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|
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN"
"http://www.w3.org/TR/html4/strict.dtd">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8">
<link rel="stylesheet" href="llvm.css" type="text/css">
<title>LLVM 1.8 Release Notes</title>
</head>
<body>
<div class="doc_title">LLVM 1.8 Release Notes</div>
<ol>
<li><a href="#intro">Introduction</a></li>
<li><a href="#whatsnew">What's New?</a></li>
<li><a href="GettingStarted.html">Installation Instructions</a></li>
<li><a href="#portability">Portability and Supported Platforms</a></li>
<li><a href="#knownproblems">Known Problems</a>
<li><a href="#additionalinfo">Additional Information</a></li>
</ol>
<div class="doc_author">
<p>Written by the <a href="http://llvm.org">LLVM Team</a><p>
</div>
<!-- *********************************************************************** -->
<div class="doc_section">
<a name="intro">Introduction</a>
</div>
<!-- *********************************************************************** -->
<div class="doc_text">
<p>This document contains the release notes for the LLVM compiler
infrastructure, release 1.8. Here we describe the status of LLVM, including any
known problems and major improvements from the previous release. The most
up-to-date version of this document (corresponding to LLVM CVS) can be found
on the <a
href="http://llvm.org/releases/">LLVM releases web site</a>. If you are
not reading this on the LLVM web pages, you should probably go there because
this document may be updated after the release.</p>
<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>
<p>Note that if you are reading this file from CVS 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 the current or previous releases, see the <a
href="http://llvm.org/releases/">releases page</a>.</p>
</div>
<!-- *********************************************************************** -->
<div class="doc_section">
<a name="whatsnew">What's New?</a>
</div>
<!-- *********************************************************************** -->
<div class="doc_text">
<p>This is the ninth public release of the LLVM Compiler Infrastructure. This
release incorporates a large number of enhancements and new features,
including DWARF debugging support (C and C++ on Darwin/PPC), improved inline
assembly support, a new <a href="http://llvm.org/nightlytest/">nightly
tester</a>, llvm-config enhancements, many bugs
fixed, and performance and compile time improvements.
</p>
</div>
<!--=========================================================================-->
<div class="doc_subsection">
<a name="newfeatures">New Features in LLVM 1.8</a>
</div>
<!--_________________________________________________________________________-->
<div class="doc_subsubsection"><a name="dwarf">DWARF debugging
support </a></div>
<div class="doc_text">
<p>The llvm-gcc4 C front-end now generates debugging info for C and C++. This
information is propagated through the compiler and the code generator can
currently produce DWARF debugging information from it. DWARF is a standard
debugging format used on many platforms, but currently LLVM only includes
target support for Mac OS X targets for the 1.8 release.
</p>
</div>
<!--_________________________________________________________________________-->
<div class="doc_subsubsection"><a name="inlineasm">Inline Assembly
Support</a></div>
<div class="doc_text">
<p>Inline assembly support is substantially improved in LLVM 1.8 over LLVM 1.7.
Many unsupported features are now supported, and inline asm support in the X86
backend is far better. llvm-gcc4 now supports global register variables as
well.</p>
</div>
<!--_________________________________________________________________________-->
<div class="doc_subsubsection"><a name="loopopt">Loop Optimizer Improvements</a></div>
<div class="doc_text">
<p>The loop optimizer passes now uses "Loop-Closed SSA Form", which makes it
easier to update SSA form as loop transformations change the code. An
immediate benefit of this is that the loop unswitching pass can now unswitch
loops in more cases.
</p>
</div>
<!--_________________________________________________________________________-->
<div class="doc_subsubsection"><a name="jumptab">Jump Table Support for Switches
</a></div>
<div class="doc_text">
<p>The code generator now lowers switch statements to jump tables, providing
significant performance boosts for applications (e.g. interpreters) whose
performance is highly correlated to switch statement performance.</p>
</div>
<!--_________________________________________________________________________-->
<div class="doc_subsubsection"><a name="jitrelease">Deallocation of JIT'd
Machine Code
</a></div>
<div class="doc_text">
<p>The LLVM JIT now allows clients to deallocate machine code JIT'd to its code
buffer. This is important for long living applications that depend on the JIT.
</p>
</div>
<!--_________________________________________________________________________-->
<div class="doc_subsubsection"><a name="other">Other Improvements</a></div>
<div class="doc_text">
<p>This release includes many other improvements, including improvements to
the optimizers and code generators (improving the generated code) changes to
speed up the compiler in many ways (improving algorithms and fine tuning
code), and changes to reduce the code size of the compiler itself.</p>
<p>More specific changes include:</p>
<ul>
<li>LLVM 1.8 includes an initial ARM backend. This backend is in early
development stages.</li>
<li>LLVM 1.8 now includes significantly better support for mingw and
cygwin.</li>
<li>The <a href="CommandGuide/html/llvm-config.html">llvm-config</a> tool is
now built by default and has several new features.</li>
<li>The X86 and PPC backends now use the correct platform ABI for passing
vectors as arguments to functions.</li>
<li>The X86 backend now includes support for the Microsoft ML assembler
("MASM").</li>
<li>The PowerPC backend now pattern matches the 'rlwimi' instruction more
aggressively.</li>
<li>Most of LLVM is now built with "-pedantic", ensuring better portability
to more C++ Compilers.</li>
<li>The PowerPC backend now includes initial 64-bit support. The JIT is not
complete, and the static compiler has a couple of known bugs, but support
is mostly in place. LLVM 1.9 will include completed PPC-64 support. </li>
</ul>
</div>
<!--=========================================================================-->
<div class="doc_subsection">
<a name="changes">Significant Changes in LLVM 1.8</a>
</div>
<div class="doc_text">
<ul>
<li>The LLVM "SparcV9" backend (deprecated in LLVM 1.7) has been removed in
LLVM 1.8. The LLVM "Sparc" backend replaces it.</li>
<li>The --version option now prints more useful information, including the
build configuration for the tool.</li>
</ul>
</div>
<!-- *********************************************************************** -->
<div class="doc_section">
<a name="portability">Portability and Supported Platforms</a>
</div>
<!-- *********************************************************************** -->
<div class="doc_text">
<p>LLVM is known to work on the following platforms:</p>
<ul>
<li>Intel and AMD machines running Red Hat Linux, Fedora Core and FreeBSD
(and probably other unix-like systems).</li>
<li>Intel and AMD machines running on Win32 using MinGW libraries (native)</li>
<li>Sun UltraSPARC workstations running Solaris 8.</li>
<li>Intel and AMD machines running on Win32 with the Cygwin libraries (limited
support is available for native builds with Visual C++).</li>
<li>PowerPC and X86-based Mac OS X systems, running 10.2 and above.</li>
<li>Alpha-based machines running Debian GNU/Linux.</li>
<li>Itanium-based machines running Linux and HP-UX.</li>
</ul>
<p>The core LLVM infrastructure uses
<a href="http://www.gnu.org/software/autoconf/">GNU autoconf</a> to adapt itself
to the machine and operating system on which it is built. However, minor
porting may be required to get LLVM to work on new platforms. We welcome your
portability patches and reports of successful builds or error messages.</p>
</div>
<!-- *********************************************************************** -->
<div class="doc_section">
<a name="knownproblems">Known Problems</a>
</div>
<!-- *********************************************************************** -->
<div class="doc_text">
<p>This section contains all known problems with the LLVM system, listed by
component. As new problems are discovered, they will be added to these
sections. If you run into a problem, please check the <a
href="http://llvm.org/bugs/">LLVM bug database</a> and submit a bug if
there isn't already one.</p>
</div>
<!-- ======================================================================= -->
<div class="doc_subsection">
<a name="experimental">Experimental features included with this release</a>
</div>
<div class="doc_text">
<p>The following components of this LLVM release are either untested, known to
be broken or unreliable, or are in early development. These components should
not be relied on, and bugs should not be filed against them, but they may be
useful to some people. In particular, if you would like to work on one of these
components, please contact us on the <a href="http://lists.cs.uiuc.edu/mailman/listinfo/llvmdev">LLVMdev list</a>.</p>
<ul>
<li>The <tt>-cee</tt> pass is known to be buggy, and may be removed in in a
future release.</li>
<li>The IA64 code generator is experimental.</li>
<li>The Alpha JIT is experimental.</li>
<li>"<tt>-filetype=asm</tt>" (the default) is the only supported value for the
<tt>-filetype</tt> llc option.</li>
</ul>
</div>
<!-- ======================================================================= -->
<div class="doc_subsection">
<
|
