llvm/llvm-project on Hacker News

https://www.amd.com/content/dam/amd/en/documents/instinct-te... The compiler is LLVM https://github.com/llvm/llvm-project/tree/main/llvm/lib/Targ... It's all there. For the driver/runtime everything is also open and upstreamed into the…

comment by almostgotcaught · 2025-03-20 · in Looking Ahead at Intel's Xe3 GPU Architecture

LLD has a new option "--randomize-section-padding" for this purpose: https://github.com/llvm/llvm-project/pull/117653

comment by McP · 2025-03-10 · in Performance of the Python 3.14 tail-call interpreter

The article includes a link to the pull request which fixes the regression in LLVM: https://github.com/llvm/llvm-project/pull/114990

comment by aeyes · 2025-03-10 · in Performance of the Python 3.14 tail-call interpreter

…especially the segmented ones. The LLVM scheduling models give some insight: * SiFive P670: https://github.com/llvm/llvm-project/blob/main/llvm/lib/Targ... * Tenstorrent Ascalon: https://github.com/llvm/llvm-project/blob/main/llvm/lib/Targ.…

comment by camel-cdr · 2025-03-09 · in Europe bets once again on RISC-V for supercomputing

Github issue: https://github.com/llvm/llvm-project/issues/127365

comment by no_identd · 2025-02-26 · in A Clang regression related to switch statements and inlining

…I have a confirmed bug in Clang [1] and a non-rejected bug in GCC [2], so it does happen. [1]: https://github.com/llvm/llvm-project/issues/61133 [2]: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=108448

comment by gavinhoward · 2025-02-24 · in It is not a compiler error (2017)

…by C++ clang only related contributions instead of LLVM ones? Most likely not, only clicked here https://github.com/llvm/llvm-project/graphs/contributors and came right away to reply.

comment by pjmlp · 2025-02-24 · in OpenBSD Innovations

…own subsystems or putting down markers documenting how the subsystems are supposed to work. Maybe https://github.com/llvm/llvm-project/issues/74205 would help once it trickles down into the kernel, but I suspect that people are still going…

comment by vlovich123 · 2025-02-18 · in I helped fix sleep-wake hangs on Linux with AMD GPUs

> there's an open bug ticket noting that it doesn't protect against contraction ( https://github.com/llvm/llvm-project/issues/91674 ). Huh. ¯\_(ツ)_/¯ I didn't really mean the loop thing as much of a problem for the goal of reproducibility…

comment by dzaima · 2025-02-13 · in Elementary Functions and Not Following IEEE754 Floating-Point Standard (2020)

…though there's an open bug ticket noting that it doesn't protect against contraction ( https://github.com/llvm/llvm-project/issues/91674 ). Still worth trying though. I was aware of GCC __builtin_assoc_barrier, but it wasn't documented to…

comment by AlotOfReading · 2025-02-13 · in Elementary Functions and Not Following IEEE754 Floating-Point Standard (2020)

…//github.com/openzfs/zfs/commit/677c6f8457943fe5b56d7a... There is an open LLVM issue regarding this: https://github.com/llvm/llvm-project/issues/62790 The issue explains why __builtin_unpredictable() does not address the problem. In…

comment by ryao · 2025-02-09 · in Don't "optimize" conditional moves in shaders with mix()+step()

I'm excited about -fbounds-safety coming soon: https://github.com/llvm/llvm-project/commit/64360899c76c

comment by 1over137 · 2025-02-01 · in Falsehoods programmers believe about null pointers

okay can you at least tell me how the architecture of https://github.com/llvm/llvm-project is "bad"?

comment by almostgotcaught · 2025-01-31 · in A better build system for OCaml

…huh? since you fancy yourself an architect can you let me know how we might fix the architecture of https://github.com/llvm/llvm-project such that CMake is no longer needed?

comment by almostgotcaught · 2025-01-31 · in A better build system for OCaml

…before ratification, where it wasn't clear that Zbs needs to be supported. See the discussion here: https://github.com/llvm/llvm-project/pull/122164#issuecommen...

comment by camel-cdr · 2025-01-28 · in SiFive's P550 Microarchitecture

Both fantastic and 35 years too late? more refs https://github.com/llvm/llvm-project/blob/main/clang/docs/Bo...

comment by keyle · 2025-01-24 · in The preview of -fbounds-safety is now accessible to the community

▲ 1

Clang getting more aggressive about optimizing undefined behavior

story by blackhole · 2025-01-22 · 1 comment

▲ 4

Clang now more aggressively uses undefined behavior on pointer addition overflow

story by remexre · 2025-01-20 · 1 comment

…mapped file, while compressed debug symbols probably need to be extracted to anonymous memory. https://github.com/llvm/llvm-project/issues/63290

comment by CodesInChaos · 2025-01-19 · in Rust: Investigating an Out of Memory Error

…First of all, a recent LLVM patch apparently changes codegen to use CMOV instead of a branch: https://github.com/llvm/llvm-project/pull/102885 Beyond that, Intel recently updated their manual to retroactively define the behavior of BSR/BSF…

comment by comex · 2025-01-17 · in Branchless UTF-8 Encoding

…manner without a hardware instruction using a conditional move and a de Bruijn sequence; see https://github.com/llvm/llvm-project/blob/main/flang/include... .

comment by pklausler · 2025-01-17 · in Branchless UTF-8 Encoding

Bolt can do quite a lot of optimizations: https://github.com/llvm/llvm-project/tree/main/bolt

comment by pajko · 2025-01-07 · in Size Optimization Tricks (2022)

…the intention of those macros is to generate uniquely named local lambda. Cleaner version is like: https://github.com/llvm/llvm-project/issues/100869#issue-243...

comment by fuhsnn · 2025-01-07 · in C: Simple Defer, Ready to Use

…warnings, which is the next best thing: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=118263 https://github.com/llvm/llvm-project/issues/121427

comment by ryao · 2025-01-01 · in Debugging memory corruption: who the hell writes "2" into my stack? (2016)

…against both GCC and LLVM requesting warnings: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=118263 https://github.com/llvm/llvm-project/issues/121427 If/when they are implemented, they will become errors with -Werror.

comment by ryao · 2025-01-01 · in Debugging memory corruption: who the hell writes "2" into my stack? (2016)

…against both GCC and LLVM requesting warnings: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=118263 https://github.com/llvm/llvm-project/issues/121427

comment by ryao · 2025-01-01 · in Debugging memory corruption: who the hell writes "2" into my stack? (2016)

…against both GCC and LLVM requesting warnings: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=118263 https://github.com/llvm/llvm-project/issues/121427 Once the compilers begin emitting warnings, this should not be an issue anymore as long…

comment by ryao · 2025-01-01 · in Debugging memory corruption: who the hell writes "2" into my stack? (2016)

…warnings to protect people from doing this: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=118263 https://github.com/llvm/llvm-project/issues/121427

comment by ryao · 2025-01-01 · in Debugging memory corruption: who the hell writes "2" into my stack? (2016)

…against both GCC and LLVM asking for one: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=118263 https://github.com/llvm/llvm-project/issues/121427

comment by ryao · 2025-01-01 · in Debugging memory corruption: who the hell writes "2" into my stack? (2016)

…a C function or to a C++ noexcept function: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=118263 https://github.com/llvm/llvm-project/issues/121427 Perhaps the C++ standards committee should specify that doing this should cause a compiler…

comment by ryao · 2025-01-01 · in Debugging memory corruption: who the hell writes "2" into my stack? (2016)

…against both GCC and LLVM requesting warnings: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=118263 https://github.com/llvm/llvm-project/issues/121427

comment by ryao · 2025-01-01 · in Debugging memory corruption: who the hell writes "2" into my stack? (2016)

…compilers issue them and developers heed them: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=118263 https://github.com/llvm/llvm-project/issues/121427

comment by ryao · 2025-01-01 · in Debugging memory corruption: who the hell writes "2" into my stack? (2016)

…against both GCC and LLVM asking for one: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=118263 https://github.com/llvm/llvm-project/issues/121427

comment by ryao · 2025-01-01 · in Debugging memory corruption: who the hell writes "2" into my stack? (2016)

…that would inform developers of the risk: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=118263 https://github.com/llvm/llvm-project/issues/121427

comment by ryao · 2025-01-01 · in Debugging memory corruption: who the hell writes "2" into my stack? (2016)

this is an LLVM project... you want this to work on Metal, ask apple to add a Metal backend to LLVM https://github.com/llvm/llvm-project/tree/main/llvm/lib/Targ...

comment by almostgotcaught · 2024-12-14 · in Using Libc for GPUs

…can generate non-temporal ops if you ask for it explicitly in some form. And they are problematic: https://github.com/llvm/llvm-project/issues/64521

comment by dzaima · 2024-12-13 · in Programming Language Memory Models (2021)

…that has already been through PGO/FDO. ...assuming your workload matches the profiled workload. see https://github.com/llvm/llvm-project/blob/main/bolt/docs/Opt...

comment by canucker2016 · 2024-11-19 · in Ubuntu Praises 5~7% PGO Compiler Optimization Performance Benefits

…allocated to the operator new implementation. If you want to experiment here’s the implementation: https://github.com/llvm/llvm-project/pull/113510

comment by olliej · 2024-11-15 · in Speculations on arenas and custom strings in C++

…to implement it competitively. Is that actually what's happening? From the discussion you link ( https://github.com/llvm/llvm-project/pull/104574 ), it seems like the X280 behavior is currently still widespread. Do we know when the…

comment by janwas · 2024-11-09 · in RISC-V Vector Extension for Integer Workloads: An Informal Gap Analysis

▲ 4

Show HN: SSO – Small String Optimization

story by feelamee · 2024-10-12 · 4 comments

…back in early 2022, thus closing a feature request that had been open for 11 years at the time: https://github.com/llvm/llvm-project/commit/79d08e398c17e83b... I think the other two major vendors had already switched by then, although I'm…

comment by quuxplusone · 2024-08-30 · in Calendar Queues: A Fast O(1) Priority Queue Implementation (1988)

…all over kilobytes of machine code. For comparison, see the x86 implementations in LLVM libc. https://github.com/llvm/llvm-project/blob/main/libc/src/stri...

comment by jeffbee · 2024-08-26 · in Linux Pipes Are Slow

▲ 16

RP2350 Hazard3 Added to LLVM

story by hasheddan · 2024-08-20 · 7 comments

…preserve_none was incompatible with the sanitizers, but I believe this may have been fixed by: https://github.com/llvm/llvm-project/pull/81048

comment by haberman · 2024-08-19 · in Parsing protobuf at 2+GB/s: how I learned to love tail calls in C (2021)

…from the previous stack frame after a tail call, and that would include Gerben's first example in https://github.com/llvm/llvm-project/issues/72555 Your slimcc project looks really interesting, thanks for the pointer.

comment by haberman · 2024-08-19 · in Parsing protobuf at 2+GB/s: how I learned to love tail calls in C (2021)

…and argument stack don't exceed what's provided. Debug/profiling side might hate it, though. [0] https://github.com/llvm/llvm-project/issues/72555 [1] https://github.com/fuhsnn/slimcc/

comment by fuhsnn · 2024-08-19 · in Parsing protobuf at 2+GB/s: how I learned to love tail calls in C (2021)

…that will make preserve_none allocate arguments in the registers that are usually callee-saved: https://github.com/llvm/llvm-project/pull/88333 This will make [[musttail]] + preserve_none a winning combination when used together,…

comment by haberman · 2024-08-19 · in Parsing protobuf at 2+GB/s: how I learned to love tail calls in C (2021)

…since some architectures will allow tail calls even for functions that do not perfectly match: https://github.com/llvm/llvm-project/issues/54964 "But then the code would be nonportable." True, but tail call optimization is inherently…

comment by haberman · 2024-08-19 · in Parsing protobuf at 2+GB/s: how I learned to love tail calls in C (2021)

…://gcc.gnu.org/bugzilla/show_bug.cgi?id=55522 Early 2023: bug is fixed. Feb 2024: clang follows suit: https://github.com/llvm/llvm-project/pull/80475 And maybe later this year this problem will finally be gone in common Linux distros.

comment by amluto · 2024-08-11 · in Someone's been messing with Python's floating point subnormals

I am being silenced for speaking the truth! https://github.com/llvm/llvm-project/commit/12728e144994efe8... https://clang.llvm.org/docs/LanguageExtensions.html#c11-gene...

comment by Conscat · 2024-08-05 · in Improving _Generic in C2y