For the complete documentation index, see llms.txt. Markdown versions of all pages are available by appending .md to any URL (e.g. /max/get-started.md).

Mojo module

mha_prefill

RDNA Wave32 MHA prefill kernel.

Recipe (per KV tile):

• K loaded to LDS strip-by-strip; QK MMA fragments emitted per strip.
• V is prefetched as a side DMA during the second-to-last K strip so it overlaps the QK compute.
• Mask + online softmax + barriers between QK and PV.
• P (post-softmax scores) cast and staged in SMEM, then PV MMA reads P from SMEM as the A operand and V from LDS as B.

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