CMake Options

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

cmake -D<option_name>=<value> /path/to/thrust/sources

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

Thrust supports two build modes. By default, a single configuration is built that targets a specific host system, device system, and C++ dialect. When THRUST_ENABLE_MULTICONFIG is ON, multiple configurations targeting a variety of systems and dialects are generated.

The CMake options are divided into these categories:

1. Generic CMake Options: Options applicable to all Thrust builds.

2. Single Config CMake Options Options applicable only when THRUST_ENABLE_MULTICONFIG is disabled.

3. Multi Config CMake Options Options applicable only when THRUST_ENABLE_MULTICONFIG is enabled.

4. CUDA Specific CMake Options Options that control CUDA compilation. Only available when one or more configurations targets the CUDA system.

5. TBB Specific CMake Options Options that control TBB compilation. Only available when one or more configurations targets the TBB system.

Generic CMake Options

• CMAKE_BUILD_TYPE={Release, Debug, RelWithDebInfo, MinSizeRel}

  • Standard CMake build option. Default: RelWithDebInfo

• THRUST_ENABLE_HEADER_TESTING={ON, OFF}

  • Whether to test compile public headers. Default is ON.

• THRUST_ENABLE_TESTING={ON, OFF}

  • Whether to build unit tests. Default is ON.

• THRUST_ENABLE_EXAMPLES={ON, OFF}

  • Whether to build examples. Default is ON.

• THRUST_ENABLE_MULTICONFIG={ON, OFF}

  • Toggles single-config and multi-config modes. Default is OFF (single config).

• THRUST_ENABLE_EXAMPLE_FILECHECK={ON, OFF}

  • Enable validation of example outputs using the LLVM FileCheck utility. Default is OFF.

• THRUST_ENABLE_INSTALL_RULES={ON, OFF}

  • If true, installation rules will be generated for thrust. Default is ON.

• THRUST_DISPATCH_TYPE={Dynamic, Force32bit, Force64bit}

  • Allows the user to force Thrust to use a specific size for the offset type. Default is Dynamic.

    • Dynamic lets Thrust choose the index type based on input size, allowing large inputs and optimal performance at the cost of increased compile time and binary size, as Thrust will compile each kernel twice, once for 32 bit and once for 64 bit.

    • Force32bit forces Thrust to use a 32 bit offset type. This improves compile time and binary size but limits the input size.

    • Force64bit forces Thrust to use a 64 bit offset type. This improves compile time and binary size and allows large input sizes. However, it might degrade runtime performance.

Single Config CMake Options

• THRUST_HOST_SYSTEM={CPP, TBB, OMP}

  • Selects the host system. Default: CPP

• THRUST_DEVICE_SYSTEM={CUDA, TBB, OMP, CPP}

  • Selects the device system. Default: CUDA

• THRUST_CPP_DIALECT={11, 14, 17}

  • Selects the C++ standard dialect to use. Default is 14 (C++14).

Multi Config CMake Options

• THRUST_MULTICONFIG_ENABLE_DIALECT_CPPXX={ON, OFF}

  • Toggle whether a specific C++ dialect will be targeted.

  • Possible values of XX are {11, 14, 17}.

  • By default, only C++14 is enabled.

• THRUST_MULTICONFIG_ENABLE_SYSTEM_XXXX={ON, OFF}

  • Toggle whether a specific system will be targeted.

  • Possible values of XXXX are {CPP, CUDA, TBB, OMP}

  • By default, only CPP and CUDA are enabled.

• THRUST_MULTICONFIG_WORKLOAD={SMALL, MEDIUM, LARGE, FULL}

  • Restricts the host/device combinations that will be targeted.

  • By default, the SMALL workload is used.

  • The full cross product of host x device systems results in 12 configurations, some of which are more important than others. This option can be used to prune some of the less important ones.

  • SMALL: (3 configs) Minimal coverage and validation of each device system against the CPP host.

  • MEDIUM: (6 configs) Cheap extended coverage.

  • LARGE: (8 configs) Expensive extended coverage. Includes all useful build configurations.

  • FULL: (12 configs) The complete cross product of all possible build configurations.

Config	Workloads	Value	Expense	Note
CPP/CUDA	F L M S	Essential	Expensive	Validates CUDA against CPP
CPP/OMP	F L M S	Essential	Cheap	Validates OMP against CPP
CPP/TBB	F L M S	Essential	Cheap	Validates TBB against CPP
CPP/CPP	F L M	Important	Cheap	Tests CPP as device
OMP/OMP	F L M	Important	Cheap	Tests OMP as host
TBB/TBB	F L M	Important	Cheap	Tests TBB as host
TBB/CUDA	F L	Important	Expensive	Validates TBB/CUDA interop
OMP/CUDA	F L	Important	Expensive	Validates OMP/CUDA interop
TBB/OMP	F	Not useful	Cheap	Mixes CPU-parallel systems
OMP/TBB	F	Not useful	Cheap	Mixes CPU-parallel systems
TBB/CPP	F	Not Useful	Cheap	Parallel host, serial device
OMP/CPP	F	Not Useful	Cheap	Parallel host, serial device

CUDA Specific CMake Options

• THRUST_ENABLE_RDC_TESTS={ON, OFF}

  • Enable tests that require separable compilation.

  • Default is ON.

• THRUST_FORCE_RDC={ON, OFF}

  • Enable separable compilation on all targets that are agnostic of RDC.

  • Targets that explicitly require RDC to be enabled or disabled will ignore this setting.

  • Default is OFF.