mirror of
https://github.com/RPCSX/llvm.git
synced 2024-11-25 12:50:00 +00:00
72270aabf7
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@204598 91177308-0d34-0410-b5e6-96231b3b80d8
126 lines
5.3 KiB
ReStructuredText
126 lines
5.3 KiB
ReStructuredText
======================
|
|
LLVM 3.5 Release Notes
|
|
======================
|
|
|
|
.. contents::
|
|
:local:
|
|
|
|
.. warning::
|
|
These are in-progress notes for the upcoming LLVM 3.5 release. You may
|
|
prefer the `LLVM 3.4 Release Notes <http://llvm.org/releases/3.4/docs
|
|
/ReleaseNotes.html>`_.
|
|
|
|
|
|
Introduction
|
|
============
|
|
|
|
This document contains the release notes for the LLVM Compiler Infrastructure,
|
|
release 3.5. 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.cs.uiuc.edu/mailman/listinfo/llvmdev>`_ 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
|
|
=================================================
|
|
|
|
* All backends have been changed to use the MC asm printer and support for the
|
|
non MC one has been removed.
|
|
|
|
* Clang can now successfully self-host itself on Linux/Sparc64 and on
|
|
FreeBSD/Sparc64.
|
|
|
|
* LLVM now assumes the assembler supports ``.loc`` for generating debug line
|
|
numbers. The old support for printing the debug line info directly was only
|
|
used by ``llc`` and has been removed.
|
|
|
|
* All inline assembly is parsed by the integrated assembler when it is enabled.
|
|
Previously this was only the case for object-file output. It is now the case
|
|
for assembly output as well. The integrated assembler can be disabled with
|
|
the ``-no-integrated-as`` option,
|
|
|
|
* llvm-ar now handles IR files like regular object files. In particular, a
|
|
regular symbol table is created for symbols defined in IR files.
|
|
|
|
.. 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 ARM Backend
|
|
--------------------------
|
|
|
|
Since release 3.3, a lot of new features have been included in the ARM
|
|
back-end but weren't production ready (ie. well tested) on release 3.4.
|
|
Just after the 3.4 release, we started heavily testing two major parts
|
|
of the back-end: the integrated assembler (IAS) and the ARM exception
|
|
handling (EHABI), and now they are enabled by default on LLVM/Clang.
|
|
|
|
The IAS received a lot of GNU extensions and directives, as well as some
|
|
specific pre-UAL instructions. Not all remaining directives will be
|
|
implemented, as we made judgement calls on the need versus the complexity,
|
|
and have chosen simplicity and future compatibility where hard decisions
|
|
had to be made. The major difference is, as stated above, the IAS validates
|
|
all inline ASM, not just for object emission, and that cause trouble with
|
|
some uses of inline ASM as pre-processor magic.
|
|
|
|
So, while the IAS is good enough to compile large projects (including most
|
|
of the Linux kernel), there are a few things that we can't (and probably
|
|
won't) do. For those cases, please use ``-fno-integrated-as`` in Clang.
|
|
|
|
Exception handling is another big change. After extensive testing and
|
|
changes to cooperate with Dwarf unwinding, EHABI is enabled by default.
|
|
The options ``-arm-enable-ehabi`` and ``-arm-enable-ehabi-descriptors``,
|
|
which were used to enable EHABI in the previous releases, are removed now.
|
|
|
|
This means all ARM code will emit EH unwind tables, or CFI unwinding (for
|
|
debug/profiling), or both. To avoid run-time inconsistencies, C code will
|
|
also emit EH tables (in case they interoperate with C++ code), as is the
|
|
case for other architectures (ex. x86_64).
|
|
|
|
External Open Source Projects Using LLVM 3.5
|
|
============================================
|
|
|
|
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 3.5.
|
|
|
|
|
|
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>`_.
|
|
|