相关疑难解决方法(0)

我是指令优化的新手.

我对一个简单的函数dotp进行了简单的分析,该函数用于获取两个浮点数组的点积.

C代码如下:

float dotp(               
    const float  x[],   
    const float  y[],     
    const short  n      
)
{
    short i;
    float suma;
    suma = 0.0f;

    for(i=0; i<n; i++) 
    {    
        suma += x[i] * y[i];
    } 
    return suma;
}

我用昂纳雾在网络上提供的测试框架testp.

在这种情况下使用的数组是对齐的:

int n = 2048;
float* z2 = (float*)_mm_malloc(sizeof(float)*n, 64);
char *mem = (char*)_mm_malloc(1<<18,4096);
char *a = mem;
char *b = a+n*sizeof(float);
char *c = b+n*sizeof(float);

float *x = (float*)a;
float *y = (float*)b;
float *z = (float*)c;

然后我调用函数dotp,n = 2048,repeat …

嗨我有以下代码：

public unsafe class MultiplyAndAdd : IDisposable
{
    float[] rawFirstData = new float[1024];
    float[] rawSecondData = new float[1024];

    static int alignment = 32;
    float[] alignedFirstData = new float[1024 + alignment / sizeof(float)];
    int alignedFirstDataOffset;
    GCHandle alignedFirstDataHandle;
    float* alignedFirstDataPointer;
    float[] alignedSecondData = new float[1024 + alignment / sizeof(float)];
    int alignedSecondDataOffset;
    GCHandle alignedSecondDataHandle;
    float* alignedSecondDataPointer;

    public IEnumerable<object[]> Data { get; set; }

    public void Dispose()
    {
        this.alignedFirstDataHandle.Free();
        this.alignedSecondDataHandle.Free();
    }

    //Calculate the offset that needs to be applied to ensure that the array …