X-Git-Url: http://demsky.eecs.uci.edu/git/?a=blobdiff_plain;f=docs%2FReleaseNotes.html;h=56dd66a21aa53860577177cb78dd5c89a3456dc3;hb=6fa1c051dc515b6fd1f9a26ac12fed985469bff5;hp=d8835b10273143983956e312b91967cbefdf8d30;hpb=052bae6268fee4657dd733e1fd0a8b478277144b;p=oota-llvm.git diff --git a/docs/ReleaseNotes.html b/docs/ReleaseNotes.html index d8835b10273..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 2.2. 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.
@@ -55,108 +56,236 @@ current one. To see the release notes for a specific releases, please see theThis is the thirteenth public release of the LLVM Compiler Infrastructure. -It includes many features and refinements from LLVM 2.1.
+This is the fourteenth public release of the LLVM Compiler Infrastructure. +It includes a large number of features and refinements from LLVM 2.2.
LLVM 2.2 fully supports both the llvm-gcc 4.0 and llvm-gcc 4.2 front-ends (in -LLVM 2.1, llvm-gcc 4.2 was beta). Since LLVM 2.1, the llvm-gcc 4.2 front-end -has made leaps and bounds and is now at least as good as 4.0 in virtually every -area, and is better in several areas (for example, exception handling -correctness). We strongly recommend that you migrate from llvm-gcc 4.0 to -llvm-gcc 4.2 in this release cycle because LLVM 2.2 is the last release -that will support llvm-gcc 4.0: LLVM 2.3 will only support the llvm-gcc -4.2 front-end.
+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.
-The clang project is an effort to build -a set of new 'llvm native' front-end technologies for the LLVM optimizer -and code generator. Currently, its C and Objective-C support is maturing -nicely, and it has advanced source-to-source analysis and transformation -capabilities. If you are interested in building source-level tools for C and -Objective-C (and eventually C++), you should take a look. However, note that -clang is not an official part of the LLVM 2.2 release. If you are interested in -this project, please see the web site.
+LLVM API Changes:
++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. +
+Dale contributed full support for long double on x86/x86-64 (where it is 80 -bits) and on Darwin PPC/PPC64 (where it is 128 bits).
- -Ada, gfortran
+ +-debug improvements -O0 -EH. +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: +
-Gordon: GC Revamp. docs/GarbageCollection.html +svn co http://llvm.org/svn/llvm-project/vmkit/trunk vmkit+
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. +
Some of the most noticable feature improvements this release have been in the -optimizer, speeding it up and making it more aggressive. For example:
+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.
foci of this release was performance tuning and bug - fixing. In addition to these, several new major changes occurred:
+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.
+
In addition to a huge array of bug fixes and minor performance tweaks, the +LLVM 2.3 optimizers support a few major 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 ++
New features include: + +
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:
+ +New target-specific features include:
New features include: +
New target-specific 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.
@@ -283,15 +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-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.
-llvm-gcc does not support __builtin_apply yet. - See Constructing Calls: Dispatching a call to another function.
-llvm-gcc partially supports these GCC extensions:
-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).
- Declaring that functions have no side effects or that they can never - return.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.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. +