polyval_mul_generic
polyval_mul_generic(&key->h_powers[i],
polyval_mul_generic(acc, &key->h_powers[NUM_H_POWERS - 1]);
polyval_mul_generic(acc, key);
polyval_mul_generic(&ctx->acc, &ctx->key->h);
polyval_mul_generic(&key->h_powers[i],
polyval_mul_generic(acc, &key->h_powers[NUM_H_POWERS - 1]);