def ri_k

bend-collections-laws-crypto@1.0.0.0 · src/math/f64.bend:705

import Base
import bend-collections-laws-crypto@1.0.0.0/src/math/u64.bend as W
import bend-collections-laws-crypto@1.0.0.0/src/math/w64.bend as X

705# k < 64 fractional bits: q = w >> k, r = w - (q << k), h = 2^(k-1)
706def ri_k(m: RMode, +s: Bool, +w: W.U64, +k: Nat, small: Bool) -> F64:
707  match small:
708    case True{}:
709      ri_q(m, s, X.shr(w, k), X.sub(w, X.shl(X.shr(w, k), k)), X.shl(W.U64{1, 0}, Nat.sub(k, 1n)))
710    case False{}:
711      ri_q(m, s, W.U64{0, 0}, w, W.U64{0, 2147483648})