LLVM Weekly - #655, July 20th 2026
If you prefer, you can read the canonical version of this issue at https://llvmweekly.org/issue/655.
Welcome to the six hundred and fifty-fifth 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.
News and articles from around the web and events
The next LLVM Meetup in Munich will take place on July 29th.
A new set of C++ proposal papers is out.
According to the LLVM Calendar in the coming week there will be the following:
- Office hours with the following hosts: Johannes Doerfert, Amara Emerson.
- Online sync-ups on the following topics: Flang, vectorizer, modules, lifetime safety, LLVM/Offload, OpenMP for flang, HLSL, reflection.
- For more details see the LLVM calendar, getting involved documentation on online sync ups and office hours.
On the forums
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LLVM 23.x has branched.
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Another month has passed already and Bruno Cardoso Lopes has posted July’s progress report for ClangIR.
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Peter Smith posted an RFC on adding full support for the AArch64 ELF Pointer Authentication ABI.
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Saleem Abdulrasool proposed the DS2 debug server be incubated within LLVM. A number of responses discuss the fact this would be the third in-tree debug server and what the plan would be for reducing that number.
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Following on from the previous meta-RFC on ADTs without a C++ runtime dependency, Robert Imschweiler’s new RFC is seeking approval of the concrete implementation details.
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Arjun Harikumar proposed a new generalised strategy for vectorising early exit loops with multiple early exits.
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Jiacong Ye started an RFC discussing on adding a probe dialect to CIRCT.
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Luke Lau announced that lnt.llvm.org is now tracking RISC-V RVA23U64 performance for Clang and GCC on the new SpacemiT-X100. The results are also published to cc-perf.igalia.com.
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Serge Pavlov proposed custom formatters for constant values in LLVM IR, motivated by the desire for more readable printing of
llvm.is_fpclass. -
Elaine Gibson is seeking feedback to their RFC on porting libcxx to Haiku.
LLVM commits
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lit’s new
-pass-env FOOoption can be used to allow the named environment variable to be passed through without having to edit the source to add it to the allow list. f1b5b06. -
LLVM’s ADT library gained a non-owning view of a buffer formatted as a binary search tree in Eytzinger (breadth-first) order as well as EytzingerTable, an owning container shoring elements in that order. 8042e61, 75403b0.
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The Arm backend’s ability to estimate the function size in bytes for Thumb1 was improved. 3a61e72.
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MC layer support was added for the SpacemiT Xvsmtvdotii extension. 13e9cc2.
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The SLPVectorizer can now vectorize straight-line code with may-alias dependencies by versioning the block (adding a branch to check for overlap). 36dd090.
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There was a big series of patches converting AMDGPU tests from
-mtriple=amdgcn ... -mcpu=<gfx>to a new “folded subarch triple” form e.g.-mtriple=amdgpu9.00-amd-amdhsa. 194f7a3 and many more. -
The MetaRenamer pass now call prefixes basic block names with
bblrather thanbb. f7491ea. -
Support for running LLVM tests with external shell in lit was dropped. 3f46a5e.
Clang commits
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Clang’s “Templight” template debugger was removed due to being unmaintained. 5f7060c.
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The DanglingPtrDeref checker was implemented to detect user-after-scope lifetime errors. e1d7480.
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A range of Clang docs were moved to Markdown. 1514df3.
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clang-doc’s markdown and YAML generators were removed. c6ebd7a2, 1bd4601.