<li>Introduced many new warnings, including <code>-Wmissing-field-initializers</code>, <code>-Wshadow</code>, <code>-Wno-protocol</code>, <code>-Wtautological-compare</code>, <code>-Wstrict-selector-match</code>, <code>-Wcast-align</code>, <code>-Wunused</code> improvements, and greatly improved format-string checking.</li>
<li>Introduced the "libclang" library, a C interface to Clang intended to support IDE clients.</li>
<li>Added support for <code>#pragma GCC visibility</code>, <code>#pragma align</code>, and others.</li>
- <li>Added support for SSE, ARM NEON, and Altivec.</li>
+ <li>Added support for SSE, AVX, ARM NEON, and AltiVec.</li>
+ <li>Improved support for many Microsoft extensions.</li>
<li>Implemented support for blocks in C++.</li>
<li>Implemented precompiled headers for C++.</li>
<li>Improved abstract syntax trees to retain more accurate source information.</li>
+ <li>Added driver support for handling LLVM IR and bitcode files directly.</li>
+ <li>Major improvements to compiler correctness for exception handling.</li>
+ <li>Improved generated code quality in some areas:
+ <ul>
+ <li>Good code generation for X86-32 and X86-64 ABI handling.</li>
+ <li>Improved code generation for bit-fields, although important work remains.</li>
+ </ul>
+ </li>
</ul>
</div>
<li>Fortran programs using common variables now link correctly.</li>
<li>GNU OMP constructs no longer crash the compiler.</li>
</ul>
-</p>
</div>
<div class="doc_text">
<p>
-<a href="http://libc++.llvm.org/">libc++</a> is another new member of the LLVM
+<a href="http://libcxx.llvm.org/">libc++</a> is another new member of the LLVM
family. It is an implementation of the C++ standard library, written from the
ground up to specifically target the forthcoming C++'0X standard and focus on
delivering great performance.</p>
</div>
+
+<!--=========================================================================-->
+<div class="doc_subsection">
+<a name="klee">KLEE: A Symbolic Execution Virtual Machine</a>
+</div>
+
+<div class="doc_text">
+<p>
+<a href="http://klee.llvm.org/">KLEE</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 some algorithms.
+</p>
+
+<p>Although KLEE does not have any major new features as of 2.8, we have made
+various minor improvements, particular to ease development:</p>
+<ul>
+ <li>Added support for LLVM 2.8. KLEE currently maintains compatibility with
+ LLVM 2.6, 2.7, and 2.8.</li>
+ <li>Added a buildbot for 2.6, 2.7, and trunk. A 2.8 buildbot will be coming
+ soon following release.</li>
+ <li>Fixed many C++ code issues to allow building with Clang++. Mostly
+ complete, except for the version of MiniSAT which is inside the KLEE STP
+ version.</li>
+ <li>Improved support for building with separate source and build
+ directories.</li>
+ <li>Added support for "long double" on x86.</li>
+ <li>Initial work on KLEE support for using 'lit' test runner instead of
+ DejaGNU.</li>
+ <li>Added <tt>configure</tt> support for using an external version of
+ STP.</li>
+</ul>
+
+</div>
+
+
<!-- *********************************************************************** -->
<div class="doc_section">
<a name="externalproj">External Open Source Projects Using LLVM 2.8</a>
language and compiler written on top of LLVM, intended for producing
single-address-space managed code operating systems that
run faster than the equivalent multiple-address-space C systems.
-More in-depth blurb is available on <a
-href="http://www.quokforge.org/projects/horizon/wiki/Wiki">the wiki</a>.</p>
+More in-depth blurb is available on the <a
+href="http://www.quokforge.org/projects/horizon/wiki/Wiki">wiki</a>.</p>
</div>
<div class="doc_text">
<p>
-<a href=http://www.clamav.net>Clam AntiVirus</a> is an open source (GPL)
+<a href="http://www.clamav.net">Clam AntiVirus</a> is an open source (GPL)
anti-virus toolkit for UNIX, designed especially for e-mail scanning on mail
gateways. Since version 0.96 it has <a
href="http://vrt-sourcefire.blogspot.com/2010/09/introduction-to-clamavs-low-level.html">bytecode
signatures</a> that allow writing detections for complex malware. It
uses LLVM's JIT to speed up the execution of bytecode on
-X86,X86-64,PPC32/64, falling back to its own interpreter otherwise.
-The git version was updated to work with LLVM 2.8
+X86, X86-64, PPC32/64, falling back to its own interpreter otherwise.
+The git version was updated to work with LLVM 2.8.
</p>
<p>The <a
<a href="http://tm.inf.tu-dresden.de">DTMC</a> provides support for
Transactional Memory, which is an easy-to-use and efficient way to synchronize
accesses to shared memory. Transactions can contain normal C/C++ code (e.g.,
-__transaction { list.remove(x); x.refCount--; }) and will be executed
+<code>__transaction { list.remove(x); x.refCount--; }</code>) and will be executed
virtually atomically and isolated from other transactions.</p>
</div>
<!--=========================================================================-->
<div class="doc_subsection">
-<a name="Kai">Kai Interpreter</a>
+<a name="Kai">Kai Programming Language</a>
</div>
<div class="doc_text">
<li>LLVM 2.8 now has pretty decent support for debugging optimized code. You
should be able to reliably get debug info for function arguments, assuming
that the value is actually available where you have stopped.</li>
-</ul>
<li>A new 'llvm-diff' tool is available that does a semantic diff of .ll
files.</li>
<li>The <a href="#mc">MC subproject</a> has made major progress in this release.
be 13 in one of the predecessors of a block. It does this in conjunction
with the new LazyValueInfo analysis pass.</li>
<li>The new RegionInfo analysis pass identifies single-entry single-exit regions
- in the CFG. You can play with it with the "opt -regions analyze" or
+ in the CFG. You can play with it with the "opt -regions -analyze" or
"opt -view-regions" commands.</li>
<li>The loop optimizer has significantly improved strength reduction and analysis
capabilities. Notably it is able to build on the trap value and signed
is available from a previous instruction.</li>
<li>Atomic operations now get legalized into simpler atomic operations if not
natively supported, easing the implementation burden on targets.</li>
-<li>The bottom-up pre-allocation scheduler is now register pressure aware,
- allowing it to avoid overscheduling in high pressure situations while still
- aggressively scheduling when registers are available.</li>
-<li>A new instruction-level-parallelism pre-allocation scheduler is available,
- which is also register pressure aware. This scheduler has shown substantial
- wins on X86-64 and is on by default.</li>
+<li>We have added two new bottom-up pre-allocation register pressure aware schedulers:
+<ol>
+<li>The hybrid scheduler schedules aggressively to minimize schedule length when registers are available and avoid overscheduling in high pressure situations.</li>
+<li>The instruction-level-parallelism scheduler schedules for maximum ILP when registers are available and avoid overscheduling in high pressure situations.</li>
+</ol></li>
<li>The tblgen type inference algorithm was rewritten to be more consistent and
diagnose more target bugs. If you have an out-of-tree backend, you may
find that it finds bugs in your target description. This support also
<ul>
<li>The X86 backend now supports holding X87 floating point stack values
in registers across basic blocks, dramatically improving performance of code
- that uses long double, and when targetting CPUs that don't support SSE.</li>
+ that uses long double, and when targeting CPUs that don't support SSE.</li>
<li>The X86 backend now uses a SSEDomainFix pass to optimize SSE operations. On
Nehalem ("Core i7") and newer CPUs there is a 2 cycle latency penalty on
<li>When printing .s files in verbose assembly mode (the default for clang -S),
the X86 backend now decodes X86 shuffle instructions and prints human
- readable comments after the most inscrutible of them, e.g.:
+ readable comments after the most inscrutable of them, e.g.:
<pre>
insertps $113, %xmm3, %xmm0 <i># xmm0 = zero,xmm0[1,2],xmm3[1]</i>
variables can be accessed via same base address) and potentially reducing
register pressure.</li>
-<li>The ARM has received many minor improvements and tweaks which lead to
-substantially better performance in a wide range of different scenarios.</li>
+<li>The ARM backend has received many minor improvements and tweaks which lead
+ to substantially better performance in a wide range of different scenarios.
+</li>
<li>The ARM NEON intrinsics have been substantially reworked to reduce
redundancy and improve code generation. Some of the major changes are:
</li>
<li>
The llvm.arm.neon.vabdl and llvm.arm.neon.vabal intrinsics (lengthening
- vector absolute difference with and without accumlation) have been removed.
+ vector absolute difference with and without accumulation) have been removed.
They are represented using the llvm.arm.neon.vabd intrinsic (vector absolute
difference) followed by a vector zero-extend operation, and for vabal,
a vector add.
operands are now address-space qualified.
If you were creating these intrinsic calls and prototypes yourself (as opposed
to using Intrinsic::getDeclaration), you can use
- UpgradeIntrinsicFunction/UpgradeIntrinsicCall to be portable accross releases.
+ UpgradeIntrinsicFunction/UpgradeIntrinsicCall to be portable across releases.
</li>
<li>
SetCurrentDebugLocation takes a DebugLoc now instead of a MDNode.
LLVM. The Triple::normalize utility method has been added to help front-ends
deal with funky triples.
</li>
+<li>
+ The signature of the <tt>GCMetadataPrinter::finishAssembly</tt> virtual
+ function changed: the <tt>raw_ostream</tt> and <tt>MCAsmInfo</tt> arguments
+ were dropped. GC plugins which compute stack maps must be updated to avoid
+ having the old definition overload the new signature.
+</li>
+<li>
+ The signature of <tt>MemoryBuffer::getMemBuffer</tt> changed. Unfortunately
+ calls intended for the old version still compile, but will not work correctly,
+ leading to a confusing error about an invalid header in the bitcode.
+</li>
<li>
- Some APIs got renamed:
+ Some APIs were renamed:
<ul>
<li>llvm_report_error -> report_fatal_error</li>
<li>llvm_install_error_handler -> install_fatal_error_handler</li>
</ul>
</li>
+<li>
+ Some public headers were renamed:
+ <ul>
+ <li><tt>llvm/Assembly/AsmAnnotationWriter.h</tt> was renamed
+ to <tt>llvm/Assembly/AssemblyAnnotationWriter.h</tt>
+ </li>
+ </ul>
</ul>
</div>
+<!--=========================================================================-->
+<div class="doc_subsection">
+<a name="devtree_changes">Development Infrastructure Changes</a>
+</div>
+
+<div class="doc_text">
+
+<p>This section lists changes to the LLVM development infrastructure. This
+mostly impacts users who actively work on LLVM or follow development on
+mainline, but may also impact users who leverage the LLVM build infrastructure
+or are interested in LLVM qualification.</p>
+
+<ul>
+ <li>The default for <tt>make check</tt> is now to use
+ the <a href="http://llvm.org/cmds/lit.html">lit</a> testing tool, which is
+ part of LLVM itself. You can use <tt>lit</tt> directly as well, or use
+ the <tt>llvm-lit</tt> tool which is created as part of a Makefile or CMake
+ build (and knows how to find the appropriate tools). See the <tt>lit</tt>
+ documentation and the <a href="http://blog.llvm.org/2009/12/lit-it.html">blog
+ post</a>, and <a href="http://llvm.org/bugs/show_bug.cgi?id=5217">PR5217</a>
+ for more information.</li>
+
+ <li>The LLVM <tt>test-suite</tt> infrastructure has a new "simple" test format
+ (<tt>make TEST=simple</tt>). The new format is intended to require only a
+ compiler and not a full set of LLVM tools. This makes it useful for testing
+ released compilers, for running the test suite with other compilers (for
+ performance comparisons), and makes sure that we are testing the compiler as
+ users would see it. The new format is also designed to work using reference
+ outputs instead of comparison to a baseline compiler, which makes it run much
+ faster and makes it less system dependent.</li>
+
+ <li>Significant progress has been made on a new interface to running the
+ LLVM <tt>test-suite</tt> (aka the LLVM "nightly tests") using
+ the <a href="http://llvm.org/docs/lnt">LNT</a> infrastructure. The LNT
+ interface to the <tt>test-suite</tt> brings significantly improved reporting
+ capabilities for monitoring the correctness and generated code quality
+ produced by LLVM over time.</li>
+</ul>
+</div>
<!-- *********************************************************************** -->
<div class="doc_section">
href="http://lists.cs.uiuc.edu/mailman/listinfo/llvmdev">LLVMdev list</a>.</p>
<ul>
-<li>The Alpha, Blackfin, CellSPU, MicroBlaze, MSP430, MIPS, PIC16, SystemZ
+<li>The Alpha, Blackfin, CellSPU, MicroBlaze, MSP430, MIPS, SystemZ
and XCore backends are experimental.</li>
<li><tt>llc</tt> "<tt>-filetype=obj</tt>" is experimental on all targets
other than darwin-i386 and darwin-x86_64.</li>
4.2. If you are interested in Fortran, we recommend that you consider using
<a href="#dragonegg">dragonegg</a> instead.</p>
-<p>The llvm-gcc 4.2 Ada compiler has basic functionality. However, this is not a
-mature technology, and problems should be expected. For example:</p>
-<ul>
-<li>The Ada front-end currently only builds on X86-32. This is mainly due
-to lack of trampoline support (pointers to nested functions) on other platforms.
-However, it <a href="http://llvm.org/PR2006">also fails to build on X86-64</a>
-which does support trampolines.</li>
-<li>The Ada front-end <a href="http://llvm.org/PR2007">fails to bootstrap</a>.
-This is due to lack of LLVM support for <tt>setjmp</tt>/<tt>longjmp</tt> style
-exception handling, which is used internally by the compiler.
-Workaround: configure with <tt>--disable-bootstrap</tt>.</li>
-<li>The c380004, <a href="http://llvm.org/PR2010">c393010</a>
-and <a href="http://llvm.org/PR2421">cxg2021</a> ACATS tests fail
-(c380004 also fails with gcc-4.2 mainline).
-If the compiler is built with checks disabled then <a href="http://llvm.org/PR2010">c393010</a>
-causes the compiler to go into an infinite loop, using up all system memory.</li>
-<li>Some GCC specific Ada tests continue to crash the compiler.</li>
-<li>The <tt>-E</tt> binder option (exception backtraces)
-<a href="http://llvm.org/PR1982">does not work</a> and will result in programs
-crashing if an exception is raised. Workaround: do not use <tt>-E</tt>.</li>
-<li>Only discrete types <a href="http://llvm.org/PR1981">are allowed to start
-or finish at a non-byte offset</a> in a record. Workaround: do not pack records
-or use representation clauses that result in a field of a non-discrete type
-starting or finishing in the middle of a byte.</li>
-<li>The <tt>lli</tt> interpreter <a href="http://llvm.org/PR2009">considers
-'main' as generated by the Ada binder to be invalid</a>.
-Workaround: hand edit the file to use pointers for <tt>argv</tt> and
-<tt>envp</tt> rather than integers.</li>
-<li>The <tt>-fstack-check</tt> option <a href="http://llvm.org/PR2008">is
-ignored</a>.</li>
-</ul>
+<p>The llvm-gcc 4.2 Ada compiler has basic functionality, but is no longer being
+actively maintained. If you are interested in Ada, we recommend that you
+consider using <a href="#dragonegg">dragonegg</a> instead.</p>
</div>
<!-- *********************************************************************** -->