https://libre-soc.org/3d_gpu/architecture/dynamic_simd/logicops/ how these operators work requires documenting
partition: P P P (3 bits) a : .... .... .... .... (32 bits) xor-a : x0 P x1 P x2 P x3 (4+3 bits, P=1 if no partition) added an adapted version from add page