cristina.oprean

dot product & bidimesional stream storage

Discussion created by cristina.oprean on Jul 30, 2008
Latest reply on Aug 1, 2008 by cristina.oprean

 Hi,

I have 3 questions:

- I tried to use kernel intrinsic function dot(x,y).  Brook+ specification says "dot(x,y) - Dot product of the two vectors x and y". What does vector means: an unidimensional stream or an unidimensional table? Using this function, I observed that dot(x,y) is equivalent with x*y, where x and y are numbers, not streams nor vectors.  Can anybody provide an example where   this function is applied on 2 streams ?

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- How are bidimensional streams organised in memory: row after row (linke in C) or column after colums?  Suppose  we have:

kernel void test(float x[][], ... )

{

  float2 idx={2,3};

 x[idx.xy]=5;

 ... .

}

Which element is getting the value 5: the element from the row 2 and colums 3 or the element from the row 3 and column 2? 

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- Suppose that I have global stream variable, when calling a kernel having as parameter this stream, it is created a local copy of this stream or all the operations within the kernel are executed directly on the global stream?

                                                                                         Thank you .

 

 

 

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