Kernel for finding the minimum element in the array

I am writing an OpenCL code which parallelizes finding the minimum number in an array.

Here is my kernel function:

What i am doing is comparing all the elements with all the other elements and the element which is greater i am changing the corresponding value of M[i] to 1. At last we have only one element in M array with value 0, with that index we can look in the A array and have our minimum value

__kernel void array(__global int *A, __global int *M) {

// Get index of the element

int i = get_global_id(0);

int j = get_global_id(1);

//barrier(CLK_LOCAL_MEM_FENCE);

// Do the operation

if(A[i]<A[j] && i!=j)

{M[j]=1;}

}

I am getting all the values M array as 0.

But the output should be that only one value of the M array should be 0. and that index would give me the min number index in array A.

Re: Kernel for finding the minimum element in the array

You could get yourself some good ideas from this approach

https://developer.nvidia.com/content/th ... uction-gpu

Or search for oher sorting algorihms in cuda. there is an implementation on a parallel bubble sort.

Re: Kernel for finding the minimum element in the array

can you please give me a simple kernel function which gives you the minimum element in an array.

Re: Kernel for finding the minimum element in the array

Re: Kernel for finding the minimum element in the array

__kernel void u(__global int *A, __global int *B, __global int *C,int k)

{

// Get the index of the current element

int i = get_global_id(0); //this will get you the index

int j;

int v=0;

//Checking the A[i] value with all the values of Set B

//k is the size of set B

for(j=0;j<k;j++)

{

if(A[i] == B[j])

{

v=1;

}

}

if(v == 0)C[i]=A[i];

}

This is the kernel function to compute A - B(A and B are two vectors) but the problem is

size_t global_item_size = s;

size_t local_item_size = s;

s is the size of A array and if i change the global_item_size and the local_item_size i don't get the answer

Re: Kernel for finding the minimum element in the array

In the above kernel function k is the size of B vector