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| LLVM {{env.config.release}} Release Notes |
| ========================================= |
| |
| ```{contents} |
| ``` |
| |
| ````{only} PreRelease |
| ```{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). |
| ``` |
| ```` |
| |
| Introduction |
| ============ |
| |
| 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](https://llvm.org/releases/). |
| |
| For more information about LLVM, including information about the latest |
| release, please check out the [main LLVM web site](https://llvm.org/). If you |
| have questions or comments, the [Discourse forums](https://discourse.llvm.org) |
| 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](https://llvm.org/releases/). |
| |
| Non-comprehensive list of changes in this release |
| ================================================= |
| |
| <!-- For small 1-3 sentence descriptions, just add an entry at the end of |
| this list. If your description won't fit comfortably in one bullet |
| point (e.g. maybe you would like to give an example of the |
| functionality, or simply have a lot to talk about), see the comment below |
| for adding a new subsection. --> |
| |
| * ... |
| |
| <!-- If you would like to document a larger change, then you can add a |
| subsection about it right here. You can copy the following boilerplate: |
| |
| Special New Feature |
| ------------------- |
| |
| Makes programs 10x faster by doing Special New Thing. |
| --> |
| |
| Changes to the LLVM IR |
| ---------------------- |
| |
| * The `ptrtoaddr` instruction was introduced. This instruction returns the |
| address component of a pointer type variable but unlike `ptrtoint` does not |
| capture provenance ([#139357](https://github.com/llvm/llvm-project/pull/139357)). |
| * The alignment argument of the `@llvm.masked.load`, `@llvm.masked.store`, |
| `@llvm.masked.gather` and `@llvm.masked.scatter` intrinsics has been removed. |
| Instead, the `align` attribute should be placed on the pointer (or vector of |
| pointers) argument. |
| * A `load atomic` may now be used with vector types on x86. |
| * Added `@llvm.reloc.none` intrinsic to emit null relocations to symbols. This |
| emits an undefined symbol reference without adding any dedicated code or data to |
| to bear the relocation. |
| * Added `modular-format` attribute to dynamically pull in aspects of libc |
| format string function implementations from statically-linked libc's based on |
| the requirements of each call. Currently only `float` is supported; this can |
| keep floating point support out of printf if it can be proven unused. |
| * Case values are no longer operands of `SwitchInst`. |
| * Allow metadata to be attached to IFuncs. |
| |
| Changes to LLVM infrastructure |
| ------------------------------ |
| * On AIX, fixed the OS version in target triples on PASE. |
| * On AIX, automatically raise soft memory limits to hard limits on tool startup ([#167928](https://github.com/llvm/llvm-project/pull/167928)). |
| |
| Changes to building LLVM |
| ------------------------ |
| |
| * On AIX, remove default flag `-fno-semantic-interposition`. |
| * On AIX, LLVM shared libraries are now built as shared library archives by default ([#155686](https://github.com/llvm/llvm-project/pull/155686)). |
| * On AIX, enable building with CMake 4.0 and above ([#154537](https://github.com/llvm/llvm-project/pull/154537)). |
| * On AIX, enable building with the AIX form of the lto cache dir option ([#168868](https://github.com/llvm/llvm-project/pull/168868)). |
| |
| Changes to TableGen |
| ------------------- |
| |
| * The `!getop` and `!setop` bang operators have been removed in favor of |
| `!getdagop` and `!setdagop`. |
| |
| Changes to Interprocedural Optimizations |
| ---------------------------------------- |
| |
| * Added `-enable-machine-outliner={optimistic-pgo,conservative-pgo}` to read |
| profile data to guide the machine outliner |
| ([#154437](https://github.com/llvm/llvm-project/pull/154437)). |
| * Fixed static resolution of indirect calls to versioned functions on AArch64, |
| by separating unrelated caller versions which were previously mixed together. |
| Also improved the accuracy of the algorithm for low version counts. |
| |
| Changes to Vectorizers |
| ---------------------------------------- |
| |
| * Added initial support for copyable elements in SLP, which models copyable |
| elements as add <element>, 0, i.e. uses identity constants for missing lanes. |
| * SLP vectorizer supports initial recognition of FMA/FMAD pattern |
| |
| Changes to the AArch64 Backend |
| ------------------------------ |
| |
| * Assembler/disassembler support has been added for Armv9.7-A (2025) |
| architecture extensions. |
| |
| * Assembler/disassembler support has been added for 'Virtual Tagging |
| Extension (vMTE)' and 'Permission Overlay Extension version 2 (POE2)' |
| Future Architecture Technologies extensions. |
| |
| * `FEAT_TME` support has been removed, as it has been withdrawn from |
| all future versions of the A-profile architecture. |
| |
| * Added support for C1-Nano, C1-Pro, C1-Premium, and C1-Ultra CPUs. |
| |
| * Added support for Ampere1C cores. |
| |
| Changes to the AMDGPU Backend |
| ----------------------------- |
| |
| * Removed `llvm.amdgcn.atomic.cond.sub.u32` and |
| `llvm.amdgcn.atomic.csub.u32` intrinsics. Users should use the |
| `atomicrmw` instruction with `usub_cond` and `usub_sat` instead. |
| |
| 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 |
| -------------------------------- |
| |
| * RuntimeDyld now supports the `Large` code model for LoongArch64. |
| * The `PreserveMost` calling convention is now supported. |
| * An option named `loongarch-enable-merge-offset` is added to allow disabling the `MergeBaseOffset` pass. |
| * A macro instruction named `ud` is added. |
| * `la.abs` now generates `R_LARCH_MARK_LA` relocation. |
| * LASX and LSX conversion intrinsics are added. |
| * Tail calls for `sret` and `byval` functions are now supported. |
| * Always emit symbol-based relocations regardless of relaxation. |
| * DWARF fission is now compatible with linker relaxations, allowing `-gsplit-dwarf` and `-mrelax` |
| to be used together when building for the LoongArch platform. |
| * Improved LoongArch32 support by adding LA32R/LA32S relocations, PC-relative address materialization, and `call`/`tail` macro instructions. |
| * Assorted codegen improvements. |
| |
| Changes to the MIPS Backend |
| --------------------------- |
| |
| Changes to the PowerPC Backend |
| ------------------------------ |
| |
| * `half` now uses a soft float ABI, which works correctly in more cases. |
| * Add ``mtpidr`` alias introduced in ISA3.0. |
| * Update `tlbie` instruction implementation for ISA3.0+. |
| * Update ``strlen``, ``strcpy`` and ``memcmp`` to use milicode calls instead of library calls. |
| * Prototyped intrinsic for xvrlw and load/store with right length left-justified. |
| * Prototyped Elliptic Curve Cryptography (ECC) Instructions. |
| * Prototyped VSX Vector Integer Arithmetic Instructions. |
| * Prototyped AES Acceleration Instructions. |
| * Prototyped vector uncompress instructions. |
| * Prototyped vector unpack instructions. |
| * Prototyped 32-byte indexed paired load and store instructions. |
| * Prototyped Context Switch instruction ``mtlpl``. |
| * Prototyped VSX rotate left word instruction. |
| * Prototyped paddis. |
| * Prototyped eTCE instructions. |
| * Prototyped Dense Math Facility and DMR COPY support. |
| * Implement the trampoline intrinsics and nest parameter for AIX. |
| * Introduced a minimum threshold for the largest number of comparisons needed to trigger bit test generation during switch lowering. |
| * Relax strictfp to constrain only ``libm`` libcalls, permitting non-FP optimizations. |
| * Use ``bne-`` for atomic operations after store conditional. |
| * Consolidated predicate definitions into ``PPC.td``. |
| * Cleanup asm parser code to use template functions for the various versions of |
| ``getImm*Encoding()`` and ``is*Imm()`` used in ``PPCRegisterInfo.td``. |
| |
| Changes to the RISC-V Backend |
| ----------------------------- |
| |
| * The loop vectorizer now performs tail folding by default on RISC-V, which |
| removes the need for a scalar epilogue loop. To restore the previous behaviour |
| use `-prefer-predicate-over-epilogue=scalar-epilogue`. |
| * `llvm-objdump` now has basic support for switching between disassembling code |
| and data using mapping symbols such as `$x` and `$d`. Switching architectures |
| using `$x` with an architecture string suffix is not yet supported. |
| * Ssctr and Smctr extensions are no longer experimental. |
| * Add support for Zvfbfa (Additional BF16 vector compute support) |
| * Adds experimental support for the 'Zibi` (Branch with Immediate) extension. |
| * Add support for Zvfofp8min (OFP8 conversion extension) |
| * Adds assembler support for the Andes `XAndesvsinth` (Andes Vector Small Int Handling Extension). |
| * DWARF fission is now compatible with linker relaxations, allowing `-gsplit-dwarf` and `-mrelax` |
| to be used together when building for the RISC-V platform. |
| * The Xqci Qualcomm uC Vendor Extension is no longer marked as experimental. |
| * The Xqccmp Qualcomm Vendor Extension is no longer marked as experimental. |
| |
| Changes to the WebAssembly Backend |
| ---------------------------------- |
| |
| * `half` now uses a soft float lowering, which resolves various precision and |
| bitcast issues. |
| |
| - The `wasm32-wasi` target has been renamed to `wasm32-wasip1`. The old |
| option is still recognized, though by default will emit a deprecation |
| warning. |
| |
| Changes to the Windows Target |
| ----------------------------- |
| |
| * `-fpseudo-probe-for-profiling` is now supported for COFF. |
| |
| Changes to the X86 Backend |
| -------------------------- |
| |
| * `-mcpu=wildcatlake` is now supported. |
| * `-mcpu=novalake` is now supported. |
| |
| Changes to the OCaml bindings |
| ----------------------------- |
| |
| * The IR reader bindings renamed `parse_ir` to |
| `parse_ir_bitcode_or_assembly` to clarify that the parser accepts both |
| textual IR and bitcode. This rename is intentional to force existing code to |
| update because the ownership semantics changed: the function no longer takes |
| ownership of the input memory buffer. |
| |
| Changes to the Python bindings |
| ------------------------------ |
| |
| Changes to the C API |
| -------------------- |
| |
| * Add `LLVMGetOrInsertFunction` to get or insert a function, replacing the combination of `LLVMGetNamedFunction` and `LLVMAddFunction`. |
| * Allow `LLVMGetVolatile` to work with any kind of Instruction. |
| * Add `LLVMConstFPFromBits` to get a constant floating-point value from an array of 64 bit values. |
| * Add `LLVMParseIRInContext2`, which is equivalent to `LLVMParseIRInContext` |
| but does not take ownership of the input `LLVMMemoryBufferRef`. This matches |
| the underlying C++ API and avoids ownership surprises in language bindings |
| and examples. |
| * Functions working on the global context have been deprecated. Use the |
| functions that work on a specific context instead. |
| |
| * `LLVMGetGlobalContext` -> use `LLVMContextCreate` context instead |
| * `LLVMInt1Type` -> `LLVMInt1TypeInContext` |
| * `LLVMInt8Type` -> `LLVMInt8TypeInContext` |
| * `LLVMInt16Type` -> `LLVMInt16TypeInContext` |
| * `LLVMInt32Type` -> `LLVMInt32TypeInContext` |
| * `LLVMInt64Type` -> `LLVMInt64TypeInContext` |
| * `LLVMInt128Type` -> `LLVMInt128TypeInContext` |
| * `LLVMIntType` -> `LLVMIntTypeInContext` |
| * `LLVMHalfType` -> `LLVMHalfTypeInContext` |
| * `LLVMBFloatType` -> `LLVMBFloatTypeInContext` |
| * `LLVMFloatType` -> `LLVMFloatTypeInContext` |
| * `LLVMDoubleType` -> `LLVMDoubleTypeInContext` |
| * `LLVMX86FP80Type` -> `LLVMX86FP80TypeInContext` |
| * `LLVMFP128Type` -> `LLVMFP128TypeInContext` |
| * `LLVMPPCFP128Type` -> `LLVMPPCFP128TypeInContext` |
| * `LLVMStructType` -> `LLVMStructTypeInContext` |
| * `LLVMVoidType` -> `LLVMVoidTypeInContext` |
| * `LLVMLabelType` -> `LLVMLabelTypeInContext` |
| * `LLVMX86AMXType` -> `LLVMX86AMXTypeInContext` |
| * `LLVMConstString` -> `LLVMConstStringInContext2` |
| * `LLVMConstStruct` -> `LLVMConstStructInContext` |
| * `LLVMMDString` -> `LLVMMDStringInContext2` |
| * `LLVMMDNode` -> `LLVMMDNodeInContext2` |
| * `LLVMAppendBasicBlock` -> `LLVMAppendBasicBlockInContext` |
| * `LLVMInsertBasicBlock` -> `LLVMInsertBasicBlockInContext` |
| * `LLVMCreateBuilder` -> `LLVMCreateBuilderInContext` |
| * `LLVMIntPtrType` -> `LLVMIntPtrTypeInContext` |
| * `LLVMIntPtrTypeForAS` -> `LLVMIntPtrTypeForASInContext` |
| * `LLVMParseBitcode` -> `LLVMParseBitcodeInContext2` |
| * `LLVMParseBitcode2` -> `LLVMParseBitcodeInContext2` |
| * `LLVMGetBitcodeModule` -> `LLVMGetBitcodeModuleInContext2` |
| * `LLVMGetBitcodeModule2` -> `LLVMGetBitcodeModuleInContext2` |
| * Add `LLVMGetSwitchCaseValue` and `LLVMSetSwitchCaseValue` to get and set switch case values; switch case values are no longer operands of the instruction. |
| |
| Changes to the CodeGen infrastructure |
| ------------------------------------- |
| |
| Changes to the Metadata Info |
| --------------------------------- |
| |
| Changes to the Debug Info |
| --------------------------------- |
| |
| Changes to the LLVM tools |
| --------------------------------- |
| |
| * `llvm-profgen` now supports decoding pseudo probe for COFF binaries. |
| |
| * `llvm-readelf` now dumps all hex format values in lower-case mode. |
| * Some code paths for supporting Python 2.7 in `llvm-lit` have been removed. |
| * Support for `%T` in lit has been removed. |
| * Add `--save-stats` option to `llc` to save LLVM statistics to a file. Compatible with the Clang option. |
| * Add `--save-stats` option to `opt` to save LLVM statistics to a file. Compatible with the Clang option. |
| |
| * `llvm-config` gained a new flag `--quote-paths` which quotes and escapes paths |
| emitted on stdout, to account for spaces or other special characters in path. |
| (`#97305 <https://github.com/llvm/llvm-project/pull/97305>`_). |
| |
| * `llvm-objdump` now supports using `--mcpu=help` and `--mattr=help` with the `--triple` option |
| without requiring an input file or the `-d` (disassemble) flag. |
| |
| Changes to LLDB |
| --------------------------------- |
| |
| * LLDB can now set breakpoints, show backtraces, and display variables when |
| debugging Wasm with supported runtimes (WAMR and V8). |
| * LLDB now has a Wasm platform, which can be configured to run WebAssembly |
| binaries directly under a Wasm runtime. Configurable through the |
| platform.plugin.wasm settings. |
| * LLDB no longer stops processes by default when receiving SIGWINCH signals |
| (window resize events) on Linux. This is the default on other Unix platforms. |
| You can re-enable it using `process handle --notify=true --stop=true SIGWINCH`. |
| * The `show-progress` setting, which became a NOOP with the introduction of the |
| statusline, now defaults to off and controls using OSC escape codes to show a |
| native progress bar in supporting terminals like Ghostty and ConEmu. |
| * The default PDB reader on Windows was changed from DIA to native, which uses |
| LLVM's PDB and CodeView support. You can switch back to the DIA reader with |
| `settings set plugin.symbol-file.pdb.reader dia`. Note that support for the |
| DIA reader will be removed in a future version of LLDB. |
| * A `--verbose` option was added to the `version` command. When `--verbose` is used, |
| LLDB's build configuration is included in the command's output. This includes |
| all the supported targets, along with the presence of (or lack of) optional |
| features like XML parsing. |
| * LLDB now includes formatters for many types from the MSVC STL. |
| * DIL (the new `frame variable` implementation) now uses ':' as a bitfield |
| extraction range character. '-' is deprecated and will output an error when used. |
| * LLDB 22 is the last release supporting FreeBSD 13 and below. As a result, |
| LLDB 23 will remove support for FreeBSD on MIPS64 and assume that FreeBSD targets |
| have watchpoint support. |
| |
| Changes to BOLT |
| --------------------------------- |
| |
| * Added support for lite mode on AArch64. It can be enabled with -lite=1. When |
| used, BOLT avoids duplicating cold code by reusing the original code, which |
| reduces output binary size. |
| |
| Changes to Sanitizers |
| --------------------- |
| |
| * Support running TypeSanitizer with UndefinedBehaviourSanitizer. |
| * TypeSanitizer no longer inlines all instrumentation by default. Added the |
| `-f[no-]sanitize-type-outline-instrumentation` flags to give users control |
| over this behaviour. |
| |
| Other Changes |
| ------------- |
| |
| * Introduces the `AllocToken` pass, an instrumentation pass providing tokens to |
| memory allocators enabling various heap organization strategies, such as heap |
| partitioning. |
| |
| * Integrated Distributed ThinLTO (DTLTO) aims to support distribution of ThinLTO |
| backend compilations for any in-process ThinLTO invocation. To enable this, |
| support for the ThinLTO cache (for incremental builds) has been added in this |
| release, and support for additional input file types has been implemented. |
| |
| Bitcode objects contained in static libraries and archives (e.g. libc.a) are |
| now handled transparently by temporarily extracting referenced objects for |
| distribution. When thin archives are used (supported since LLVM 21), no |
| extraction is required. |
| |
| DTLTO creates a number of temporary files during operation, which are now |
| cleaned up correctly when the process exits abnormally, for example due to |
| Ctrl+C or similar termination events. |
| |
| A new DTLTO linker option, --thinlto-remote-compiler-prepend-arg, has been |
| added to support multi-call LLVM drivers. This option allows specifying an |
| additional argument to select the desired subcommand, for example |
| `llvm clang ....` |
| |
| Note that ELF and COFF remain the only supported platforms. |
| |
| External Open Source Projects Using LLVM {{env.config.release}} |
| =============================================================== |
| |
| * A project... |
| |
| Additional Information |
| ====================== |
| |
| A wide variety of additional information is available on the |
| [LLVM web page](https://llvm.org/), in particular in the |
| [documentation](https://llvm.org/docs/) 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](https://discourse.llvm.org). |
