tilelang.contrib.ptodsl.allreduce
=================================

.. py:module:: tilelang.contrib.ptodsl.allreduce

.. autoapi-nested-parse::

   SIMT cross-workitem all-reduce.

   Vendored from the PTOAS project (``ptodsl/ptodsl/_allreduce.py``); upstream
   commit f5eff3ee249697f6157088f649c6434fcc9d7c5b ("refactor(ptodsl): remove
   the SIMT allreduce helpers") removed the module expecting TileLang to own the
   implementation. contrib.ptodsl's integer-signedness compatibility, previously
   applied as monkey patches from ``simt.py``, is merged directly into the
   reducer tables and the dtype dispatch.

   All-reduce ops are emitted **inline** at the current insertion point.
   Three reducer variants: ``simt_allreduce_sum``, ``simt_allreduce_max``, ``simt_allreduce_min``.

   Dispatch tree (compile-time, since *threads* / *scale* are Python ints)::

       threads <= scale                                       →  identity
       threads ≤ 32,  pow2(threads), pow2(scale)              →  warp_reduce
       threads ≤ 32                                           →  ub_reduce
       threads > 32,  pow2(threads), scale≤32, pow2(scale)   →  cross_warp_reduce
       otherwise                                              →  ub_reduce (fallback)



Functions
---------

.. autoapisummary::

   tilelang.contrib.ptodsl.allreduce.simt_allreduce_sum
   tilelang.contrib.ptodsl.allreduce.simt_allreduce_max
   tilelang.contrib.ptodsl.allreduce.simt_allreduce_min


Module Contents
---------------

.. py:function:: simt_allreduce_sum(value, *, threads, scale=1, thread_offset=0, scratch=None)

   Sum reduce across SIMT work-items.


.. py:function:: simt_allreduce_max(value, *, threads, scale=1, thread_offset=0, scratch=None)

   Max reduce across SIMT work-items.


.. py:function:: simt_allreduce_min(value, *, threads, scale=1, thread_offset=0, scratch=None)

   Min reduce across SIMT work-items.