def gf128.gcm.word
import bend-osdev-gf@0.1.2.0/gf128.bend as Gf128import Base
128# the 32 bits of the word x, from its top bit
129def gf128.gcm.word(n: Nat, +x: U32, zv: Gf128 & Gf128) -> Gf128 & Gf128:
130 match n:
131 case 0n:
132 zv
133 case 1n+k:
134 gf128.gcm.word(k, U32.shl(x), gf128.gcm.bit(x, zv))