LLVM Weekly - #521, December 25th 2023
If you prefer, you can read the canonical version of this issue at http://llvmweekly.org/issue/521.
Welcome to the five hundred and twenty-first 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 http://llvmweekly.org and pass it on to anyone else you think may be interested. Please send any tips or feedback to asb@asbradbury.org, @llvmweekly or @asbradbury on Twitter, or @llvmweekly@fosstodon.org or @asb@fosstodon.org.
For those who celebrate it, Merry Christmas!
News and articles from around the web and events
The next LLVM bay area meetup will take place on Jan 29th.
A few more LLVM Dev Meeting videos have been posted on YouTube.
I didn’t spot any more LLVM related news articles over the last week, but if you’ll allow me a little bit of cross-promotion, you might be interested in my recent posts on a somewhat overlooked reference counting paper and my appreciation for terminal bells.
According to the LLVM calendar in the coming week there will be (note: I’d double check if these are still going ahead - I’d imagine with the holidays many of these are events that just weren’t cancelled on the calendar):
- Office hours with the following hosts: Johannes Doerfert, Amara Emerson.
- Online sync-ups on the following topics: Flang, libc++, OpenMP, classic flang, loop optimisations.
- For more details see the LLVM calendar, getting involved documentation on online sync ups and office hours.
On the forums
-
Konstantin Varlamov posted an RFC on adding
__builtin_verbose_trap
. Unlike__builtin_trap
, this provides a message about what went wrong. -
Ariel Burton suggested adding support for IBM’s hexademical floating-point format.
-
I think I missed this thread first time round. Johannes Doerfert started a thread about unifying clang flags / language options for offloading languages.
-
The 59th edition of MLIR news is now available.
-
Oskar Wirga proposed extending Clang’s CFI to support dynamically resolved function pointers.
-
Anton Lydike provided a summary of the discussion on an MPI MLIR dialect so far and proposed a path forwards.
-
Ramkumar Ramachandra suggested a Mastodon instance for the LLVM community (e.g. something like social.llvm.org, similar to social.kernel.org). Though based on feedback received, noted that the moderation cost may be too high.
LLVM commits
-
Usage instructions were added for FatLTO. 8190e09.
-
The dominance algorithm used in RegAllocFast was made O(1) rather than O(n). 40ec791.
-
Release branches will now start numbered as N.1.0. 4532617.
-
LoopAccessAnalysis will now hoist runtime checks by default. 49b0e6d.
-
The X86 assembly parser learned to error for an out of range displacement. 83680f8.
-
The RISC-V vector crypto extensions are no longer marked as experimental, however the C intrinsics are not yet finalised. 0905865.
-
The AArch64LoadStoreOptimizer pass can now merge an index address with a large offset into the base address. 32878c2.
-
MC layer and codegen support was introduced for the Armv9.5-A pointer authentication code enhancement instructions. 192f720, 7bd1721.
Clang commits
-
The multilib reuse logic for RISC-V bare-metal toolchains was improved. 379d32d.
-
Support for the
counted_by
attribute was reverted. cca4d6c.
Other project commits
-
The libcxx codebase was reformatted. 9783f28.
-
ranges::contains
andranges::fold_left[_with_iter]
was implemented in libcxx. fdd089b, 3903438. -
Non-interprocedural dataflow analysis is now supported in MLIR, rather than just interprocedural analysis. 32a4e3f.
-
The
emitc.expression
operation was introduced for the MLIRemitc
dialect. d980384.