GitLab

* check in the two ways of approaching backwards for softcapping, both functional

* prepare the softcap switch for backwards

* temporary

* cleanup to the way Tri prefers

* calculate dtanh when copying from scores -> dtanh Tensor

* no ternary operators allowed for constexpr, so just use some hack found online

* fix maybe_dtanh, restore some files

* restore another file

* move calculate_dtanh to utils and colocate with apply_softcap

* cleanup

* maybe last cleanup

* save for another pr

* remove a stray line

* fix spacing

* fix an issue, and make test_flash_attn.py ready to test softcapping backwards

These tests are failing so I'm just disabling this case for now

* Softcap v2 (fwd only).

* Some missing interface + remove overrides in tests.

Co-authored-by: moshuosha <moshuosha@qq.com>

* Support unpadded LSE layout.
Co-authored-by: Xinfeng Xie <xfxie.ceca@gmail.com>
Co-authored-by: Jianyu Huang <hjyahead@gmail.com>

* Cleanup

* Fix unpadded LSE on split-kv path

* Fix formatting and comments

* Fix inline vs forceinline

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Co-authored-by: Xinfeng Xie <xfxie.ceca@gmail.com>
Co-authored-by: Jianyu Huang <hjyahead@gmail.com>

* Enable paged attention in varlen forward

* Format + fix padding

Co-authored-by: ljss <450993438@qq.com>

Co-authored-by: Timothee Lacroix <t@mistral.ai>