# rocRAND

The rocRAND project provides functions that generate pseudorandom and quasirandom numbers.
The rocRAND library is implemented in the [HIP](https://github.com/ROCm/HIP)
programming language and optimized for AMD's latest discrete GPUs. It is designed to run on top
of AMD's [ROCm](https://rocm.docs.amd.com) runtime, but it also works on CUDA-enabled GPUs.

Prior to ROCm version 5.0, this project included the
[hipRAND](https://github.com/ROCm/hipRAND.git) wrapper. As of version 5.0, it was
split into a separate library. As of version 6.0, hipRAND can no longer be built from rocRAND.

## Supported random number generators

* XORWOW
* MRG31k3p
* MRG32k3a
* Mersenne Twister (MT19937)
* Mersenne Twister for Graphic Processors (MTGP32)
* Philox (4x32, 10 rounds)
* LFSR113
* Sobol32
* Scrambled Sobol32
* Sobol64
* Scrambled Sobol64
* ThreeFry

## Documentation

> [!NOTE]
> The published rocRAND documentation is available at [rocRAND](https://rocm.docs.amd.com/projects/rocRAND/en/latest/) in an organized, easy-to-read format, with search and a table of contents. The documentation source files reside in the rocRAND/docs folder of this repository. As with all ROCm projects, the documentation is open source. For more information, see [Contribute to ROCm documentation](https://rocm.docs.amd.com/en/latest/contribute/contributing.html).

To build documentation locally, use the following code:

```sh
# Go to the docs directory
cd docs

# Install Python dependencies
python3 -m pip install -r sphinx/requirements.txt

# Build the documentation
python3 -m sphinx -T -E -b html -d _build/doctrees -D language=en . _build/html

# E.g. serve the HTML docs locally
cd _build/html
python3 -m http.server
```

## Requirements

* CMake (3.16 or later)
* C++ compiler with C++17 support to build the library.
  * Recommended to use at least gcc 9
  * clang uses the development headers and libraries from gcc, so a recent version of it must still
    be installed when compiling with clang
* C++ compiler with C++11 support to consume the library.
* For AMD platforms:
  * [ROCm](https://rocm.docs.amd.com/projects/install-on-linux/en/latest/how-to/native-install/index.html) (1.7 or later)
  * [HIP-clang](https://github.com/ROCm/HIP/blob/master/INSTALL.md#hip-clang) compiler, which must be
    set as C++ compiler on ROCm platform.
* For CUDA platforms:
  * [HIP](https://github.com/ROCm/HIP)
  * Latest CUDA SDK
* Python 3.6 or higher (HIP on Windows only, only required for install script)
* Visual Studio 2019 with clang support (HIP on Windows only)
* Strawberry Perl (HIP on Windows only)

Optional:

* [GoogleTest](https://github.com/google/googletest) (required only for tests; building tests is enabled
  by default)
  * Use `GTEST_ROOT` to specify the GoogleTest location (see also
    [FindGTest](https://cmake.org/cmake/help/latest/module/FindGTest.html))
  * Note: If GoogleTest is not already installed, it will be automatically downloaded and built
* Fortran compiler (required only for Fortran wrapper)
  * `gfortran` is recommended
* Python 3.5+ (required only for Python wrapper)
* [doxygen](https://www.doxygen.nl/) to build the documentation

If some dependencies are missing, the CMake script automatically downloads, builds, and installs them.
Setting the `DEPENDENCIES_FORCE_DOWNLOAD` option to `ON` forces the script to download all
dependencies, rather than using the system-installed libraries.

## Build and install

```shell
git clone https://github.com/ROCm/rocRAND.git

# Go to rocRAND directory, create and go to build directory
cd rocRAND; mkdir build; cd build

# Configure rocRAND, setup options for your system
# Build options: BUILD_TEST (off by default), BUILD_BENCHMARK (off by default), BUILD_SHARED_LIBS (on by default)
# Additionally, the ROCm installation prefix should be passed using CMAKE_PREFIX_PATH or by setting the ROCM_PATH environment variable.
#
# ! IMPORTANT !
# Set C++ compiler to HIP-clang. You can do it by adding 'CXX=<path-to-compiler>'
# before 'cmake' or setting cmake option 'CMAKE_CXX_COMPILER' to path to the compiler.
#
# The python interface do not work with static library.
#
[CXX=hipcc] cmake -DBUILD_BENCHMARK=ON ../. -DCMAKE_PREFIX_PATH=/opt/rocm # or cmake-gui ../.

# To configure rocRAND for NVIDIA platforms, the CXX compiler must be set to a host compiler. The CUDA compiler can
# be set explicitly using `-DCMAKE_CUDA_COMPILER=<path-to-nvcc>`.
# Additionally, the path to FindHIP.cmake should be passed via CMAKE_MODULE_PATH. By default, this is module is
# installed in /opt/rocm/hip/cmake.
cmake -DBUILD_BENCHMARK=ON ../. -DCMAKE_PREFIX_PATH=/opt/rocm -DCMAKE_MODULE_PATH=/opt/rocm/hip/cmake # or cmake-gui ../.
# or
[CXX=g++] cmake -DBUILD_BENCHMARK=ON -DCMAKE_CUDA_COMPILER=/usr/local/cuda/bin/nvcc -DCMAKE_PREFIX_PATH=/opt/rocm -DCMAKE_MODULE_PATH=/opt/rocm/hip/cmake ../. # or cmake-gui ../.

# Build
make -j4

# Optionally, run tests if they're enabled
ctest --output-on-failure

# Install
[sudo] make install
```

### HIP on Windows

We've added initial support for HIP on Windows, which you can install using the `rmake.py` python
script:

```shell
git clone https://github.com/ROCm/rocRAND.git
cd rocRAND

# the -i option will install rocPRIM to C:\hipSDK by default
python rmake.py -i

# the -c option will build all clients including unit tests
python rmake.py -c
```

The existing GoogleTest library in the system (especially static GoogleTest libraries built with other
compilers) may cause a build failure; if you encounter errors with the existing GoogleTest library or
other dependencies, you can pass the `DEPENDENCIES_FORCE_DOWNLOAD` flag to CMake, which can
help to solve the problem.

To disable inline assembly optimizations in rocRAND (for both the host library and
the device functions provided in `rocrand_kernel.h`), set the CMake option `ENABLE_INLINE_ASM`
to `OFF`.

## Running unit tests

```shell
# Go to rocRAND build directory
cd rocRAND; cd build

# To run all tests
ctest

# To run unit tests
./test/<unit-test-name>
```

## Running benchmarks

```shell
# Go to rocRAND build directory
cd rocRAND; cd build

# To run benchmark for the host generate functions:
# The benchmarks are registered with Google Benchmark as `device_generate<engine,distribution>`, where
# engine -> xorwow, mrg31k3p, mrg32k3a, mtgp32, philox, lfsr113, mt19937,
#           threefry2x32, threefry2x64, threefry4x32, threefry4x64,
#           sobol32, scrambled_sobol32, sobol64, scrambled_sobol64
# distribution -> uniform-uint, uniform-uchar, uniform-ushort,
#                 uniform-half, uniform-float, uniform-double,
#                 normal-half, normal-float, normal-double,
#                 log-normal-half, log-normal-float, log-normal-double, poisson
# Further option can be found using --help
./benchmark/benchmark_rocrand_host_api
# To run specific benchmarks:
./benchmark/benchmark_rocrand_host_api --benchmark_filter=<regex>
# For example to run benchmarks with engine sobol64:
./benchmark/benchmark_rocrand_host_api --benchmark_filter="device_generate<sobol64*"
# To view all registered benchmarks:
./benchmark/benchmark_rocrand_host_api --benchmark_list_tests=true
# The benchmark also supports user input:
./benchmark/benchmark_rocrand_host_api --size <number> --trials <number> --offset <number> --dimensions <number> --lambda <float float float ...>
# And can print output in different formats:
./benchmark/benchmark_rocrand_host_api --benchmark_format=<console|json|csv>

# To run benchmark for device kernel functions:
# The benchmarks are registered with Google Benchmark as `device_kernel<engine,distribution>`, where
# engine -> xorwow, mrg31k3p, mrg32k3a, mtgp32, philox, lfsr113,
#           threefry2x32, threefry2x64, threefry4x32, threefry4x64,
#           sobol32, scrambled_sobol32, sobol64, scrambled_sobol64
# distribution -> uniform-uint or uniform-ullong, uniform-float, uniform-double, normal-float, normal-double,
#                 log-normal-float, log-normal-double, poisson, discrete-poisson, discrete-custom
# Further option can be found using --help
./benchmark/benchmark_rocrand_device_api
# To run specific benchmarks:
./benchmark/benchmark_rocrand_device_api --benchmark_filter=<regex>
# For example to run benchmarks with engine sobol64:
./benchmark/benchmark_rocrand_device_api --benchmark_filter="device_kernel<sobol64*"
# To view all registered benchmarks:
./benchmark/benchmark_rocrand_device_api --benchmark_list_tests=true
# The benchmark also supports user input:
./benchmark/benchmark_rocrand_device_api --size <number> --trials <number> --dimensions <number> --lambda <float float float ...>
# And can print output in different formats:
./benchmark/benchmark_rocrand_device_api --benchmark_format=<console|json|csv>

# To compare against cuRAND (cuRAND must be supported):
./benchmark/benchmark_curand_host_api [google benchmark options]
./benchmark/benchmark_curand_device_api [google benchmark options]
```

### Legacy benchmarks

You can disable legacy benchmarks (those used prior to Google Benchmark) by setting the
CMake option `BUILD_LEGACY_BENCHMARK` to `OFF`. For compatibility, the default setting is `ON`
when `BUILD_BENCHMARK` is set.

Legacy benchmarks are deprecated and will be removed in a future version once all benchmarks have
been migrated to the new framework.

## Wrappers

* C++ wrappers for the rocRAND host API are in [`rocrand.hpp`](./library/include/rocrand/rocrand.hpp).
* [Fortran wrappers](./library/src/fortran/).
* [Python wrappers](./python/): [rocRAND](./python/rocrand).

## Support

Bugs and feature requests can be reported through the
[issue tracker](https://github.com/ROCm/rocRAND/issues).

## Contributions and license

Contributions of any kind are most welcome! You can find more information at
[CONTRIBUTING](./CONTRIBUTING.md).

Licensing information is located at [LICENSE](./LICENSE.txt).
