X-Git-Url: http://demsky.eecs.uci.edu/git/?a=blobdiff_plain;ds=sidebyside;f=docs%2FReleaseNotes.html;h=56dd66a21aa53860577177cb78dd5c89a3456dc3;hb=6fa1c051dc515b6fd1f9a26ac12fed985469bff5;hp=c3449e51e96b40655a0ded2c02a8a3de5c006074;hpb=57a460e63d170a67debc10199f6477adef7ba57a;p=oota-llvm.git diff --git a/docs/ReleaseNotes.html b/docs/ReleaseNotes.html index c3449e51e96..56dd66a21aa 100644 --- a/docs/ReleaseNotes.html +++ b/docs/ReleaseNotes.html @@ -1,17 +1,19 @@ +
-Written by the LLVM Team
+ +
This document contains the release notes for the LLVM compiler -infrastructure, release 2.0. Here we describe the status of LLVM, including +infrastructure, release 2.3. 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 LLVM releases web site.
@@ -43,430 +47,495 @@ web site. If you have questions or comments, the LLVM developer's mailing list is a good place to send them. -Note that if you are reading this file from CVS or the main LLVM web page, -this document applies to the next release, not the current one. To see -the release notes for the current or previous releases, see the releases page.
+Note that if you are reading this file from a Subversion checkout or the +main LLVM web page, this document applies to the next release, not the +current one. To see the release notes for a specific releases, please see the +releases page.
This is the eleventh public release of the LLVM Compiler Infrastructure. -Being the first major release since 1.0, this release is different in several -ways from our previous releases:
- -Note that while this is a major version bump, this release has been - extensively tested on a wide range of software. It is easy to say that this - is our best release yet, in terms of both features and correctness. This is - the first LLVM release to correctly compile and optimize major software like - LLVM itself, Mozilla/Seamonkey, Qt 4.3rc1, kOffice, etc out of the box on - linux/x86. -
+This is the fourteenth public release of the LLVM Compiler Infrastructure. +It includes a large number of features and refinements from LLVM 2.2.
Changes to the LLVM IR itself:
+LLVM 2.3 no longer supports llvm-gcc 4.0, it has been replaced with + llvm-gcc 4.2.
-LLVM 2.3 no longer includes the llvm-upgrade 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.
-The llvm2cpp tool has been folded into llc, use + llc -march=cpp instead of llvm2cpp.
-Major new features:
+LLVM API Changes:
New features include: +
+The core LLVM 2.3 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 vmkit Project +and the Clang Project.
++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 +implementation of the CLI) using the Just-In-Time compiler of LLVM.
+ +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.
+ +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: +
-svn co http://llvm.org/svn/llvm-project/vmkit/trunk vmkit+
New features include: -
-The Clang project is an effort to build +a set of new 'LLVM native' front-end technologies for the LLVM optimizer +and code generator. Clang is continuing to make major strides forward in all +areas. Its C and Objective-C parsing support is very solid, and the code +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.
-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 static +analysis tool in development. This tool focuses on automatically finding +bugs in C and Objective-C code.
-LLVM 2.3 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. +
-New features include: -
+ +LLVM 2.3 includes several major new capabilities:
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 LLVM IR Reference for more details.
+ +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.
LLVM 2.3 includes a complete reimplementation of the "llvmc" + tool. It is designed to overcome several problems with the original + llvmc and to provide a superset of the features of the + 'gcc' driver.
+ +The main features of llvmc2 are: +
LLVM 2.3 includes a completely rewritten interface for Link Time Optimization. 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.
The Kaleidoscope tutorial now + includes a "port" of the tutorial that uses the Ocaml bindings to implement + the Kaleidoscope language.
LLVM 2.3 fully supports the llvm-gcc 4.2 front-end, and includes support +for the C, C++, Objective-C, Ada, and Fortran front-ends.
-Other improvements include: -
-New features include: +
-In addition, the LLVM target description format has itself been extended in - several ways:
-X86-specific Code Generator Enhancements: -
+In addition to a huge array of bug fixes and minor performance tweaks, the +LLVM 2.3 optimizers support a few major enhancements:
ARM-specific Code Generator Enhancements:
+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,
-+for (i = LB; i < UB; ++i) + if (i <= NV) + LOOP_BODY ++
is transformed into:
-+NUB = min(NV+1, UB) +for (i = LB; i < NUB; ++i) + LOOP_BODY ++
PowerPC-specific Code Generator Enhancements:
+We put a significant amount of work into the code generator infrastructure, +which allows us to implement more aggressive algorithms and make it run +faster:
-More specific changes include:
+New target-specific features include: +
LLVM 2.0 contains a revamp of the type system and several other significant -internal changes. If you are programming to the C++ API, be aware of the -following major changes:
+New target-specific features include: +
- Value *Ops[] = { Op1, Op2, Op3 }; - GEP = new GetElementPtrInst(BasePtr, Ops, 3); -- - This avoids creation of a temporary vector (and a call to malloc/free). If - you have an std::vector, use code like this: -
- std::vector<Value*> Ops = ...; - GEP = new GetElementPtrInst(BasePtr, &Ops[0], Ops.size()); -+
New features include: +
+ +LLVM is known to work on the following platforms:
The core LLVM infrastructure uses -GNU autoconf to adapt itself +
The core LLVM infrastructure uses GNU autoconf 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.
@@ -526,17 +594,13 @@ there isn't already one. 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 LLVMdev list. +components, please contact us on the LLVMdev list.llvm-gcc4 does not currently support Link-Time -Optimization on most platforms "out-of-the-box". Please inquire on the +
llvm-gcc does not currently support Link-Time +Optimization on most platforms "out-of-the-box". Please inquire on the llvmdev mailing list if you are interested.
-"long double" is silently transformed by the front-end into "double". There -is no support for floating point data types of any size other than 32 and 64 -bits.
llvm-gcc does not support __builtin_apply yet. - See Constructing Calls: Dispatching a call to another function.
-llvm-gcc partially supports these GCC extensions:
-llvm-gcc supports the vast majority of GCC extensions, including:
- -typeof
: referring to the type of an expression.?:
, ",
" and casts in lvalues.?:
expression.void
-pointers and function pointers.\e
stands for the character <ESC>.__const__
, __asm__
, etc., for header files.enum foo;
, with details to follow.The only major language feature of GCC not supported by llvm-gcc is + the __builtin_apply family of builtins. However, some extensions + are only supported on some targets. For example, trampolines are only + supported on some targets (these are used when you take the address of a + nested function).
-If you run into GCC extensions which have not been included in any of these -lists, please let us know (also including whether or not they work).
+If you run into GCC extensions which are not supported, please let us know. +
A wide variety of additional information is available on the LLVM web page, in particular in the documentation section. The web page also -contains versions of the API documentation which is up-to-date with the CVS -version of the source code. +contains versions of the API documentation which is up-to-date with the +Subversion version of the source code. You can access versions of these documents specific to this release by going into the "llvm/doc/" directory in the LLVM tree.
@@ -850,7 +838,7 @@ lists. + src="http://www.w3.org/Icons/valid-html401" alt="Valid HTML 4.01!"> LLVM Compiler Infrastructure