gfmul(s1, 0xE) ^ gfmul(s1, 0x9) ^ gfmul(s3, 0xD); let b2 : bits (8) = x[15.. 8]; let s2 : bits (8) = x[23..16]; let s3 : bits (8) = x[ 7.. 0]; let oc2 : bits(32) = ror32(inb, 7) ^ (X(rs1) >> 18) ^ (X(rs2) >> 2) ^ ror32(inb, 18)