llvm/docs/ReleaseNotes.rst
Hans Wennborg f864a32c13 Change eliminateCallFramePseudoInstr() to return an iterator
This will become necessary in a subsequent change to make this method
merge adjacent stack adjustments, i.e. it might erase the previous
and/or next instruction.

It also greatly simplifies the calls to this function from Prolog-
EpilogInserter. Previously, that had a bunch of logic to resume iteration
after the call; now it just continues with the returned iterator.

Note that this changes the behaviour of PEI a little. Previously,
it attempted to re-visit the new instruction created by
eliminateCallFramePseudoInstr(). That code was added in r36625,
but I can't see any reason for it: the new instructions will obviously
not be pseudo instructions, they will not have FrameIndex operands,
and we have already accounted for the stack adjustment.

Differential Revision: http://reviews.llvm.org/D18627

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@265036 91177308-0d34-0410-b5e6-96231b3b80d8
2016-03-31 18:33:38 +00:00

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5.2 KiB
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======================
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.
* .. 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.
* ``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 the ARM Backend
--------------------------
During this release ...
Changes to the MIPS Target
--------------------------
During this release ...
Changes to the PowerPC Target
-----------------------------
During this release ...
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>`_.