LLVM 14.0.0 Release Notes

Warning

These are in-progress notes for the upcoming LLVM 14 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 14.0.0. 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 LLVM Developer’s Mailing List is a good place to send 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

  • Using the legacy pass manager for the optimization pipeline is deprecated and will be removed after LLVM 14. In the meantime, only minimal effort will be made to maintain the legacy pass manager for the optimization pipeline.
  • Max allowed integer type was reduced from 2^24-1 bits to 2^23 bits.
  • Max allowed alignment was increased from 2^29 to 2^32.

Changes to the AArch64 Backend

  • Added support for the Armv9-A, Armv9.1-A and Armv9.2-A architectures.
  • The compiler now recognises the “tune-cpu” function attribute to support the use of the -mtune frontend flag. This allows certain scheduling features and optimisations to be enabled independently of the architecture. If the “tune-cpu” attribute is absent it tunes according to the “target-cpu”.

Changes to the ARM Backend

  • Added support for the Armv9-A, Armv9.1-A and Armv9.2-A architectures.
  • Added support for the Armv8.1-M PACBTI-M extension.

Changes to the MIPS Target

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Changes to the PowerPC Target

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Changes to the X86 Target

During this release …

  • Support for AVX512-FP16 instructions has been added.

Changes to the AMDGPU Target

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Changes to the AVR Target

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Changes to the WebAssembly Target

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Changes to the C API

  • LLVMSetInstDebugLocation has been deprecated in favor of the more general LLVMAddMetadataToInst.

Changes to the Debug Info

During this release …

Changes to the LLVM tools

  • llvm-cov: -name-allowlist is now accepted in addition to -name-whitelist. -name-whitelist is marked as deprecated and to be removed in future releases.

Changes to LLDB

  • A change in Clang’s type printing has changed the way LLDB names array types (from int [N] to int[N]) - LLDB pretty printer type name matching code may need to be updated to handle this.
  • The following commands now ignore non-address bits (e.g. AArch64 pointer signatures) in address arguments. In addition, non-address bits will not be shown in the output of the commands.
    • memory find
    • memory read
    • memory tag read
    • memory tag write

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.

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