/* Zupt — AES-256-CTR 4-Block Pipeline via AES-NI (Jasmin)
 * Copyright (c) 2026 Cristian Cezar Moisés
 * SPDX-License-Identifier: AGPL-3.0-or-later
 *
 * CT-REQUIRED: AES-NI has no data-dependent timing.
 *
 * Interleaves 4 independent counter blocks through the AES round
 * pipeline. AES-NI has 4-cycle latency, 1-cycle throughput — so
 * 4 independent blocks saturate the pipeline for ~4× throughput.
 *
 * Expected: ~3.5 GB/s AES-256-CTR on modern x86-64 (Zen3/Alder Lake).
 *
 * Interface:
 *   zupt_aes256_ctr4(out, in, key, ctr, nblocks)
 *   Encrypts nblocks×16 bytes. Counter is incremented in the last 8 bytes
 *   (big-endian) after each block. Processes 4 blocks per iteration;
 *   remaining 1-3 blocks fall back to zupt_aes256_blk.
 *
 * NOTE: This is the Jasmin source for documentation. The actual linked
 * assembly is in zupt_aes_ctr4.s (hand-written to match this logic).
 */

/* See zupt_aes_ctr4.s for the production assembly.
 * This .jazz file documents the algorithm but is not compiled
 * (jasminc is not required at build time). */