/* * Copyright (c) 2016 Thomas Pornin <pornin@bolet.org> * * Permission is hereby granted, free of charge, to any person obtaining * a copy of this software and associated documentation files (the * "Software"), to deal in the Software without restriction, including * without limitation the rights to use, copy, modify, merge, publish, * distribute, sublicense, and/or sell copies of the Software, and to * permit persons to whom the Software is furnished to do so, subject to * the following conditions: * * The above copyright notice and this permission notice shall be * included in all copies or substantial portions of the Software. * * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE * SOFTWARE. */ #include "inner.h" /* see inner.h */ uint32_t br_i32_add(uint32_t *a, const uint32_t *b, uint32_t ctl) { uint32_t cc; size_t u, m; cc = 0; m = (a[0] + 63) >> 5; for (u = 1; u < m; u ++) { uint32_t aw, bw, naw; aw = a[u]; bw = b[u]; naw = aw + bw + cc; /* * Carry is 1 if naw < aw. Carry is also 1 if naw == aw * AND the carry was already 1. */ cc = (cc & EQ(naw, aw)) | LT(naw, aw); a[u] = MUX(ctl, naw, aw); } return cc; } |