forked from OSchip/llvm-project
171 lines
5.9 KiB
ReStructuredText
171 lines
5.9 KiB
ReStructuredText
======================
|
|
LLVM 3.9 Release Notes
|
|
======================
|
|
|
|
.. contents::
|
|
:local:
|
|
|
|
.. warning::
|
|
These are in-progress notes for the upcoming LLVM 3.9 release. You may
|
|
prefer the `LLVM 3.8 Release Notes <http://llvm.org/releases/3.8.0/docs
|
|
/ReleaseNotes.html>`_.
|
|
|
|
|
|
Introduction
|
|
============
|
|
|
|
This document contains the release notes for the LLVM Compiler Infrastructure,
|
|
release 3.9. 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 <http://llvm.org/releases/>`_.
|
|
|
|
For more information about LLVM, including information about the latest
|
|
release, please check out the `main LLVM web site <http://llvm.org/>`_. If you
|
|
have questions or comments, the `LLVM Developer's Mailing List
|
|
<http://lists.llvm.org/mailman/listinfo/llvm-dev>`_ is a good place to send
|
|
them.
|
|
|
|
Note that if you are reading this file from a Subversion 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 <http://llvm.org/releases/>`_.
|
|
|
|
Non-comprehensive list of changes in this release
|
|
=================================================
|
|
* The LLVMContext gains a new runtime check (see
|
|
LLVMContext::discardValueNames()) that can be set to discard Value names
|
|
(other than GlobalValue). This is intended to be used in release builds by
|
|
clients that are interested in saving CPU/memory as much as possible.
|
|
|
|
* There is no longer a "global context" available in LLVM, except for the C API.
|
|
|
|
* .. note about autoconf build having been removed.
|
|
|
|
* .. note about C API functions LLVMParseBitcode,
|
|
LLVMParseBitcodeInContext, LLVMGetBitcodeModuleInContext and
|
|
LLVMGetBitcodeModule having been removed. LLVMGetTargetMachineData has been
|
|
removed (use LLVMGetDataLayout instead).
|
|
|
|
* The C API function LLVMLinkModules has been removed.
|
|
|
|
* The C API function LLVMAddTargetData has been removed.
|
|
|
|
* The C API function LLVMGetDataLayout is deprecated
|
|
in favor of LLVMGetDataLayoutStr.
|
|
|
|
* The C API enum LLVMAttribute is deprecated in favor of
|
|
LLVMGetAttrKindID.
|
|
|
|
* ``TargetFrameLowering::eliminateCallFramePseudoInstr`` now returns an
|
|
iterator to the next instruction instead of ``void``. Targets that previously
|
|
did ``MBB.erase(I); return;`` now probably want ``return MBB.erase(I);``.
|
|
|
|
.. NOTE
|
|
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 `NOTE` below
|
|
for adding a new subsection.
|
|
|
|
* ... next change ...
|
|
|
|
.. NOTE
|
|
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
|
|
and un-indent it (the indentation causes it to be inside this comment).
|
|
|
|
Special New Feature
|
|
-------------------
|
|
|
|
Makes programs 10x faster by doing Special New Thing.
|
|
|
|
Changes to the LLVM IR
|
|
----------------------
|
|
|
|
* New intrinsics ``llvm.masked.load``, ``llvm.masked.store``,
|
|
``llvm.masked.gather`` and ``llvm.masked.scatter`` were introduced to the
|
|
LLVM IR to allow selective memory access for vector data types.
|
|
|
|
Changes to LLVM's IPO model
|
|
---------------------------
|
|
|
|
LLVM no longer does inter-procedural analysis and optimization (except
|
|
inlining) on functions with comdat linkage. Doing IPO over such
|
|
functions is unsound because the implementation the linker chooses at
|
|
link-time may be differently optimized than the one what was visible
|
|
during optimization, and may have arbitrarily different observable
|
|
behavior. See `PR26774 <http://llvm.org/PR26774>`_ for more details.
|
|
|
|
Changes to the ARM Backend
|
|
--------------------------
|
|
|
|
During this release ...
|
|
|
|
|
|
Changes to the MIPS Target
|
|
--------------------------
|
|
|
|
During this release ...
|
|
|
|
|
|
Changes to the PowerPC Target
|
|
-----------------------------
|
|
|
|
Moved some optimizations from O3 to O2 (D18562)
|
|
|
|
* Enable sibling call optimization on ppc64 ELFv1/ELFv2 abi
|
|
|
|
Changes to the X86 Target
|
|
-------------------------
|
|
|
|
* LLVM now supports the Intel CPU codenamed Skylake Server with AVX-512
|
|
extensions using ``-march=skylake-avx512``. The switch enables the
|
|
ISA extensions AVX-512{F, CD, VL, BW, DQ}.
|
|
|
|
* LLVM now supports the Intel CPU codenamed Knights Landing with AVX-512
|
|
extensions using ``-march=knl``. The switch enables the ISA extensions
|
|
AVX-512{F, CD, ER, PF}.
|
|
|
|
Changes to the AMDGPU Target
|
|
-----------------------------
|
|
|
|
* Mesa 11.0.x is no longer supported
|
|
|
|
|
|
Changes to the OCaml bindings
|
|
-----------------------------
|
|
|
|
During this release ...
|
|
|
|
Support for attribute 'notail' has been added
|
|
---------------------------------------------
|
|
|
|
This marker prevents optimization passes from adding 'tail' or
|
|
'musttail' markers to a call. It is used to prevent tail call
|
|
optimization from being performed on the call.
|
|
|
|
External Open Source Projects Using LLVM 3.9
|
|
============================================
|
|
|
|
An exciting aspect of LLVM is that it is used as an enabling technology for
|
|
a lot of other language and tools projects. This section lists some of the
|
|
projects that have already been updated to work with LLVM 3.9.
|
|
|
|
* A project
|
|
|
|
|
|
Additional Information
|
|
======================
|
|
|
|
A wide variety of additional information is available on the `LLVM web page
|
|
<http://llvm.org/>`_, in particular in the `documentation
|
|
<http://llvm.org/docs/>`_ section. The web page also contains versions of the
|
|
API documentation which is up-to-date with the Subversion 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 `mailing lists <http://llvm.org/docs/#maillist>`_.
|
|
|