Added autograd support for torch.orgqr (#52637)
Summary:
This PR adds autograd support for `torch.orgqr`.
Since `torch.orgqr` is one of few functions that expose LAPACK's naming and all other linear algebra routines were renamed a long time ago, I also added a new function with a new name and `torch.orgqr` now is an alias for it.
The new proposed name is `householder_product`. For a matrix `input` and a vector `tau` LAPACK's orgqr operation takes columns of `input` (called Householder vectors or elementary reflectors) scalars of `tau` that together represent Householder matrices and then the product of these matrices is computed. See https://www.netlib.org/lapack/lug/node128.html.
Other linear algebra libraries that I'm aware of do not expose this LAPACK function, so there is some freedom in naming it. It is usually used internally only for QR decomposition, but can be useful for deep learning tasks now when it supports differentiation.
Resolves https://github.com/pytorch/pytorch/issues/50104
Pull Request resolved: https://github.com/pytorch/pytorch/pull/52637
Reviewed By: agolynski
Differential Revision: D27114246
Pulled By: mruberry
fbshipit-source-id: 9ab51efe52aec7c137aa018c7bd486297e4111ce
