# TDLS - Tiny Device-callable Linear Solvers

TDLS is a header-only C++20 library of direct solvers for small
general linear systems. It is written to be callable from device code:
one thread solves one system, on CPU as well as inside a CUDA, HIP,
SYCL, Kokkos, RAJA, OpenMP, OpenACC or parallel STL kernel. The
solvers are designed for maximum GPU performance. The library has no
dependency.

TDLS is designed to be embedded in
[TFEL/MFront](https://github.com/thelfer/tfel). Its solvers accept the
`tfel::math` objects directly, without including TFEL.

## Solvers

As of today, TDLS implements one solver family:

- {doc}`TiledLUpp <tiled_lupp/index>`: LU factorization with logical
  partial pivoting on a tile grid, in a compile-time dimension and a
  runtime dimension variant.

## Documentation map

- {doc}`getting_started`: requirements, installation, building the
  tests and examples, a first solve, and the calling convention shared
  by every solver.
- {doc}`TiledLUpp <tiled_lupp/index>`: how the solvers work, their
  configuration, and their snippets: one entry point per snippet, on a
  small system.
- {doc}`TFEL interoperability <tfel/index>`: how the `tfel::math`
  objects are accepted, with snippets per solver family.
- {doc}`tests`: the method, the generic suites, then the suites and
  the example programs of each solver family. The examples are complete
  programs solving a physical problem on every execution scale.
- {doc}`api_reference`: the Doxygen reference of the headers.
- {doc}`ai_usage`: the use of AI assistants in the project.

```{toctree}
:maxdepth: 2
:hidden:

Overview <self>
getting_started
tiled_lupp/index
tfel/index
tests
api_reference
ai_usage
```