LLVM Weekly - #598, June 16th 2025

Welcome to the five hundred and ninety-eighth issue of LLVM Weekly, a weekly newsletter (published every Monday) covering developments in LLVM, Clang, and related projects. LLVM Weekly is brought to you by Alex Bradbury. Subscribe to future issues at https://llvmweekly.org and pass it on to anyone else you think may be interested. Please send any tips or feedback via email: asb@asbradbury.org, or Mastodon: @llvmweekly@fosstodon.org / @asb@fosstodon.org, or Bluesky: @llvmweekly.org / @asbradbury.org.

The first Bristol UK LLVM/MLIR meetup will take place on 2nd July.

Applications are open for the US LLVM Developers' Meeting student travel grants.

According to the LLVM Calendar in the coming week there will be the following:

Office hours with the following hosts: Phoebe Wang, Johannes Doerfert, Aaron Ballman.
Online sync-ups on the following topics: MLIR C/C++ frontend, ClangIR, pointer authentication, vectorisation, security response, OpenMP, C/C++ language working group, Flang, RISC-V, LLVM embedded toolchains.
For more details see the LLVM calendar, getting involved documentation on online sync ups and office hours.

Uzair Nawaz and “sribee8” wrote a proposal on adding widechar support to LLVM libc.
Aaron Ballman proposed removing the PSTL top-level project as development appears to have ceased.
Félix Cloutier started a discussion about correctness issues if a bool has a value assigned to it other than 0 or 1 (e.g. via memcpy).
Antonio Frighetto proposed adding a dead_on_return attribute which indicates the memory point to by the argument is dead upon function return.
Caroline Concatto posted a proposal for improving handling of the AArch64 FPMR state register used by FP8 intrinsics.
LLVM 20.1.7 was released. This is expected to be the last 20.1.x released
Martin Storsjö started a thread about PGO for cross compilation.
Jonas Devlieghere proposed adding Model Context Protocol (MCP) support to LLDB.
Roy Margalit proposes the robustness sanitizer, aiming to complement TSan.
Sjoerd Meijer notes that loop interchange is ready to be enabled.
Paschalis Mpeis posts about adding a new AArch64 BOLT buildbot and improving testing.

PatLeaf can now be imported in GISel. f3ffee6.
The IR autoupgrader can now convert old debug-info. 3d7aa961.
LLVM’s MC layer now prefers foo = bar rather than .set foo bar, unless overridden by the target.. 28bda77.
The RISC-V backend now supports memcmp expansion for vectors. 4903c11.

LoongArch now supports __bf16. 0ed5d9a.
Clang documented its behaviour for underspecified object declarations. b896d26.
After an RFC discussion, delayed typo correction was removed from Clang. 9eef4d1.
Clang’s build system no longer passes -fno-strict-aliasing when building with GCC. 4ed10db.
A JSON generator was added for clang-doc. 1c3320c.