LLVM Weekly - #514, November 6th 2023

LLVM Weekly - #514, November 6th 2023

If you prefer, you can read a HTML version of this email at http://llvmweekly.org/issue/514.

Welcome to the five hundred and fourteenth 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.

News and articles from around the web and events

LLVM 17.0.4 was released.

According to the LLVM calendar in the coming week there will be:

  • Office hours with the following hosts: Tobias Grosser, Kristof Beyls, Johannes Doerfert, BOLT maintainers.
  • Online sync-ups on the following topics: Pointer authentication, OpenMP, RISC-V, MLIR open meeting, embedded toolchains…
  • For more details see the LLVM calendar, getting involved documentation on online sync ups and office hours.

On the forums

LLVM commits

  • Wording for “what is considered a security issue” in LLVM’s security documentation was clarified. d16d149e.

  • The nneg flag was introduced for the zext instruction, which asserts that the argument is non-negative. This allows zext to be converted back into sext later, if deemed profitable. ed3f06b, 3f2ed81.

  • Some post-isel RISC-V vector peepholes were moved to a MachineFunction pass. 72e6c1c.

  • MC/DC (modified condition/decision coverage) source-based code coverage support was relanded. f95b2f1.

  • MachineInstr gained an insert operation. a41b149.

  • The ‘writable’ attribute was added to LLVM IR. 6b8ed78.

  • zext and sext constant expressions were removed. e4a4122.

Clang commits

  • APINotesReader was upstreamed from Apple’s Clang tree. bb352b6.

  • -fassume-nothrow-exception-dtor was added, which assumes the destructor of a thrown exception object will not throw. c0a7391.

Other project commits

  • MLIR learned to handle mapping OpenMP array sections to LLVM IR. 6a62707.

  • Typed pointer support was removed from various MLIR dialects. 4279a64, fd8be1e, 02307a1, and more.

  • LLDB gained support for AArch64’s SME2 ZTO register. b8150c8.