LLVM 20.0.0git Release Notes¶
Warning
These are in-progress notes for the upcoming LLVM 20 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 20.0.0git. 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¶
…
Update on required toolchains to build LLVM¶
Changes to the LLVM IR¶
The
x86_mmxIR type has been removed. It will be translated to the standard vector type<1 x i64>in bitcode upgrade.
Changes to LLVM infrastructure¶
Changes to building LLVM¶
Changes to TableGen¶
Changes to Interprocedural Optimizations¶
Changes to the AArch64 Backend¶
.balign N, 0, .p2align N, 0, .align N, 0 in code sections will now fill the required alignment space with a sequence of 0x0 bytes (the requested fill value) rather than NOPs.
Changes to the AMDGPU Backend¶
Changes to the ARM Backend¶
.balign N, 0, .p2align N, 0, .align N, 0 in code sections will now fill the required alignment space with a sequence of 0x0 bytes (the requested fill value) rather than NOPs.
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¶
.balign N, 0, .p2align N, 0, .align N, 0 in code sections will now fill the required alignment space with a sequence of 0x0 bytes (the requested fill value) rather than NOPs.
Changes to the WebAssembly Backend¶
Changes to the Windows Target¶
Changes to the X86 Backend¶
.balign N, 0x90, .p2align N, 0x90, and .align N, 0x90 in code sections now fill the required alignment space with repeating 0x90 bytes, rather than using optimised NOP filling. Optimised NOP filling fills the space with NOP instructions of various widths, not just those that use the 0x90 byte encoding. To use optimised NOP filling in a code section, leave off the “fillval” argument, i.e. .balign N, .p2align N or .align N respectively.
Due to the removal of the
x86_mmxIR type, functions withx86_mmxarguments or return values will use a different, incompatible, calling convention ABI. Such functions are not generally seen in the wild (Clang never generates them!), so this is not expected to result in real-world compatibility problems.
Changes to the OCaml bindings¶
Changes to the Python bindings¶
Changes to the C API¶
The following symbols are deleted due to the removal of the
x86_mmxIR type:LLVMX86_MMXTypeKindLLVMX86MMXTypeInContextLLVMX86MMXType
Changes to the CodeGen infrastructure¶
Changes to the Metadata Info¶
Changes to the Debug Info¶
Changes to the LLVM tools¶
Changes to LLDB¶
Changes to BOLT¶
Changes to Sanitizers¶
Other Changes¶
External Open Source Projects Using LLVM 19¶
A project…
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.