CONTRIBUTING.md

Table of Contents

1. Contributing to CUB
2. CMake Options
3. Development Model

Contributing to CUB

CUB uses Github to manage all open-source development, including bug tracking, pull requests, and design discussions. CUB is tightly coupled to the Thrust project, and a compatible version of Thrust is required when working on the development version of CUB.

To setup a CUB development branch, it is recommended to recursively clone the Thrust repository and use the CUB submodule at dependencies/cub to stage changes. CUB's tests and examples can be built by configuring Thrust with the CMake option THRUST_INCLUDE_CUB_CMAKE=ON.

This process is described in more detail in Thrust's CONTRIBUTING.md.

The CMake options in the following section may be used to customize CUB's build process. Note that some of these are controlled by Thrust for compatibility and may not have an effect when building CUB through the Thrust build system. This is pointed out in the documentation below where applicable.

CMake Options

A CUB build is configured using CMake options. These may be passed to CMake using

cmake -D<option_name>=<value> [Thrust or CUB project source root]

or configured interactively with the ccmake or cmake-gui interfaces.

The configuration options for CUB are:

• CMAKE_BUILD_TYPE={Release, Debug, RelWithDebInfo, MinSizeRel}
  • Standard CMake build option. Default: RelWithDebInfo
• CUB_ENABLE_HEADER_TESTING={ON, OFF}
  • Whether to test compile public headers. Default is ON.
• CUB_ENABLE_TESTING={ON, OFF}
  • Whether to build unit tests. Default is ON.
• CUB_ENABLE_EXAMPLES={ON, OFF}
  • Whether to build examples. Default is ON.
• CUB_ENABLE_DIALECT_CPPXX={ON, OFF}
  • Setting this has no effect when building CUB as a component of Thrust. See Thrust's dialect options, which CUB will inherit.
  • Toggle whether a specific C++ dialect will be targeted.
  • Multiple dialects may be targeted in a single build.
  • Possible values of XX are {11, 14, 17}.
  • By default, only C++14 is enabled.
• CUB_ENABLE_COMPUTE_XX={ON, OFF}
  • Setting this has no effect when building CUB as a component of Thrust. See Thrust's architecture options, which CUB will inherit.
  • Controls the targeted CUDA architecture(s)
  • Multiple options may be selected when using NVCC as the CUDA compiler.
  • Valid values of XX are: {35, 37, 50, 52, 53, 60, 61, 62, 70, 72, 75, 80}
  • Default value depends on CUB_DISABLE_ARCH_BY_DEFAULT:
• CUB_ENABLE_COMPUTE_FUTURE={ON, OFF}
  • Setting this has no effect when building CUB as a component of Thrust. See Thrust's architecture options, which CUB will inherit.
  • If enabled, CUDA objects will target the most recent virtual architecture in addition to the real architectures specified by the CUB_ENABLE_COMPUTE_XX options.
  • Default value depends on CUB_DISABLE_ARCH_BY_DEFAULT:
• CUB_DISABLE_ARCH_BY_DEFAULT={ON, OFF}
  • Setting this has no effect when building CUB as a component of Thrust. See Thrust's architecture options, which CUB will inherit.
  • When ON, all CUB_ENABLE_COMPUTE_* options are initially OFF.
  • Default: OFF (meaning all architectures are enabled by default)
• CUB_ENABLE_TESTS_WITH_RDC={ON, OFF}
  • Whether to enable Relocatable Device Code when building tests. Default is OFF.
• CUB_ENABLE_EXAMPLES_WITH_RDC={ON, OFF}
  • Whether to enable Relocatable Device Code when building examples. Default is OFF.
• CUB_ENABLE_INSTALL_RULES={ON, OFF}
  • Setting this has no effect when building CUB as a component of Thrust. See Thrust's THRUST_INSTALL_CUB_HEADERS option, which controls this behavior.
  • If true, installation rules will be generated for CUB. Default is ON when building CUB alone, and OFF when CUB is a subproject added via CMake's add_subdirectory.

Development Model

CUB follows the same development model as Thrust, described here.