1 ========================
2 LLVM 4.0.0 Release Notes
3 ========================
9 These are in-progress notes for the upcoming LLVM 4.0.0 release. You may
10 prefer the `LLVM 3.9 Release Notes <http://llvm.org/releases/3.9.0/docs
11 /ReleaseNotes.html>`_.
17 This document contains the release notes for the LLVM Compiler Infrastructure,
18 release 4.0.0. 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 Non-comprehensive list of changes in this release
30 =================================================
31 * The C API functions LLVMAddFunctionAttr, LLVMGetFunctionAttr,
32 LLVMRemoveFunctionAttr, LLVMAddAttribute, LLVMRemoveAttribute,
33 LLVMGetAttribute, LLVMAddInstrAttribute and
34 LLVMRemoveInstrAttribute have been removed.
36 * The C API enum LLVMAttribute has been deleted.
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.
45 * The definition and uses of LLVM_ATRIBUTE_UNUSED_RESULT in the LLVM source
46 were replaced with LLVM_NODISCARD, which matches the C++17 [[nodiscard]]
47 semantics rather than gcc's __attribute__((warn_unused_result)).
49 * Minimum compiler version to build has been raised to GCC 4.8 and VS 2015.
51 * The Timer related APIs now expect a Name and Description. When upgrading code
52 the previously used names should become descriptions and a short name in the
53 style of a programming language identifier should be added.
55 * LLVM now handles invariant.group across different basic blocks, which makes
56 it possible to devirtualize virtual calls inside loops.
61 If you would like to document a larger change, then you can add a
62 subsection about it right here. You can copy the following boilerplate
63 and un-indent it (the indentation causes it to be inside this comment).
68 Makes programs 10x faster by doing Special New Thing.
70 Changes to the LLVM IR
71 ----------------------
73 Changes to the ARM Backend
74 --------------------------
76 During this release ...
79 Changes to the MIPS Target
80 --------------------------
82 During this release ...
85 Changes to the PowerPC Target
86 -----------------------------
88 During this release ...
90 Changes to the X86 Target
91 -------------------------
93 During this release ...
95 Changes to the AMDGPU Target
96 -----------------------------
98 During this release ...
100 Changes to the AVR Target
101 -----------------------------
103 * The entire backend has been merged in-tree with all tests passing. All of
104 the instruction selection code and the machine code backend has landed
105 recently and is fully usable.
107 Changes to the OCaml bindings
108 -----------------------------
110 * The attribute API was completely overhauled, following the changes
114 External Open Source Projects Using LLVM 4.0.0
115 ==============================================
120 Additional Information
121 ======================
123 A wide variety of additional information is available on the `LLVM web page
124 <http://llvm.org/>`_, in particular in the `documentation
125 <http://llvm.org/docs/>`_ section. The web page also contains versions of the
126 API documentation which is up-to-date with the Subversion version of the source
127 code. You can access versions of these documents specific to this release by
128 going into the ``llvm/docs/`` directory in the LLVM tree.
130 If you have any questions or comments about LLVM, please feel free to contact
131 us via the `mailing lists <http://llvm.org/docs/#maillist>`_.