<div class="doc_title">LLVM 2.7 Release Notes</div>
+<img align=right src="http://llvm.org/img/DragonSmall.png"
+ width="136" height="136">
+
<ol>
<li><a href="#intro">Introduction</a></li>
<li><a href="#subproj">Sub-project Status Update</a></li>
<p>Written by the <a href="http://llvm.org">LLVM Team</a></p>
</div>
+<!--
<h1 style="color:red">These are in-progress notes for the upcoming LLVM 2.7
release.<br>
You may prefer the
<a href="http://llvm.org/releases/2.6/docs/ReleaseNotes.html">LLVM 2.6
-Release Notes</a>.</h1>
+Release Notes</a>.</h1>-->
<!-- *********************************************************************** -->
<div class="doc_section">
<p>For more information about LLVM, including information about the latest
release, please check out the <a href="http://llvm.org/">main LLVM
web site</a>. If you have questions or comments, the <a
-href="http://mail.cs.uiuc.edu/mailman/listinfo/llvmdev">LLVM Developer's Mailing
-List</a> is a good place to send them.</p>
+href="http://lists.cs.uiuc.edu/mailman/listinfo/llvmdev">LLVM Developer's
+Mailing List</a> is a good place to send them.</p>
<p>Note that if you are reading this file from a Subversion checkout or the
main LLVM web page, this document applies to the <i>next</i> release, not the
current one. To see the release notes for a specific release, please see the
<a href="http://llvm.org/releases/">releases page</a>.</p>
+
+<p>FIXME: llvm.org moved to new server, mention new logo, Ted and Doug new code
+ owners, web page in llvm-www repos.</p>
+
</div>
include/llvm/Analysis/LiveValues.h => Dan
lib/Transforms/IPO/MergeFunctions.cpp => consider for 2.8.
llvm/Analysis/PointerTracking.h => Edwin wants this, consider for 2.8.
- ABCD, SCCVN, GEPSplitterPass
+ ABCD, GEPSplitterPass
MSIL backend?
+ lib/Transforms/Utils/SSI.cpp -> ABCD depends on it.
-->
loop dependence analysis
ELF Writer? How stable?
<li>PostRA scheduler improvements, ARM adoption (David Goodwin).</li>
- 2.7 supports the GDB 7.0 jit interfaces for debug info.
- 2.7 eliminates ADT/iterator.h
-->
<!-- for announcement email:
compiler_rt
KLEE web page at klee.llvm.org
Many new papers added to /pubs/
- Mention gcc plugin.
-
+ Mention gcc plugin.
-->
<!-- *********************************************************************** -->
<p>In the LLVM 2.7 time-frame, the Clang team has made many improvements:</p>
<ul>
-<li>...</li>
+<li>FIXME: C++! Include a link to cxx_compatibility.html</li>
+
+<li>FIXME: Static Analyzer improvements?</li>
+
+<li>CIndex API and Python bindings: Clang now includes a C API as part of the
+CIndex library. Although we make make some changes to the API in the future, it
+is intended to be stable and has been designed for use by external projects. See
+the Clang
+doxygen <a href="http://clang.llvm.org/doxygen/group__CINDEX.html">CIndex</a>
+documentation for more details. The CIndex API also includings an preliminary
+set of Python bindings.</li>
+
+<li>ARM Support: Clang now has ABI support for both the Darwin and Linux ARM
+ABIs. Coupled with many improvements to the LLVM ARM backend, Clang is now
+suitable for use as a a beta quality ARM compiler.</li>
</ul>
</div>
in C and Objective-C programs. The tool performs checks to find
bugs that occur on a specific path within a program.</p>
-<p>In the LLVM 2.7 time-frame, the analyzer core has ...</p>
+<p>In the LLVM 2.7 time-frame, the analyzer core has sprouted legs and...</p>
</div>
compilation.</p>
<p>
-VMKit version ?? builds with LLVM 2.7 and you can find it on its
-<a href="http://vmkit.llvm.org/releases/">web page</a>. The release includes
-bug fixes, cleanup and new features. The major changes are:</p>
+With the release of LLVM 2.7, VMKit has shifted to a great framework for writing
+virtual machines. VMKit now offers precise and efficient garbage collection with
+multi-threading support, thanks to the MMTk memory management toolkit, as well
+as just in time and ahead of time compilation with LLVM. The major changes in
+VMKit 0.27 are:</p>
<ul>
-<li>...</li>
+<li>Garbage collection: VMKit now uses the MMTk toolkit for garbage collectors.
+ The first collector to be ported is the MarkSweep collector, which is precise,
+ and drastically improves the performance of VMKit.</li>
+<li>Line number information in the JVM: by using the debug metadata of LLVM, the
+ JVM now supports precise line number information, useful when printing a stack
+ trace.</li>
+<li>Interface calls in the JVM: we implemented a variant of the Interface Method
+ Table technique for interface calls in the JVM.
+</li>
</ul>
</div>
<!--=========================================================================-->
<div class="doc_subsection">
-<a name="klee">KLEE: Symbolic Execution and Automatic Test Case Generator</a>
+<a name="dragonegg">DragonEgg: llvm-gcc ported to gcc-4.5</a>
</div>
<div class="doc_text">
<p>
-The new LLVM <a href="http://klee.llvm.org/">KLEE project</a> is a symbolic
-execution framework for programs in LLVM bitcode form. KLEE tries to
-symbolically evaluate "all" paths through the application and records state
-transitions that lead to fault states. This allows it to construct testcases
-that lead to faults and can even be used to verify algorithms. For more
-details, please see the <a
-href="http://llvm.org/pubs/2008-12-OSDI-KLEE.html">OSDI 2008 paper</a> about
-KLEE.</p>
-
-</div>
+<a href="http://dragonegg.llvm.org/">DragonEgg</a> is a port of llvm-gcc to
+gcc-4.5. Unlike llvm-gcc, which makes many intrusive changes to the underlying
+gcc-4.2 code, dragonegg in theory does not require any gcc-4.5 modifications
+whatsoever (currently one small patch is needed). This is thanks to the new
+<a href="http://gcc.gnu.org/wiki/plugins">gcc plugin architecture</a>, which
+makes it possible to modify the behaviour of gcc at runtime by loading a plugin,
+which is nothing more than a dynamic library which conforms to the gcc plugin
+interface. DragonEgg is a gcc plugin that causes the LLVM optimizers to be run
+instead of the gcc optimizers, and the LLVM code generators instead of the gcc
+code generators, just like llvm-gcc. To use it, you add
+"-fplugin=path/dragonegg.so" to the gcc-4.5 command line, and gcc-4.5 magically
+becomes llvm-gcc-4.5!
+</p>
-<!--=========================================================================-->
-<div class="doc_subsection">
-<a name="dragonegg">DragonEgg: GCC-4.5 as an LLVM frontend</a>
-</div>
+<p>
+DragonEgg is still a work in progress. Currently C works very well, while C++,
+Ada and Fortran work fairly well. All other languages either don't work at all,
+or only work poorly. For the moment only the x86-32 and x86-64 targets are
+supported, and only on linux and darwin (darwin needs an additional gcc patch).
+</p>
-<div class="doc_text">
<p>
-The goal of <a href="http://dragonegg.llvm.org/">DragonEgg</a> is to make
-gcc-4.5 act like llvm-gcc without requiring any gcc modifications whatsoever.
-<a href="http://dragonegg.llvm.org/">DragonEgg</a> is a shared library (dragonegg.so)
-that is loaded by gcc at runtime. It ...
+The first dragonegg release will occur shortly after llvm-2.7 is released.
</p>
</div>
</div>
<div class="doc_text">
+Need update.
+<!--
<p><a href="http://github.com/evanphx/rubinius">Rubinius</a> is an environment
for running Ruby code which strives to write as much of the core class
implementation in Ruby as possible. Combined with a bytecode interpreting VM, it
<p>Since LLVM 2.5, Rubinius has made several major leaps forward, implementing
a counter based JIT, type feedback and speculative method inlining.
+-->
</p>
</div>
<div class="doc_text">
<p>
+Need update.
+<!--
<a href="http://macruby.org">MacRuby</a> is an implementation of Ruby on top of
core Mac OS X technologies, such as the Objective-C common runtime and garbage
collector and the CoreFoundation framework. It is principally developed by
<p>
MacRuby uses LLVM for optimization passes, JIT and AOT compilation of Ruby
expressions. It also uses zero-cost DWARF exceptions to implement Ruby exception
-handling.</p>
+handling.--> </p>
</div>
an easy-to-use C interface. The interpreter uses LLVM as a backend to
JIT-compile Pure programs to fast native code.</p>
-<p>Pure versions ??? and later have been tested and are known to work with
-LLVM 2.7 (and continue to work with older LLVM releases >= 2.3 as well).
-</p>
+<p>Pure versions 0.43 and later have been tested and are known to work with
+LLVM 2.7 (and continue to work with older LLVM releases >= 2.5).</p>
+
</div>
<div class="doc_text">
<p>
+Need update.
+<!--
<a href="http://www.dsource.org/projects/ldc">LDC</a> is an implementation of
the D Programming Language using the LLVM optimizer and code generator.
The LDC project works great with the LLVM 2.6 release. General improvements in
cycle have included new inline asm constraint handling, better debug info
support, general bug fixes and better x86-64 support. This has allowed
some major improvements in LDC, getting it much closer to being as
-fully featured as the original DMD compiler from DigitalMars.
+fully featured as the original DMD compiler from DigitalMars.-->
</p>
</div>
<a href="http://code.roadsend.com/rphp">Roadsend PHP</a> (rphp) is an open
source implementation of the PHP programming
language that uses LLVM for its optimizer, JIT and static compiler. This is a
-reimplementation of an earlier project that is now based on LLVM.</p>
+reimplementation of an earlier project that is now based on LLVM.
+</p>
</div>
<!--=========================================================================-->
<a href="http://code.google.com/p/unladen-swallow/">Unladen Swallow</a> is a
branch of <a href="http://python.org/">Python</a> intended to be fully
compatible and significantly faster. It uses LLVM's optimization passes and JIT
-compiler.</p>
+compiler.
+</p>
</div>
<!--=========================================================================-->
<div class="doc_text">
<p>
+Need update.
+<!--
<a href="http://code.google.com/p/llvm-lua/">LLVM-Lua</a> uses LLVM to add JIT
and static compiling support to the Lua VM. Lua bytecode is analyzed to
remove type checks, then LLVM is used to compile the bytecode down to machine
-code.</p>
+code.-->
+</p>
</div>
<!--=========================================================================-->
<div class="doc_text">
<p>
+Need update.
+<!--
<a href="http://icedtea.classpath.org/wiki/Main_Page">IcedTea</a> provides a
harness to build OpenJDK using only free software build tools and to provide
replacements for the not-yet free parts of OpenJDK. One of the extensions that
IcedTea provides is a new JIT compiler named <a
href="http://icedtea.classpath.org/wiki/ZeroSharkFaq">Shark</a> which uses LLVM
to provide native code generation without introducing processor-dependent
-code.
+code.-->
</p>
</div>
+<!--=========================================================================-->
+<div class="doc_subsection">
+<a name="tce">TTA-based Codesign Environment (TCE)</a>
+</div>
+
+<div class="doc_text">
+<p>
+<a href="http://tce.cs.tut.fi/">TCE</a> is a toolset for designing
+application-specific processors (ASP) based on the Transport triggered
+architecture (TTA). The toolset provides a complete co-design flow from C/C++
+programs down to synthesizable VHDL and parallel program binaries. Processor
+customization points include the register files, function units, supported
+operations, and the interconnection network.</p>
+
+<p>TCE uses llvm-gcc/Clang and LLVM for C/C++ language support, target
+independent optimizations and also for parts of code generation. It generates
+new LLVM-based code generators "on the fly" for the designed TTA processors and
+loads them in to the compiler backend as runtime libraries to avoid per-target
+recompilation of larger parts of the compiler chain.</p>
+
+</div>
+
+<!--=========================================================================-->
+<div class="doc_subsection">
+<a name="safecode">SAFECode Compiler</a>
+</div>
+
+<div class="doc_text">
+<p>
+<a href="http://safecode.cs.illinois.edu">SAFECode</a> is a memory safe C
+compiler built using LLVM. It takes standard, unannotated C code, analyzes the
+code to ensure that memory accesses and array indexing operations are safe, and
+instruments the code with run-time checks when safety cannot be proven
+statically.
+</p>
+</div>
+
<!-- *********************************************************************** -->
<div class="doc_section">
<li>...</li>
</ul>
+Extensible metadata solid.
+
+Debug info improvements: using metadata instead of llvm.dbg global variables.
+This brings several enhancements including improved compile times.
+
+New instruction selector.
+GHC Haskell ABI/ calling conv support.
+Pre-Alpha support for unions in IR.
+New InlineHint and StackAlignment function attributes
+Code generator MC'ized except for debug info and EH.
+New SCEV AA pass: -scev-aa
+Inliner reuses arrays allocas when inlining multiple callers to reduce stack usage.
+MC encoding and disassembler apis.
+Optimal Edge Profiling?
+Instcombine is now a library, has its own IRBuilder to simplify itself.
+New llvm/Support/Regex.h API. FileCheck now does regex's
+Many subtle pointer invalidation bugs in Callgraph have been fixed and it now uses asserting value handles.
+MC Disassembler (with blog post), MCInstPrinter. Many X86 backend and AsmPrinter simplifications
+Various tools like llc and opt now read either .ll or .bc files as input.
+Malloc and free instructions got removed, along with LowerAllocations pass.
+compiler-rt support for ARM.
+completely llvm-gcc NEON support.
+Can transcode from GAS to intel syntax with "llvm-mc foo.s -output-asm-variant=1"
+JIT debug information with GDB 7.0
+New CodeGen Level CSE
+CMake can now run tests, what other improvements?
+ARM/Thumb using reg scavenging for stack object address materialization (PEI).
+New SSAUpdater and MachineSSAUpdater classes for unstructured ssa updating,
+ changed jump threading, GVN, etc to use it which simplified them and speed
+ them up.
+Combiner-AA improvements, why not on by default?
+Pre-regalloc tail duplication
+x86 sibcall / tailcall optimization in CCC mode.
+New LSR with "full strength reduction" mode. Description?
+Codegen level OptimizeExtsPass pass, takes advantage of x86 subregs.
+Better code size analysis in loop unswitch, inliner code split out to a new
+ CodeMetrics class for reuse.
+The ARM backend now has good support for ARMv4 backend (tested on StrongARM
+ hardware), previously only supported ARMv4T and newer.
+Half-float support in APFloat
+Indirect branch + address of label (blog post), particularly useful for interpreters.
+Many changes to the pass ordering for improved optimization effectiveness.
+BasicAA improved to be less dependent on "type safe" pointers, it can now look
+ through bitcasts more aggressively.
+GVN PHI Translation improvements. blog post: http://blog.llvm.org/2009/12/advanced-topics-in-redundant-load.html
+llvm.objectsize.
+MachineSSAUpdater.h
+PostRA scheduler for X86?
+llvm.dbg.value, not being used by default though, more in 2.8. Many improvements to debug info
+Support for the GCC option -fno-schedule-insns
+non-temporal load/store
+libllvm2.7.so?? configure with --enable-shared
+dbgs() and -debug-buffer-size=N
+New MicroBlaze backend. http://en.wikipedia.org/wiki/MicroBlaze
+XMM subreg modeling for extraction of the low element.
+
+
+Opt now works conservatively if no target data is set (is this fully working?)
+Target data now has notion of 'native' integer data types which optimizations can use.
+ARM backend generates instructions in unified assembly syntax.
+New Analysis/InstructionSimplify.h interface for simplifying instructions that don't exist.
+Jump threading is now much more aggressive at simplifying correlated
+ conditionals and threading blocks with otherwise complex logic. CondProp pass
+ removed (functionality merged into jump threading).
+X86 and XCore supports returning arbitrary return values, returning too many values is
+ supported by returning through a hidden pointer.
+verbose-asm now produces information about spill slots and loop nests
+
+
+Defaults to RTTI off (smaller code size!), packagers should build with make REQUIRE_RTTI=1.
+AndersAA got removed
+PredSimplify, LoopVR, GVNPRE, RSProfiling (random sampling profiling) got removed.
+LLVM command line tools now overwrite their output, before they would only do this with -f.
+DOUT removed, use DEBUG(errs() instead.
+Much stuff converted to use raw_ostream instead of std::ostream.
+TargetAsmInfo renamed to MCAsmInfo
+llvm/ADT/iterator.h gone.
+
+
</div>
<!--=========================================================================-->
</ul>
+<p>Also, -anders-aa was removed</p>
+
</div>
href="http://llvm.org/bugs/">LLVM bug database</a> and submit a bug if
there isn't already one.</p>
-<ul>
-<li>The llvm-gcc bootstrap will fail with some versions of binutils (e.g. 2.15)
- with a message of "<tt><a href="http://llvm.org/PR5004">Error: can not do 8
- byte pc-relative relocation</a></tt>" when building C++ code. We intend to
- fix this on mainline, but a workaround is to upgrade to binutils 2.17 or
- later.</li>
-
+<ul>
<li>LLVM will not correctly compile on Solaris and/or OpenSolaris
using the stock GCC 3.x.x series 'out the box',
See: <a href="GettingStarted.html#brokengcc">Broken versions of GCC and other tools</a>.
href="http://lists.cs.uiuc.edu/mailman/listinfo/llvmdev">LLVMdev list</a>.</p>
<ul>
-<li>The MSIL, Alpha, SPU, MIPS, PIC16, Blackfin, MSP430 and SystemZ backends are
- experimental.</li>
+<li>The MSIL, Alpha, SPU, MIPS, PIC16, Blackfin, MSP430, SystemZ and MicroBlaze
+ backends are experimental.</li>
<li>The <tt>llc</tt> "<tt>-filetype=asm</tt>" (the default) is the only
- supported value for this option. The ELF writer is experimental.</li>
+ supported value for this option. The MachO writer is experimental, and
+ works much better in mainline SVN.</li>
</ul>
</div>
<!-- ======================================================================= -->
<div class="doc_subsection">
- <a name="c-fe">Known problems with the llvm-gcc C front-end</a>
+ <a name="c-fe">Known problems with the llvm-gcc C and C++ front-end</a>
</div>
<div class="doc_text">
</div>
-<!-- ======================================================================= -->
-<div class="doc_subsection">
- <a name="c++-fe">Known problems with the llvm-gcc C++ front-end</a>
-</div>
-
-<div class="doc_text">
-
-<p>The C++ front-end is considered to be fully
-tested and works for a number of non-trivial programs, including LLVM
-itself, Qt, Mozilla, etc.</p>
-
-<ul>
-<li>Exception handling works well on the X86 and PowerPC targets. Currently
- only Linux and Darwin targets are supported (both 32 and 64 bit).</li>
-</ul>
-
-</div>
-
<!-- ======================================================================= -->
<div class="doc_subsection">
<a name="fortran-fe">Known problems with the llvm-gcc Fortran front-end</a>
</ul>
</div>
-<!-- ======================================================================= -->
-<div class="doc_subsection">
- <a name="ocaml-bindings">Known problems with the O'Caml bindings</a>
-</div>
-
-<div class="doc_text">
-
-<p>The <tt>Llvm.Linkage</tt> module is broken, and has incorrect values. Only
-<tt>Llvm.Linkage.External</tt>, <tt>Llvm.Linkage.Available_externally</tt>, and
-<tt>Llvm.Linkage.Link_once</tt> will be correct. If you need any of the other linkage
-modes, you'll have to write an external C library in order to expose the
-functionality. This has been fixed in the trunk.</p>
-</div>
-
<!-- *********************************************************************** -->
<div class="doc_section">
<a name="additionalinfo">Additional Information</a>
projects / oota-llvm.git / blobdiff