llvm/llvm-project/pull/91022/files#r16026... and as I note there, the setting seems to have become very divorced from…

comment by asb · 2024-05-16 · in Qualcomm's Oryon LLVM Patches

…to in that GH issue is showing that LLVM will attempt constant folding of various trig functions: https://github.com/llvm/llvm-project/blob/faa43a80f70c639f40... but the IEEE-754 spec does also recommend correctly rounded results for those…

comment by boulos · 2024-05-11 · in Why the CORDIC algorithm lives rent-free in my head

…people have written tooling for those checks for various CPUs? Also, is it that ‘simple’? Reading https://github.com/llvm/llvm-project/issues/62479 , calculations that the compiler does and that only end up in the executable as constants…

comment by Someone · 2024-05-11 · in Why the CORDIC algorithm lives rent-free in my head

…[1] to libc++ [2]. [1]: https://github.com/gcc-mirror/gcc/blob/065dddc/libstdc++-v3/... [2]: https://github.com/llvm/llvm-project/blob/1a96179/libcxx/inc... Basically libstdc++ is paying an extra 8 bytes of storage, and losing trivial…

comment by quuxplusone · 2024-05-08 · in Qt and C++ Trivial Relocation (Part 1)

…is still in preview[2], and GCC 14 isn't even out yet. This can't be nearer the bleeding edge. [1]: https://github.com/llvm/llvm-project/releases/tag/llvmorg-18... [2]: https://learn.microsoft.com/en-us/visualstudio/releases/2022...

comment by delta_p_delta_x · 2024-04-29 · in Speeding up C++ build times

See https://github.com/llvm/llvm-project/issues/88344 https://fortran-lang.discourse.group/t/flang-new-how-to-forc...

comment by zaikunzhang · 2024-04-14 · in Flang-new: How to force arrays to be allocated on the heap?

…guarantees (like memory fences) from loops, not just the data as it appears to a single thread. [1] https://github.com/llvm/llvm-project/issues/64188

comment by dataflow · 2024-04-07 · in A memory model for Rust code in the kernel

Pull requests are always welcome ( https://github.com/llvm/llvm-project ), and one can contact the general LLVM Fortran development community ( https://discourse.llvm.org/c/subprojects/flang/33 ) for help. I am focused on things needed to…

comment by pklausler · 2024-04-05 · in Fortran on WebAssembly

…ifunc has real uses and it indeed does not work when sanitizer is enabled. Similar change in llvm: https://github.com/llvm/llvm-project/commit/1ef3de6b09f6b21a...

comment by nialv7 · 2024-03-29 · in Backdoor in upstream xz/liblzma leading to SSH server compromise

There is a related issue for LLVM/clang by this person: https://github.com/llvm/llvm-project/issues/63957

comment by mxmlnkn · 2024-03-29 · in Backdoor in upstream xz/liblzma leading to SSH server compromise

…being able to cache and reuse compiled queries. Actually, it's implemented in LLVM for years :) https://github.com/llvm/llvm-project/commit/a98546ebcd2a692e...

comment by weliveindetail · 2024-03-18 · in I wrote a new JIT compiler for PostgreSQL

…fixed in both major C++ libraries: https://github.com/gcc-mirror/gcc/commit/ebf6175464768983a2d... https://github.com/llvm/llvm-project/commit/4f67a909902d8ab9... So what C++ community refused to regard this as an issue and refused to fix…

comment by kllrnohj · 2024-03-12 · in C++ Safety, in Context

…a bit on this aspect. [^1]: https://github.com/gcc-mirror/gcc/commit/ebf6175464768983a2d... [^2]: https://github.com/llvm/llvm-project/commit/4f67a909902d8ab9...

comment by adev_ · 2024-03-12 · in C++ Safety, in Context

Ok, I've restored the URL you submitted ( https://github.com/llvm/llvm-project/blob/8ec28af8eaff5acd0d... ).

comment by dang · 2024-03-02 · in Clang accepts MSVC arguments and targets Windows if its binary is named clang-cl

…from several other places as well. `IsClangCL()` that returns true if the driver mode is "cl": https://github.com/llvm/llvm-project/blob/8ec28af8eaff5acd0d... `setDriverMode()` which sets the above: https://github.com/llvm/llvm-project/blob…

comment by delta_p_delta_x · 2024-03-02 · in Clang accepts MSVC arguments and targets Windows if its binary is named clang-cl

For everyone else looking for the magic in this almost 7k lines monster, look at line 6610 [1]. [1] https://github.com/llvm/llvm-project/blob/8ec28af8eaff5acd0d...

comment by mschuster91 · 2024-03-02 · in Clang accepts MSVC arguments and targets Windows if its binary is named clang-cl

…I don't know, and apparently it's so complex that it requires over 9000 lines of C++ to express: https://github.com/llvm/llvm-project/blob/main/llvm/lib/Anal...

comment by tinco · 2024-02-28 · in Rewrite the VP9 codec library in Rust

https://github.com/llvm/llvm-project/blob/main/flang/docs/F2...

comment by pklausler · 2024-02-22 · in Fortran 2023

…from memory, even when the original location is still available, as can be seen in this issue: https://github.com/llvm/llvm-project/issues/53348 I vaguely remember that it could allow high-end CPUs to use something similar to register…

comment by newpavlov · 2024-02-06 · in Avoiding register spills in vectorized code with many constants

…support for debuginfod server topologies now, it would be great to see Rust tools get on the train. https://github.com/llvm/llvm-project/commit/36f01909a0e29c10... And naturally we already have a port: https://crates.io/crates/debuginfod-rs

comment by raggi · 2024-01-26 · in Making Rust binaries smaller by default

…false but still worthwhile. [1] https://gcc.gnu.org/bugzilla/show_bug.cgi?id=55522 (GCC), https://github.com/llvm/llvm-project/issues/57589 (LLVM)

comment by lifthrasiir · 2024-01-24 · in From slow to SIMD: A Go optimization story

Looks like llvm recently got some RISC-V fusion support via -mtune: https://github.com/llvm/llvm-project/commits/main/llvm/lib/T...

comment by camel-cdr · 2024-01-20 · in MRISC32 – An Open 32-Bit RISC/Vector ISA (Suitable for FPGA CPU)

https://github.com/llvm/llvm-project/issues/57589 Turn on fast-math, it flips the FTZ/DAZ bit for the entire application. Even if you turned it on for just a shared library!

comment by jcranmer · 2024-01-16 · in Std: Clamp generates less efficient assembly than std:min(max,std:max(min,v))

…and it gets loaded, it sets the register, causing the whole process to flush it's subnormals. i.e https://github.com/llvm/llvm-project/issues/57589

comment by borodi · 2024-01-16 · in Std: Clamp generates less efficient assembly than std:min(max,std:max(min,v))

…uses a functionally same but slightly different stub file [1] because it prints no newlines. [1] https://github.com/llvm/llvm-project/blob/d7642b2/lld/COFF/W...

comment by lifthrasiir · 2024-01-11 · in Research paper is also an executable x86 program [pdf]

…maybe it wasn't actually fixed--note: I only skimmed the comments and I probably misunderstood): https://github.com/llvm/llvm-project/issues/13989 Edit again: I forgot about the comment at the end of the article that clarifies that…

comment by schemescape · 2023-12-03 · in Clang now makes binaries an original Pi B+ can't run

…days. References: see the LLVM Flang documentation on extensions, non-standard features, &c. in https://github.com/llvm/llvm-project/blob/main/flang/docs/Ex... and a suite of various incompatible feature tests in…

comment by pklausler · 2023-11-30 · in Potential of the Julia programming language for high energy physics computing

…C or C++ I'd strongly recommend using `__builtin_popcount` (provided by both Clang and GCC). [1]: https://github.com/llvm/llvm-project/blob/08a6968127f04a40d7... [2]: https://llvm.org/docs/LangRef.html#llvm-ctpop-intrinsic

comment by asb · 2023-11-28 · in Designing a SIMD Algorithm from Scratch

flang [1], it's part of the LLVM project. [1] https://github.com/llvm/llvm-project/tree/main/flang

comment by rsecora · 2023-11-22 · in Fortran 2023

…because of long compile times, spooky action at a distance, etc. Take these two files from LLVM: https://github.com/llvm/llvm-project/blob/main/libcxx/includ... https://github.com/llvm/llvm-project/blob/main/libcxx/includ... Is this "clean…

comment by gizmo · 2023-11-08 · in Hard-to-swallow truths they won't tell you about software engineer job

…all, I haven't checked 100%). For example, their libc stdio implementation is completely in C++. https://github.com/llvm/llvm-project/tree/main/libc/src/stdi... You could say the same thing about Rust and Relibc, but it seems much less…

comment by trealira · 2023-10-03 · in Glibc dynamic loader hit by a nasty local privilege escalation vulnerability

…of currently caught exceptions. For example in llvm this is available with a cxa_get_globals call: https://github.com/llvm/llvm-project/blob/b05f1d93469fbd6451... These need to be saved/restored when switching fibers, otherwise fiber…

comment by snaury · 2023-09-24 · in Fiber in C++: Understanding the Basics

…been to drag some of these issues into the sunlight, as it did for aliasing problems previously. https://github.com/llvm/llvm-project/issues/45725 Once the GCC work is closer to finished, I expect we'll see the same there. I disagree that…

comment by tialaramex · 2023-09-19 · in Changing the Rules of Rust

That would mean you can't use LLVM either. Similar issues exists there: https://github.com/llvm/llvm-project/labels/miscompilation

comment by wdb · 2023-09-07 · in Bun 1.0 announcement [video]

…This file implements an analysis, but the results of the analysis is used by transformations. https://github.com/llvm/llvm-project/blob/main/llvm/lib/Anal... > 3. there's no guarentee this malloc is a per-spec malloc, it can be a…

comment by nlewycky · 2023-09-04 · in Using uninitialized memory for fun and profit (2008)

…and it _does_ usually treat intrinsics like malloc specially A quick google reveals https://github.com/llvm/llvm-project/issues/52930 , LLVM recognising uninitialised memory as 'undef', and needing to treat it as poisoned (IIRC propogation…

comment by dwattttt · 2023-09-04 · in Using uninitialized memory for fun and profit (2008)

…list of restrictions imposed on code in the construct. I summarized the two specific problems in https://github.com/llvm/llvm-project/blob/main/flang/docs/Do... .

comment by pklausler · 2023-08-31 · in Fortran

No, LLVM definitely still has big problems. https://github.com/llvm/llvm-project/issues/45725 is an example, the symptom in Rust is that you can write what is in effect a pointer comparison in which LLVM ends up claiming that two things…

comment by tialaramex · 2023-08-18 · in A Guide to Undefined Behavior in C and C++ (2010)

…get started. I think it could be made a bit more beginner friendly. I found the standalone example https://github.com/llvm/llvm-project/tree/main/mlir/examples... in the MLIR repo to be very useful, on the other hand.

comment by the_svd_doctor · 2023-08-17 · in MLIR For Beginners: A series of articles on the MLIR framework

__builtin_unpredictable is gonna be fixed in LLVM/clang 17: https://github.com/llvm/llvm-project/commit/09515f2c20111628... (also, bugs.llvm.org is old; the more up-to-date (but still open) issue is https://github.com/llvm/llvm-project/issu…

comment by dzaima · 2023-08-11 · in Fastest branchless binary search

Here's a fancy trick from LLVM source: https://github.com/llvm/llvm-project/blob/main/llvm/lib/Targ... #define A 0xf0 #define B 0xcc #define C 0xaa And then you can build immediate for VPTERNLOG operation by writing bitwise expression with…

comment by mmozeiko · 2023-06-20 · in The least interesting part about AVX-512 is the 512 bits vector width

…codegen bugs. I'm still waiting for a longjmp bug in clang from over a decade ago to be fixed: https://github.com/llvm/llvm-project/issues/21557

comment by cperciva · 2023-06-07 · in Is That a Compiler Bug?

…reduction strategy in a more accurate way for trig functions in LLVM libc: - with FMA instructions: https://github.com/llvm/llvm-project/blob/main/libc/src/math/generic/range_reduction_fma.h - without FMA instructions:…

comment by lntue · 2023-06-05 · in Implementing Cosine in C from Scratch (2020)

…ttps://gcc.gnu.org/bugzilla/show_bug.cgi?id=98677 https://gcc.gnu.org/bugzilla/show_bug.cgi?id=105729 https://github.com/llvm/llvm-project/issues/59432 https://github.com/boostorg/dll/issues/30 https://github.com/boostorg/asio/commit/71964b…

comment by yeputons · 2023-06-05 · in Never trust a programmer who says they know C++

…with the receipts, in the form of LLVM IR that is lowered to machine code which makes no sense e.g. https://github.com/llvm/llvm-project/issues/45725

comment by tialaramex · 2023-06-03 · in Neverflow: C macros that guard against buffer overflows

…easier to optimize are its rules against dummy argument aliasing in most (but not all) cases. (See https://github.com/llvm/llvm-project/blob/main/flang/docs/Al... for the full story.)

comment by pklausler · 2023-05-16 · in Optimization Without Derivatives: Prima Fortran Version and Inclusion in SciPy

…). you can also (as of very recently) build mlir-opt plugins just like for clang: https://github.com/llvm/llvm-project/tree/main/mlir/examples...

comment by mathisfun123 · 2023-05-02 · in Building a Compiler with Multi-Level Intermediate Representation (MLIR) (2020) [pdf]

…happen because they are too slow. This is not completely accurate, as clangd does support this: https://github.com/llvm/llvm-project/blob/main/clang-tools-e... Getting a syntax tree from clangd is faster than you might think because it…

comment by eklitzke · 2023-05-01 · in VSCode-WASM: Implement a first version of a WebShell

…project: https://github.com/rutgers-apl/The-RLIBM-Project/blob/main/l... - The LLVM libc project: https://github.com/llvm/llvm-project/blob/main/libc/src/math...

comment by lntue · 2023-03-31 · in Cosine Implementation in C