AMP (GPU parallel computing, C #, VC ++ 11) Learning (1)

I feel that the amp code is very understandable.

 

I. VC ++ 11 code

   1: #include "stdafx.h"

   2: #include <amp.h>

   3:  

   4: using namespace concurrency;

   5:  

   6: extern "C" __declspec ( dllexport ) void _stdcall square_array(float* arr, int n)

   7: {

   8:     // Create a view over the data on the CPU

   9:     array_view<float,1> dataView(n, &arr[0]);

  10:  

  11:     // Run code on the GPU

  12:     parallel_for_each(dataView.extent, [=] (index<1> idx) restrict(amp)

  13:     {

  14:         dataView[idx] = dataView[idx] * dataView[idx];

  15:     });

  16:  

  17:     // Copy data from GPU to CPU

  18:     dataView.synchronize();

  19: }

 

Concurrency is the same as the thread security data structure name of C. So it is easy to understand

Parallel_for_each is similar to parallel. foreach of C #.

Lambda on the fifth line is used every day in C #. I am very excited to see it.

 

Dataview. Extend seems to be the number of operators to be started at the same time

[=] Is the abbreviation of [dataview,

 

In C #, Lambda does not include "[]". [] indicates the variable to enter the closure of the lambda function.

C # is automatically analyzed, and VC ++ 11 needs to manually list input variables.

 

Array_view (Amp reference array)

Array upload reference (Amp array) (upload reference plus &)

 

Restrict (AMP) is a mark that limits this function to perform a syntax check. You can write the amp or CPU in the brackets.

If it is an amp (GPU), the content in the function body can only be a subset of C ++ 11, and some writing methods are not allowed. Specific descriptions on msdn

 

The function body is not interpreted. Idx can be interpreted as the number of parallel operators.

Dataview. Synchronize ();

Write GPU data back to cpu

 

Very simple, really, almost no line does not understand.

 

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II. C # Call Code

   1: [DllImport("Win32Project1", CallingConvention = CallingConvention.StdCall)]

   2: extern unsafe static void square_array(float* array, int length);

   3:  

   4: unsafe void Do()

   5: {

   6:     // Allocate an array

   7:     float[] arr = this.textBox1.Text

   8:         .Split(' ')

   9:         .Select(v=> Convert.ToSingle(v) ).ToArray();

  10:  

  11:     // Square the array elements using C++ AMP

  12:     fixed (float* arrPt = &arr[0])

  13:     {

  14:         square_array(arrPt, arr.Length);

  15:     }

  16:  

  17:  

  18:     this.textBox2.Text = string.Join(" ", arr);

  19: }

Convert the string that reads the textbox to a floating point group, call the amp function, and output it to another textbox.

 

Iii. Running Effect

 

 

4. code files

Http://files.cnblogs.com/xzbrillia/%E5%AD%A6%E4%B9%A0amp1.rar

 

V. Reference address

 

Http://blogs.msdn.com/ B /pfxteam/archive/2011/09/21/10214538.aspx