cuda

Building the CUDA compiler tools and runtime

Prerequisite: gnat-llvm with NVPTX support, python

To build the CUDA compiler wrapper llvm-cuda and the device-cuda runtime you will need a copy of the gnat and bb-runtimes sources in the folder containing the cuda project, i.e:

development/
  |--> bb-runtimes
  |--> cuda
  \--> gnat

Once set up, you can then build and install llvm-cuda and the device-cuda runtime by running make from the CUDA project directory.

If required, llvm-cuda can be built directly using wrapper.gpr project file in the wrapper directory.

Building the CUDA bindings

CUDA API changes a lot from version to version, and even within a single version from configuration to configuration. It's not practical to write or keep all possible versions in version control. Instead, we can generate the API with -fdump-ada-specs and Uwrap.

For that to work, you need a recent gnat, langkit and libadalang installation, e.g. using anod:

anod install libadalang_for_customers
anod install langkit

eval `anod printenv libadalang_for_customers`
eval `anod printenv langkit`

git clone [email protected]:AdaCore/uwrap.git
cd uwrap
cd lang_test
make
cd ../lang_template
make
cd ..
source env.sh
gprbuild
export PATH=`pwd`/obj:$PATH

Set CUDA_ROOT to point to your cuda installation. For example:

export CUDA_ROOT=/usr/local/cuda-10.0

Next you will run the cuda bind.sh script. ("cuda" is from the AdaCore github project, there's a link above.) However, this must be done from the directory it appears in, so use

cd cuda/api
sh ./bind.sh

This should create CUDA bindings under cuda/api.

Using CUDA with your Ada application

Device Code

A minimal project file for the device target takes the following form:

with "<path to>/api/cuda_device.gpr";

project Marching_Device_Code is
   for Languages use ("Ada");
   for Target use "cuda";
   for Runtime ("ada") use "device-cuda";

   for Source_Dirs use ("src");
   for Object_Dir use "obj";
end Marching_Device_Code;

Host Code

In your host project reference the cuda_host.gpr project file.