|
| 1 | +============================ |
| 2 | +LLVM |release| Release Notes |
| 3 | +============================ |
| 4 | + |
| 5 | +.. contents:: |
| 6 | + :local: |
| 7 | + |
| 8 | +.. only:: PreRelease |
| 9 | + |
| 10 | + .. warning:: |
| 11 | + These are in-progress notes for the upcoming LLVM |version| release. |
| 12 | + Release notes for previous releases can be found on |
| 13 | + `the Download Page <https://releases.llvm.org/download.html>`_. |
| 14 | + |
| 15 | + |
| 16 | +Introduction |
| 17 | +============ |
| 18 | + |
| 19 | +This document contains the release notes for the LLVM Compiler Infrastructure, |
| 20 | +release |release|. Here we describe the status of LLVM, including major improvements |
| 21 | +from the previous release, improvements in various subprojects of LLVM, and |
| 22 | +some of the current users of the code. All LLVM releases may be downloaded |
| 23 | +from the `LLVM releases web site <https://llvm.org/releases/>`_. |
| 24 | + |
| 25 | +For more information about LLVM, including information about the latest |
| 26 | +release, please check out the `main LLVM web site <https://llvm.org/>`_. If you |
| 27 | +have questions or comments, the `Discourse forums |
| 28 | +<https://discourse.llvm.org>`_ is a good place to ask |
| 29 | +them. |
| 30 | + |
| 31 | +Note that if you are reading this file from a Git checkout or the main |
| 32 | +LLVM web page, this document applies to the *next* release, not the current |
| 33 | +one. To see the release notes for a specific release, please see the `releases |
| 34 | +page <https://llvm.org/releases/>`_. |
| 35 | + |
| 36 | +Non-comprehensive list of changes in this release |
| 37 | +================================================= |
| 38 | +.. NOTE |
| 39 | + For small 1-3 sentence descriptions, just add an entry at the end of |
| 40 | + this list. If your description won't fit comfortably in one bullet |
| 41 | + point (e.g. maybe you would like to give an example of the |
| 42 | + functionality, or simply have a lot to talk about), see the `NOTE` below |
| 43 | + for adding a new subsection. |
| 44 | +
|
| 45 | +* ... |
| 46 | + |
| 47 | +Update on required toolchains to build LLVM |
| 48 | +------------------------------------------- |
| 49 | + |
| 50 | +Changes to the LLVM IR |
| 51 | +---------------------- |
| 52 | + |
| 53 | +* The ``x86_mmx`` IR type has been removed. It will be translated to |
| 54 | + the standard vector type ``<1 x i64>`` in bitcode upgrade. |
| 55 | +* Renamed ``llvm.experimental.stepvector`` intrinsic to ``llvm.stepvector``. |
| 56 | + |
| 57 | +* Added ``usub_cond`` and ``usub_sat`` operations to ``atomicrmw``. |
| 58 | + |
| 59 | +* Added ``U<address space>`` to data layout to represent undesirable address space |
| 60 | + if a target has it. |
| 61 | + |
| 62 | +Changes to LLVM infrastructure |
| 63 | +------------------------------ |
| 64 | + |
| 65 | +Changes to building LLVM |
| 66 | +------------------------ |
| 67 | + |
| 68 | +Changes to TableGen |
| 69 | +------------------- |
| 70 | + |
| 71 | +Changes to Interprocedural Optimizations |
| 72 | +---------------------------------------- |
| 73 | + |
| 74 | +Changes to the AArch64 Backend |
| 75 | +------------------------------ |
| 76 | + |
| 77 | +* `.balign N, 0`, `.p2align N, 0`, `.align N, 0` in code sections will now fill |
| 78 | + the required alignment space with a sequence of `0x0` bytes (the requested |
| 79 | + fill value) rather than NOPs. |
| 80 | + |
| 81 | +Changes to the AMDGPU Backend |
| 82 | +----------------------------- |
| 83 | + |
| 84 | +* Removed ``llvm.amdgcn.flat.atomic.fadd`` and |
| 85 | + ``llvm.amdgcn.global.atomic.fadd`` intrinsics. Users should use the |
| 86 | + :ref:`atomicrmw <i_atomicrmw>` instruction with `fadd` and |
| 87 | + addrspace(0) or addrspace(1) instead. |
| 88 | + |
| 89 | +Changes to the ARM Backend |
| 90 | +-------------------------- |
| 91 | + |
| 92 | +* `.balign N, 0`, `.p2align N, 0`, `.align N, 0` in code sections will now fill |
| 93 | + the required alignment space with a sequence of `0x0` bytes (the requested |
| 94 | + fill value) rather than NOPs. |
| 95 | + |
| 96 | +Changes to the AVR Backend |
| 97 | +-------------------------- |
| 98 | + |
| 99 | +Changes to the DirectX Backend |
| 100 | +------------------------------ |
| 101 | + |
| 102 | +Changes to the Hexagon Backend |
| 103 | +------------------------------ |
| 104 | + |
| 105 | +Changes to the LoongArch Backend |
| 106 | +-------------------------------- |
| 107 | + |
| 108 | +Changes to the MIPS Backend |
| 109 | +--------------------------- |
| 110 | + |
| 111 | +Changes to the PowerPC Backend |
| 112 | +------------------------------ |
| 113 | + |
| 114 | +Changes to the RISC-V Backend |
| 115 | +----------------------------- |
| 116 | + |
| 117 | +* `.balign N, 0`, `.p2align N, 0`, `.align N, 0` in code sections will now fill |
| 118 | + the required alignment space with a sequence of `0x0` bytes (the requested |
| 119 | + fill value) rather than NOPs. |
| 120 | +* Added Syntacore SCR4 and SCR5 CPUs: ``-mcpu=syntacore-scr4/5-rv32/64`` |
| 121 | +* ``-mcpu=sifive-p470`` was added. |
| 122 | +* Added Hazard3 CPU as taped out for RP2350: ``-mcpu=rp2350-hazard3`` (32-bit |
| 123 | + only). |
| 124 | +* Fixed length vector support using RVV instructions now requires VLEN>=64. This |
| 125 | + means Zve32x and Zve32f will also require Zvl64b. The prior support was |
| 126 | + largely untested. |
| 127 | +* The ``Zvbc32e`` and ``Zvkgs`` extensions are now supported experimentally. |
| 128 | +* Added ``Smctr`` and ``Ssctr`` extensions. |
| 129 | +* ``-mcpu=syntacore-scr7`` was added. |
| 130 | + |
| 131 | +Changes to the WebAssembly Backend |
| 132 | +---------------------------------- |
| 133 | + |
| 134 | +Changes to the Windows Target |
| 135 | +----------------------------- |
| 136 | + |
| 137 | +Changes to the X86 Backend |
| 138 | +-------------------------- |
| 139 | + |
| 140 | +* `.balign N, 0x90`, `.p2align N, 0x90`, and `.align N, 0x90` in code sections |
| 141 | + now fill the required alignment space with repeating `0x90` bytes, rather than |
| 142 | + using optimised NOP filling. Optimised NOP filling fills the space with NOP |
| 143 | + instructions of various widths, not just those that use the `0x90` byte |
| 144 | + encoding. To use optimised NOP filling in a code section, leave off the |
| 145 | + "fillval" argument, i.e. `.balign N`, `.p2align N` or `.align N` respectively. |
| 146 | + |
| 147 | +* Due to the removal of the ``x86_mmx`` IR type, functions with |
| 148 | + ``x86_mmx`` arguments or return values will use a different, |
| 149 | + incompatible, calling convention ABI. Such functions are not |
| 150 | + generally seen in the wild (Clang never generates them!), so this is |
| 151 | + not expected to result in real-world compatibility problems. |
| 152 | + |
| 153 | +* Support ISA of ``AVX10.2-256`` and ``AVX10.2-512``. |
| 154 | + |
| 155 | +Changes to the OCaml bindings |
| 156 | +----------------------------- |
| 157 | + |
| 158 | +Changes to the Python bindings |
| 159 | +------------------------------ |
| 160 | + |
| 161 | +Changes to the C API |
| 162 | +-------------------- |
| 163 | + |
| 164 | +* The following symbols are deleted due to the removal of the ``x86_mmx`` IR type: |
| 165 | + |
| 166 | + * ``LLVMX86_MMXTypeKind`` |
| 167 | + * ``LLVMX86MMXTypeInContext`` |
| 168 | + * ``LLVMX86MMXType`` |
| 169 | + |
| 170 | + * The following functions are added to further support non-null-terminated strings: |
| 171 | + |
| 172 | + * ``LLVMGetNamedFunctionWithLength`` |
| 173 | + * ``LLVMGetNamedGlobalWithLength`` |
| 174 | + |
| 175 | +* The following functions are added to access the ``LLVMContextRef`` associated |
| 176 | + with ``LLVMValueRef`` and ``LLVMBuilderRef`` objects: |
| 177 | + |
| 178 | + * ``LLVMGetValueContext`` |
| 179 | + * ``LLVMGetBuilderContext`` |
| 180 | + |
| 181 | +* The new pass manager can now be invoked with a custom alias analysis pipeline, using |
| 182 | + the ``LLVMPassBuilderOptionsSetAAPipeline`` function. |
| 183 | + |
| 184 | +* It is now also possible to run the new pass manager on a single function, by calling |
| 185 | + ``LLVMRunPassesOnFunction`` instead of ``LLVMRunPasses``. |
| 186 | + |
| 187 | +* Support for creating instructions with custom synchronization scopes has been added: |
| 188 | + |
| 189 | + * ``LLVMGetSyncScopeID`` to map a synchronization scope name to an ID. |
| 190 | + * ``LLVMBuildFenceSyncScope``, ``LLVMBuildAtomicRMWSyncScope`` and |
| 191 | + ``LLVMBuildAtomicCmpXchgSyncScope`` versions of the existing builder functions |
| 192 | + with an additional synchronization scope ID parameter. |
| 193 | + * ``LLVMGetAtomicSyncScopeID`` and ``LLVMSetAtomicSyncScopeID`` to get and set the |
| 194 | + synchronization scope of any atomic instruction. |
| 195 | + * ``LLVMIsAtomic`` to check if an instruction is atomic, for use with the above functions. |
| 196 | + Because of backwards compatibility, ``LLVMIsAtomicSingleThread`` and |
| 197 | + ``LLVMSetAtomicSingleThread`` continue to work with any instruction type. |
| 198 | + |
| 199 | +* The `LLVMSetPersonalityFn` and `LLVMSetInitializer` APIs now support clearing the |
| 200 | + personality function and initializer respectively by passing a null pointer. |
| 201 | + |
| 202 | +* The following functions are added to allow iterating over debug records attached to |
| 203 | + instructions: |
| 204 | + |
| 205 | + * ``LLVMGetFirstDbgRecord`` |
| 206 | + * ``LLVMGetLastDbgRecord`` |
| 207 | + * ``LLVMGetNextDbgRecord`` |
| 208 | + * ``LLVMGetPreviousDbgRecord`` |
| 209 | + |
| 210 | + |
| 211 | +Changes to the CodeGen infrastructure |
| 212 | +------------------------------------- |
| 213 | + |
| 214 | +Changes to the Metadata Info |
| 215 | +--------------------------------- |
| 216 | + |
| 217 | +Changes to the Debug Info |
| 218 | +--------------------------------- |
| 219 | + |
| 220 | +Changes to the LLVM tools |
| 221 | +--------------------------------- |
| 222 | + |
| 223 | +Changes to LLDB |
| 224 | +--------------------------------- |
| 225 | + |
| 226 | +Changes to BOLT |
| 227 | +--------------------------------- |
| 228 | + |
| 229 | +Changes to Sanitizers |
| 230 | +--------------------- |
| 231 | + |
| 232 | +Other Changes |
| 233 | +------------- |
| 234 | + |
| 235 | +External Open Source Projects Using LLVM 19 |
| 236 | +=========================================== |
| 237 | + |
| 238 | +* A project... |
| 239 | + |
| 240 | +Additional Information |
| 241 | +====================== |
| 242 | + |
| 243 | +A wide variety of additional information is available on the `LLVM web page |
| 244 | +<https://llvm.org/>`_, in particular in the `documentation |
| 245 | +<https://llvm.org/docs/>`_ section. The web page also contains versions of the |
| 246 | +API documentation which is up-to-date with the Git version of the source |
| 247 | +code. You can access versions of these documents specific to this release by |
| 248 | +going into the ``llvm/docs/`` directory in the LLVM tree. |
| 249 | + |
| 250 | +If you have any questions or comments about LLVM, please feel free to contact |
| 251 | +us via the `Discourse forums <https://discourse.llvm.org>`_. |
0 commit comments