Add OpInfo and ref for linspace and logspace (#81826)
Implements linspace with arange, and logspace with linspace.
- Implements a more precise path in linspace's ref when dtype is integral to avoid off-by-one issues when output of computation is casted to int. The trade off is that there's an increased chance of overflow.
- Files several issues #82242, #82230, #81996, on preexisting issues with the linspace and logspace. These mainly concern when dtype is integral - the affect tests are xfailed in this PR.
- Fixes the check that the reference implementation is closer to precise implementation than torch implementation to also update the dtype kwarg to the precise dtype.
TODO:
- ~support negative bases~ (not in this PR)
- ~support complex. Since arange does not support complex, but linspace does, one solution is to just call linspace separately on the real and imag components and sum the results in the end~ (not in this PR)
- ~default dtypes need to be explicitly handled since computation is done in a different dtype than result~ (done)
Pull Request resolved: https://github.com/pytorch/pytorch/pull/81826
Approved by: https://github.com/ngimel
