// /*************************************************************************** // Aaru Data Preservation Suite // ---------------------------------------------------------------------------- // // Filename : neon.cs // Author(s) : Natalia Portillo // The Chromium Authors // // Component : Checksums. // // --[ Description ] ---------------------------------------------------------- // // Compute Adler32 checksum using NEON vectorization. // // --[ License ] -------------------------------------------------------------- // // Redistribution and use in source and binary forms, with or without // modification, are permitted provided that the following conditions are // met: // // * Redistributions of source code must retain the above copyright // notice, this list of conditions and the following disclaimer. // * Redistributions in binary form must reproduce the above // copyright notice, this list of conditions and the following disclaimer // in the documentation and/or other materials provided with the // distribution. // * Neither the name of Google Inc. nor the names of its // contributors may be used to endorse or promote products derived from // this software without specific prior written permission. // // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS // "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT // LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR // A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT // OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, // SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT // LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, // DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY // THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. // // ---------------------------------------------------------------------------- // Copyright © 2011-2022 Natalia Portillo // Copyright 2017 The Chromium Authors. All rights reserved. // ****************************************************************************/ namespace Aaru.Checksums.Adler32; using System.Runtime.Intrinsics; using System.Runtime.Intrinsics.Arm; static class Neon { internal static void Step(ref ushort preSum1, ref ushort preSum2, byte[] buf, uint len) { /* * Split Adler-32 into component sums. */ uint s1 = preSum1; uint s2 = preSum2; var bufPos = 0; /* * Process the data in blocks. */ uint blockSize = 1 << 5; uint blocks = len / blockSize; len -= blocks * blockSize; while(blocks != 0) { uint n = Adler32Context.NMAX / blockSize; /* The NMAX constraint. */ if(n > blocks) n = blocks; blocks -= n; /* * Process n blocks of data. At most NMAX data bytes can be * processed before s2 must be reduced modulo ADLER_MODULE. */ var vS2 = Vector128.Create(s1 * n, 0, 0, 0); var vS1 = Vector128.Create(0u, 0, 0, 0); Vector128 vColumnSum1 = AdvSimd.DuplicateToVector128((ushort)0); Vector128 vColumnSum2 = AdvSimd.DuplicateToVector128((ushort)0); Vector128 vColumnSum3 = AdvSimd.DuplicateToVector128((ushort)0); Vector128 vColumnSum4 = AdvSimd.DuplicateToVector128((ushort)0); do { /* * Load 32 input bytes. */ var bytes1 = Vector128.Create(buf[bufPos], buf[bufPos + 1], buf[bufPos + 2], buf[bufPos + 3], buf[bufPos + 4], buf[bufPos + 5], buf[bufPos + 6], buf[bufPos + 7], buf[bufPos + 8], buf[bufPos + 9], buf[bufPos + 10], buf[bufPos + 11], buf[bufPos + 12], buf[bufPos + 13], buf[bufPos + 14], buf[bufPos + 15]); bufPos += 16; var bytes2 = Vector128.Create(buf[bufPos], buf[bufPos + 1], buf[bufPos + 2], buf[bufPos + 3], buf[bufPos + 4], buf[bufPos + 5], buf[bufPos + 6], buf[bufPos + 7], buf[bufPos + 8], buf[bufPos + 9], buf[bufPos + 10], buf[bufPos + 11], buf[bufPos + 12], buf[bufPos + 13], buf[bufPos + 14], buf[bufPos + 15]); bufPos += 16; /* * Add previous block byte sum to v_s2. */ vS2 = AdvSimd.Add(vS2, vS1); /* * Horizontally add the bytes for s1. */ vS1 = AdvSimd.AddPairwiseWideningAndAdd(vS1, AdvSimd. AddPairwiseWideningAndAdd(AdvSimd.AddPairwiseWidening(bytes1), bytes2)); /* * Vertically add the bytes for s2. */ vColumnSum1 = AdvSimd.AddWideningLower(vColumnSum1, bytes1.GetLower()); vColumnSum2 = AdvSimd.AddWideningLower(vColumnSum2, bytes1.GetUpper()); vColumnSum3 = AdvSimd.AddWideningLower(vColumnSum3, bytes2.GetLower()); vColumnSum4 = AdvSimd.AddWideningLower(vColumnSum4, bytes2.GetUpper()); } while(--n != 0); vS2 = AdvSimd.ShiftLeftLogical(vS2, 5); /* * Multiply-add bytes by [ 32, 31, 30, ... ] for s2. */ vS2 = AdvSimd.MultiplyWideningLowerAndAdd(vS2, vColumnSum1.GetLower(), Vector64.Create((ushort)32, 31, 30, 29)); vS2 = AdvSimd.MultiplyWideningLowerAndAdd(vS2, vColumnSum1.GetUpper(), Vector64.Create((ushort)28, 27, 26, 25)); vS2 = AdvSimd.MultiplyWideningLowerAndAdd(vS2, vColumnSum2.GetLower(), Vector64.Create((ushort)24, 23, 22, 21)); vS2 = AdvSimd.MultiplyWideningLowerAndAdd(vS2, vColumnSum2.GetUpper(), Vector64.Create((ushort)20, 19, 18, 17)); vS2 = AdvSimd.MultiplyWideningLowerAndAdd(vS2, vColumnSum3.GetLower(), Vector64.Create((ushort)16, 15, 14, 13)); vS2 = AdvSimd.MultiplyWideningLowerAndAdd(vS2, vColumnSum3.GetUpper(), Vector64.Create((ushort)12, 11, 10, 9)); vS2 = AdvSimd.MultiplyWideningLowerAndAdd(vS2, vColumnSum4.GetLower(), Vector64.Create((ushort)8, 7, 6, 5)); vS2 = AdvSimd.MultiplyWideningLowerAndAdd(vS2, vColumnSum4.GetUpper(), Vector64.Create((ushort)4, 3, 2, 1)); /* * Sum epi32 ints v_s1(s2) and accumulate in s1(s2). */ Vector64 sum1 = AdvSimd.AddPairwise(vS1.GetLower(), vS1.GetUpper()); Vector64 sum2 = AdvSimd.AddPairwise(vS2.GetLower(), vS2.GetUpper()); Vector64 s1S2 = AdvSimd.AddPairwise(sum1, sum2); s1 += AdvSimd.Extract(s1S2, 0); s2 += AdvSimd.Extract(s1S2, 1); /* * Reduce. */ s1 %= Adler32Context.ADLER_MODULE; s2 %= Adler32Context.ADLER_MODULE; } /* * Handle leftover data. */ if(len != 0) { if(len >= 16) { s2 += s1 += buf[bufPos++]; s2 += s1 += buf[bufPos++]; s2 += s1 += buf[bufPos++]; s2 += s1 += buf[bufPos++]; s2 += s1 += buf[bufPos++]; s2 += s1 += buf[bufPos++]; s2 += s1 += buf[bufPos++]; s2 += s1 += buf[bufPos++]; s2 += s1 += buf[bufPos++]; s2 += s1 += buf[bufPos++]; s2 += s1 += buf[bufPos++]; s2 += s1 += buf[bufPos++]; s2 += s1 += buf[bufPos++]; s2 += s1 += buf[bufPos++]; s2 += s1 += buf[bufPos++]; s2 += s1 += buf[bufPos++]; len -= 16; } while(len-- != 0) s2 += s1 += buf[bufPos++]; if(s1 >= Adler32Context.ADLER_MODULE) s1 -= Adler32Context.ADLER_MODULE; s2 %= Adler32Context.ADLER_MODULE; } /* * Return the recombined sums. */ preSum1 = (ushort)(s1 & 0xFFFF); preSum2 = (ushort)(s2 & 0xFFFF); } }