LLVM Weekly - #381, April 19th 2021
Welcome to the three hundred and nineteenth 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 to asb@asbradbury.org, or @llvmweekly or @asbradbury on Twitter.
News and articles from around the web
LLVM 12.0.0 has been released. As always, thank you and congratulations to everyone involved.
Michał Górny has written a blog post on adding support for fork(2) and vfork(2) to LLDB, in order to provide follow-[v]fork functionality on par with GNU GDB.
On the mailing lists
ORC JIT Weekly #32 provides a preview of the ORC runtime. Lang Hames has also proposed the ORC runtime library for inclusion in compiler-rt.
LLVM GPU News Issue #10 is out.
Kristof Beyls announced a regular LLVM sync-up call on pointer authentication.
Haowei Wu posted an RFC on generating LLD reproducers on crashes. Fangrui Song pointed out that crash reporting is easier to implement in a shell script rather than the LLD
Chen Liue proposed always emitting unaligned vector move instructions on AVX machines, with an options to disable this behaviour. Some respondents had concerns.
Yevgeny Rouban proposed intrinsics to get the base pointer and offset of GC pointers.
Xiang Zhiang posted on RFC on supporting AMX faster register allocation at O0.
LLVM commits
llvm.expect intrinsics are now lowered before running simplifycfg. 661cc71.
A pass was added to convert lookup tables to relative lookup tables in order to make them PIC-friendly. e96df3e.
The M68k assembly parser was committed. 6e098e1.
llvm-objdump’s command-line parsing was migrated from llvm::cl to OptTable. 1035123.
The PowerPC backend gained MC-layer support for new ROP protection instructions introduced in Power 10. f28cb01.
The LLVM language reference was extended to clarify the semantics of ‘nocapture’. 1bcadb0.
The semantics of ‘nofree’ were clarified. ff55d01.
Clang commits
The newly introduced
[[clang::musttail]]attribute can be used for guaranteed tail calls. 8344675.A new clang-tidy check ‘bugprone-unhandled-exception-at-new’ was added to find calls to
newwith a missing exception handler forstd::bad_alloc. 530456c.clang-rename can now handle designated initialisers. 7dd6068.
clang-tidy gained a check for implicit widening of a multiplication result. 46b8ea2.