LLVM 24.0.0git Release Notes

Warning

These are in-progress notes for the upcoming LLVM 24.0.0git release. Release notes for previous releases can be found on the Download Page.

Introduction

This document contains the release notes for the LLVM Compiler Infrastructure, release 24.0.0git. Here we describe the status of LLVM, including major improvements from the previous release, improvements in various subprojects of LLVM, and some of the current users of the code. All LLVM releases may be downloaded from the LLVM releases web site.

For more information about LLVM, including information about the latest release, please check out the main LLVM web site. If you have questions or comments, the Discourse forums is a good place to ask them.

Note that if you are reading this file from a Git checkout or the main LLVM web page, this document applies to the next release, not the current one. To see the release notes for a specific release, please see the releases page.

Non-comprehensive list of changes in this release

  • …

Changes to the LLVM IR

Changes to LLVM infrastructure

Changes to building LLVM

Changes to TableGen

  • !cond operator short-circuits at the first true condition. Subsequent condition : value pairs, along with their corresponding side effects, are left unresolved.

Changes to Interprocedural Optimizations

Changes to Vectorizers

Changes to the AArch64 Backend

  • On AArch64 Windows targets, return address signing now uses the B-key by default because Windows unwind information only supports B-key signing.

Changes to the AMDGPU Backend

Changes to the ARM Backend

Changes to the AVR Backend

Changes to the DirectX Backend

Changes to the Hexagon Backend

Changes to the LoongArch Backend

Changes to the MIPS Backend

Changes to the PowerPC Backend

Changes to the RISC-V Backend

Changes to the WebAssembly Backend

Changes to the Windows Target

Changes to the X86 Backend

Changes to the OCaml bindings

Changes to the Python bindings

Changes to the C API

Changes to the CodeGen infrastructure

Changes to the Metadata Info

Changes to the Debug Info

Changes to the LLVM tools

Changes to LLDB

Windows

  • Python 3.11 or later is now recommended for building LLDB 23 on Windows. From LLDB 24, Python 3.11 or later will be required.

  • Messages from OutputDebugString[A|W] are now shown inline when using LLDB from the command-line and in the output window when using lldb-dap.

  • LLDB now uses lldb-server.exe to launch and manage the program being debugged, instead of running it within LLDB’s own process. To revert to the previous behavior, set the environment variable LLDB_USE_LLDB_SERVER=0.

  • Support for PDB symbol servers has been added. By default, no symbol servers are used. You can control this either through the _NT_SYMBOL_PATH environment variable or by setting plugin.symbol-locator.symstore.urls (see plugin.symbol-locator.symstore for more info).

  • LLDB no longer depends on the Python private API on Windows. Users are now free to use any Python version they want, as long as it is 3.8 or later and LLDB can find it (i.e. it is on their PATH).

Changes to BOLT

Changes to Sanitizers

Other Changes

External Open Source Projects Using LLVM 24.0.0git

Additional Information

A wide variety of additional information is available on the LLVM web page, in particular in the documentation section. The web page also contains versions of the API documentation which is up-to-date with the Git version of the source code. You can access versions of these documents specific to this release by going into the llvm/docs/ directory in the LLVM tree.

If you have any questions or comments about LLVM, please feel free to contact us via the Discourse forums.