Date: Sat, 14 Apr 2012 13:54:10 +0000 Subject: Vendor import of llvm trunk r154661: http://llvm.org/svn/llvm-project/llvm/trunk@r154661 --- docs/ReleaseNotes.html | 1195 ++++++++++-------------------------------------- 1 file changed, 237 insertions(+), 958 deletions(-) (limited to 'docs/ReleaseNotes.html') diff --git a/docs/ReleaseNotes.html b/docs/ReleaseNotes.html index 56d0eb9..bcac293 100644 --- a/docs/ReleaseNotes.html +++ b/docs/ReleaseNotes.html @@ -4,20 +4,22 @@ - LLVM 3.0 Release Notes + LLVM 3.1 Release Notes -

LLVM 3.0 Release Notes

LLVM 3.1 Release Notes

Introduction
Sub-project Status Update
External Projects Using LLVM 3.0
What's New in LLVM 3.0?
External Projects Using LLVM 3.1
What's New in LLVM?
Installation Instructions
Known Problems
Additional Information

Written by the LLVM Team

@@ -44,8 +44,9 @@ Release Notes.

This document contains the release notes for the LLVM Compiler - Infrastructure, release 3.0. Here we describe the status of LLVM, including - major improvements from the previous release and significant known problems. + Infrastructure, release 3.1. Here we describe the status of LLVM, including + major improvements from the previous release, improvements in various + subprojects of LLVM, and some of the current users of the code. All LLVM releases may be downloaded from the LLVM releases web site.

@@ -61,16 +62,8 @@ Release Notes. releases page.

Sub-project Status Update @@ -79,9 +72,9 @@ Release Notes.

The LLVM 3.0 distribution currently consists of code from the core LLVM +

The LLVM 3.1 distribution currently consists of code from the core LLVM repository (which roughly includes the LLVM optimizers, code generators and - supporting tools), the Clang repository and the llvm-gcc repository. In + supporting tools), and the Clang repository. In addition to this code, the LLVM Project includes other sub-projects that are in development. Here we include updates on these subprojects.

@@ -99,37 +92,18 @@ Release Notes. provides a modular, library-based architecture that makes it suitable for creating or integrating with other development tools. Clang is considered a production-quality compiler for C, Objective-C, C++ and Objective-C++ on x86 - (32- and 64-bit), and for darwin/arm targets.

- -

In the LLVM 3.0 time-frame, the Clang team has made many improvements:

+ (32- and 64-bit), and for Darwin/ARM targets.

In the LLVM 3.1 time-frame, the Clang team has made many improvements:

Greatly improved support for building C++ applications, with greater - stability and better diagnostics.
Improved support for - the C++ - 2011 standard, including implementations of non-static data member - initializers, alias templates, delegating constructors, the range-based - for loop, and implicitly-generated move constructors and move assignment - operators, among others.
Implemented support for some features of the upcoming C1x standard, - including static assertions and generic selections.
Better detection of include and linking paths for system headers and - libraries, especially for Linux distributions.
Implemented support - for Automatic - Reference Counting for Objective-C.
Implemented a number of optimizations in libclang, the Clang C - interface, to improve the performance of code completion and the mapping - from source locations to abstract syntax tree nodes.
...

- +

For more details about the changes to Clang since the 2.9 release, see the +Clang release notes +

+ +

If Clang rejects your code but another compiler accepts it, please take a look at the language compatibility guide to make sure this is not intentional or a known @@ -145,19 +119,18 @@ Release Notes.

DragonEgg is a gcc plugin that replaces GCC's - optimizers and code generators with LLVM's. Currently it requires a patched - version of gcc-4.5. The plugin can target the x86-32 and x86-64 processor - families and has been used successfully on the Darwin, FreeBSD and Linux - platforms. The Ada, C, C++ and Fortran languages work well. The plugin is - capable of compiling plenty of Obj-C, Obj-C++ and Java but it is not known - whether the compiled code actually works or not!

+ optimizers and code generators with LLVM's. It works with gcc-4.5 or gcc-4.6, + targets the x86-32 and x86-64 processor families, and has been successfully + used on the Darwin, FreeBSD, KFreeBSD, Linux and OpenBSD platforms. It fully + supports Ada, C, C++ and Fortran. It has partial support for Go, Java, Obj-C + and Obj-C++.

The 3.0 release has the following notable changes:

The 3.1 release has the following notable changes:

+ +

@@ -178,7 +151,7 @@ Release Notes. implementations of this and other low-level routines (some are 3x faster than the equivalent libgcc routines).

In the LLVM 3.0 timeframe,

....

LLDB has advanced by leaps and bounds in the 3.0 timeframe. It is - dramatically more stable and useful, and includes both a - new tutorial and - a side-by-side comparison with - GDB.

LLDB is a ground-up implementation of a command line debugger, as well as a + debugger API that can be used from other applications. LLDB makes use of the + Clang parser to provide high-fidelity expression parsing (particularly for + C++) and uses the LLVM JIT for target support.

+ +

...

-LLBrowse: IR Browser -

- -

- LLBrowse is an interactive viewer for LLVM modules. It can load any LLVM - module and displays its contents as an expandable tree view, facilitating an - easy way to inspect types, functions, global variables, or metadata nodes. It - is fully cross-platform, being based on the popular wxWidgets GUI - toolkit.

...

The VMKit project is an implementation - of a Java Virtual Machine (Java VM or JVM) that uses LLVM for static and - just-in-time compilation. As of LLVM 3.0, VMKit now supports generational - garbage collectors. The garbage collectors are provided by the MMTk - framework, and VMKit can be configured to use one of the numerous implemented - collectors of MMTk.

The VMKit project is an + implementation of a Java Virtual Machine (Java VM or JVM) that uses LLVM for + static and just-in-time compilation. -

- External Open Source Projects Using LLVM 3.0 + External Open Source Projects Using LLVM 3.1

An exciting aspect of LLVM is that it is used as an enabling technology for a lot of other language and tools projects. This section lists some of the - projects that have already been updated to work with LLVM 3.0.

AddressSanitizer

- -

AddressSanitizer - uses compiler instrumentation and a specialized malloc library to find C/C++ - bugs such as use-after-free and out-of-bound accesses to heap, stack, and - globals. The key feature of the tool is speed: the average slowdown - introduced by AddressSanitizer is less than 2x.

- -

ClamAV

- -

Clam AntiVirus is an open source (GPL) - anti-virus toolkit for UNIX, designed especially for e-mail scanning on mail - gateways.

- -

Since version 0.96 it - has bytecode - signatures that allow writing detections for complex malware.

- -

It uses LLVM's JIT to speed up the execution of bytecode on X86, X86-64, - PPC32/64, falling back to its own interpreter otherwise. The git version was - updated to work with LLVM 3.0.

- -

clReflect

- -

clReflect is a C++ - parser that uses clang/LLVM to derive a light-weight reflection database - suitable for use in game development. It comes with a very simple runtime - library for loading and querying the database, requiring no external - dependencies (including CRT), and an additional utility library for object - management and serialisation.

- -

Cling C++ Interpreter

- -

Cling is an interactive compiler interface - (aka C++ interpreter). It uses LLVM's JIT and clang; it currently supports - C++ and C. It has a prompt interface, runs source files, calls into shared - libraries, prints the value of expressions, even does runtime lookup of - identifiers (dynamic scopes). And it just behaves like one would expect from - an interpreter.

- -

Glasgow Haskell Compiler (GHC)

- -

GHC is an open source, state-of-the-art programming suite for Haskell, a - standard lazy functional programming language. It includes an optimizing - static compiler generating good code for a variety of platforms, together - with an interactive system for convenient, quick development.

- -

GHC 7.0 and onwards include an LLVM code generator, supporting LLVM 2.8 and - later. Since LLVM 2.9, GHC now includes experimental support for the ARM - platform with LLVM 3.0.

- -

gwXscript

- -

gwXscript is an object oriented, - aspect oriented programming language which can create both executables (ELF, - EXE) and shared libraries (DLL, SO, DYNLIB). The compiler is implemented in - its own language and translates scripts into LLVM-IR which can be optimized - and translated into native code by the LLVM framework. Source code in - gwScript contains definitions that expand the namespaces. So you can build - your project and simply 'plug out' features by removing a file. The remaining - project does not leave scars since you directly separate concerns by the - 'template' feature of gwX. It is also possible to add new features to a - project by just adding files and without editing the original project. This - language is used for example to create games or content management systems - that should be extendable.

- -

gwXscript is strongly typed and offers comfort with its native types string, - hash and array. You can easily write new libraries in gwXscript or native - code. gwXscript is type safe and users should not be able to crash your - program or execute malicious code except code that is eating CPU time.

- -

include-what-you-use

- -

include-what-you-use - is a tool to ensure that a file directly #includes - all .h files that provide a symbol that the file uses. It also - removes superfluous #includes from source files.

- -

LanguageKit and Pragmatic Smalltalk

- -

LanguageKit is - a framework for implementing dynamic languages sharing an object model with - Objective-C. It provides static and JIT compilation using LLVM along with - its own interpreter. Pragmatic Smalltalk is a dialect of Smalltalk, built on - top of LanguageKit, that interfaces directly with Objective-C, sharing the - same object representation and message sending behaviour. These projects are - developed as part of the Étoié desktop environment.

- -

LuaAV

- -

LuaAV is a real-time - audiovisual scripting environment based around the Lua language and a - collection of libraries for sound, graphics, and other media protocols. LuaAV - uses LLVM and Clang to JIT compile efficient user-defined audio synthesis - routines specified in a declarative syntax.

- -

Mono

- -

An open source, cross-platform implementation of C# and the CLR that is - binary compatible with Microsoft.NET. Has an optional, dynamically-loaded - LLVM code generation backend in Mini, the JIT compiler.

- -

Note that we use a Git mirror of LLVM with some patches. See: - https://github.com/mono/llvm

- -

Portable OpenCL (pocl)

- -

Portable OpenCL is an open source implementation of the OpenCL standard which - can be easily adapted for new targets. One of the goals of the project is - improving performance portability of OpenCL programs, avoiding the need for - target-dependent manual optimizations. A "native" target is included, which - allows running OpenCL kernels on the host (CPU).

- -

Pure

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. The interpreter uses LLVM as a backend to JIT-compile Pure - programs to fast native code. Pure offers dynamic typing, eager and lazy - evaluation, lexical closures, a hygienic macro system (also based on term - rewriting), built-in list and matrix support (including list and matrix - comprehensions) and an easy-to-use interface to C and other programming - languages (including the ability to load LLVM bitcode modules, and inline C, - C++, Fortran and Faust code in Pure programs if the corresponding LLVM-enabled - compilers are installed).

- -

Pure version 0.48 has been tested and is known to work with LLVM 3.0 - (and continues to work with older LLVM releases >= 2.5).

- -

Renderscript

- -

Renderscript - is Android's advanced 3D graphics rendering and compute API. It provides a - portable C99-based language with extensions to facilitate common use cases - for enhancing graphics and thread level parallelism. The Renderscript - compiler frontend is based on Clang/LLVM. It emits a portable bitcode format - for the actual compiled script code, as well as reflects a Java interface for - developers to control the execution of the compiled bitcode. Executable - machine code is then generated from this bitcode by an LLVM backend on the - device. Renderscript is thus able to provide a mechanism by which Android - developers can improve performance of their applications while retaining - portability.

- -

SAFECode

- -

SAFECode is a memory safe C/C++ - compiler built using LLVM. It takes standard, unannotated C/C++ code, - analyzes the code to ensure that memory accesses and array indexing - operations are safe, and instruments the code with run-time checks when - safety cannot be proven statically. SAFECode can be used as a debugging aid - (like Valgrind) to find and repair memory safety bugs. It can also be used - to protect code from security attacks at run-time.

- -

The Stupid D Compiler (SDC)

- -

The Stupid D Compiler is a - project seeking to write a self-hosting compiler for the D programming - language without using the frontend of the reference compiler (DMD).

- -

TTA-based Co-design Environment (TCE)

- -

TCE is a toolset for designing application-specific processors (ASP) based on - the Transport triggered architecture (TTA). The toolset provides a complete - co-design flow from C/C++ programs down to synthesizable VHDL and parallel - program binaries. Processor customization points include the register files, - function units, supported operations, and the interconnection network.

- -

TCE uses Clang and LLVM for C/C++ language support, target independent - optimizations and also for parts of code generation. It generates new - LLVM-based code generators "on the fly" for the designed TTA processors and - loads them in to the compiler backend as runtime libraries to avoid - per-target recompilation of larger parts of the compiler chain.

- -

Tart Programming Language

- -

Tart is a general-purpose, - strongly typed programming language designed for application - developers. Strongly inspired by Python and C#, Tart focuses on practical - solutions for the professional software developer, while avoiding the clutter - and boilerplate of legacy languages like Java and C++. Although Tart is still - in development, the current implementation supports many features expected of - a modern programming language, such as garbage collection, powerful - bidirectional type inference, a greatly simplified syntax for template - metaprogramming, closures and function literals, reflection, operator - overloading, explicit mutability and immutability, and much more. Tart is - flexible enough to accommodate a broad range of programming styles and - philosophies, while maintaining a strong commitment to simplicity, minimalism - and elegance in design.

- -

ThreadSanitizer

- -

ThreadSanitizer is a - data race detector for (mostly) C and C++ code, available for Linux, Mac OS - and Windows. On different systems, we use binary instrumentation frameworks - (Valgrind and Pin) as frontends that generate the program events for the race - detection algorithm. On Linux, there's an option of using LLVM-based - compile-time instrumentation.

- -

The ZooLib C++ Cross-Platform Application Framework

- -

ZooLib is Open Source under the MIT - License. It provides GUI, filesystem access, TCP networking, thread-safe - memory management, threading and locking for Mac OS X, Classic Mac OS, - Microsoft Windows, POSIX operating systems with X11, BeOS, Haiku, Apple's iOS - and Research in Motion's BlackBerry.

- -

My current work is to use CLang's static analyzer to improve ZooLib's code - quality. I also plan to set up LLVM compiles of the demo programs and test - programs using CLang and LLVM on all the platforms that CLang, LLVM and - ZooLib all support.

- -

- What's New in LLVM 3.0? + What's New in LLVM 3.1?

LLVM 3.0 includes several major new capabilities:

+ + + + +

LLVM 3.1 includes several major changes and big features:

- - +

AddressSanitizer, + a fast memory error detector.
MachineInstr Bundles, + Support to model instruction bundling / packing.
ARM Integrated Assembler, + A full featured assembler and direct-to-object support for ARM.
....

- +

LLVM IR and Core Improvements @@ -721,117 +285,15 @@ Faust compiler can now generate LLVM bitcode, and works with LLVM 2.7-3.0.

LLVM IR has several new features for better support of new targets and that expose new optimization opportunities:

One of the biggest changes is that 3.0 has a new exception handling - system. The old system used LLVM intrinsics to convey the exception handling - information to the code generator. It worked in most cases, but not - all. Inlining was especially difficult to get right. Also, the intrinsics - could be moved away from the invoke instruction, making it hard - to recover that information.

- -

The new EH system makes exception handling a first-class member of the IR. It - adds two new instructions:

- -

landingpad — - this instruction defines a landing pad basic block. It contains all of the - information that's needed by the code generator. It's also required to be - the first non-PHI instruction in the landing pad. In addition, a landing - pad may be jumped to only by the unwind edge of an invoke - instruction.
resume — this - instruction causes the current exception to resume traveling up the - stack. It replaces the @llvm.eh.resume intrinsic.

- -

Converting from the old EH API to the new EH API is rather simple, because a - lot of complexity has been removed. The two intrinsics, - @llvm.eh.exception and @llvm.eh.selector have been - superceded by the landingpad instruction. Instead of generating - a call to @llvm.eh.exception and @llvm.eh.selector: - -

-Function *ExcIntr = Intrinsic::getDeclaration(TheModule,
-                                              Intrinsic::eh_exception);
-Function *SlctrIntr = Intrinsic::getDeclaration(TheModule,
-                                                Intrinsic::eh_selector);
-
-// The exception pointer.
-Value *ExnPtr = Builder.CreateCall(ExcIntr, "exc_ptr");
-
-std::vector<Value*> Args;
-Args.push_back(ExnPtr);
-Args.push_back(Builder.CreateBitCast(Personality,
-                                     Type::getInt8PtrTy(Context)));
-
-// Add selector clauses to Args.
-
-// The selector call.
-Builder.CreateCall(SlctrIntr, Args, "exc_sel");
-

- -

You should instead generate a landingpad instruction, that - returns an exception object and selector value:

- -

-LandingPadInst *LPadInst =
-  Builder.CreateLandingPad(StructType::get(Int8PtrTy, Int32Ty, NULL),
-                           Personality, 0);
-
-Value *LPadExn = Builder.CreateExtractValue(LPadInst, 0);
-Builder.CreateStore(LPadExn, getExceptionSlot());
-
-Value *LPadSel = Builder.CreateExtractValue(LPadInst, 1);
-Builder.CreateStore(LPadSel, getEHSelectorSlot());
-

- -

It's now trivial to add the individual clauses to the landingpad - instruction.

- -

-// Adding a catch clause
-Constant *TypeInfo = getTypeInfo();
-LPadInst->addClause(TypeInfo);
-
-// Adding a C++ catch-all
-LPadInst->addClause(Constant::getNullValue(Builder.getInt8PtrTy()));
-
-// Adding a cleanup
-LPadInst->setCleanup(true);
-
-// Adding a filter clause
-std::vector<Constant*> TypeInfos;
-Constant *TypeInfo = getFilterTypeInfo();
-TypeInfos.push_back(Builder.CreateBitCast(TypeInfo, Builder.getInt8PtrTy()));
-
-ArrayType *FilterTy = ArrayType::get(Int8PtrTy, TypeInfos.size());
-LPadInst->addClause(ConstantArray::get(FilterTy, TypeInfos));
-

- -

Converting from using the @llvm.eh.resume intrinsic to - the resume instruction is trivial. It takes the exception - pointer and exception selector values returned by - the landingpad instruction:

- -

-Type *UnwindDataTy = StructType::get(Builder.getInt8PtrTy(),
-                                     Builder.getInt32Ty(), NULL);
-Value *UnwindData = UndefValue::get(UnwindDataTy);
-Value *ExcPtr = Builder.CreateLoad(getExceptionObjSlot());
-Value *ExcSel = Builder.CreateLoad(getExceptionSelSlot());
-UnwindData = Builder.CreateInsertValue(UnwindData, ExcPtr, 0, "exc_ptr");
-UnwindData = Builder.CreateInsertValue(UnwindData, ExcSel, 1, "exc_sel");
-Builder.CreateResume(UnwindData);
-

- +

IR support for half float
IR support for vectors of pointers, including vector GEPs.
Module flags have been introduced. They convey information about the + module as a whole to LLVM subsystems.
Loads can now have range metadata attached to them to describe the + possible values being loaded.
....

@@ -841,16 +303,12 @@ Builder.CreateResume(UnwindData);

In addition to a large array of minor performance tweaks and bug fixes, this +

In addition to many minor performance tweaks and bug fixes, this release includes a few major enhancements and additions to the optimizers:

....

@@ -865,18 +323,14 @@ Builder.CreateResume(UnwindData);

The LLVM Machine Code (aka MC) subsystem was created to solve a number of problems in the realm of assembly, disassembly, object file format handling, and a number of other related areas that CPU instruction-set level tools work - in.

+ in. For more information, please see + the Intro + to the LLVM MC Project Blog Post.

....

For more information, please see - the Intro - to the LLVM MC Project Blog Post.

- @@ -886,15 +340,39 @@ Builder.CreateResume(UnwindData);

We have changed the way that the Type Legalizer legalizes vectors. The type + legalizer now attempts to promote integer elements. This enabled the + implementation of vector-select. Additionally, we see a performance boost on + workloads which use vectors of chars and shorts, since they are now promoted + to 32-bit types, which are better supported by the SIMD instruction set. + Floating point types are still widened as before.

+ +

We have put a significant amount of work into the code generator infrastructure, which allows us to implement more aggressive algorithms and make it run faster:

TableGen can now synthesize register classes that are only needed to + represent combinations of constraints from instructions and sub-registers. + The synthetic register classes inherit most of their properties form their + closest user-defined super-class.
MachineRegisterInfo now allows the reserved registers to be + frozen when register allocation starts. Target hooks should use the + MRI->canReserveReg(FramePtr) method to avoid accidentally + disabling frame pointer elimination during register allocation.
A new kind of MachineOperand provides a compact + representation of large clobber lists on call instructions. The register + mask operand references a bit mask of preserved registers. Everything else + is clobbered.

+ +

We added new TableGen infrastructure to support bundling for + Very Long Instruction Word (VLIW) architectures. TableGen can now + automatically generate a deterministic finite automaton from a VLIW + target's schedule description which can be queried to determine + legal groupings of instructions in a bundle.

@@ -907,13 +385,12 @@ Builder.CreateResume(UnwindData);

New features and major changes in the X86 target include:

The CRC32 intrinsics have been renamed. The intrinsics were previously - @llvm.x86.sse42.crc32.[8|16|32] - and @llvm.x86.sse42.crc64.[8|64]. They have been renamed to - @llvm.x86.sse42.crc32.32.[8|16|32] and - @llvm.x86.sse42.crc32.64.[8|64].
Bug fixes and improved support for AVX1
Support for AVX2 (still incomplete at this point)
Call instructions use the new register mask operands for faster compile + times and better support for different calling conventions. The old WINCALL + instructions are no longer needed.
DW2 Exception Handling is enabled on Cygwin and MinGW.

@@ -928,386 +405,188 @@ Builder.CreateResume(UnwindData);

New features of the ARM target include:

The constant island pass now supports basic block and constant pool entry + alignments greater than 4 bytes.
On Darwin, the ARM target now has a full-featured integrated assembler. +

- - - -

-Other Target Specific Improvements -

PPC32/ELF va_arg was implemented.

PPC32 initial support for .o file writing was implemented.

+ARM Integrated Assembler +

The ARM target now includes a full featured macro assembler, including +direct-to-object module support for clang. The assembler is currently enabled +by default for Darwin only pending testing and any additional necessary +platform specific support for Linux.

- - +

Full support is included for Thumb1, Thumb2 and ARM modes, along with +subtarget and CPU specific extensions for VFP2, VFP3 and NEON.

The assembler is Unified Syntax only (see ARM Architecural Reference Manual +for details). While there is some, and growing, support for pre-unfied (divided) +syntax, there are still significant gaps in that support.

-Major Changes and Removed Features +MIPS Target Improvements

If you're already an LLVM user or developer with out-of-tree changes based on - LLVM 2.9, this section lists some "gotchas" that you may run into upgrading - from the previous release.

This release has seen major new work on just about every aspect of the MIPS + backend. Some of the major new features include:

The LLVMC front end code was removed while separating - out language independence.
The LowerSetJmp pass wasn't used effectively by any - target and has been removed.
The old TailDup pass was not used in the standard pipeline - and was unable to update ssa form, so it has been removed. -
The syntax of volatile loads and stores in IR has been changed to - "load volatile"/"store volatile". The old - syntax ("volatile load"/"volatile store") - is still accepted, but is now considered deprecated.
The old atomic intrinscs (llvm.memory.barrier and - llvm.atomic.*) are now gone. Please use the new atomic - instructions, described in the atomics guide. +
....

- -

Windows (32-bit)

- -

On Win32(MinGW32 and MSVC), Windows 2000 will not be supported. - Windows XP or higher is required.

- -

-Internal API Changes +Other Target Specific Improvements

In addition, many APIs have changed in this release. Some of the major - LLVM API changes are:

The biggest and most pervasive change is that llvm::Type's are no longer - returned or accepted as 'const' values. Instead, just pass around - non-const Type's.
PHINode::reserveOperandSpace has been removed. Instead, you - must specify how many operands to reserve space for when you create the - PHINode, by passing an extra argument - into PHINode::Create.
PHINodes no longer store their incoming BasicBlocks as operands. Instead, - the list of incoming BasicBlocks is stored separately, and can be accessed - with new functions PHINode::block_begin - and PHINode::block_end.
Various functions now take an ArrayRef instead of either a - pair of pointers (or iterators) to the beginning and end of a range, or a - pointer and a length. Others now return an ArrayRef instead - of a reference to a SmallVector - or std::vector. These include: -
- CallInst::Create
- ComputeLinearIndex (in llvm/CodeGen/Analysis.h)
- ConstantArray::get
- ConstantExpr::getExtractElement
- ConstantExpr::getGetElementPtr
- ConstantExpr::getInBoundsGetElementPtr
- ConstantExpr::getIndices
- ConstantExpr::getInsertElement
- ConstantExpr::getWithOperands
- ConstantFoldCall (in llvm/Analysis/ConstantFolding.h)
- ConstantFoldInstOperands (in llvm/Analysis/ConstantFolding.h)
- ConstantVector::get
- DIBuilder::createComplexVariable
- DIBuilder::getOrCreateArray
- ExtractValueInst::Create
- ExtractValueInst::getIndexedType
- ExtractValueInst::getIndices
- FindInsertedValue (in llvm/Analysis/ValueTracking.h)
- gep_type_begin (in llvm/Support/GetElementPtrTypeIterator.h)
- gep_type_end (in llvm/Support/GetElementPtrTypeIterator.h)
- GetElementPtrInst::Create
- GetElementPtrInst::CreateInBounds
- GetElementPtrInst::getIndexedType
- InsertValueInst::Create
- InsertValueInst::getIndices
- InvokeInst::Create
- IRBuilder::CreateCall
- IRBuilder::CreateExtractValue
- IRBuilder::CreateGEP
- IRBuilder::CreateInBoundsGEP
- IRBuilder::CreateInsertValue
- IRBuilder::CreateInvoke
- MDNode::get
- MDNode::getIfExists
- MDNode::getTemporary
- MDNode::getWhenValsUnresolved
- SimplifyGEPInst (in llvm/Analysis/InstructionSimplify.h)
- TargetData::getIndexedOffset
All forms of StringMap::getOrCreateValue have been remove - except for the one which takes a StringRef.
The LLVMBuildUnwind function from the C API was removed. The - LLVM unwind instruction has been deprecated for a long time - and isn't used by the current front-ends. So this was removed during the - exception handling rewrite.
The LLVMAddLowerSetJmpPass function from the C API was - removed because the LowerSetJmp pass was removed.
....
The DIBuilder interface used by front ends to encode - debugging information in the LLVM IR now expects clients to - use DIBuilder::finalize() at the end of translation unit to - complete debugging information encoding.
The way the type system works has been - rewritten: PATypeHolder and OpaqueType are gone, - and all APIs deal with Type* instead of const - Type*. If you need to create recursive structures, then create a - named structure, and use setBody() when all its elements are - built. Type merging and refining is gone too: named structures are not - merged with other structures, even if their layout is identical. (of - course anonymous structures are still uniqued by layout).
TargetSelect.h moved to Support/ from Target/
UpgradeIntrinsicCall no longer upgrades pre-2.9 intrinsic calls (for - example llvm.memset.i32).
It is mandatory to initialize all out-of-tree passes too and their dependencies now with - INITIALIZE_PASS{BEGIN,END,} - and INITIALIZE_{PASS,AG}_DEPENDENCY.
The interface for MemDepResult in MemoryDependenceAnalysis has been - enhanced with new return types Unknown and NonFuncLocal, in addition to - the existing types Clobber, Def, and NonLocal.

- Known Problems -

- -

This section contains significant known problems with the LLVM system, listed - by component. If you run into a problem, please check - the LLVM bug database and submit a bug if - there isn't already one.

- - +

- Experimental features included with this release +Major Changes and Removed Features

The following components of this LLVM release are either untested, known to - 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.

If you're already an LLVM user or developer with out-of-tree changes based on + LLVM 3.1, this section lists some "gotchas" that you may run into upgrading + from the previous release.

The Alpha, Blackfin, CellSPU, MicroBlaze, MSP430, MIPS, PTX, SystemZ and - XCore backends are experimental.
llc "-filetype=obj" is experimental on all targets other - than darwin and ELF X86 systems.
LLVM 3.1 removes support for reading LLVM 2.9 bitcode files. Going + forward, we aim for all future versions of LLVM to read bitcode files and + .ll files produced by LLVM 3.0 and later.
The unwind instruction is now gone. With the introduction of the + new exception handling system in LLVM 3.0, the unwind instruction + became obsolete.
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- +

- Known problems with the X86 back-end +Internal API Changes

The X86 backend does not yet support - all inline assembly that uses the X86 - floating point stack. It supports the 'f' and 't' constraints, but - not 'u'.
The X86-64 backend does not yet support the LLVM IR instruction - va_arg. Currently, front-ends support variadic argument - constructs on X86-64 by lowering them manually.
Windows x64 (aka Win64) code generator has a few issues. -
- llvm-gcc cannot build the mingw-w64 runtime currently due to lack of - support for the 'u' inline assembly constraint and for X87 floating - point inline assembly.
- On mingw-w64, you will see unresolved symbol __chkstk due - to Bug 8919. - It is fixed - in r128206.
- Miss-aligned MOVDQA might crash your program. It is due to - Bug 9483, lack - of handling aligned internal globals.
-

- -

- - -

- Known problems with the PowerPC back-end -

- -

In addition, many APIs have changed in this release. Some of the major + LLVM API changes are:

The PPC32/ELF support lacks PIC support.

- -

- - -

- Known problems with the ARM back-end -

- -

- +

Target specific options have been moved from global variables to members + on the new TargetOptions class, which is local to each + TargetMachine. As a consequence, the associated flags will + no longer be accepted by clang -mllvm. This includes:

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.
llvm::PrintMachineCode
llvm::NoFramePointerElim
llvm::NoFramePointerElimNonLeaf
llvm::DisableFramePointerElim(const MachineFunction &)
llvm::LessPreciseFPMADOption
llvm::LessPrecideFPMAD()
llvm::NoExcessFPPrecision
llvm::UnsafeFPMath
llvm::NoInfsFPMath
llvm::NoNaNsFPMath
llvm::HonorSignDependentRoundingFPMathOption
llvm::HonorSignDependentRoundingFPMath()
llvm::UseSoftFloat
llvm::FloatABIType
llvm::NoZerosInBSS
llvm::JITExceptionHandling
llvm::JITEmitDebugInfo
llvm::JITEmitDebugInfoToDisk
llvm::GuaranteedTailCallOpt
llvm::StackAlignmentOverride
llvm::RealignStack
llvm::DisableJumpTables
llvm::EnableFastISel
llvm::getTrapFunctionName()
llvm::EnableSegmentedStacks

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- +

- Known problems with the SPARC back-end +Tools Changes

The SPARC backend only supports the 32-bit SPARC ABI (-m32); it does not - support the 64-bit SPARC ABI (-m64).

In addition, some tools have changed in this release. Some of the changes + are:

- - -

- Known problems with the MIPS back-end -

- -

64-bit MIPS targets are not supported yet.
llvm-stress is a command line tool for generating random .ll files to fuzz + different LLVM components.
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- - -

- Known problems with the Alpha back-end -

- -

On 21164s, some rare FP arithmetic sequences which may trap do not have - the appropriate nops inserted to ensure restartability.
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- -

- Known problems with the C back-end -

- -

The C backend has numerous problems and is not being actively maintained. - Depending on it for anything serious is not advised.

- -

The C backend has only basic support for - 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.
The C backend does not support all exception handling constructs.
The C backend does not support arbitrary precision integers.

- - -

- Known problems with the llvm-gcc front-end -

+ +

+ Known Problems +

LLVM 2.9 was the last release of llvm-gcc.

LLVM is generally a production quality compiler, and is used by a broad range + of applications and shipping in many products. That said, not every + subsystem is as mature as the aggregate, particularly the more obscure + targets. If you run into a problem, please check the LLVM bug database and submit a bug if + there isn't already one or ask on the LLVMdev + list.

llvm-gcc is generally very stable for the C family of languages. 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).

Known problem areas include:

Fortran support generally works, but there are still several unresolved bugs - in Bugzilla. Please see the - tools/gfortran component for details. Note that llvm-gcc is missing major - Fortran performance work in the frontend and library that went into GCC after - 4.2. If you are interested in Fortran, we recommend that you consider using - dragonegg instead.

- -

The llvm-gcc 4.2 Ada compiler has basic functionality, but is no longer being - actively maintained. If you are interested in Ada, we recommend that you - consider using dragonegg instead.

The Alpha, Blackfin, CellSPU, MSP430, PTX, SystemZ and + XCore backends are experimental, and the Alpha, Blackfin and SystemZ + targets have already been removed from mainline.
The integrated assembler, disassembler, and JIT is not supported by + several targets. If an integrated assembler is not supported, then a + system assembler is required. For more details, see the Target Features Matrix. +

The C backend has numerous problems and is not being actively maintained. + Depending on it for anything serious is not advised.

LLVM Compiler Infrastructure