X-Git-Url: http://demsky.eecs.uci.edu/git/?a=blobdiff_plain;f=docs%2FReleaseNotes.html;h=56dd66a21aa53860577177cb78dd5c89a3456dc3;hb=95df6b3603e228cea714be21997fec82cb03011e;hp=932ddc5d8dc986d59726c113ddd03ac14f843253;hpb=2629922054f1266552cb3dcc54691b15674399a3;p=oota-llvm.git diff --git a/docs/ReleaseNotes.html b/docs/ReleaseNotes.html index 932ddc5d8dc..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 1.9. 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 LLVM releases web site. 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.
+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.For more information about LLVM, including information about the latest release, please check out the main LLVM @@ -46,185 +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 tenth public release of the LLVM Compiler Infrastructure. This -release incorporates a large number of enhancements, new features, and bug -fixes. We recommend that all users of previous LLVM versions upgrade. -
+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 1.9 now fully supports the x86-64 instruction set on Mac OS/X, and -supports it on Linux (and other operating systems) when compiling in -static -mode. LLVM includes JIT support for X86-64, and supports both Intel EMT-64T -and AMD-64 architectures. The X86-64 instruction set permits addressing a -64-bit addressing space and provides the compiler with twice the -number of integer registers to use.
+ +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.
+ +LLVM API Changes:
+ +LLVM now includes liblto which can -be used to integrate LLVM Link-Time Optimization support into a native linker. -This allows LLVM .bc to transparently participate with linking an application, -even when some .o files are in LLVM form and some are not.
++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. +
+llvm-gcc4 now supports generating debugging info for Linux, Cygwin and MinGW. -This extends the PPC/Darwin and X86/Darwin debugging support available in the -1.8 release. DWARF is a standard debugging format used on many platforms.
++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+
The mid-level optimizer is now faster and produces better code in many cases. - Significant changes 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.
+-The LLVM Target-Independent code generator now supports more target features and -optimizes many cases more aggressively. New features include: + +
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.
+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.
In addition, the LLVM target description format has itself been extended in - several ways:
- +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.
+ +
Further, several significant target-specific enhancements are included in -LLVM 1.9:
+New features include: +
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.
-More specific changes include:
+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 ++
Several significant API changes have been made. If you are maintaining -out-of-tree code, please be aware that:
+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: +
As a step towards making LLVM's integer types signless, several new -instructions have been added to LLVM. The Div instruction is now -UDiv, SDiv, and FDiv. The Rem instruction -is now URem, SRem and FRem. See the -Language Reference for details on these new -instructions.
-ConstantBool::True and ConstantBool::False have been - renamed to ConstantBool::getTrue() and - ConstantBool::getFalse().
New target-specific features include: +
+ +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.
@@ -284,16 +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-gcc4 is far more stable and produces better code than llvm-gcc3, but -does not currently support Link-Time -Optimization or C++ Exception Handling, -which llvm-gcc3 does.
+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).
-llvm-gcc4 does not support the GCC indirect -goto extension, but llvm-gcc3 does.
+If you run into GCC extensions which are not supported, please let us know. +
The following GCC extensions are partially supported. An ignored - attribute means that the LLVM compiler ignores the presence of the attribute, - but the code should still work. An unsupported attribute is one which is - ignored by the LLVM compiler and will cause a different interpretation of - the program.
- -The following extensions are known to be supported:
- -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 C++ front-end is considered to be fully +tested and works for a number of non-trivial programs, including LLVM +itself, Qt, Mozilla, etc.
+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).
-For this release, the C++ front-end is considered to be fully -tested and works for a number of non-trivial programs, including LLVM -itself.
- -A wide variety of additional information is available on the LLVM web page, including documentation and publications describing algorithms and -components implemented in LLVM. The web page also contains versions of the -API documentation which is up-to-date with the CVS version of the source code. +href="http://llvm.org">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 +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.
@@ -676,9 +838,9 @@ lists.