nx_intlog.nx

nx_intlog.nx -- INTEGER fixed-point base-2 logarithm (no floats anywhere -- the ecosystem's no-float doctrine). ilog2_1024(x) returns round(1024 * log2(x)) for x >= 1 via msb + 10 mantissa-squaring refinement steps (each step decides one fractional bit; y stays < 2^17 so y*y < 2^34 -- no overflow). The BM25/IDF ranking rung composes this: idf_q10(N, n_t) = ilog2_1024(N+1) - ilog2_1024(n_t) >= 0-ish, clamped at 0 (a term in every doc carries ~no signal -- correct BM25 behavior). license_tier: ORIGINAL