======================
-LLVM 3.6 Release Notes
+LLVM 3.7 Release Notes
======================
.. contents::
:local:
.. warning::
- These are in-progress notes for the upcoming LLVM 3.6 release. You may
- prefer the `LLVM 3.5 Release Notes <http://llvm.org/releases/3.5.0/docs
+ These are in-progress notes for the upcoming LLVM 3.7 release. You may
+ prefer the `LLVM 3.6 Release Notes <http://llvm.org/releases/3.6.0/docs
/ReleaseNotes.html>`_.
============
This document contains the release notes for the LLVM Compiler Infrastructure,
-release 3.6. Here we describe the status of LLVM, including major improvements
+release 3.7. 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/>`_.
functionality, or simply have a lot to talk about), see the `NOTE` below
for adding a new subsection.
-* Support for AuroraUX has been removed.
+* The minimum required Visual Studio version for building LLVM is now 2013
+ Update 4.
-* Added support for a `native object file-based bitcode wrapper format
- <BitCodeFormat.html#native-object-file>`_.
+* A new documentation page, :doc:`Frontend/PerformanceTips`, contains a
+ collection of tips for frontend authors on how to generate IR which LLVM is
+ able to effectively optimize.
+
+* The DataLayout is no longer optional. All the IR level optimizations expects
+ it to be present and the API has been changed to use a reference instead of
+ a pointer to make it explicit. The Module owns the datalayout and it has to
+ match the one attached to the TargetMachine for generating code.
* ... next change ...
Makes programs 10x faster by doing Special New Thing.
-Prefix data rework
-------------------
-
-The semantics of the ``prefix`` attribute have been changed. Users
-that want the previous ``prefix`` semantics should instead use
-``prologue``. To motivate this change, let's examine the primary
-usecases that these attributes aim to serve,
-
- 1. Code sanitization metadata (e.g. Clang's undefined behavior
- sanitizer)
-
- 2. Function hot-patching: Enable the user to insert ``nop`` operations
- at the beginning of the function which can later be safely replaced
- with a call to some instrumentation facility.
-
- 3. Language runtime metadata: Allow a compiler to insert data for
- use by the runtime during execution. GHC is one example of a
- compiler that needs this functionality for its
- tables-next-to-code functionality.
-
-Previously ``prefix`` served cases (1) and (2) quite well by allowing the user
-to introduce arbitrary data at the entrypoint but before the function
-body. Case (3), however, was poorly handled by this approach as it
-required that prefix data was valid executable code.
-
-In this release the concept of prefix data has been redefined to be
-data which occurs immediately before the function entrypoint (i.e. the
-symbol address). Since prefix data now occurs before the function
-entrypoint, there is no need for the data to be valid code.
-
-The previous notion of prefix data now goes under the name "prologue
-data" to emphasize its duality with the function epilogue.
-
-The intention here is to handle cases (1) and (2) with prologue data and
-case (3) with prefix data. See the language reference for further details
-on the semantics of these attributes.
-
-This refactoring arose out of discussions_ with Reid Kleckner in
-response to a proposal to introduce the notion of symbol offsets to
-enable handling of case (3).
-
-.. _discussions: http://lists.cs.uiuc.edu/pipermail/llvmdev/2014-May/073235.html
-
-
Changes to the ARM Backend
--------------------------
Changes to the MIPS Target
--------------------------
-During this release the MIPS target has reached a few major milestones. It has
-gained support for MIPS-II and MIPS-III, become ABI-compatible with GCC for big
-and little endian O32, N32, and N64, and it is now able to compile the Linux
-kernel for 32-bit targets.
-
-ABI
-^^^
-
-A large number of bugs have been fixed for big-endian MIPS targets using the
-N32 and N64 ABI's as well as a small number of bugs affecting other ABI's.
-Please note that some of these bugs will still affect LLVM-IR generated by
-LLVM 3.5 since correct code generation depends on appropriate usage of the
-``inreg``, ``signext``, and ``zeroext`` attributes on all function arguments
-and returns.
-
-There are far too many corrections to provide a complete list but here are a
-few notable ones:
-
-* Big-endian N32 and N64 now interlinks successfully with GCC compiled code.
- Previously this didn't work for the majority of cases.
-
-* The registers used to return a structure containing a single 128-bit floating
- point member on the N32/N64 ABI's have been changed from those specified by
- the ABI documentation to match those used by GCC. The documentation specifies
- that ``$f0`` and ``$f2`` should be used but GCC has used ``$f0`` and ``$f1``
- for many years.
-
-* Returning a zero-byte struct no longer causes arguments to be read from the
- wrong registers when using the O32 ABI.
-
-* The exception personality has been changed for 64-bit MIPS targets to
- eliminate warnings about relocations in a read-only section.
-
-* Incorrect usage of odd-numbered single-precision floating point registers
- has been fixed when the fastcc calling convention is used with 64-bit FPU's
- and -mno-odd-spreg.
-
-LLVMLinux
-^^^^^^^^^
-
-It is now possible to compile the Linux kernel. This currently requires a small
-number of kernel patches. See the `LLVMLinux project
-<http://llvm.linuxfoundation.org/index.php/Main_Page>`_ for details.
-
-* Added -mabicalls and -mno-abicalls. The implementation may not be complete
- but works sufficiently well for the Linux kernel.
-
-* Fixed multiple compatibility issues between LLVM's inline assembly support
- and GCC's.
-
-* Added support for a number of directives used by Linux to the Integrated
- Assembler.
-
-Miscellaneous
-^^^^^^^^^^^^^
+ During this release ...
-* Attempting to disassemble l[wd]c[23], s[wd]c[23], cache, and pref no longer
- triggers an assertion.
-* Added -muclibc and -mglibc to support toolchains that provide both uClibC and
- GLibC.
+Changes to the PowerPC Target
+-----------------------------
-* __SIZEOF_INT128__ is no longer defined for 64-bit targets since 128-bit
- integers do not work at this time for this target.
+ During this release ...
-* Using $t4-$t7 with the N32 and N64 ABI is deprecated when ``-fintegrated-as``
- is in use and will be removed in LLVM 3.7. These names have never been
- supported by the GNU Assembler for these ABI's.
-Changes to the PowerPC Target
+Changes to the OCaml bindings
-----------------------------
-During this release ...
+ During this release ...
+
-External Open Source Projects Using LLVM 3.6
+External Open Source Projects Using LLVM 3.7
============================================
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 3.6.
+projects that have already been updated to work with LLVM 3.7.
* A project
projects / oota-llvm.git / blobdiff