Function lower_gemm_source 

pub fn lower_gemm_source(
    source: &str,
    ts: usize,
    its: usize,
    ip: usize,
) -> Result<(usize, usize, usize, String, String), String>

A LOGOS matmul, recognized (tensor_recognize::recognize_matmul) and emitted as Spatial’s GEMM regression app with tiles ts/its and an ip-lane reduce: (m, n, k, class name, Spatial source), or a typed reason (not a matmul; tiles that do not divide the shape).