Intel MKL Error: Parameter 9 was incorrect on entry to cblas_zgemm (C# Linux)

Question

我使用以下命令构建了一个 custom MKL library (2019 Update 2) for Windows (10) and Linux (Ubuntu 18.04)：

nmake libintel64 MKLROOT="C:\Program Files (x86)\IntelSWTools\compilers_and_libraries\windows\mkl" name=win\intel64\custom_mkl interface="lp64"

和

make libintel64 MKLROOT="opt/intel/mkl" name=linux/intel64/custom_mkl interface=lp64

我正在使用 C# 中的 DllImport 来调用 cblas_zgemm

[DllImport(DLLName, CallingConvention = CallingConvention.Cdecl, ExactSpelling = true, SetLastError = false)]
internal static extern void cblas_zgemm(
    int Order, int TransA, int TransB, int M, int N, int K,
    ComplexDouble alpha, [In] ComplexDouble[,] A, int lda, [In] ComplexDouble[,] B, int ldb,
    ComplexDouble beta, [In, Out] ComplexDouble[,] C, int ldc);

见https://software.intel.com/en-us/mkl-developer-reference-c-cblas-gemm

其中 ComplexDouble 定义为：

public struct ComplexDouble
{
    public double real;
    public double imag;

    public static implicit operator ComplexDouble(double d)
    {
        return new ComplexDouble() { real = d };
    }
}

我为矩阵乘法定义了以下静态方法：

public static ComplexDouble[,] Dot(ComplexDouble[,] a, ComplexDouble[,] b)
{
    int n1 = a.GetLength(0);
    int n2 = a.GetLength(1);
    int n3 = b.GetLength(0);
    int n4 = b.GetLength(1);
    if (n2 != n3) throw new System.Exception("Inner matrix dimensions must agree");
    int Order = 101; // row-major arrays
    int TransA = 111; // trans='N'
    int TransB = 111; // trans='N'
    int M = n1, N = n4, K = n2;
    int lda = K, ldb = N, ldc = N;
    ComplexDouble alpha = 1, beta = 0;
    ComplexDouble[,] c = new ComplexDouble[n1, n4];
    _mkl.cblas_zgemm(Order, TransA, TransB, M, N, K, alpha, a, lda, b, ldb, beta, c, ldc);
    return c;
}

最后我得到了以下测试代码，它在 Windows 下运行良好但在 Linux 上失败（进入 cblas_zgemm 时参数 9 不正确）。

ComplexDouble[,] A = new ComplexDouble[,] { { 1, 2, 3 }, { 4, 5, 6 } };
ComplexDouble[,] B = new ComplexDouble[,] { { 0, 1, 0, 1 }, { 1, 0, 0, 1 }, { 1, 0, 1, 0 } };
ComplexDouble[,] C = MKL.Dot(A, B);

我做了以下观察：

适用于 Windows
它在 Linux（单声道）上失败，参数 9 在进入 cblas_zgemm 或空引用时不正确。
如果我用 cblas_dgemm 和 double 重复实验，它在 Windows 和 Linux 上有效。

Answer 1

仔细看看 cblas_zgemm

void cblas_zgemm (
    const CBLAS_LAYOUT Layout, const CBLAS_TRANSPOSE transa, const CBLAS_TRANSPOSE transb, const MKL_INT m, const MKL_INT n, const MKL_INT k, 
    const void *alpha, const void *a, const MKL_INT lda, const void *b, const MKL_INT ldb, 
    const void *beta, void *c, const MKL_INT ldc);

表明参数 alpha 和 beta 必须通过引用传递。所以 DllImport 必须看起来像这样：

[DllImport(DLLName, CallingConvention = CallingConvention.Cdecl, ExactSpelling = true, SetLastError = false)]
internal static extern void cblas_zgemm(
    int Order, int TransA, int TransB, int M, int N, int K,
    ref ComplexDouble alpha, [In] ComplexDouble[,] A, int lda, [In] ComplexDouble[,] B, int ldb,
    ref ComplexDouble beta, [In, Out] ComplexDouble[,] C, int ldc);

我不知何故错过了，因为 cblas_dgemm

void cblas_dgemm (
    const CBLAS_LAYOUT Layout, const CBLAS_TRANSPOSE transa, const CBLAS_TRANSPOSE transb, const MKL_INT m, const MKL_INT n, const MKL_INT k, 
    const double alpha, const double *a, const MKL_INT lda, const double *b, const MKL_INT ldb, 
    const double beta, double *c, const MKL_INT ldc);

参数 alpha 和 beta 是按值传递的。

[DllImport(DLLName, CallingConvention = CallingConvention.Cdecl, ExactSpelling = true, SetLastError = false)]
internal static extern void cblas_dgemm(
    int Order, int TransA, int TransB, int M, int N, int K,
    double alpha, [In] double[,] A, int lda, [In] double[,] B, int ldb,
    double beta, [In, Out] double[,] C, int ldc);

就像 cblas_zgemm 在 Windows 和 Linux 上工作一样。我仍然不明白为什么它在 Windows 上使用 ref?

Intel MKL Error: Parameter 9 was incorrect on entry to cblas_zgemm (C# Linux)

Intel MKL Error: Parameter 9 was incorrect on entry to cblas_zgemm (C# Linux)

c#

linux

cross-platform

dllimport

intel-mkl