target-specific intrinsics
gold lto plugin
pre-alloc splitter, strong phi elim
- llc -enable-value-prop, propagation of value info (sign/zero ext info) from
- one MBB to another
+ <tt>llc -enable-value-prop</tt>, propagation of value info
+ (sign/zero ext info) from one MBB to another
debug info for optimized code
interpreter + libffi
postalloc scheduler: anti dependence breaking, hazard recognizer?
continuing to make major strides forward in all areas. Its C and Objective-C
parsing and code generation support is now very solid. For example, it is
capable of successfully building many real-world applications for X86-32
-andX86-64,
-including <a href="http://wiki.freebsd.org/BuildingFreeBSDWithClang">the FreeBSD
-kernel</a>. C++ is also
+and X86-64,
+including the <a href="http://wiki.freebsd.org/BuildingFreeBSDWithClang">FreeBSD
+kernel</a> and <a href="http://gcc.gnu.org/gcc-4.2/">gcc 4.2</a>. C++ is also
making <a href="http://clang.llvm.org/cxx_status.html">incredible progress</a>,
-and work on templates has recently started.</p>
-
-<p>While Clang is not yet production quality, it is progressing very nicely and
-is quite usable for building many C and Objective-C applications. If you are
+and work on templates has recently started. If you are
interested in fast compiles and good diagnostics, we encourage you to try it out
by <a href="http://clang.llvm.org/get_started.html">building from mainline</a>
and reporting any issues you hit to the <a
<ul>
<li>Clang now has a new driver, which is focused on providing a GCC-compatible
interface.</li>
-<li>The X86-64 ABI is now supported.</li>
+<li>The X86-64 ABI is now supported, including support for the Apple
+ 64-bit Objective-C runtime and zero cost exception handling.</li>
<li>Precompiled header support is now implemented.</li>
<li>Objective-C support is significantly improved beyond LLVM 2.4, supporting
many features, such as Objective-C Garbage Collection.</li>
+<li>Variable length arrays are now fully supported.</li>
+<li>C99 designated initializers are now fully supported.</li>
+<li>Clang now includes all major compiler headers, including a
+ redesigned <i>tgmath.h</i> and several more intrinsic headers.</li>
<li>Many many bugs are fixed and many features have been added.</li>
</ul>
</div>
better job of reasoning about inequality relationships (e.g., <tt>x > 2</tt>)
between variables and constants.
-<p>The set of checks performed by the static analyzer continue to expand, and
+<p>The set of checks performed by the static analyzer continues to expand, and
future plans for the tool include full source-level inter-procedural analysis
and deeper checks such as buffer overrun detection. There are many opportunities
to extend and enhance the static analyzer, and anyone interested in working on
a JVM and a CLI Virtual Machines (Microsoft .NET is an
implementation of the CLI) using the Just-In-Time compiler of LLVM.</p>
-<p>Following LLVM 2.5, VMKit has its first release that you can find on its
+<p>Following LLVM 2.5, VMKit has its second release that you can find on its
<a href="http://vmkit.llvm.org/releases/">webpage</a>. The release includes
bug fixes, cleanup and new features. The major changes are:</p>
<ul>
<li>Ahead of Time compiler: compiles .class files to llvm .bc. VMKit uses this
-functionality to native compile the standard classes (eg java.lang.String).
-Users can compile AOT .class files into dynamic libraries and run them with the
+functionality to native compile the standard classes (e.g. java.lang.String).
+Users can compile AoT .class files into dynamic libraries and run them with the
help of VMKit.</li>
<li>New exception model: the dwarf exception model is very slow for
gain for exception-intensive applications. For example the jack benchmark in
Spec JVM98 is 6x faster (performance gain of 83%).</li>
-<li>New support for OSX/X64, Linux/X64 (with the Boehm GC), Linux/ppc32.</li>
+<li>User-level management of thread stacks, so that thread local data access
+at runtime is fast and portable. </li>
+
+<li>Implementation of biased locking for faster object synchronizations at
+runtime.</li>
+
+<li>New support for OSX/X64, Linux/X64 (with the Boehm GC) and Linux/ppc32.</li>
</ul>
</div>
<p>
<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.
-LDC project works great with the LLVM 2.5 release. General improvements in this
+The LDC project works great with the LLVM 2.5 release. General improvements in
+this
cycle have included new inline asm constraint handling, better debug info
support, general bugfixes, and better x86-64 support. This has allowed
some major improvements in LDC, getting us much closer to being as
<div class="doc_text">
<p><a href="http://code.roadsend.com/rphp">Roadsend PHP</a> (rphp) is an open
-source compiler for 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 the LLVM.</p>
+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>
</div>
only supported by the interpreter. Note that the C backend still does not
support these.</li>
-<li>LLVM 2.5 no longer uses 'bison', so it is easier to build on Windows.</li>
+<li>LLVM 2.5 no longer uses 'bison,' so it is easier to build on Windows.</li>
</ul>
</div>
<li>LLVM IR supports two new attributes for better alias analysis. The <a
href="LangRef.html#paramattrs">noalias</a> attribute can now be used on the
return value of a function to indicate that it returns new memory (e.g.
-'malloc', 'calloc', etc).</li>
-
-<li>The new <a href="LangRef.html#paramattrs">nocapture</a> attribute can be
-used on pointer arguments to functions that access through but do not return the
-pointer in a data structure that out lives the call (e.g. 'strlen', 'memcpy',
-and many others). The simplifylibcalls pass applies these attributes to
-standard libc functions.</li>
+'malloc', 'calloc', etc).
+The new <a href="LangRef.html#paramattrs">nocapture</a> attribute can be used
+on pointer arguments to indicate that the function does not return the pointer,
+store it in an object that outlives the call, or let the value of the pointer
+escape from the function in any other way.
+Note that it is the pointer itself that must not escape, not the value it
+points to: loading a value out of the pointer is perfectly fine.
+Many standard library functions (e.g. 'strlen', 'memcpy') have this property.
+<!-- The simplifylibcalls pass applies these attributes to standard libc functions. -->
+</li>
<li>The parser for ".ll" files in lib/AsmParser is now completely rewritten as a
recursive descent parser. This parser produces better error messages (including
-caret diagnostics) is less fragile (less likely to crash on strange things) does
-not leak memory, is more efficient, and eliminates LLVM's last use of the
+caret diagnostics), is less fragile (less likely to crash on strange things),
+does not leak memory, is more efficient, and eliminates LLVM's last use of the
'bison' tool.</li>
<li>Debug information representation and manipulation internals have been
consolidated to use a new set of classes in
- <tt>llvm/Analysis/DebugInfo.h</tt> classes. These routines are more
+ <tt>llvm/Analysis/DebugInfo.h</tt>. These routines are more
efficient, robust, and extensible and replace the older mechanisms.
llvm-gcc, clang, and the code generator now use them to create and process
debug information.</li>
<div class="doc_text">
-<p>In addition to a huge array of bug fixes and minor performance tweaks, this
+<p>In addition to a large array of bug fixes and minor performance tweaks, this
release includes a few major enhancements and additions to the optimizers:</p>
<ul>
several ways, including adding shadow induction variables to avoid
"integer <-> floating point" conversions in loops when safe.</li>
-<li>The "-mem2reg" pass is now much faster on code with huge basic blocks.</li>
+<li>The "-mem2reg" pass is now much faster on code with large basic blocks.</li>
<li>The "-jump-threading" pass is more powerful: it is iterative
and handles threading based on values with fully and partially redundant
<li>The SelectionDAG type legalization logic has been completely rewritten, is
now more powerful (it supports arbitrary precision integer types for example),
-and more correct in several corner cases. The type legalizer converts
+and is more correct in several corner cases. The type legalizer converts
operations on types that are not natively supported by the target machine into
equivalent code sequences that only use natively supported types. The old type
legalizer is still available (for now) and will be used if
<li>The assembly printers for each target are now split out into their own
libraries that are separate from the main code generation logic. This reduces
-code size of JIT compilers by not requiring them to be linked in.</li>
+the code size of JIT compilers by not requiring them to be linked in.</li>
<li>The 'fast' instruction selection path (used at -O0 and for fast JIT
compilers) now supports accelerating codegen for code that uses exception
</p>
<ul>
-<li>The "<a href="LangRef.html#int_returnaddress">llvm.returnaddress</a>"
-intrinsic (which is used to implement "__builtin_return_address") now supports
-non-zero stack depths on X86.</li>
+<li>The <tt><a href="LangRef.html#int_returnaddress">llvm.returnaddress</a></tt>
+intrinsic (which is used to implement <tt>__builtin_return_address</tt>) now
+supports non-zero stack depths on X86.</li>
<li>The X86 backend now supports code generation of vector shift operations
using SSE instructions.</li>
-<li>X86-64 code generation now takes advantage of red zone (unless
--mno-red-zone option is specified).</li>
+<li>X86-64 code generation now takes advantage of red zone, unless the
+<tt>-mno-red-zone</tt> option is specified.</li>
<li>The X86 backend now supports using address space #256 in LLVM IR as a way of
performing memory references off the GS segment register. This allows a
front-end to take advantage of very low-level programming techniques when
-targetting X86 CPUs. See test/CodeGen/X86/movgs.ll for a simple example.</li>
+targeting X86 CPUs. See <tt>test/CodeGen/X86/movgs.ll</tt> for a simple
+example.</li>
<li>The X86 backend now supports a <tt>-disable-mmx</tt> command line option to
prevent use of MMX even on chips that support it. This is important for cases
- where code does not contain the proper "llvm.x86.mmx.emms" intrinsics.</li>
+ where code does not contain the proper <tt>llvm.x86.mmx.emms</tt>
+ intrinsics.</li>
-<li>The X86 JIT now detects the new Intel
"<a
- href="http://en.wikipedia.org/wiki/Intel_Core_i7">Core i7</a>
" and <a
- href="http://en.wikipedia.org/wiki/Intel_Atom">Atom</a>" chips,
- auto-configuring itself appropriately for the features of these chips.</li>
+<li>The X86 JIT now detects the new Intel <a
+ href="http://en.wikipedia.org/wiki/Intel_Core_i7">Core i7</a> and <a
+ href="http://en.wikipedia.org/wiki/Intel_Atom">Atom</a> chips and
+ auto-configures itself appropriately for the features of these chips.</li>
<li>The JIT now supports exception handling constructs on Linux/X86-64 and
Darwin/x86-64.</li>
+
<li>The JIT supports Thread Local Storage (TLS) on Linux/X86-32 but not yet on
X86-64.</li>
</ul>
-
</div>
<!--=========================================================================-->
types.</li>
<li>Function calls involving basic types work now.</li>
<li>Support for integer arrays.</li>
-<li>Compiler can now emit libcalls for operations not support by m/c insns.</li>
-<li>Support for both data and rom address spaces.</li>
+<li>The compiler can now emit libcalls for operations not supported by m/c
+instructions.</li>
+<li>Support for both data and ROM address spaces.</li>
</ul>
<p>Things not yet supported:</p>
<ul>
<li>Floating point.</li>
-<li>Passing/returning aggregate types to/from functions.</li>
+<li>Passing/returning aggregate types to and from functions.</li>
<li>Variable arguments.</li>
<li>Indirect function calls.</li>
<li>Interrupts/programs.</li>
by default. The command <tt>llvmc --clang</tt> can be now used as a
synonym to <tt>ccc</tt>.</li>
-<li>There is now a <tt>--check-graph</tt> option which is supposed to catch
+<li>There is now a <tt>--check-graph</tt> option, which is supposed to catch
common errors like multiple default edges, mismatched output/input language
names and cycles. In general, these checks can't be done at compile-time
because of the need to support plugins.</li>
<li>Plugins are now more flexible and can refer to compilation graph nodes and
options defined in other plugins. To manage dependencies, a priority-sorting
- mechanism was introduced. This change affects the TableGen file syntax; see the
+ mechanism was introduced. This change affects the TableGen file syntax. See the
documentation for details.</li>
<li>Hooks can now be provided with arguments. The syntax is "<tt>$CALL(MyHook,
- 'Arg1', 'Arg2', 'Arg #3')</tt>".</li>
+ 'Arg1', 'Arg2', 'Arg3')</tt>".</li>
<li>A new option type: multi-valued option, for options that take more than one
argument (for example, "<tt>-foo a b c</tt>").</li>
<ul>
-<li>llvm-gcc defaults to -fno-math-errno on all X86 targets.</li>
+<li>llvm-gcc defaults to <tt>-fno-math-errno</tt> on all X86 targets.</li>
+
</ul>
API changes are:</p>
<ul>
-<li>?</li>
-</ul>
-
-<ul>
-<li>?</li>
+<li>Some deprecated interfaces to create <tt>Instruction</tt> subclasses, that
+ were spelled with lower case "create," have been removed.</li>
</ul>
</div>
<ul>
<li>The MSIL, IA64, Alpha, SPU, MIPS, and PIC16 backends are experimental.</li>
-<li>The llc "<tt>-filetype=asm</tt>" (the default) is the only supported
- value for this option.</li>
+<li>The <tt>llc</tt> "<tt>-filetype=asm</tt>" (the default) is the only
+ supported value for this option.</li>
</ul>
</div>
<li>The X86 backend generates inefficient floating point code when configured
to generate code for systems that don't have SSE2.</li>
<li>Win64 code generation wasn't widely tested. Everything should work, but we
- expect small issues to happen. Also, llvm-gcc cannot build mingw64 runtime
- currently due
+ expect small issues to happen. Also, llvm-gcc cannot build the mingw64
+ runtime currently due
to <a href="http://llvm.org/PR2255">several</a>
- <a href="http://llvm.org/PR2257">bugs</a> due to lack of support for the
- 'u' inline assembly constraint and X87 floating point inline assembly.</li>
+ <a href="http://llvm.org/PR2257">bugs</a> and due to lack of support for
+ the
+ 'u' inline assembly constraint and for X87 floating point inline assembly.</li>
<li>The X86-64 backend does not yet support the LLVM IR instruction
<tt>va_arg</tt>. Currently, the llvm-gcc and front-ends support variadic
argument constructs on X86-64 by lowering them manually.</li>
<li>Thumb mode works only on ARMv6 or higher processors. On sub-ARMv6
processors, thumb programs can crash or produce wrong
results (<a href="http://llvm.org/PR1388">PR1388</a>).</li>
-<li>Compilation for ARM Linux OABI (old ABI) is supported, but not fully tested.
+<li>Compilation for ARM Linux OABI (old ABI) is supported but not fully tested.
</li>
<li>There is a bug in QEMU-ARM (<= 0.9.0) which causes it to incorrectly
execute
<div class="doc_text">
<ul>
-<li>The SPARC backend only supports the 32-bit SPARC ABI (-m32), it does not
+<li>The SPARC backend only supports the 32-bit SPARC ABI (-m32); it does not
support the 64-bit SPARC ABI (-m64).</li>
</ul>
<div class="doc_text">
<ul>
-<li>The Itanium backend is highly experimental, and has a number of known
+<li>The Itanium backend is highly experimental and has a number of known
issues. We are looking for a maintainer for the Itanium backend. If you
are interested, please contact the LLVMdev mailing list.</li>
</ul>
inline assembly code</a>.</li>
<li><a href="http://llvm.org/PR1658">The C backend violates the ABI of common
C++ programs</a>, preventing intermixing between C++ compiled by the CBE and
- C++ code compiled with llc or native compilers.</li>
+ C++ code compiled with <tt>llc</tt> or native compilers.</li>
<li>The C backend does not support all exception handling constructs.</li>
<li>The C backend does not support arbitrary precision integers.</li>
</ul>
<ul>
<li>Fortran support generally works, but there are still several unresolved bugs
in Bugzilla. Please see the tools/gfortran component for details.</li>
-
-<li>The Fortran front-end currently does not build on Darwin (without tweaks)
- due to unresolved dependencies on the C front-end.</li>
</ul>
</div>
</div>
<div class="doc_text">
-The llvm-gcc 4.2 Ada compiler works fairly well, however this is not a mature
-technology and problems should be expected.
+The llvm-gcc 4.2 Ada compiler works fairly well; however, this is not a mature
+technology, and problems should be expected.
<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>
+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
(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>Some GCC specific Ada tests continue to crash the compiler.</li>
<li>The -E 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 -E.</li>
projects / oota-llvm.git / blobdiff