Make torch.svd return V, not V.conj() for complex inputs (#51012)
Summary:
**BC-breaking note:**
torch.svd() added support for complex inputs in PyTorch 1.7, but was not documented as doing so. The complex "V" tensor returned was actually the complex conjugate of what's expected. This PR fixes the discrepancy.
This will silently break all users of torch.svd() with complex inputs.
**Original PR Summary:**
This PR resolves https://github.com/pytorch/pytorch/issues/45821.
The problem was that when introducing the support of complex inputs for `torch.svd` it was overlooked that LAPACK/MAGMA returns the conjugate transpose of V matrix, not just the transpose of V. So `torch.svd` was silently returning U, S, V.conj() instead of U, S, V.
Behavior of `torch.linalg.pinv`, `torch.pinverse` and `torch.linalg.svd` (they depend on `torch.svd`) is not changed in this PR.
Pull Request resolved: https://github.com/pytorch/pytorch/pull/51012
Reviewed By: bdhirsh
Differential Revision: D26047593
Pulled By: albanD
fbshipit-source-id: d1e08dbc3aab9ce1150a95806ef3b5da98b5d3ca
