LLVM 3.9 Release Notes¶

Introduction
Non-comprehensive list of changes in this release
External Open Source Projects Using LLVM 3.9
Additional Information

Warning

These are in-progress notes for the upcoming LLVM 3.9 release. You may prefer the LLVM 3.8 Release Notes.

Introduction ¶

This document contains the release notes for the LLVM Compiler Infrastructure, release 3.9. 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 ¶

The LLVMContext gains a new runtime check (see LLVMContext::discardValueNames()) that can be set to discard Value names (other than GlobalValue). This is intended to be used in release builds by clients that are interested in saving CPU/memory as much as possible.
The C API function LLVMLinkModules has been removed.
The C API function LLVMAddTargetData has been removed.
The C API function LLVMGetDataLayout is deprecated in favor of LLVMGetDataLayoutStr.
TargetFrameLowering::eliminateCallFramePseudoInstr now returns an iterator to the next instruction instead of void. Targets that previously did MBB.erase(I); return; now probably want return MBB.erase(I);.

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Changes to the LLVM IR ¶

New intrinsics llvm.masked.load, llvm.masked.store, llvm.masked.gather and llvm.masked.scatter were introduced to the LLVM IR to allow selective memory access for vector data types.

Changes to the ARM Backend ¶

During this release ...

Changes to the MIPS Target ¶

During this release ...

Changes to the PowerPC Target ¶

During this release ...

Changes to the X86 Target ¶

LLVM now supports the Intel CPU codenamed Skylake Server with AVX-512 extensions using -march=skylake-avx512. The switch enables the ISA extensions AVX-512{F, CD, VL, BW, DQ}.
LLVM now supports the Intel CPU codenamed Knights Landing with AVX-512 extensions using -march=knl. The switch enables the ISA extensions AVX-512{F, CD, ER, PF}.

Changes to the AMDGPU Target ¶

Mesa 11.0.x is no longer supported

Changes to the OCaml bindings ¶

During this release ...

Support for attribute ‘notail’ has been added ¶

This marker prevents optimization passes from adding ‘tail’ or ‘musttail’ markers to a call. It is used to prevent tail call optimization from being performed on the call.

External Open Source Projects Using LLVM 3.9 ¶

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 3.9.

A project

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.