======================== LLVM 6.0.0 Release Notes ======================== .. contents:: :local: .. warning:: These are in-progress notes for the upcoming LLVM 6 release. Release notes for previous releases can be found on `the Download Page `_. Introduction ============ This document contains the release notes for the LLVM Compiler Infrastructure, release 6.0.0. 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 `_. For more information about LLVM, including information about the latest release, please check out the `main LLVM 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 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 release, please see the `releases page `_. Non-comprehensive list of changes in this release ================================================= .. NOTE For small 1-3 sentence descriptions, just add an entry at the end of this list. If your description won't fit comfortably in one bullet point (e.g. maybe you would like to give an example of the functionality, or simply have a lot to talk about), see the `NOTE` below for adding a new subsection. * The ``Redirects`` argument of ``llvm::sys::ExecuteAndWait`` and ``llvm::sys::ExecuteNoWait`` was changed to an ``ArrayRef`` of optional ``StringRef``'s to make it safer and more convenient to use. * The backend name was added to the Target Registry to allow run-time information to be fed back into TableGen. Out-of-tree targets will need to add the name used in the `def X : Target` definition to the call to `RegisterTarget`. * The ``Debugify`` pass was added to ``opt`` to facilitate testing of debug info preservation. This pass attaches synthetic ``DILocations`` and ``DIVariables`` to the instructions in a ``Module``. The ``CheckDebugify`` pass determines how much of the metadata is lost. * Significantly improved quality of CodeView debug info for Windows. * Note.. .. NOTE If you would like to document a larger change, then you can add a subsection about it right here. You can copy the following boilerplate and un-indent it (the indentation causes it to be inside this comment). Special New Feature ------------------- Makes programs 10x faster by doing Special New Thing. Changes to the LLVM IR ---------------------- Changes to the AArch64 Target ----------------------------- During this release: * Enabled the new GlobalISel instruction selection framework by default at ``-O0``. Changes to the ARM Target ------------------------- During this release the ARM target has: * Got support for enabling SjLj exception handling on platforms where it isn't the default. Changes to the MIPS Target -------------------------- During this release ... Changes to the PowerPC Target ----------------------------- During this release ... Changes to the X86 Target ------------------------- During this release ... * Got support for enabling SjLj exception handling on platforms where it isn't the default. Changes to the AMDGPU Target ----------------------------- During this release ... Changes to the AVR Target ----------------------------- During this release ... Changes to the OCaml bindings ----------------------------- During this release ... Changes to the C API -------------------- During this release ... External Open Source Projects Using LLVM 6 ========================================== JFS - JIT Fuzzing Solver ------------------------ `JFS `_ is an experimental constraint solver designed to investigate using coverage guided fuzzing as an incomplete strategy for solving boolean, BitVector, and floating-point constraints. It is built on top of LLVM, Clang, LibFuzzer, and Z3. The solver works by generating a C++ program where the reachability of an `abort()` statement is equivalent to finding a satisfying assignment to the constraints. This program is then compiled by Clang with `SanitizerCoverage `_ instrumentation and then fuzzed using :doc:`LibFuzzer `. Zig Programming Language ------------------------ `Zig `_ is an open-source programming language designed for robustness, optimality, and clarity. It is intended to replace C. It provides high level features such as Generics, Compile Time Function Execution, and Partial Evaluation, yet exposes low level LLVM IR features such as Aliases. Zig uses Clang to provide automatic import of .h symbols - even inline functions and macros. Zig uses LLD combined with lazily building compiler-rt to provide out-of-the-box cross-compiling for all supported targets. LDC - the LLVM-based D compiler ------------------------------- `D `_ is a language with C-like syntax and static typing. It pragmatically combines efficiency, control, and modeling power, with safety and programmer productivity. D supports powerful concepts like Compile-Time Function Execution (CTFE) and Template Meta-Programming, provides an innovative approach to concurrency and offers many classical paradigms. `LDC `_ uses the frontend from the reference compiler combined with LLVM as backend to produce efficient native code. LDC targets x86/x86_64 systems like Linux, OS X, FreeBSD and Windows and also Linux on ARM and PowerPC (32/64 bit). Ports to other architectures like AArch64 and MIPS64 are underway. Additional Information ====================== 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 Subversion version of the source code. You can access versions of these documents specific to this release by going into the ``llvm/docs/`` directory in the LLVM tree. If you have any questions or comments about LLVM, please feel free to contact us via the `mailing lists `_.