C API: functions to get mask of a ShuffleVector

This commit fixes a regression (from LLVM 10 to LLVM 11 RC3) in the LLVM
C API.

Previously, commit 1ee6ec2bf removed the mask operand from the
ShuffleVector instruction, storing the mask data separately in the
instruction instead; this reduced the number of operands of
ShuffleVector from 3 to 2. AFAICT, this change unintentionally caused
a regression in the LLVM C API. Specifically, it is no longer possible
to get the mask of a ShuffleVector instruction through the C API. This
patch introduces new functions which together allow a C API user to get
the mask of a ShuffleVector instruction, restoring the functionality
which was previously available through LLVMGetOperand().

This patch also adds tests for this change to the llvm-c-test
executable, which involved adding support for InsertElement,
ExtractElement, and ShuffleVector itself (as well as constant vectors)
to echo.cpp. Previously, vector operations weren't tested at all in
echo.ll.

I also fixed some typos in comments and help-text nearby these changes,
which I happened to spot while developing this patch. Since the typo
fixes are technically unrelated other than being in the same files, I'm
happy to take them out if you'd rather they not be included in the patch.

Differential Revision: https://reviews.llvm.org/D88190

(cherry picked from commit 51cad041e0cb26597c7ccc0fbfaa349b8fffbcda)
5 files changed
tree: 067b44527da8b5a08ec8f44cde1505d50e259bae
  1. clang/
  2. clang-tools-extra/
  3. compiler-rt/
  4. debuginfo-tests/
  5. flang/
  6. libc/
  7. libclc/
  8. libcxx/
  9. libcxxabi/
  10. libunwind/
  11. lld/
  12. lldb/
  13. llvm/
  14. mlir/
  15. openmp/
  16. parallel-libs/
  17. polly/
  18. pstl/
  19. utils/
  20. .arcconfig
  21. .arclint
  22. .clang-format
  23. .clang-tidy
  24. .git-blame-ignore-revs
  25. .gitignore
  26. CONTRIBUTING.md
  27. README.md
README.md

The LLVM Compiler Infrastructure

This directory and its sub-directories contain source code for LLVM, a toolkit for the construction of highly optimized compilers, optimizers, and run-time environments.

The README briefly describes how to get started with building LLVM. For more information on how to contribute to the LLVM project, please take a look at the Contributing to LLVM guide.

Getting Started with the LLVM System

Taken from https://llvm.org/docs/GettingStarted.html.

Overview

Welcome to the LLVM project!

The LLVM project has multiple components. The core of the project is itself called “LLVM”. This contains all of the tools, libraries, and header files needed to process intermediate representations and converts it into object files. Tools include an assembler, disassembler, bitcode analyzer, and bitcode optimizer. It also contains basic regression tests.

C-like languages use the Clang front end. This component compiles C, C++, Objective-C, and Objective-C++ code into LLVM bitcode -- and from there into object files, using LLVM.

Other components include: the libc++ C++ standard library, the LLD linker, and more.

Getting the Source Code and Building LLVM

The LLVM Getting Started documentation may be out of date. The Clang Getting Started page might have more accurate information.

This is an example work-flow and configuration to get and build the LLVM source:

  1. Checkout LLVM (including related sub-projects like Clang):

    • git clone https://github.com/llvm/llvm-project.git

    • Or, on windows, git clone --config core.autocrlf=false https://github.com/llvm/llvm-project.git

  2. Configure and build LLVM and Clang:

    • cd llvm-project

    • mkdir build

    • cd build

    • cmake -G <generator> [options] ../llvm

      Some common build system generators are:

      • Ninja --- for generating Ninja build files. Most llvm developers use Ninja.
      • Unix Makefiles --- for generating make-compatible parallel makefiles.
      • Visual Studio --- for generating Visual Studio projects and solutions.
      • Xcode --- for generating Xcode projects.

      Some Common options:

      • -DLLVM_ENABLE_PROJECTS='...' --- semicolon-separated list of the LLVM sub-projects you'd like to additionally build. Can include any of: clang, clang-tools-extra, libcxx, libcxxabi, libunwind, lldb, compiler-rt, lld, polly, or debuginfo-tests.

        For example, to build LLVM, Clang, libcxx, and libcxxabi, use -DLLVM_ENABLE_PROJECTS="clang;libcxx;libcxxabi".

      • -DCMAKE_INSTALL_PREFIX=directory --- Specify for directory the full path name of where you want the LLVM tools and libraries to be installed (default /usr/local).

      • -DCMAKE_BUILD_TYPE=type --- Valid options for type are Debug, Release, RelWithDebInfo, and MinSizeRel. Default is Debug.

      • -DLLVM_ENABLE_ASSERTIONS=On --- Compile with assertion checks enabled (default is Yes for Debug builds, No for all other build types).

    • cmake --build . [-- [options] <target>] or your build system specified above directly.

      • The default target (i.e. ninja or make) will build all of LLVM.

      • The check-all target (i.e. ninja check-all) will run the regression tests to ensure everything is in working order.

      • CMake will generate targets for each tool and library, and most LLVM sub-projects generate their own check-<project> target.

      • Running a serial build will be slow. To improve speed, try running a parallel build. That's done by default in Ninja; for make, use the option -j NNN, where NNN is the number of parallel jobs, e.g. the number of CPUs you have.

    • For more information see CMake

Consult the Getting Started with LLVM page for detailed information on configuring and compiling LLVM. You can visit Directory Layout to learn about the layout of the source code tree.