// /*************************************************************************** // Aaru Data Preservation Suite // ---------------------------------------------------------------------------- // // Filename : ssse3.cs // Author(s) : Natalia Portillo // The Chromium Authors // // Component : Checksums. // // --[ Description ] ---------------------------------------------------------- // // Compute Adler32 checksum using SSSE3 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. // ****************************************************************************/ using System; using System.Runtime.Intrinsics; using System.Runtime.Intrinsics.X86; namespace Aaru.Checksums.Adler32; internal static class Ssse3 { internal static void Step(ref ushort sum1, ref ushort sum2, byte[] buf, uint len) { uint s1 = sum1; uint s2 = sum2; int bufPos = 0; /* * Process the data in blocks. */ uint BLOCK_SIZE = 1 << 5; uint blocks = len / BLOCK_SIZE; len -= blocks * BLOCK_SIZE; while(blocks != 0) { uint n = Adler32Context.NMAX / BLOCK_SIZE; /* The NMAX constraint. */ if(n > blocks) n = blocks; blocks -= n; Vector128 tap1 = Vector128.Create(32, 31, 30, 29, 28, 27, 26, 25, 24, 23, 22, 21, 20, 19, 18, 17). AsByte(); Vector128 tap2 = Vector128.Create(16, 15, 14, 13, 12, 11, 10, 9, 8, 7, 6, 5, 4, 3, 2, 1).AsByte(); Vector128 zero = Vector128.Create(0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0).AsByte(); Vector128 ones = Vector128.Create(1, 1, 1, 1, 1, 1, 1, 1); /* * Process n blocks of data. At most NMAX data bytes can be * processed before s2 must be reduced modulo BASE. */ Vector128 v_ps = Vector128.Create(s1 * n, 0, 0, 0); Vector128 v_s2 = Vector128.Create(s2, 0, 0, 0); Vector128 v_s1 = Vector128.Create(0u, 0, 0, 0); do { /* * Load 32 input bytes. */ Vector128 bytes1 = Vector128.Create(BitConverter.ToUInt32(buf, bufPos), BitConverter.ToUInt32(buf, bufPos + 4), BitConverter.ToUInt32(buf, bufPos + 8), BitConverter.ToUInt32(buf, bufPos + 12)); bufPos += 16; Vector128 bytes2 = Vector128.Create(BitConverter.ToUInt32(buf, bufPos), BitConverter.ToUInt32(buf, bufPos + 4), BitConverter.ToUInt32(buf, bufPos + 8), BitConverter.ToUInt32(buf, bufPos + 12)); bufPos += 16; /* * Add previous block byte sum to v_ps. */ v_ps = Sse2.Add(v_ps, v_s1); /* * Horizontally add the bytes for s1, multiply-adds the * bytes by [ 32, 31, 30, ... ] for s2. */ v_s1 = Sse2.Add(v_s1, Sse2.SumAbsoluteDifferences(bytes1.AsByte(), zero).AsUInt32()); Vector128 mad1 = System.Runtime.Intrinsics.X86.Ssse3.MultiplyAddAdjacent(bytes1.AsByte(), tap1.AsSByte()); v_s2 = Sse2.Add(v_s2, Sse2.MultiplyAddAdjacent(mad1.AsInt16(), ones.AsInt16()).AsUInt32()); v_s1 = Sse2.Add(v_s1, Sse2.SumAbsoluteDifferences(bytes2.AsByte(), zero).AsUInt32()); Vector128 mad2 = System.Runtime.Intrinsics.X86.Ssse3.MultiplyAddAdjacent(bytes2.AsByte(), tap2.AsSByte()); v_s2 = Sse2.Add(v_s2, Sse2.MultiplyAddAdjacent(mad2.AsInt16(), ones.AsInt16()).AsUInt32()); } while(--n != 0); v_s2 = Sse2.Add(v_s2, Sse2.ShiftLeftLogical(v_ps, 5)); /* * Sum epi32 ints v_s1(s2) and accumulate in s1(s2). */ v_s1 = Sse2.Add(v_s1, Sse2.Shuffle(v_s1, 177)); v_s1 = Sse2.Add(v_s1, Sse2.Shuffle(v_s1, 78)); s1 += (uint)Sse2.ConvertToInt32(v_s1.AsInt32()); v_s2 = Sse2.Add(v_s2, Sse2.Shuffle(v_s2, 177)); v_s2 = Sse2.Add(v_s2, Sse2.Shuffle(v_s2, 78)); s2 = (uint)Sse2.ConvertToInt32(v_s2.AsInt32()); /* * 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. */ sum1 = (ushort)(s1 & 0xFFFF); sum2 = (ushort)(s2 & 0xFFFF); } }