Original release notes
hexagon: flash attention rework (optimizations, accuracy improvements, etc) (#25085)
- hex-mm: fold mm quant tasks into the main matmul threads
- hex-mm: minor formatting fixes
- hex-mm: cleanup is_quant checks in dma dispatch
- hex-mm: fix dst-spad alignment
- hex-mm: move fp kernels in the hvx-mm-kernels header
- hex-mm: fuse with ADD
- hex-fa: factor out ukernels into separate headers and unify the rest
- hex-fa: move kernel-params compute into the host
- hex-fa: refactor vtcm alloc for consistency
- hex-fa: add support for FA_SELECT
- hex-fa: update tracing insrumentation to cover all functions
- hex-fa: update hvx fallback thresholds to recover t/g regressions
- hex-fa: update tracing instrumentation
- hex-fa: improved tracing with additional events
- hex-fa: optimize mask processing (fastdiv, etc)
- hex-fa: improve mask dma caching
- hmx-fa: change loop order to maximize mask cache hits
- hex-fa: remove over instrumentation
- hex-fa: breakdown QKV prep trace events
- hmx-fa: further mask proc optimizations
- hex-fa: mask broadcast is the common case, optimize for that
- hex-fa: use aligned loads where possible
- hex-fa: update loops to use uint32_t indices
- hmx-fa: fold vtcm init into q prep task
- hex-fa: update rest of the hmx funcs to use uint32_t
- hmx-fa: fold build_d into the main softmax loop
- hmx-fa: start kv dmas earlier
- hmx-fa: start mask dma a bit earlier
- hex-fa: precompute rows per task to avoid divs
- hmx-fa: specialize fa_o_store for f16 and f32
- hmx-fa: prelim support for Sinks
- hmx-fa: keep softmax accumulators in fp32
- hex-fa: add tanh_f16 and exp2_f16 and use that in FA
- hex-fa: use fp16 math in the hvx kernel
- hex-fa: avoid expensive float -> __fp16 cast for slopes and softcap
- hex-fa: replace most vec_exp_f32 with vec_exp2_f16
- hmx-fa: vectorize sinks update
- hex-fa: minor formatting
- hmx-fa: fold softcap loop into the tile load
- hmx-fa: use vectoralias to populate sinks
- hex-fa: remove redudant check
- hex-fa: fix vtcm size compute to use fp32 for accumulators
- hex-mm: fix trailing spaces
- hmx-fa: dont use -inf to init mask to avoid conversion overflows
- hex-fa: no need to explicitly guard -inf in the f16->f32 converter now
- hmx-fa: cleanup fa sinks handling
- hex-mm: fixed src2 stride handling when mm is fused with add
- hex-fa: make lto happy
UI:
