Applies the remaining flake8-comprehension fixes and checks. This changes replace all remaining unnecessary generator expressions with list/dict/set comprehensions which are more succinct, performant, and better supported by our torch.jit compiler. It also removes useless generators such as 'set(a for a in b)`, resolving it into just the set call.
Pull Request resolved: https://github.com/pytorch/pytorch/pull/94676
Approved by: https://github.com/ezyang
Sometimes you want to query the small element of a set of elements and use `sorted(elements)[0]` without a second thought. However, this is not optimal, since the entire list must be sorted first `O(n log n)`. It would be better to use the `min(elements)` method provided for this purpose `O(n)`.
Furthermore `sorted(elements)[::-1]` is not very efficient, because it would be better to use `sorted(elements, reverse=True)` to save the slice operation.
**TLDR: using `sorted(elements)[0]` is slow and can be replaced with `min(elements)`.**
I stumbled across these code snippets while playing around with CodeQL (see https://lgtm.com/query/4148064474379348546/).
Pull Request resolved: https://github.com/pytorch/pytorch/pull/86995
Approved by: https://github.com/jansel
Previously, our handling for contiguity was inconsistent in the following ways:
- is_strides_like 2d/3d and is_non_overlapping_and_dense always were computed
based on sizes_and_strides_, even if you had symbolic ints
- Furthermore, even if you set custom policy for strides, these quantities were
not overridable by subclasses
- Furthermore, we didn't even store these fields on ExtraMeta
- We duplicate implementations of compute_contiguous (plain, channels last,
channels last 3d)
- We inconsistently called refresh_numel()/refresh_contiguous(), versus
recomputing it ourselves
This factor makes a consistent strategy for all of the boolean fields, and
for numel computation. After this refactor:
- All layout boolean fields are interposable via strides policy
and can be overridden from Python; you will never access a garbage field
- All layout boolean fields are on ExtraMeta
- You can always call refresh_numel/contiguous, no matter if your Tensor is
contiguous or not
- The numel/layout boolean fields are always populated consistently with
the sizes strides fields (either on Tensor or ExtraMeta), even if you
have custom policy
- There is only one implementation of the actual computation logic
Signed-off-by: Edward Z. Yang <ezyang@fb.com>
Differential Revision: [D39907696](https://our.internmc.facebook.com/intern/diff/D39907696)
Pull Request resolved: https://github.com/pytorch/pytorch/pull/85858
Approved by: https://github.com/albanD
