Strip out 2.3 info, make space for 2.4 info. I'd appreciate it if

various component owners could look through and update their areas in the known-problems section. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@57376 91177308-0d34-0410-b5e6-96231b3b80d8
author: Chris Lattner <sabre@nondot.org> 2008-10-11 18:18:28 +0000
committer: Chris Lattner <sabre@nondot.org> 2008-10-11 18:18:28 +0000
commit: 857fb1309f6bcd5e8d050f047d0ac93be9d1a0d7 (patch)
tree: 769bf1c0a6c7940bfb10989e91c31046be0bbd89
parent: ce91ec285d89867f2048f93f31da198a227bba7a (diff)
1 files changed, 40 insertions, 274 deletions
diff --git a/docs/ReleaseNotes.html b/docs/ReleaseNotes.html
index 56dd66a21a..b152d98744 100644
--- a/docs/ReleaseNotes.html
+++ b/docs/ReleaseNotes.html
@@ -1,15 +1,14 @@
-
 <!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 2.3 Release Notes</title>
+  <title>LLVM 2.4 Release Notes</title>
 </head>
 <body>
 
-<div class="doc_title">LLVM 2.3 Release Notes</div>
+<div class="doc_title">LLVM 2.4 Release Notes</div>
  
 <ol>
   <li><a href="#intro">Introduction</a></li>
@@ -36,7 +35,7 @@
 <div class="doc_text">
 
 <p>This document contains the release notes for the LLVM compiler
-infrastructure, release 2.3.  Here we describe the status of LLVM, including
+infrastructure, release 2.4.  Here we describe the status of LLVM, including
 major improvements from the previous release and any known problems.  All LLVM
 releases may be downloaded from the <a href="http://llvm.org/releases/">LLVM
 releases web site</a>.</p>
@@ -62,12 +61,12 @@ current one.  To see the release notes for a specific releases, please see the
 
 <div class="doc_text">
 
-<p>This is the fourteenth public release of the LLVM Compiler Infrastructure. 
-It includes a large number of features and refinements from LLVM 2.2.</p>
+<p>This is the fifteenth public release of the LLVM Compiler Infrastructure. 
+It includes a large number of features and refinements from LLVM 2.3.</p>
 
 </div>
 
-<!-- Unfinished features in 2.3:
+<!-- Unfinished features in 2.4:
   Machine LICM
   Machine Sinking
   LegalizeDAGTypes
@@ -75,47 +74,17 @@ It includes a large number of features and refinements from LLVM 2.2.</p>
 
 <!--=========================================================================-->
 <div class="doc_subsection">
-<a name="changes">Major Changes in LLVM 2.3</a>
+<a name="changes">Major Changes in LLVM 2.4</a>
 </div>
 
 <div class="doc_text">
 
-<p>LLVM 2.3 no longer supports llvm-gcc 4.0, it has been replaced with
-   llvm-gcc 4.2.</p>
-
-<p>LLVM 2.3 no longer includes the <tt>llvm-upgrade</tt> tool.  It was useful
-   for upgrading LLVM 1.9 files to LLVM 2.x syntax, but you can always use a
-   previous LLVM release to do this.  One nice impact of this is that the LLVM
-   regression test suite no longer depends on llvm-upgrade, which makes it run
-   faster.</p>
-
-<p>The <tt>llvm2cpp</tt> tool has been folded into llc, use
-    <tt>llc -march=cpp</tt> instead of <tt>llvm2cpp</tt>.</p>
+<p>....</p>
 
 <p>LLVM API Changes:</p>
 
 <ul>
-<li>Several core LLVM IR classes have migrated to use the
-    '<tt>FOOCLASS::Create(...)</tt>' pattern instead of '<tt>new 
-    FOOCLASS(...)</tt>' (e.g. where FOOCLASS=<tt>BasicBlock</tt>).  We hope to
-    standardize on <tt>FOOCLASS::Create</tt> for all IR classes in the future,
-    but not all of them have been moved over yet.</li>
-<li>LLVM 2.3 renames the LLVMBuilder and LLVMFoldingBuilder classes to
-    <a href="http://llvm.org/doxygen/classllvm_1_1IRBuilder.html">IRBuilder</a>.
-    </li>
-<li>MRegisterInfo was renamed to
-    <a href="http://llvm.org/doxygen/classllvm_1_1TargetRegisterInfo.html">
-    TargetRegisterInfo</a>.</li>
-<li>The MappedFile class is gone, please use
-    <a href="http://llvm.org/doxygen/classllvm_1_1MemoryBuffer.html">
-    MemoryBuffer</a> instead.</li>
-<li>The '<tt>-enable-eh</tt>' flag to llc has been removed.  Now code should 
-    encode whether it is safe to omit unwind information for a function by
-    tagging the Function object with the '<tt>nounwind</tt>' attribute.</li>
-<li>The ConstantFP::get method that uses APFloat now takes one argument
-    instead of two. The type argument has been removed, and the type is
-    now inferred from the size of the given APFloat value.</li>
-
+<li>....</li>
 </ul>
 </div>
 
@@ -126,12 +95,12 @@ It includes a large number of features and refinements from LLVM 2.2.</p>
 
 <div class="doc_text">
 <p>
-The core LLVM 2.3 distribution currently consists of code from the core LLVM
+The core LLVM 2.4 distribution currently consists of code from the core LLVM
 repository (which roughly contains the LLVM optimizer, code generators and
 supporting tools) and the llvm-gcc repository.  In addition to this code, the
 LLVM Project includes other sub-projects that are in development.  The two which
-are the most actively developed are the new <a href="#vmkit">vmkit Project</a>
-and the <a href="#clang">Clang Project</a>. 
+are the most actively developed are the <a href="#clang">Clang Project</a> and
+<a href="#vmkit">vmkit Project</a>. 
 </p>
 </div>
 
@@ -142,28 +111,11 @@ and the <a href="#clang">Clang Project</a>.
 
 <div class="doc_text">
 <p>
-The "vmkit" project is a new addition to the LLVM family.  It is an
-implementation of a JVM and a CLI Virtual Machines (Microsoft .NET is an
+The <a href="http://vmkit.llvm.org/">"vmkit" project</a> is an implementation of
+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>The JVM, called JnJVM, executes real-world applications such as Apache
-projects (e.g. Felix and Tomcat) and the SpecJVM98 benchmark.  It uses the GNU
-Classpath project for the base classes.  The CLI implementation, called N3, is
-its in early stages but can execute simple applications and the "pnetmark"
-benchmark. It uses the pnetlib project as its core library.</p>
-
-<p>The 'vmkit' VMs compare in performance with industrial and top open-source
-VMs on scientific applications.  Besides the JIT, the VMs use many features of
-the LLVM framework, including the standard set of optimizations, atomic
-operations, custom function provider and memory manager for JITed methods, and
-specific virtual machine optimizations. vmkit is not an official part of LLVM
-2.3 release. It is publicly available under the LLVM license and can be
-downloaded from:
-</p>
-
-<div class="doc_code">
-<pre>svn co http://llvm.org/svn/llvm-project/vmkit/trunk vmkit</pre>
-</div>
+<p>...</p>
 
 </div>
 
@@ -182,12 +134,12 @@ generation support is far enough along to build many C applications.  While not
 yet production quality, it is progressing very nicely.  In addition, C++
 front-end work has started to make significant progress.</p>
 
-<p>At this point, Clang is most useful if you are interested in source-to-source
-transformations (such as refactoring) and other source-level tools for C and
-Objective-C.  Clang now also includes tools for turning C code into pretty HTML,
-and includes a new <a href="http://clang.llvm.org/StaticAnalysis.html">static
-analysis tool</a> in development.  This tool focuses on automatically finding
-bugs in C and Objective-C code.</p>
+<p>Codegen progress/state
+</p>
+
+<p>
+<a href="http://clang.llvm.org/StaticAnalysis.html">static analysis tool</a>
+</p>
 
 </div>
 
@@ -200,7 +152,7 @@ bugs in C and Objective-C code.</p>
 
 <div class="doc_text">
 
-<p>LLVM 2.3 includes a huge number of bug fixes, performance tweaks and minor
+<p>LLVM 2.4 includes a huge number of bug fixes, performance tweaks and minor
 improvements.  Some of the major improvements and new features are listed in
 this section.
 </p>
@@ -213,52 +165,18 @@ this section.
 
 <div class="doc_text">
 
-<p>LLVM 2.3 includes several major new capabilities:</p>
+<p>LLVM 2.4 includes several major new capabilities:</p>
 
 <ul>
-<li><p>The biggest change in LLVM 2.3 is Multiple Return Value (MRV) support.
-    MRVs allow LLVM IR to directly represent functions that return multiple
-    values without having to pass them "by reference" in the LLVM IR.  This
-    allows a front-end to generate more efficient code, as MRVs are generally
-    returned in registers if a target supports them.  See the <a
-    href="LangRef.html#i_getresult">LLVM IR Reference</a> for more details.</p>
-    
- <p>MRVs are fully supported in the LLVM IR, but are not yet fully supported in
-    on all targets.  However, it is generally safe to return up to 2 values from
-    a function: most targets should be able to handle at least that.  MRV
-    support is a critical requirement for X86-64 ABI support, as X86-64 requires
-    the ability to return multiple registers from functions, and we use MRVs to
-    accomplish this in a direct way.</p></li>
-
-<li><p>LLVM 2.3 includes a complete reimplementation of the "<tt>llvmc</tt>"
-    tool.  It is designed to overcome several problems with the original 
-    <tt>llvmc</tt> and to provide a superset of the features of the
-    '<tt>gcc</tt>' driver.</p>
-
-    <p>The main features of <tt>llvmc2</tt> are:
-    <ul>
-    <li>Extended handling of command line options and smart rules for
-    dispatching them to different tools.</li>
-    <li>Flexible (and extensible) rules for defining different tools.</li>
-    <li>The different intermediate steps performed by tools are represented
-    as edges in the abstract graph.</li>
-    <li>The 'language' for driver behavior definition is tablegen and thus
-    it's relatively easy to add new features.</li>
-    <li>The definition of driver is transformed into set of C++ classes, thus
-    no runtime interpretation is needed.</li>
-    </ul>
-</li>
+<li>
+ <p>MRVs got generalized to FCAs.</p>
+ </li>
 
-<li><p>LLVM 2.3 includes a completely rewritten interface for <a
-    href="LinkTimeOptimization.html">Link Time Optimization</a>.  This interface
-    is written in C, which allows for easier integration with C code bases, and
-    incorporates improvements we learned about from the first incarnation of the
-    interface.</p></li>
+<li><p>fast isel, -O0 compile times</p></li>
+    
+<li><p>Attrs changes?</p></li>
 
-<li><p>The <a href="tutorial/LangImpl1.html">Kaleidoscope tutorial</a> now
-    includes a "port" of the tutorial that <a 
-    href="tutorial/OCamlLangImpl1.html">uses the Ocaml bindings</a> to implement
-    the Kaleidoscope language.</p></li>
+<li><p>...</p></li>
 
 </ul>
 
@@ -272,19 +190,12 @@ this section.
 
 <div class="doc_text">
 
-<p>LLVM 2.3 fully supports the llvm-gcc 4.2 front-end, and includes support
+<p>LLVM 2.4 fully supports the llvm-gcc 4.2 front-end, and includes support
 for the C, C++, Objective-C, Ada, and Fortran front-ends.</p>
 
 <p>
 <ul>
-<li>llvm-gcc 4.2 includes numerous fixes to better support the Objective-C
-front-end.  Objective-C now works very well on Mac OS/X.</li>
-
-<li>Fortran <tt>EQUIVALENCE</tt>s are now supported by the gfortran
-front-end.</li>
-
-<li>llvm-gcc 4.2 includes many other fixes which improve conformance with the
-relevant parts of the GCC testsuite.</li>
+<li>...</li>
 
 </ul>
 
@@ -301,17 +212,7 @@ relevant parts of the GCC testsuite.</li>
 </p>
 
 <ul>
-<li>LLVM IR now directly represents "common" linkage, instead of representing it
-as a form of weak linkage.</li>
-
-<li>LLVM IR now has support for atomic operations, and this functionality can be
-accessed through the llvm-gcc "<tt>__sync_synchronize</tt>",
-"<tt>__sync_val_compare_and_swap</tt>", and related builtins.  Support for
-atomics are available in the Alpha, X86, X86-64, and PowerPC backends.</li>
-
-<li>The C and Ocaml bindings have extended to cover pass managers, several
-transformation passes, iteration over the LLVM IR, target data, and parameter
-attribute lists.</li>
+<li>...</li>
 </ul>
   
 </div>
@@ -324,64 +225,11 @@ attribute lists.</li>
 <div class="doc_text">
 
 <p>In addition to a huge array of bug fixes and minor performance tweaks, the 
-LLVM 2.3 optimizers support a few major enhancements:</p>
+LLVM 2.4 optimizers support a few major enhancements:</p>
 
 <ul>
 
-<li><p>Loop index set splitting on by default.
-This transformation hoists conditions from loop bodies and reduces a loop's
-iteration space to improve performance. For example,</p>
-
-<div class="doc_code">
-<pre>
-for (i = LB; i &lt; UB; ++i)
-  if (i &lt;= NV)
-    LOOP_BODY
-</pre>
-</div>
-
-<p>is transformed into:</p>
-
-<p><div class="doc_code">
-<pre>
-NUB = min(NV+1, UB)
-for (i = LB; i &lt; NUB; ++i)
-  LOOP_BODY
-</pre>
-</div>
-</p>
-</li>
-
-<li>LLVM now includes a new <tt>memcpy</tt> optimization pass which removes
-dead <tt>memcpy</tt> calls, unneeded copies of aggregates, and performs
-return slot optimization.  The LLVM optimizer now notices long sequences of
-consecutive stores and merges them into <tt>memcpy</tt>'s where profitable.</li>
-
-<li>Alignment detection for vector memory references and for <tt>memcpy</tt> and
-<tt>memset</tt> is now more aggressive.</li> 
-
-<li>The Aggressive Dead Code Elimination (ADCE) optimization has been rewritten
-to make it both faster and safer in the presence of code containing infinite
-loops.  Some of its prior functionality has been factored out into the loop
-deletion pass, which <em>is</em> safe for infinite loops.  The new ADCE pass is
-no longer based on control dependence, making it run faster.</li>
-
-<li>The 'SimplifyLibCalls' pass, which optimizes calls to libc and libm
-    functions for C-based languages, has been rewritten to be a FunctionPass
-    instead a ModulePass.  This allows it to be run more often and to be
-    included at -O1 in llvm-gcc.  It was also extended to include more
-    optimizations and several corner case bugs were fixed.</li>
-
-<li>LLVM now includes a simple 'Jump Threading' pass, which attempts to simplify
-    conditional branches using information about predecessor blocks, simplifying
-    the control flow graph.  This pass is pretty basic at this point, but
-    catches some important cases and provides a foundation to build on.</li>
-    
-<li>Several corner case bugs which could lead to deleting volatile memory
-    accesses have been fixed.</li>
-
-<li>Several optimizations have been sped up, leading to faster code generation
-    with the same code quality.</li>
+<li>.</li>
   
 </ul>
 
@@ -399,45 +247,9 @@ which allows us to implement more aggressive algorithms and make it run
 faster:</p>
 
 <ul>
-<li>The code generator now has support for carrying information about memory
-    references throughout the entire code generation process, via the
-    <a href="http://llvm.org/doxygen/classllvm_1_1MachineMemOperand.html">
-    MachineMemOperand</a> class. In the future this will be used to improve
-    both pre-pass and post-pass scheduling, and to improve compiler-debugging
-    output.</li>
-
-<li>The target-independent code generator infrastructure now uses LLVM's
-    <a href="http://llvm.org/doxygen/classllvm_1_1APInt.html">APInt</a>
-    class to handle integer values, which allows it to support integer types
-    larger than 64 bits (for example i128). Note that support for such types is
-    also dependent on target-specific support.  Use of APInt is also a step
-    toward support for non-power-of-2 integer sizes.</li>
-    
-<li>LLVM 2.3 includes several compile time speedups for code with large basic
-    blocks, particularly in the instruction selection phase, register
-    allocation, scheduling, and tail merging/jump threading.</li>
+<li>Selection dag speedups</li>
+<li>...</li>
 
-<li>LLVM 2.3 includes several improvements which make llc's
-    <tt>--view-sunit-dags</tt> visualization of scheduling dependency graphs
-    easier to understand.</li>
-    
-<li>The code generator allows targets to write patterns that generate subreg
-    references directly in .td files now.</li>
-    
-<li><tt>memcpy</tt> lowering in the backend is more aggressive, particularly for
-    <tt>memcpy</tt> calls introduced by the code generator when handling
-    pass-by-value structure argument copies.</li>
-    
-<li>Inline assembly with multiple register results now returns those results
-    directly in the appropriate registers, rather than going through memory.
-    Inline assembly that uses constraints like "ir" with immediates now use the
-    'i' form when possible instead of always loading the value in a register.
-    This saves an instruction and reduces register use.</li>
-
-<li>Added support for PIC/GOT style <a 
-    href="CodeGenerator.html#tailcallopt">tail calls</a> on X86/32 and initial
-    support for tail calls on PowerPC 32 (it may also work on PowerPC 64 but is
-    not thoroughly tested).</li>
 </ul>
 
 </div>
@@ -453,48 +265,7 @@ faster:</p>
 </p>
 
 <ul>
-<li>llvm-gcc's X86-64 ABI conformance is far improved, particularly in the
-    area of passing and returning structures by value.  llvm-gcc compiled code
-    now interoperates very well on X86-64 systems with other compilers.</li>
-
-<li>Support for Win64 was added. This includes code generation itself, JIT
-    support, and necessary changes to llvm-gcc.</li>
-
-<li>The LLVM X86 backend now supports the support SSE 4.1 instruction set, and
-    the llvm-gcc 4.2 front-end supports the SSE 4.1 compiler builtins.  Various
-    generic vector operations (insert/extract/shuffle) are much more efficient
-    when SSE 4.1 is enabled.  The JIT automatically takes advantage of these
-    instructions, but llvm-gcc must be explicitly told to use them, e.g. with
-    <tt>-march=penryn</tt>.</li>
-
-<li>The X86 backend now does a number of optimizations that aim to avoid
-    converting numbers back and forth from SSE registers to the X87 floating
-    point stack.  This is important because most X86 ABIs require return values
-    to be on the X87 Floating Point stack, but most CPUs prefer computation in
-    the SSE units.</li>
-
-<li>The X86 backend supports stack realignment, which is particularly useful for
-    vector code on OS's without 16-byte aligned stacks, such as Linux and
-    Windows.</li>
-
-<li>The X86 backend now supports the "sseregparm" options in GCC, which allow
-    functions to be tagged as passing floating point values in SSE
-    registers.</li>
-
-<li>Trampolines (taking the address of a nested function) now work on
-    Linux/X86-64.</li>
-
-<li><tt>__builtin_prefetch</tt> is now compiled into the appropriate prefetch
-    instructions instead of being ignored.</li>
-
-<li>128-bit integers are now supported on X86-64 targets.  This can be used
-    through <tt>__attribute__((TImode))</tt> in llvm-gcc.</li>
-
-<li>The register allocator can now rematerialize PIC-base computations, which is
-    an important optimization for register use.</li>
-
-<li>The "t" and "f" inline assembly constraints for the X87 floating point stack
-    now work.  However, the "u" constraint is still not fully supported.</li>
+<li>...</li>
 
 </ul>
   
@@ -510,9 +281,7 @@ faster:</p>
 </p>
 
 <ul>
-<li>The LLVM C backend now supports vector code.</li>
-<li>The Cell SPU backend includes a number of improvements. It generates better
-    code and its stability/completeness is improving.</li>
+<li>....</li>
 </ul>
   
 </div>
@@ -529,10 +298,7 @@ faster:</p>
 </p>
 
 <ul>
-<li>LLVM now builds with GCC 4.3.</li>
-<li>Bugpoint now supports running custom scripts (with the <tt>-run-custom</tt>
-    option) to determine how to execute the command and whether it is making
-    forward process.</li>
+<li>...</li>
 </ul>
   
 </div>
author	Chris Lattner <sabre@nondot.org>	2008-10-11 18:18:28 +0000
committer	Chris Lattner <sabre@nondot.org>	2008-10-11 18:18:28 +0000
commit	857fb1309f6bcd5e8d050f047d0ac93be9d1a0d7 (patch)
tree	769bf1c0a6c7940bfb10989e91c31046be0bbd89
parent	ce91ec285d89867f2048f93f31da198a227bba7a (diff)