LLVM 13.0.0 Release Notes

Warning

These are in-progress notes for the upcoming LLVM 13 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 13.0.0. 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

  • Windows Control-flow Enforcement Technology: the -ehcontguard option now emits valid unwind entrypoints which are validated when the context is being set during exception handling.

Changes to the LLVM IR

  • The inalloca attribute now has a mandatory type field, similar to byval and sret.
  • The opaque pointer type ptr has been introduced. It is still in the process of being worked on and should not be used yet.

Changes to building LLVM

  • The build system now supports building multiple distributions, so that you can e.g. have one distribution containing just tools and another for libraries (to enable development). See Multi-distribution configurations for details.

Changes to the AArch64 Backend

  • Introduced support for Armv9-A’s Realm Management Extension.

Changes to the ARM Backend

During this release …

Changes to the MIPS Target

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Changes to the Hexagon Target

  • The Hexagon target now supports V68/HVX ISA.

Changes to the PowerPC Target

During this release …

Changes to the X86 Target

During this release …

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

  • The C API function LLVMIntrinsicCopyOverloadedName has been deprecated. Please migrate to LLVMIntrinsicCopyOverloadedName2 which takes an extra module argument and which also handles unnamed types. (‘D99173’ <https://reviews.llvm.org/D99173>’_)

Changes to the FastISel infrastructure

  • FastISel no longer tracks killed registers, and instead leaves this to the register allocator. This means that hasTrivialKill() is removed, as well as the OpNIsKill parameters to the fastEmit_*() family of functions.

Changes to the Debug Info

During this release …

Changes to the LLVM tools

  • The options --build-id-link-{dir,input,output} have been deleted. (D96310)
  • Support for in-order processors has been added to llvm-mca. (D94928)
  • llvm-objdump supports -M {att,intel} now. --x86-asm-syntax is a deprecated internal option which will be removed in LLVM 14.0.0. (D101695)
  • The llvm-readobj short aliases -s (previously --sections) and -t (previously --syms) have been changed to --syms and --section-details respectively, to match llvm-readelf. (D105055)
  • The llvm-nm short aliases -M (--print-armap), -U (--defined-only), and -W (--no-weak) are now deprecated. Use the long form versions instead. The alias --just-symbol-name is now deprecated in favor of --format=just-symbols and -j. (D105330)

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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