```{warning} These are in-progress notes for the upcoming LLVM {{env.config.release}} release. Release notes for previous releases can be found on [the Download Page](https://releases.llvm.org/download.html). ```
This document contains the release notes for the LLVM Compiler Infrastructure, release {{env.config.release}}. 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.
Removed llvm.convert.to.fp16 and llvm.convert.from.fp16 intrinsics. These are equivalent to fptrunc and fpext with half with a bitcast.
“denormal-fp-math” and “denormal-fp-math-f32” string attributes were migrated to first-class denormal_fpenv attribute.
The "nooutline" attribute is now writen as nooutline. Existing IR and bitcode will be automatically updated.
LLVM IR floating-point literals have greatly changed:
The old hexadecimal bitwise representation is deprecated and will be removed in the next revision. It is replaced with a unified f0x prefix.
Hexadecimal literals akin to C99's syntax are supported.
Special values for infinities and NaNs, including NaN payloads, are added.
Removed Constant::isZeroValue. It was functionally identical to Constant::isNullValue for all types except floating-point negative zero. All callers should use isNullValue instead. isZeroValue will be reintroduced in the future with bitwise-all-zeros semantics to support non-zero null pointers.
Removed TypePromoteFloat legalization from SelectionDAG
Removed bugpoint. Usage has been replaced by llvm-reduce and llvm/utils/reduce_pipeline.py.
The Br opcode was split into two opcodes separating unconditional (UncondBr) and conditional (CondBr) branches.
BranchInst was deprecated in favor of UncondBrInst and CondBrInst.
The operand order of CondBr instructions was adjusted to match the successor order. This can cause subtle breakage when using getOperand or setOperand to access successors.
The llvm::sys::fs link creation API has been refactored:
create_link now tries to create a symbolic link first, falling back to a hard link if that fails (previously it created a symlink on Unix and a hard link on Windows).create_symlink, which always creates a symbolic link. On windows this may fail if symlink permissions are not available.readlink, which reads the target of a symbolic link.ID{n-m} instead of ID<n-m> to be consistent with inner let statements.sysp, mrrs, and msrr instructions are now accepted without requiring the +d128 feature gating.-aarch64-emit-debug-tls-location to allow the emission of DW_AT_location for thread-local variables. This is currently disabled by default to maintain compatibility with Binutils and LLVM older toolchains that do not define the R_AARCH64_TLS_DTPREL64 static relocation type for TLS offsets."amdgpu-num-sgpr" and "amdgpu-num-vgpr" IR function attributes (generated by the Clang amdgpu_num_sgpr and amdgpu_num_vgpr attributes) are now deprecated. Use "amdgpu-waves-per-eu" instead. The backend still honors the attributes; Clang emits a -Wdeprecated-declarations warning when the source attributes are used.r14 register can now be used as an alias for the link register lr in inline assembly. Clang always canonicalizes the name to lr, but other frontends may not.-gsplit-dwarf and -mrelax to be used together when building for the LoongArch platform.sm_30 to sm_75. sm_75 is the oldest GPU variant compatible with the widest range of recent major CUDA Toolkit versions (11/12/13).llvm-objdump now has support for --symbolize-operands with RISC-V.-mcpu=spacemit-x100 was added.lpad, pause, ntl.*, c.ntl.*, sspush, sspopchk, ssrdp, c.sspush, c.sspopchk) are now always available in the assembler and disassembler without requiring their respective extensions.-mcpu=spacemit-a100 was added.-riscv-enable-p-ext-simd-codegen flag has been removed. P extension SIMD code generation is now enabled automatically if the P extension is supported.-mcpu=xt-c910v2 and -mcpu=xt-c920v2 were added.-mcpu=sifive-x160 and -mcpu=sifive-x180 were added.XRivosVisni vendor extension has been removed..seh_startchained and .seh_endchained assembly instructions have been removed and replaced with a new .seh_splitchained instruction..att_syntax directive is now emitted for assembly files when AT&T syntax is in use. This matches the behaviour of Intel syntax and aids with compatibility when changing the default Clang syntax to the Intel syntax.Replaced opcode LLVMBr with LLVMUncondBr and LLVMCondBr.
The operand order of CondBr instructions was adjusted to match the successor order. This can cause subtle breakage when using LLVMGetOperand or LLVMSetOperand to access successors.
llvm-objcopy no longer corrupts the symbol table when --update-section is called for ELF files.FileCheck option -check-prefix now accepts a comma-separated list of prefixes, making it an alias of the existing -check-prefixes option.-mtune option to llc.-mtune option to opt.webinspector-wasm platform was added to list and attach to WebAssembly processes in Safari.load-script-from-symbol-file was changed from warn to trusted. This means that scripts from code signed dSYM bundles are now loaded automatically, while untrusted bundles continue to produce a warning.frame variable repeats the command with an incremented --depth option, allowing quick expansion of nested data.. to refer to the location(s) at which the current thread is stopped. For example, breakpoint disable . disables the just-hit breakpoint location. Another usage is to automate a command to run at the current location: breakpoint command add -o 'p my_var' ..SBTarget::GetDataByteSize(), SBTarget::GetCodeByteSize(), and SBSection::GetTargetByteSize() have been deprecated. They always return 1, as before.freebsd-kernel to freebsd-kernel-core. Remote kernel debugging is still handled by the gdb-remote plugin.msgbufp are now printed when LLDB starts.plugin.process.freebsd-kernel-core.read-only must be set to false. This setting is available when using /dev/mem or a kernel dump. However, since kvm_write() does not support writing to kernel dumps, writes to a kernel dump will still fail when the setting is false.process plugin refresh-threads, enabling on-demand thread-list reconstruction from /dev/mem so users can resync live kernel thread state without restarting LLDB. Note that this has no impact on full dump and minidump files.On Arm Linux, the tpidruro register can now be read. Writing to this register is not supported.
Thread local variables are now supported on Arm and RISC-V Linux if the program being debugged is using glibc.
LLDB now supports AArch64 Linux systems that only have SME (as opposed to SVE and SME). See the AArch64 Linux documentation for more details.
Prior to this version of LLDB, there was a bug that caused LLDB to crash on startup on these systems (#138717). This affected LLDB versions from 18 up to and including 22. 17 and below are not affected. If you are using such a system and cannot change LLDB version, or want to package an affected version in a way that is compatible with these systems, the issue contains details of backports that could be done to fix the affected versions.
LLDB now supports debugging Linux Memory Protection Keys on AArch64 systems that have the Permission Overlay Extension (POE / FEAT_S1POE). See the LLDB on AArch64 Linux guide for more 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.