This kernel wasn't allowed in export, so no backwards compatibility period is required. Even so, the FFI kernels were added 6 months ago.
PiperOrigin-RevId: 724359996
Unlike the other more detailed ports, this version doesn't take full advantage of the features provided by the FFI. For example, it would be possible to update the kernels to use the ScratchAllocator instead of querying the workspace size during lowering. However, since these kernels are really only meant to be experimental, it's not obvious to me that it's worth the extra work to do anything more sophisticated.
PiperOrigin-RevId: 724016331
This feature has been in the queue for a long time (see https://github.com/jax-ml/jax/issues/1259), and some folks have found that they can use `pure_callback` to call the CPU version as a workaround. It has recently come up that there can be issues when using `pure_callback` with JAX calls in the body (https://github.com/jax-ml/jax/issues/24255; this should be investigated separately).
This change adds a native solution for computing `lax.linalg.eig` on GPU. By default, this is implemented by calling LAPACK on host directly because this has good performance for small to moderately sized problems (less than about 2048^2). For larger matrices, a GPU-backed implementation based on [MAGMA](https://icl.utk.edu/magma/) can have significantly better performance. (I should note that I haven't done a huge amount of benchmarking yet, but this was the breakeven point used by PyTorch, and I find roughly similar behavior so far.)
We don't want to add MAGMA as a required dependency, but if a user has installed it, JAX can use it when the `jax_gpu_use_magma` configuration variable is set to `"on"`. By default, we try to dlopen `libmagma.so`, but the path to a non-standard installation location can be specified using the `JAX_GPU_MAGMA_PATH` environment variable.
PiperOrigin-RevId: 697631402
There is a lot of boilerplate required for each new custom call to cuSolver / cuBLAS, and having both the FFI logic and the framework wrappers in the same library was getting unwieldy. This change adds a new "interface" target which just includes the shims to wrap cuSolver/BLAS functions, and then these are used from `solver_kernels_ffi` where the FFI logic lives.
PiperOrigin-RevId: 673832309
