{"id":10021024,"date":"2025-10-10T21:07:44","date_gmt":"2025-10-10T13:07:44","guid":{"rendered":"https:\/\/itmax.cn\/?p=10021024"},"modified":"2025-10-10T21:07:44","modified_gmt":"2025-10-10T13:07:44","slug":"c-simd%e5%90%91%e9%87%8f%e7%b4%a2%e5%bc%95%e5%ae%9e%e6%88%98%ef%bc%9a%e4%bb%8e%e7%90%86%e8%ae%ba%e5%88%b0%e9%ab%98%e6%80%a7%e8%83%bd%e5%ae%9e%e7%8e%b0","status":"publish","type":"post","link":"https:\/\/itmax.cn\/?p=10021024","title":{"rendered":"C# SIMD\u5411\u91cf\u7d22\u5f15\u5b9e\u6218\uff1a\u4ece\u7406\u8bba\u5230\u9ad8\u6027\u80fd\u5b9e\u73b0"},"content":{"rendered":"

C# SIMD\u5411\u91cf\u7d22\u5f15\u5b9e\u6218\uff1a\u4ece\u7406\u8bba\u5230\u9ad8\u6027\u80fd\u5b9e\u73b0<\/h2>\n

\u6027\u80fd\u9769\u547d\u7684\u8d77\u70b9<\/strong><\/h3>\n

\u60f3\u8c61\u8fd9\u6837\u4e00\u4e2a\u573a\u666f\uff1a\u4f60\u6b63\u5728\u5f00\u53d1\u4e00\u4e2a\u667a\u80fd\u63a8\u8350\u7cfb\u7edf\uff0c\u9700\u8981\u4ece100\u4e07\u4e2a\u5546\u54c1\u5411\u91cf\u4e2d\u5feb\u901f\u627e\u51fa\u4e0e\u7528\u6237\u67e5\u8be2\u6700\u76f8\u4f3c\u7684\u524d10\u4e2a\u5546\u54c1\u3002\u5982\u679c\u5f15\u5165Qdrant\u7684\u8bdd\u4f1a\u589e\u52a0\u90e8\u7f72\u590d\u6742\u5ea6\u3001\u5d4c\u5165\u5f0f\u7684Faiss\u5bf9.NET\u751f\u6001\u5e76\u4e0d\u53cb\u597d\uff0c\u8be5\u600e\u4e48\u529e\uff1f<\/p>\n

\u8981\u4e0d\u81ea\u5df1\u6784\u5efa\u4e00\u4e2a\u5411\u91cf\u7d22\u5f15\u5427\u3002\u786e\u4fdd\u540c\u6837\u7684\u67e5\u8be2\u4e00\u6837\u53ea\u9700\u8981\u51e0\u5341\u6beb\u79d2\uff0c\u548cFaiss\u6027\u80fd\u76f8\u5f53\uff01<\/p>\n

\u8fd9\u4e0d\u662f\u7eb8\u4e0a\u8c08\u5175\uff0c\u800c\u662f\u6211\u5728\u5b9e\u9645\u9879\u76ee\u4e2d\u5b9e\u73b0\u7684\u9ad8\u6027\u80fd\u5411\u91cf\u7d22\u5f15\u5f15\u64ce\u3002\u4eca\u5929\uff0c\u6211\u5c06\u6df1\u5165\u5206\u6790\u5176\u4e2d\u7684\u5173\u952e\u6280\u672f\u70b9\u3002<\/p>\n

\u5411\u91cf\u76f8\u4f3c\u5ea6\u8ba1\u7b97\uff1a\u6027\u80fd\u4f18\u5316\u7684\u6838\u5fc3\u6218\u573a<\/strong><\/h3>\n

\u4e09\u79cd\u8ddd\u79bb\u5ea6\u91cf\u7684SIMD\u5b9e\u73b0<\/strong><\/h4>\n

\u5728\u5411\u91cf\u68c0\u7d22\u7cfb\u7edf\u4e2d\uff0c\u8ddd\u79bb\u8ba1\u7b97\u662f\u6700\u9891\u7e41\u7684\u64cd\u4f5c\uff0c\u4e5f\u662f\u6027\u80fd\u74f6\u9888\u6240\u5728\u3002\u6211\u5b9e\u73b0\u4e86\u4e09\u79cd\u4e3b\u6d41\u7684\u76f8\u4f3c\u5ea6\u8ba1\u7b97\u65b9\u6cd5\uff0c\u5747\u91c7\u7528Vector<t>\uff0c\u786e\u4fdd\u80fd\u7528\u4e0aCPU\u7684SIMD\u6307\u4ee4\u6765\u63d0\u5347\u6548\u7387\u3002<\/p>\n

1. \u6b27\u51e0\u91cc\u5f97\u8ddd\u79bb\uff08L2\uff09<\/strong><\/p>\n

\u5f3a\u8c03\u7edd\u5bf9\u6570\u503c\u5dee\u5f02\uff0c\u5982\u679c\u5411\u91cf\u5df2\u7ecf\u505a\u8fc7\u5f52\u4e00\u5316\uff0c\u7ed3\u679c\u4e0eCosine\u7c7b\u4f3c\u3002L2\u5e38\u7528\u4e8e\u9700\u8981\u8861\u91cf\u7edd\u5bf9\u8ddd\u79bb\u5dee\u5f02\u7684\u573a\u666f\uff0c\u4f8b\u5982\u5730\u7406\u4f4d\u7f6e\u63a8\u8350\u6216\u56fe\u50cf\u8bc6\u522b\u4e2d\u7684\u50cf\u7d20\u5dee\u5f02\u6bd4\u8f83\u3002<\/p>\n

private static float L2DistanceSimd(ReadOnlySpan<float> v1, ReadOnlySpan<float> v2)\n{\n    float sum = 0f;\n    int i = 0;\n    int simdLength = Vector<float>.Count; \/\/ \u901a\u5e38\u662f8\uff08AVX\uff09\u62164\uff08SSE\uff09\n\n    \/\/ SIMD\u5411\u91cf\u5316\u5faa\u73af\uff1a\u4e00\u6b21\u5904\u7406\u591a\u4e2a\u7ef4\u5ea6\n    for (; i &lt;= v1.Length - simdLength; i += simdLength)\n    {\n        var a = new Vector<float>(v1.Slice(i));\n        var b = new Vector<float>(v2.Slice(i));\n        var diff = a - b;  \/\/ \u5411\u91cf\u51cf\u6cd5\n        sum += Vector.Dot(diff, diff); \/\/ \u70b9\u79ef\u8ba1\u7b97\u5e73\u65b9\u548c\n    }\n\n    \/\/ \u5904\u7406\u5269\u4f59\u5143\u7d20\n    for (; i &lt; v1.Length; i++)\n        sum += (v1[i] - v2[i]) * (v1[i] - v2[i]);\n\n    return MathF.Sqrt(sum);\n}<\/code><\/pre>\n
2. \u70b9\u79ef\uff08\u5185\u79ef\uff09\u8ba1\u7b97<\/strong><\/p>\n
\u591a\u7528\u4e8e\u517c\u987e\u5411\u91cf\u65b9\u5411\u548c\u6a21\u957f\u7684\u573a\u666f\uff0c\u4f8b\u5982\u63a8\u8350\u7cfb\u7edf\u4e2d\u7ed3\u5408\u7528\u6237\u504f\u597d\u548c\u7269\u54c1\u70ed\u5ea6\u7684\u534f\u540c\u8fc7\u6ee4\u3002<\/p>\n
private static float DotSimd(ReadOnlySpan<float> v1, ReadOnlySpan<float> v2)\n{\n    float dot = 0f;\n    int i = 0;\n    int simdLength = Vector<float>.Count;\n\n    \/\/ \u5411\u91cf\u5316\u70b9\u79ef\u8ba1\u7b97\n    for (; i &lt;= v1.Length - simdLength; i += simdLength)\n    {\n        var a = new Vector<float>(v1.Slice(i));\n        var b = new Vector<float>(v2.Slice(i));\n        dot += Vector.Dot(a, b); \/\/ \u9ad8\u6548\u7684SIMD\u70b9\u79ef\n    }\n\n    \/\/ \u6807\u91cf\u5904\u7406\u5269\u4f59\u90e8\u5206\n    for (; i &lt; v1.Length; i++)\n        dot += v1[i] * v2[i];\n\n    return dot;\n}<\/code><\/pre>\n
3. \u4f59\u5f26\u76f8\u4f3c\u5ea6<\/strong><\/p>\n
\u4f59\u5f26\u76f8\u4f3c\u5ea6\u662f\u6700\u590d\u6742\u7684\u8ba1\u7b97\uff0c\u9700\u8981\u5148\u8fdb\u884c\u5411\u91cf\u5f52\u4e00\u5316\uff0c\u9002\u7528\u4e8e\u8861\u91cf\u65b9\u5411\u4e00\u81f4\u6027\u800c\u5ffd\u7565\u5411\u91cf\u957f\u5ea6\u7684\u573a\u666f\uff0c\u6bd4\u5982\u6587\u672c\u76f8\u4f3c\u5ea6\u8ba1\u7b97\u6216\u63a8\u8350\u7cfb\u7edf\u4e2d\u7684\u7528\u6237\u5174\u8da3\u5339\u914d\u3002<\/p>\n
case MetricType.Cosine:\n    \/\/ \u4f7f\u7528\u4e34\u65f6\u6570\u7ec4\u505a\u5f52\u4e00\u5316\uff0c\u907f\u514d\u4fee\u6539\u539f\u59cb\u6570\u636e\n    float[] v1Norm = new float[v1.Length];\n    float[] v2Norm = new float[v2.Length];\n    NormalizeInto(v1, v1Norm);\n    NormalizeInto(v2, v2Norm);\n    return DotSimd(v1Norm, v2Norm); \/\/ \u5f52\u4e00\u5316\u540e\u7684\u70b9\u79ef\u5373\u4f59\u5f26<\/code><\/pre>\n
\u667a\u80fd\u5f52\u4e00\u5316\u7b56\u7565<\/strong><\/h4>\n
\u5f52\u4e00\u5316\u662f\u4f59\u5f26\u76f8\u4f3c\u5ea6\u8ba1\u7b97\u7684\u5173\u952e\u6b65\u9aa4\uff0c\u6211\u8bbe\u8ba1\u4e86\u4e00\u4e2a\u96f6\u62f7\u8d1d\u7684\u5f52\u4e00\u5316\u65b9\u6cd5\uff1a<\/p>\n
public static void NormalizeInto(ReadOnlySpan<float> src, Span<float> dst)\n{\n    float norm = Norm(src);\n    if (norm &lt; 1e-10f) \/\/ \u5904\u7406\u96f6\u5411\u91cf\n    {\n        for (int i = 0; i &lt; dst.Length; i++) dst[i] = 0f;\n        return;\n    }\n    \n    \/\/ \u5411\u91cf\u5f52\u4e00\u5316\uff1a\u6bcf\u4e2a\u5206\u91cf\u9664\u4ee5\u6a21\u957f\n    for (int i = 0; i &lt; src.Length; i++)\n        dst[i] = src[i] \/ norm;\n}<\/code><\/pre>\n
\u5185\u5b58\u9ad8\u6548\u7684\u5411\u91cf\u96c6\u5408\u8bbe\u8ba1<\/strong><\/h3>\n
\u6570\u636e\u7ed3\u6784\u4f18\u5316<\/strong><\/h4>\n
\u4f20\u7edf\u7684\u5411\u91cf\u5b58\u50a8\u5f80\u5f80\u91c7\u7528\u5b57\u5178\u6216\u590d\u6742\u7684\u6811\u7ed3\u6784\uff0c\u4f46\u6211\u9009\u62e9\u4e86\u66f4\u7b80\u6d01\u9ad8\u6548\u7684\u5e76\u884c\u6570\u7ec4\u8bbe\u8ba1\uff0c\u9ebb\u70e6\u4e00\u4e9b\uff0c\u4f46\u771f\u7684\u5feb\uff1a<\/p>\n
private readonly List<float[]> _vectors = new(); \/\/ \u5411\u91cf\u6570\u7ec4\nprivate readonly List<int> _ids = new(); \/\/ ID\u6570\u7ec4\uff0c\u4e25\u683c\u4fdd\u6301\u7d22\u5f15\u5bf9\u5e94<\/code><\/pre>\n
\u8fd9\u79cd\u8bbe\u8ba1\u7684\u4f18\u52bf\uff1a<\/p>\n
– \u7f13\u5b58\u53cb\u597d<\/strong>\uff1a\u8fde\u7eed\u7684\u5185\u5b58\u5e03\u5c40\u63d0\u9ad8CPU\u7f13\u5b58\u547d\u4e2d\u7387<\/p>\n
– \u7b80\u5355\u9ad8\u6548<\/strong>\uff1a\u907f\u514d\u4e86\u590d\u6742\u6307\u9488\u64cd\u4f5c\uff0c\u964d\u4f4e\u5185\u5b58\u788e\u7247<\/p>\n
– SIMD\u53cb\u597d<\/strong>\uff1a\u4e3a\u5411\u91cf\u5316\u8ba1\u7b97\u63d0\u4f9b\u7406\u60f3\u7684\u6570\u636e\u8bbf\u95ee\u6a21\u5f0f<\/p>\n
\u52a8\u6001\u7ef4\u5ea6\u68c0\u6d4b<\/strong><\/h4>\n
\u7cfb\u7edf\u652f\u6301\u6839\u636e\u5df2\u7ecf\u52a0\u5165\u7d22\u5f15\u7684\u5411\u91cf\u81ea\u52a8\u6267\u884c\u7ef4\u5ea6\u68c0\u6d4b\uff0c\u65e0\u9700\u9884\u5148\u6307\u5b9a\u5411\u91cf\u7ef4\u5ea6\uff1a<\/p>\n
public int Dimension\n{\n    get\n    {\n        if (_vectors.Count &gt; 0) return _vectors[0].Length;\n        else return DEFAULT_DIMENSION; \/\/ \u9ed8\u8ba41024\u7ef4\n    }\n}<\/code><\/pre>\n
ID\u552f\u4e00\u6027\u4fdd\u8bc1<\/strong><\/h4>\n
\u901a\u8fc7\u81ea\u52a8\u53bb\u91cd\u673a\u5236\u786e\u4fdd\u5411\u91cfID\u7684\u552f\u4e00\u6027\uff1a<\/p>\n
public void AddVector(int id, float[] vector)\n{\n    \/\/ \u7ef4\u5ea6\u68c0\u67e5\n    if (_vectors.Count &gt; 0 &amp;&amp; vector.Length != Dimension)\n        throw new ArgumentException($"\u5411\u91cf\u7ef4\u5ea6\u4e0d\u5339\u914d\uff1a{vector.Length} vs {Dimension}");\n\n    RemoveVector(id); \/\/ \u786e\u4fddID\u552f\u4e00\u6027\uff0c\u5148\u5220\u9664\u65e7\u5411\u91cf\n    \n    _ids.Add(id);\n    _vectors.Add(vector);\n}<\/code><\/pre>\n
\u9ad8\u6027\u80fd\u68c0\u7d22\u7b97\u6cd5<\/strong><\/h3>\n
\u66b4\u529b\u641c\u7d22\u7684\u6781\u81f4\u4f18\u5316<\/strong><\/h4>\n
\u867d\u7136\u662f\u66b4\u529b\u641c\u7d22\uff0c\u4f46\u901a\u8fc7SIMD\u4f18\u5316\uff0c\u6027\u80fd\u8868\u73b0\u4f9d\u7136\u51fa\u8272\uff1a<\/p>\n
public IEnumerable<searchresult> Search(float[] query, int topK = 3)\n{\n    \/\/ \u5feb\u901f\u7ef4\u5ea6\u68c0\u67e5\n    if (query.Length != Dimension) return [];\n\n    var results = new List<searchresult>(_vectors.Count);\n\n    \/\/ \u5411\u91cf\u5316\u76f8\u4f3c\u5ea6\u8ba1\u7b97\n    for (int i = 0; i &lt; _vectors.Count; i++)\n    {\n        float similarity = DistanceProvider.Similarity(query, _vectors[i], MetricTypeInUse);\n        results.Add(new SearchResult(_ids[i], similarity));\n    }\n\n    \/\/ \u9ad8\u6548Top-K\u9009\u62e9\n    return results.OrderByDescending(r =&gt; r.score).Take(topK).ToArray();\n}<\/code><\/pre>\n
\u7ed3\u679c\u6392\u5e8f\u4f18\u5316<\/strong><\/h4>\n
\u901a\u8fc7\u9884\u5206\u914d\u5bb9\u91cf\u548c\u6d41\u5f0f\u5904\u7406\uff0c\u6700\u5c0f\u5316\u5185\u5b58\u5206\u914d\uff1a<\/p>\n
var results = new List<searchresult>(_vectors.Count); \/\/ \u9884\u5206\u914d\u5bb9\u91cf\nreturn [.. results.OrderByDescending(r =&gt; r.score).Take(topK)]; \/\/ \u96c6\u5408\u8868\u8fbe\u5f0f<\/code><\/pre>\n
\u5f15\u5165\u91cf\u5316\u6280\u672f\uff1a\u5b58\u50a8\u4e0e\u8ba1\u7b97\u7684\u5e73\u8861\u827a\u672f<\/strong><\/h3>\n
8\u4f4d\u91cf\u5316\u5b9e\u73b0<\/strong><\/h4>\n
\u4e3a\u4e86\u8fdb\u4e00\u6b65\u63d0\u5347\u6027\u80fd\uff0c\u6211\u5b9e\u73b0\u4e86INT8\u91cf\u5316\u6280\u672f\uff0c\u5c06float\u8f6c\u4e3abyte\u6765\u538b\u7f29\u7a7a\u95f4\u5360\u7528\uff1a<\/p>\n
public static (byte[] quantized, QuantizationParams quantParams) QuantizeVector(float[] vector)\n{\n    float min = vector.Min();\n    float max = vector.Max();\n    \n    \/\/ \u907f\u514d\u9664\u96f6\n    if (Math.Abs(max - min) &lt; 1e-10f)\n        return (new byte[vector.Length], new QuantizationParams(1.0f, min));\n\n    \/\/ \u7ebf\u6027\u91cf\u5316\u6620\u5c04\uff1a[min, max] -&gt; [0, 255]\n    float scale = (max - min) \/ 255.0f;\n    float offset = min;\n\n    byte[] quantized = new byte[vector.Length];\n    for (int i = 0; i &lt; vector.Length; i++)\n    {\n        float normalized = (vector[i] - offset) \/ scale;\n        quantized[i] = (byte)Math.Clamp(Math.Round(normalized), 0, 255);\n    }\n\n    return (quantized, new QuantizationParams(scale, offset));\n}<\/code><\/pre>\n
\u53cd\u91cf\u5316\u6062\u590d<\/strong><\/h4>\n
\u4e0e\u91cf\u5316\u76f8\u5bf9\u5e94\u7684\u5de5\u4f5c\u3002<\/p>\n
public static float[] DequantizeVector(byte[] quantized, QuantizationParams quantParams)\n{\n    float[] result = new float[quantized.Length];\n    for (int i = 0; i &lt; quantized.Length; i++)\n    {\n        result[i] = quantized[i] * quantParams.Scale + quantParams.Offset;\n    }\n    return result;\n}<\/code><\/pre>\n
\u6570\u636e\u6301\u4e45\u5316\uff1a\u9ad8\u6027\u80fd\u5e8f\u5217\u5316\u65b9\u6848<\/strong><\/h3>\n
\u4e8c\u8fdb\u5236\u5e8f\u5217\u5316 + GZip\u538b\u7f29<\/strong><\/h4>\n
\u4f20\u7edf\u7684JSON\u5e8f\u5217\u5316\u5728\u5904\u7406\u5927\u89c4\u6a21\u5411\u91cf\u6570\u636e\u65f6\u6027\u80fd\u582a\u5fe7\uff0c\u800c\u4e14\u5b58\u50a8\u7a7a\u95f4\u5360\u7528\u8f83\u5927\uff0c\u6240\u4ee5\u6211\u8bbe\u8ba1\u4e86\u4e13\u7528\u7684\u4e8c\u8fdb\u5236\u5e8f\u5217\u5316\u5668\uff1a<\/p>\n
public static string ToZipBase64(PlainCollectionData data)\n{\n    if (data == null) return string.Empty;\n\n    using var ms = new MemoryStream();\n    using var bw = new BinaryWriter(ms);\n\n    \/\/ \u5199\u5165\u5143\u6570\u636e\u5934\n    bw.Write(data.Version);\n    bw.Write(data.Dimension);\n    bw.Write((int)data.MetricTypeInUse);\n    bw.Write(data.Ids.Count);\n\n    \/\/ \u6279\u91cf\u5199\u5165ID\u6570\u7ec4\n    foreach (var id in data.Ids)\n        bw.Write(id);\n\n    \/\/ \u8fde\u7eed\u5199\u5165\u5411\u91cf\u6570\u636e - \u7f13\u5b58\u53cb\u597d\u7684\u5185\u5b58\u5e03\u5c40\n    foreach (var vec in data.Vectors)\n        foreach (var f in vec)\n            bw.Write(f);\n\n    bw.Flush();\n    var rawBytes = ms.ToArray();\n\n    \/\/ GZip\u538b\u7f29 - \u5411\u91cf\u6570\u636e\u901a\u5e38\u6709\u5f88\u597d\u7684\u538b\u7f29\u6bd4\n    using var compressedStream = new MemoryStream();\n    using (var gzip = new GZipStream(compressedStream, CompressionLevel.Fastest))\n        gzip.Write(rawBytes, 0, rawBytes.Length);\n\n    return Convert.ToBase64String(compressedStream.ToArray());\n}<\/code><\/pre>\n
\u9ad8\u6548\u53cd\u5e8f\u5217\u5316<\/strong><\/h4>\n
\u53cd\u5e8f\u5217\u5316\u8fc7\u7a0b\u540c\u6837\u7ecf\u8fc7\u5bf9\u5e94\u7684\u4f18\u5316\uff0c\u987a\u5e8f\u548c\u6570\u636e\u7c7b\u578b\u5173\u4e4eofffset\uff0c\u9700\u8981\u8ddf\u5e8f\u5217\u5316\u4fdd\u6301\u4e00\u81f4\uff1a<\/p>\n
public static PlainCollectionData ToCollectionData(string text)\n{\n    if (string.IsNullOrEmpty(text))\n        return new PlainCollectionData();\n\n    \/\/ \u89e3\u538b\u7f29\n    var compressed = Convert.FromBase64String(text);\n    using var ms1 = new MemoryStream(compressed);\n    using var gzip = new GZipStream(ms1, CompressionMode.Decompress);\n    using var outStream = new MemoryStream();\n    gzip.CopyTo(outStream);\n\n    \/\/ \u9ad8\u6548\u4e8c\u8fdb\u5236\u8bfb\u53d6\n    var bytes = outStream.ToArray();\n    using var ms = new MemoryStream(bytes);\n    using var br = new BinaryReader(ms);\n\n    \/\/ \u8bfb\u53d6\u5143\u6570\u636e\n    int version = br.ReadInt32();\n    int dimension = br.ReadInt32();\n    var metricType = (MetricType)br.ReadInt32();\n    int count = br.ReadInt32();\n\n    var data = new PlainCollectionData\n    {\n        Version = version,\n        MetricTypeInUse = metricType,\n        Ids = new List<int>(count),      \/\/ \u9884\u5206\u914d\u5bb9\u91cf\n        Vectors = new List<float[]>(count)\n    };\n\n    \/\/ \u6279\u91cf\u8bfb\u53d6ID\n    for (int i = 0; i &lt; count; i++)\n        data.Ids.Add(br.ReadInt32());\n\n    \/\/ \u8fde\u7eed\u8bfb\u53d6\u5411\u91cf\u6570\u636e\n    for (int i = 0; i &lt; count; i++)\n    {\n        var vec = new float[dimension];\n        for (int j = 0; j &lt; dimension; j++)\n            vec[j] = br.ReadSingle();\n        data.Vectors.Add(vec);\n    }\n\n    return data;\n}<\/code><\/pre>\n
\u6027\u80fd\u4f18\u52bf<\/strong>\uff1a<\/p>\n