X-Git-Url: http://plrg.eecs.uci.edu/git/?p=oota-llvm.git;a=blobdiff_plain;f=docs%2FReleaseNotes.rst;h=831003b098c41b7b0b1ab7ee442fb855e53c7f5d;hp=ba7e436fb0ea75dc24738a8de21c96ddd4b84899;hb=27c964e2ae0b573cf1e6551a3da255539db03d3c;hpb=5d899048588e74cfed7aeb661f0b83eb8c2cab88 diff --git a/docs/ReleaseNotes.rst b/docs/ReleaseNotes.rst index ba7e436fb0e..831003b098c 100644 --- a/docs/ReleaseNotes.rst +++ b/docs/ReleaseNotes.rst @@ -5,11 +5,6 @@ LLVM 3.8 Release Notes .. contents:: :local: -.. warning:: - These are in-progress notes for the upcoming LLVM 3.8 release. You may - prefer the `LLVM 3.7 Release Notes `_. - Introduction ============ @@ -26,11 +21,6 @@ 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 ================================================= * With this release, the minimum Windows version required for running LLVM is @@ -41,6 +31,88 @@ Non-comprehensive list of changes in this release in the 3.9 release. Please migrate to using CMake. For more information see: `Building LLVM with CMake `_ +* The C API function LLVMLinkModules is deprecated. It will be removed in the + 3.9 release. Please migrate to LLVMLinkModules2. Unlike the old function the + new one + + * Doesn't take an unused parameter. + * Destroys the source instead of only damaging it. + * Does not record a message. Use the diagnostic handler instead. + +* The C API functions LLVMParseBitcode, LLVMParseBitcodeInContext, + LLVMGetBitcodeModuleInContext and LLVMGetBitcodeModule have been deprecated. + They will be removed in 3.9. Please migrate to the versions with a 2 suffix. + Unlike the old ones the new ones do not record a diagnostic message. Use + the diagnostic handler instead. + +* The deprecated C APIs LLVMGetBitcodeModuleProviderInContext and + LLVMGetBitcodeModuleProvider have been removed. + +* The deprecated C APIs LLVMCreateExecutionEngine, LLVMCreateInterpreter, + LLVMCreateJITCompiler, LLVMAddModuleProvider and LLVMRemoveModuleProvider + have been removed. + +* With this release, the C API headers have been reorganized to improve build + time. Type specific declarations have been moved to Type.h, and error + handling routines have been moved to ErrorHandling.h. Both are included in + Core.h so nothing should change for projects directly including the headers, + but transitive dependencies may be affected. + +* llvm-ar now suports thin archives. + +* llvm doesn't produce .data.rel.ro.local or .data.rel sections anymore. + +* aliases to available_externally globals are now rejected by the verifier. + +* the IR Linker has been split into IRMover that moves bits from one module to + another and Linker proper that decides what to link. + +* Support for dematerializing has been dropped. + +* RegisterScheduler::setDefault was removed. Targets that used to call into the + command line parser to set the DAGScheduler, and that don't have enough + control with setSchedulingPreference, should look into overriding the + SubTargetHook "getDAGScheduler()". + +* ``ilist_iterator`` no longer has implicit conversions to and from ``T*``, + since ``ilist_iterator`` may be pointing at the sentinel (which is usually + not of type ``T`` at all). To convert from an iterator ``I`` to a pointer, + use ``&*I``; to convert from a pointer ``P`` to an iterator, use + ``P->getIterator()``. Alternatively, explicit conversions via + ``static_cast(U)`` are still available. + +* ``ilist_node::getNextNode()`` and ``ilist_node::getPrevNode()`` now + fail at compile time when the node cannot access its parent list. + Previously, when the sentinel was was an ``ilist_half_node``, this API + could return the sentinal instead of ``nullptr``. Frustrated callers should + be updated to use ``iplist::getNextNode(T*)`` instead. Alternatively, if + the node ``N`` is guaranteed not to be the last in the list, it is safe to + call ``&*++N->getIterator()`` directly. + +* The `Kaleidoscope tutorials `_ have been updated to use + the ORC JIT APIs. + +* ORC now has a basic set of C bindings. + +* Optional support for linking clang and the LLVM tools with a single libLLVM + shared library. To enable this, pass ``-DLLVM_LINK_LLVM_DYLIB=ON`` to CMake. + See `Building LLVM with CMake`_ for more details. + +* The optimization to move the prologue and epilogue of functions in colder + code path (shrink-wrapping) is now enabled by default. + +* A new target-independent gcc-compatible emulated Thread Local Storage mode + is added. When ``-femultated-tls`` flag is used, all accesses to TLS + variables are converted to calls to ``__emutls_get_address`` in the runtime + library. + +* MSVC compatible exception handling has been completely overhauled. New + instructions have been introduced to facilitate this: + `New exception handling instructions `_. + While we have done our best to test this feature thoroughly, it would + not be completely surprising if there were a few lingering issues that + early adopters might bump into. + .. 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 @@ -60,29 +132,160 @@ Non-comprehensive list of changes in this release Makes programs 10x faster by doing Special New Thing. -Changes to the ARM Backend --------------------------- - During this release ... +Changes to the ARM Backends +--------------------------- + +During this release the AArch64 target has: + +* Added support for more sanitizers (MSAN, TSAN) and made them compatible with + all VMA kernel configurations (currently tested on 39 and 42 bits). +* Gained initial LLD support in the new ELF back-end +* Extended the Load/Store optimiser and cleaned up some of the bad decisions + made earlier. +* Expanded LLDB support, including watchpoints, native building, Renderscript, + LLDB-server, debugging 32-bit applications. +* Added support for the ``Exynos M1`` chip. + +During this release the ARM target has: + +* Gained massive performance improvements on embedded benchmarks due to finally + running the stride vectorizer in full form, incrementing the performance gains + that we already had in the previous releases with limited stride vectorization. +* Expanded LLDB support, including watchpoints, unwind tables +* Extended the Load/Store optimiser and cleaned up some of the bad decisions + made earlier. +* Simplified code generation for global variable addresses in ELF, resulting in + a significant (4% in Chromium) reduction in code size. +* Gained some additional code size improvements, though there's still a long road + ahead, especially for older cores. +* Added some EABI floating point comparison functions to Compiler-RT +* Added support for Windows+GNU triple, +features in -mcpu/-march options. Changes to the MIPS Target -------------------------- - During this release ... - +During this release the MIPS target has: + +* Significantly extended support for the Integrated Assembler. See below for + more information +* Added support for the ``P5600`` processor. +* Added support for the ``interrupt`` attribute for MIPS32R2 and later. This + attribute will generate a function which can be used as a interrupt handler + on bare metal MIPS targets using the static relocation model. +* Added support for the ``ERETNC`` instruction found in MIPS32R5 and later. +* Added support for OpenCL. See http://portablecl.org/. + + * Address spaces 1 to 255 are now reserved for software use and conversions + between them are no-op casts. + +* Removed the ``mips16`` value for the -mcpu option since it is an :abbr:`ASE + (Application Specific Extension)` and not a processor. If you were using this, + please specify another CPU and use ``-mips16`` to enable MIPS16. +* Removed ``copy_u.w`` from 32-bit MSA and ``copy_u.d`` from 64-bit MSA since + they have been removed from the MSA specification due to forward compatibility + issues. For example, 32-bit MSA code containing ``copy_u.w`` would behave + differently on a 64-bit processor supporting MSA. The corresponding intrinsics + are still available and may expand to ``copy_s.[wd]`` where this is + appropriate for forward compatibility purposes. +* Relaxed the ``-mnan`` option to allow ``-mnan=2008`` on MIPS32R2/MIPS64R2 for + compatibility with GCC. +* Made MIPS64R6 the default CPU for 64-bit Android triples. + +The MIPS target has also fixed various bugs including the following notable +fixes: + +* Fixed reversed operands on ``mthi``/``mtlo`` in the DSP :abbr:`ASE + (Application Specific Extension)`. +* The code generator no longer uses ``jal`` for calls to absolute immediate + addresses. +* Disabled fast instruction selection on MIPS32R6 and MIPS64R6 since this is not + yet supported. +* Corrected addend for ``R_MIPS_HI16`` and ``R_MIPS_PCHI16`` in MCJIT +* The code generator no longer crashes when handling subregisters of an 64-bit + FPU register with undefined value. +* The code generator no longer attempts to use ``$zero`` for operands that do + not permit ``$zero``. +* Corrected the opcode used for ``ll``/``sc`` when using MIPS32R6/MIPS64R6 and + the Integrated Assembler. +* Added support for atomic load and atomic store. +* Corrected debug info when dynamically re-aligning the stack. + +Integrated Assembler +^^^^^^^^^^^^^^^^^^^^ +We have made a large number of improvements to the integrated assembler for +MIPS. In this release, the integrated assembler isn't quite production-ready +since there are a few known issues related to bare-metal support, checking +immediates on instructions, and the N32/N64 ABI's. However, the current support +should be sufficient for many users of the O32 ABI, particularly those targeting +MIPS32 on Linux or bare-metal MIPS32. + +If you would like to try the integrated assembler, please use +``-fintegrated-as``. Changes to the PowerPC Target +----------------------------- + +There are numerous improvements to the PowerPC target in this release: + +* Shrink wrapping optimization has been enabled for PowerPC Little Endian + +* Direct move instructions are used when converting scalars to vectors + +* Thread Sanitizer (TSAN) is now supported for PowerPC + +* New MI peephole pass to clean up redundand XXPERMDI instructions + +* Add branch hints to highly biased branch instructions (code reaching + unreachable terminators and exceptional control flow consructs) + +* Promote boolean return values to integer to prevent excessive usage of + condition registers + +* Additional vector APIs for vector comparisons and vector merges have been + added to altivec.h + +* Many bugs have been identified and fixed + + +Changes to the X86 Target ----------------------------- During this release ... +* TLS is enabled for Cygwin as emutls. + +* Smaller code for materializing 32-bit 1 and -1 constants at ``-Os``. + +* More efficient code for wide integer compares. (E.g. 64-bit compares + on 32-bit targets.) + +* Tail call support for ``thiscall``, ``stdcall``, ``vectorcall``, and + ``fastcall`` functions. + +Changes to the Hexagon Target +----------------------------- + +In addition to general code size and performance improvements, Hexagon target +now has basic support for Hexagon V60 architecture and Hexagon Vector +Extensions (HVX). + +Changes to the AVR Target +------------------------- + +Slightly less than half of the AVR backend has been merged in at this point. It is still +missing a number large parts which cause it to be unusable, but is well on the +road to being completely merged and workable. Changes to the OCaml bindings ----------------------------- During this release ... +* The ocaml function link_modules has been replaced with link_modules' which + uses LLVMLinkModules2. + External Open Source Projects Using LLVM 3.8 ============================================ @@ -91,7 +294,19 @@ 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 3.8. -* A project +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 and Windows and also PowerPC (32/64 bit) +and ARM. Ports to other architectures like AArch64 and MIPS64 are underway. Additional Information