X-Git-Url: http://demsky.eecs.uci.edu/git/?a=blobdiff_plain;f=docs%2FReleaseNotes.html;h=bdaba71b7430d341e663a0b1df71528fd743ff45;hb=256be96457faf173de2ac3f8145077b7e6fb41ba;hp=035dace224d2b47e80bac383de6ed5810d13dbf5;hpb=f795ef0cd4b19aeb9b527c94c99763ae717035ba;p=oota-llvm.git
diff --git a/docs/ReleaseNotes.html b/docs/ReleaseNotes.html
index 035dace224d..bdaba71b743 100644
--- a/docs/ReleaseNotes.html
+++ b/docs/ReleaseNotes.html
@@ -14,7 +14,7 @@
The set of checks performed by the static analyzer continues to expand, and
future plans for the tool include full source-level inter-procedural analysis
and deeper checks such as buffer overrun detection. There are many opportunities
to extend and enhance the static analyzer, and anyone interested in working on
@@ -166,15 +173,15 @@ The VMKit project 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.
-
-http://pure-lang.googlecode.com/
-
-
-
-Pure is an algebraic/functional programming language based on term rewriting.
+Pure
+is an algebraic/functional programming language based on term rewriting.
Programs are collections of equations which are used to evaluate expressions in
a symbolic fashion. Pure offers dynamic typing, eager and lazy evaluation,
lexical closures, a hygienic macro system (also based on term rewriting),
@@ -231,16 +241,12 @@ it as a kind of functional scripting language for many application areas.
-http://www.dsource.org/projects/ldc
-
-
-
-I'd like to inform that the LDC project (LLVM D
-Compiler) is working with release 2.5 of LLVM. In fact we've required
-2.5 in our trunk since the release was branched.
-The improvements in 2.5 have fixed a lot of problems with LDC, more
-specifically the new inline asm constraints, better debug info
-support, general bugfixes :) and better x86-64 support have allowed
+LDC is an implementation of
+the D Programming Language using the LLVM optimizer and code generator.
+The LDC project works great with the LLVM 2.5 release. General improvements in
+this
+cycle have included new inline asm constraint handling, better debug info
+support, general bugfixes, and better x86-64 support. This has allowed
some major improvements in LDC, getting us much closer to being as
fully featured as the original DMD compiler from DigitalMars.
@@ -252,17 +258,16 @@ fully featured as the original DMD compiler from DigitalMars.
-
http://code.roadsend.com/rphp
-
-
Roadsend PHP is using LLVM for code generation. This is an open source
-project.
-
+
Roadsend PHP (rphp) is an open
+source implementation of the PHP programming
+language that uses LLVM for its optimizer, JIT, and static compiler. This is a
+reimplementation of an earlier project that is now based on LLVM.
@@ -284,73 +289,25 @@ in this section.
LLVM 2.5 includes several major new capabilities:
-The code generator now supports arbitrary precision integers.
-Types like i33 have long been valid in the LLVM IR, but previously
-could only be used with the interpreter.
-Now IR using such types can be compiled to native code on all targets.
-All operations are supported if the integer is not bigger than twice the
-target machine word size.
-Simple operations like loads, stores and shifts by a constant amount are
-supported for integers of any size.
-
-
-
+- llvm-gcc now generally supports the GFortran front-end, and the precompiled
+release binaries now support Fortran, even on Mac OS/X.
+
+- CMake is now used by the LLVM build process
+on Windows. It automatically generates Visual Studio project files (and
+more) from a set of simple text files. This makes it much easier to
+maintain. In time, we'd like to standardize on CMake for everything.
+
+- LLVM 2.5 now uses (and includes) Google Test for unit testing.
+- The LLVM native code generator now supports arbitrary precision integers.
+Types like i33 have long been valid in the LLVM IR, but were previously
+only supported by the interpreter. Note that the C backend still does not
+support these.
+
+- LLVM 2.5 no longer uses 'bison,' so it is easier to build on Windows.
@@ -368,7 +325,18 @@ front-ends and driver with the LLVM optimizer and code generator. It currently
includes support for the C, C++, Objective-C, Ada, and Fortran front-ends.
-
New features include:
+
LLVM IR has several new features that are used by our existing front-ends and
+can be useful if you are writing a front-end for LLVM:
-- ?
+- The shufflevector instruction
+has been generalized to allow different shuffle mask width than its input
+vectors. This allows you to use shufflevector to combine two
+"<4 x float>" vectors into a "<8 x float>" for example.
+
+- LLVM IR now supports new intrinsics for computing and acting on overflow of integer operations. This allows
+efficient code generation for languages that must trap or throw an exception on
+overflow. While these intrinsics work on all targets, they only generate
+efficient code on X86 so far.
+
+- LLVM IR now supports a new private
+linkage type to produce labels that are stripped by the assembler before it
+produces a .o file (thus they are invisible to the linker).
+
+- LLVM IR supports two new attributes for better alias analysis. The noalias attribute can now be used on the
+return value of a function to indicate that it returns new memory (e.g.
+'malloc', 'calloc', etc).
+The new nocapture attribute can be used
+on pointer arguments to indicate that the function does not return the pointer,
+store it in an object that outlives the call, or let the value of the pointer
+escape from the function in any other way.
+Note that it is the pointer itself that must not escape, not the value it
+points to: loading a value out of the pointer is perfectly fine.
+Many standard library functions (e.g. 'strlen', 'memcpy') have this property.
+
+
+
+- The parser for ".ll" files in lib/AsmParser is now completely rewritten as a
+recursive descent parser. This parser produces better error messages (including
+caret diagnostics), is less fragile (less likely to crash on strange things),
+does not leak memory, is more efficient, and eliminates LLVM's last use of the
+'bison' tool.
+
+- Debug information representation and manipulation internals have been
+ consolidated to use a new set of classes in
+ llvm/Analysis/DebugInfo.h. These routines are more
+ efficient, robust, and extensible and replace the older mechanisms.
+ llvm-gcc, clang, and the code generator now use them to create and process
+ debug information.
@@ -396,12 +405,26 @@ 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, this
+
In addition to a large array of bug fixes and minor performance tweaks, this
release includes a few major enhancements and additions to the optimizers:
-- ?
+- The loop optimizer now improves floating point induction variables in
+several ways, including adding shadow induction variables to avoid
+"integer <-> floating point" conversions in loops when safe.
+
+- The "-mem2reg" pass is now much faster on code with large basic blocks.
+
+- The "-jump-threading" pass is more powerful: it is iterative
+ and handles threading based on values with fully and partially redundant
+ loads.
+
+- The "-memdep" memory dependence analysis pass (used by GVN and memcpyopt) is
+ both faster and more aggressive.
+
+- The "-scalarrepl" scalar replacement of aggregates pass is more aggressive
+ about promoting unions to registers.
@@ -409,7 +432,7 @@ release includes a few major enhancements and additions to the optimizers:
@@ -419,21 +442,80 @@ infrastructure, which allows us to implement more aggressive algorithms and make
it run faster:
-- The type legalization logic has been completely rewritten, and is now
-more powerful (it supports arbitrary precision integer types for example)
-and hopefully more correct.
-The type legalizer converts operations on types that are not natively
-supported by the target machine into equivalent code sequences that only use
-natively supported types.
-The old type legalizer is still available and will be used if
--disable-legalize-types is passed to llc.
+
- The Writing an LLVM Compiler
+Backend document has been greatly expanded and is substantially more
+complete.
+
+- The SelectionDAG type legalization logic has been completely rewritten, is
+now more powerful (it supports arbitrary precision integer types for example),
+and is more correct in several corner cases. The type legalizer converts
+operations on types that are not natively supported by the target machine into
+equivalent code sequences that only use natively supported types. The old type
+legalizer is still available (for now) and will be used if
+-disable-legalize-types is passed to the code generator.
-- ?
+- The code generator now supports widening illegal vectors to larger legal
+ones (for example, converting operations on <3 x float> to work on
+<4 x float>) which is very important for common graphics
+applications.
+
+- The assembly printers for each target are now split out into their own
+libraries that are separate from the main code generation logic. This reduces
+the code size of JIT compilers by not requiring them to be linked in.
+
+- The 'fast' instruction selection path (used at -O0 and for fast JIT
+ compilers) now supports accelerating codegen for code that uses exception
+ handling constructs.
+
+- The optional PBQP register allocator now supports register coalescing.
+
+
+
+
+
New features of the X86 target include:
+
+
+
+- The llvm.returnaddress
+intrinsic (which is used to implement __builtin_return_address) now
+supports non-zero stack depths on X86.
+
+- The X86 backend now supports code generation of vector shift operations
+using SSE instructions.
+
+- X86-64 code generation now takes advantage of red zone, unless the
+-mno-red-zone option is specified.
+
+- The X86 backend now supports using address space #256 in LLVM IR as a way of
+performing memory references off the GS segment register. This allows a
+front-end to take advantage of very low-level programming techniques when
+targeting X86 CPUs. See test/CodeGen/X86/movgs.ll for a simple
+example.
+
+- The X86 backend now supports a -disable-mmx command line option to
+ prevent use of MMX even on chips that support it. This is important for cases
+ where code does not contain the proper llvm.x86.mmx.emms
+ intrinsics.
+
+- The X86 JIT now detects the new Intel Core i7 and Atom chips and
+ auto-configures itself appropriately for the features of these chips.
+
+- The JIT now supports exception handling constructs on Linux/X86-64 and
+ Darwin/x86-64.
+
+- The JIT supports Thread Local Storage (TLS) on Linux/X86-32 but not yet on
+ X86-64.
+
+
+
@@ -450,41 +532,25 @@ The old type legalizer is still available and will be used if
types.
Function calls involving basic types work now.
Support for integer arrays.
-
Compiler can now emit libcalls for operations not support by m/c insns.
-
Support for both data and rom address spaces.
-
+
The compiler can now emit libcalls for operations not supported by m/c
+instructions.
+
Support for both data and ROM address spaces.
Things not yet supported:
- Floating point.
-- Passing/returning aggregate types to/from functions.
+- Passing/returning aggregate types to and from functions.
- Variable arguments.
- Indirect function calls.
-- Interrupts/prgrams.
+- Interrupts/programs.
- Debug info.
-
-
-
-
-
-
New target-specific features include:
-
-
-
-
-
-
Improvements in LLVMC
@@ -501,18 +567,18 @@ types.
by default. The command
llvmc --clang can be now used as a
synonym to
ccc.
-
There is now a --check-graph option which is supposed to catch
+There is now a --check-graph option, which is supposed to catch
common errors like multiple default edges, mismatched output/input language
names and cycles. In general, these checks can't be done at compile-time
because of the need to support plugins.
Plugins are now more flexible and can refer to compilation graph nodes and
options defined in other plugins. To manage dependencies, a priority-sorting
- mechanism was introduced. This change affects the TableGen file syntax; see the
+ mechanism was introduced. This change affects the TableGen file syntax. See the
documentation for details.
Hooks can now be provided with arguments. The syntax is "$CALL(MyHook,
- 'Arg1', 'Arg2', 'Arg #3')".
+ 'Arg1', 'Arg2', 'Arg3')".
A new option type: multi-valued option, for options that take more than one
argument (for example, "-foo a b c").
@@ -531,22 +597,6 @@ types.
-
-
-
-
-
New features include:
-
-
-
-
-
-
Major Changes and Removed Features
@@ -560,7 +610,8 @@ from the previous release.
-- ?
+- llvm-gcc defaults to -fno-math-errno on all X86 targets.
+
@@ -568,10 +619,8 @@ from the previous release.
API changes are:
-
-
?
+
Some deprecated interfaces to create Instruction subclasses, that
+ were spelled with lower case "create," have been removed.
@@ -639,8 +688,8 @@ href="http://lists.cs.uiuc.edu/mailman/listinfo/llvmdev">LLVMdev list.
- The MSIL, IA64, Alpha, SPU, MIPS, and PIC16 backends are experimental.
-- The llc "-filetype=asm" (the default) is the only supported
- value for this option.
+- The llc "-filetype=asm" (the default) is the only
+ supported value for this option.
@@ -660,13 +709,14 @@ href="http://lists.cs.uiuc.edu/mailman/listinfo/llvmdev">LLVMdev list.
The X86 backend generates inefficient floating point code when configured
to generate code for systems that don't have SSE2.
Win64 code generation wasn't widely tested. Everything should work, but we
- expect small issues to happen. Also, llvm-gcc cannot build mingw64 runtime
- currently due
+ expect small issues to happen. Also, llvm-gcc cannot build the mingw64
+ runtime currently due
to several
- bugs due to lack of support for the
- 'u' inline assembly constraint and X87 floating point inline assembly.
+
bugs and due to lack of support for
+ the
+ 'u' inline assembly constraint and for X87 floating point inline assembly.
The X86-64 backend does not yet support the LLVM IR instruction
- va_arg. Currently, the llvm-gcc front-end supports variadic
+ va_arg. Currently, the llvm-gcc and front-ends support variadic
argument constructs on X86-64 by lowering them manually.
@@ -697,7 +747,7 @@ compilation, and lacks support for debug information.
Thumb mode works only on ARMv6 or higher processors. On sub-ARMv6
processors, thumb programs can crash or produce wrong
results (PR1388).
-
Compilation for ARM Linux OABI (old ABI) is supported, but not fully tested.
+Compilation for ARM Linux OABI (old ABI) is supported but not fully tested.
There is a bug in QEMU-ARM (<= 0.9.0) which causes it to incorrectly
execute
@@ -714,7 +764,7 @@ programs compiled with LLVM. Please use more recent versions of QEMU.
-- The SPARC backend only supports the 32-bit SPARC ABI (-m32), it does not
+
- The SPARC backend only supports the 32-bit SPARC ABI (-m32); it does not
support the 64-bit SPARC ABI (-m64).
@@ -757,7 +807,7 @@ appropriate nops inserted to ensure restartability.
-- The Itanium backend is highly experimental, and has a number of known
+
- The Itanium backend is highly experimental and has a number of known
issues. We are looking for a maintainer for the Itanium backend. If you
are interested, please contact the LLVMdev mailing list.
@@ -776,7 +826,7 @@ appropriate nops inserted to ensure restartability.
inline assembly code.
The C backend violates the ABI of common
C++ programs, preventing intermixing between C++ compiled by the CBE and
- C++ code compiled with llc or native compilers.
+ C++ code compiled with
llc or native compilers.
The C backend does not support all exception handling constructs.
The C backend does not support arbitrary precision integers.
@@ -833,9 +883,6 @@ itself, Qt, Mozilla, etc.
- Fortran support generally works, but there are still several unresolved bugs
in Bugzilla. Please see the tools/gfortran component for details.
-
-- The Fortran front-end currently does not build on Darwin (without tweaks)
- due to unresolved dependencies on the C front-end.
@@ -845,12 +892,12 @@ itself, Qt, Mozilla, etc.
-The llvm-gcc 4.2 Ada compiler works fairly well, however this is not a mature
-technology and problems should be expected.
+The llvm-gcc 4.2 Ada compiler works fairly well; however, this is not a mature
+technology, and problems should be expected.
- The Ada front-end currently only builds on X86-32. This is mainly due
-to lack of trampoline support (pointers to nested functions) on other platforms,
-however it also fails to build on X86-64
+to lack of trampoline support (pointers to nested functions) on other platforms.
+However, it also fails to build on X86-64
which does support trampolines.
- The Ada front-end fails to bootstrap.
This is due to lack of LLVM support for setjmp/longjmp style
@@ -861,7 +908,7 @@ and cxg2021 ACATS tests fail
(c380004 also fails with gcc-4.2 mainline).
If the compiler is built with checks disabled then c393010
causes the compiler to go into an infinite loop, using up all system memory.
-- Some gcc specific Ada tests continue to crash the compiler.
+- Some GCC specific Ada tests continue to crash the compiler.
- The -E binder option (exception backtraces)
does not work and will result in programs
crashing if an exception is raised. Workaround: do not use -E.