9 These are in-progress notes for the upcoming LLVM 3.8 release. You may
10 prefer the `LLVM 3.7 Release Notes <http://llvm.org/releases/3.7.0/docs
11 /ReleaseNotes.html>`_.
17 This document contains the release notes for the LLVM Compiler Infrastructure,
18 release 3.8. Here we describe the status of LLVM, including major improvements
19 from the previous release, improvements in various subprojects of LLVM, and
20 some of the current users of the code. All LLVM releases may be downloaded
21 from the `LLVM releases web site <http://llvm.org/releases/>`_.
23 For more information about LLVM, including information about the latest
24 release, please check out the `main LLVM web site <http://llvm.org/>`_. If you
25 have questions or comments, the `LLVM Developer's Mailing List
26 <http://lists.llvm.org/mailman/listinfo/llvm-dev>`_ is a good place to send
29 Note that if you are reading this file from a Subversion checkout or the main
30 LLVM web page, this document applies to the *next* release, not the current
31 one. To see the release notes for a specific release, please see the `releases
32 page <http://llvm.org/releases/>`_.
34 Non-comprehensive list of changes in this release
35 =================================================
36 * With this release, the minimum Windows version required for running LLVM is
37 Windows 7. Earlier versions, including Windows Vista and XP are no longer
40 * With this release, the autoconf build system is deprecated. It will be removed
41 in the 3.9 release. Please migrate to using CMake. For more information see:
42 `Building LLVM with CMake <CMake.html>`_
44 * The C API function LLVMLinkModules is deprecated. It will be removed in the
45 3.9 release. Please migrate to LLVMLinkModules2. Unlike the old function the
48 * Doesn't take an unused parameter.
49 * Destroys the source instead of only damaging it.
50 * Does not record a message. Use the diagnostic handler instead.
52 * The C API functions LLVMParseBitcode, LLVMParseBitcodeInContext,
53 LLVMGetBitcodeModuleInContext and LLVMGetBitcodeModule have been deprecated.
54 They will be removed in 3.9. Please migrate to the versions with a 2 suffix.
55 Unlike the old ones the new ones do not record a diagnostic message. Use
56 the diagnostic handler instead.
58 * The deprecated C APIs LLVMGetBitcodeModuleProviderInContext and
59 LLVMGetBitcodeModuleProvider have been removed.
61 * The deprecated C APIs LLVMCreateExecutionEngine, LLVMCreateInterpreter,
62 LLVMCreateJITCompiler, LLVMAddModuleProvider and LLVMRemoveModuleProvider
65 * With this release, the C API headers have been reorganized to improve build
66 time. Type specific declarations have been moved to Type.h, and error
67 handling routines have been moved to ErrorHandling.h. Both are included in
68 Core.h so nothing should change for projects directly including the headers,
69 but transitive dependencies may be affected.
71 * llvm-ar now suports thin archives.
73 * llvm doesn't produce .data.rel.ro.local or .data.rel sections anymore.
75 * aliases to available_externally globals are now rejected by the verifier.
77 * the IR Linker has been split into IRMover that moves bits from one module to
78 another and Linker proper that decides what to link.
80 * Support for dematerializing has been dropped.
82 * ``ilist_iterator<T>`` no longer has implicit conversions to and from ``T*``,
83 since ``ilist_iterator<T>`` may be pointing at the sentinel (which is usually
84 not of type ``T`` at all). To convert from an iterator ``I`` to a pointer,
85 use ``&*I``; to convert from a pointer ``P`` to an iterator, use
86 ``P->getIterator()``. Alternatively, explicit conversions via
87 ``static_cast<T>(U)`` are still available.
89 * ``ilist_node<T>::getNextNode()`` and ``ilist_node<T>::getPrevNode()`` now
90 fail at compile time when the node cannot access its parent list.
91 Previously, when the sentinel was was an ``ilist_half_node<T>``, this API
92 could return the sentinal instead of ``nullptr``. Frustrated callers should
93 be updated to use ``iplist<T>::getNextNode(T*)`` instead. Alternatively, if
94 the node ``N`` is guaranteed not to be the last in the list, it is safe to
95 call ``&*++N->getIterator()`` directly.
98 For small 1-3 sentence descriptions, just add an entry at the end of
99 this list. If your description won't fit comfortably in one bullet
100 point (e.g. maybe you would like to give an example of the
101 functionality, or simply have a lot to talk about), see the `NOTE` below
102 for adding a new subsection.
104 * ... next change ...
107 If you would like to document a larger change, then you can add a
108 subsection about it right here. You can copy the following boilerplate
109 and un-indent it (the indentation causes it to be inside this comment).
114 Makes programs 10x faster by doing Special New Thing.
116 Changes to the ARM Backend
117 --------------------------
119 During this release ...
122 Changes to the MIPS Target
123 --------------------------
125 During this release the MIPS target has:
127 * Significantly extended support for the Integrated Assembler. See below for
129 * Added support for the ``P5600`` processor.
130 * Added support for the ``interrupt`` attribute for MIPS32R2 and later. This
131 attribute will generate a function which can be used as a interrupt handler
132 on bare metal MIPS targets using the static relocation model.
133 * Added support for the ``ERETNC`` instruction found in MIPS32R5 and later.
134 * Added support for OpenCL. See http://portablecl.org/.
136 * Address spaces 1 to 255 are now reserved for software use and conversions
137 between them are no-op casts.
139 * Removed the ``mips16`` value for the -mcpu option since it is an :abbr:`ASE
140 (Application Specific Extension)` and not a processor. If you were using this,
141 please specify another CPU and use ``-mips16`` to enable MIPS16.
142 * Removed ``copy_u.w`` from 32-bit MSA and ``copy_u.d`` from 64-bit MSA since
143 they have been removed from the MSA specification due to forward compatibility
144 issues. For example, 32-bit MSA code containing ``copy_u.w`` would behave
145 differently on a 64-bit processor supporting MSA. The corresponding intrinsics
146 are still available and may expand to ``copy_s.[wd]`` where this is
147 appropriate for forward compatibility purposes.
148 * Relaxed the ``-mnan`` option to allow ``-mnan=2008`` on MIPS32R2/MIPS64R2 for
149 compatibility with GCC.
150 * Made MIPS64R6 the default CPU for 64-bit Android triples.
152 The MIPS target has also fixed various bugs including the following notable
155 * Fixed reversed operands on ``mthi``/``mtlo`` in the DSP :abbr:`ASE
156 (Application Specific Extension)`.
157 * The code generator no longer uses ``jal`` for calls to absolute immediate
159 * Disabled fast instruction selection on MIPS32R6 and MIPS64R6 since this is not
161 * Corrected addend for ``R_MIPS_HI16`` and ``R_MIPS_PCHI16`` in MCJIT
162 * The code generator no longer crashes when handling subregisters of an 64-bit
163 FPU register with undefined value.
164 * The code generator no longer attempts to use ``$zero`` for operands that do
165 not permit ``$zero``.
166 * Corrected the opcode used for ``ll``/``sc`` when using MIPS32R6/MIPS64R6 and
167 the Integrated Assembler.
168 * Added support for atomic load and atomic store.
169 * Corrected debug info when dynamically re-aligning the stack.
173 We have made a large number of improvements to the integrated assembler for
174 MIPS. In this release, the integrated assembler isn't quite production-ready
175 since there are a few known issues related to bare-metal support, checking
176 immediates on instructions, and the N32/N64 ABI's. However, the current support
177 should be sufficient for many users of the O32 ABI, particularly those targeting
178 MIPS32 on Linux or bare-metal MIPS32.
180 If you would like to try the integrated assembler, please use
183 Changes to the PowerPC Target
184 -----------------------------
186 During this release ...
189 Changes to the X86 Target
190 -----------------------------
192 During this release ...
194 * TLS is enabled for Cygwin as emutls.
197 Changes to the OCaml bindings
198 -----------------------------
200 During this release ...
202 * The ocaml function link_modules has been replaced with link_modules' which
203 uses LLVMLinkModules2.
206 External Open Source Projects Using LLVM 3.8
207 ============================================
209 An exciting aspect of LLVM is that it is used as an enabling technology for
210 a lot of other language and tools projects. This section lists some of the
211 projects that have already been updated to work with LLVM 3.8.
213 LDC - the LLVM-based D compiler
214 -------------------------------
216 `D <http://dlang.org>`_ is a language with C-like syntax and static typing. It
217 pragmatically combines efficiency, control, and modeling power, with safety and
218 programmer productivity. D supports powerful concepts like Compile-Time Function
219 Execution (CTFE) and Template Meta-Programming, provides an innovative approach
220 to concurrency and offers many classical paradigms.
222 `LDC <http://wiki.dlang.org/LDC>`_ uses the frontend from the reference compiler
223 combined with LLVM as backend to produce efficient native code. LDC targets
224 x86/x86_64 systems like Linux, OS X and Windows and also PowerPC (32/64 bit)
225 and ARM. Ports to other architectures like AArch64 and MIPS64 are underway.
228 Additional Information
229 ======================
231 A wide variety of additional information is available on the `LLVM web page
232 <http://llvm.org/>`_, in particular in the `documentation
233 <http://llvm.org/docs/>`_ section. The web page also contains versions of the
234 API documentation which is up-to-date with the Subversion version of the source
235 code. You can access versions of these documents specific to this release by
236 going into the ``llvm/docs/`` directory in the LLVM tree.
238 If you have any questions or comments about LLVM, please feel free to contact
239 us via the `mailing lists <http://llvm.org/docs/#maillist>`_.