Persist accumulated WIP across rtx-tensor / rtx-transformers / rtx-runtime.
Two related feature groups:
GPU enablement (unblocks the Phase-3 spec §8 CUDA Mamba path):
- rtx-tensor: `Tensor::cuda_device_ptr()` + storage GPU-buffer accessors
(`raw_ptr.rs`) expose the raw CUdeviceptr that kernel launches need —
the "rtx-tensor GPU memory access API" the Mamba CUDA kernels were
blocked on.
- rtx-transformers: `MambaBlock::forward_cuda` runs the four linear
projections through cuBLAS on-device (in/out/x/dt_proj), keeping the
selective scan + conv1d + activations on CPU; dispatched automatically
from `forward` when on a CUDA device under the `cuda` feature. Updated
`mamba_cuda_kernels.rs` accordingly.
- supporting plumbing in rtx-runtime stream/bridge and rtx-tensor
storage/conversion/concatenation/creation + rtx-flash-attention.
Linear algebra (rtx-tensor):
- `linalg/matrix_exp.rs`: real matrix exponential via scaling-and-squaring
with a degree-13 Padé approximant (Higham 2005), f64 internally.
- `complex/linalg.rs`: complex matmul/adjoint, Hermitian eigendecomposition
(`ComplexEigenResult`), and the complex matrix exponential, nalgebra-backed.
- tests for both.
Builds verified on the CPU path (`cargo check -p rtx-tensor -p rtx-transformers
-p rtx-runtime -p rtx-flash-attention` clean). The `cuda` feature and the
rtx-backend-cuda NVCC build remain unbuildable on this host (CUDA/glibc header
mismatch) — pre-existing and unrelated to these changes.
osobh
redclawsystems