Archives Discussions

[spectral]

Hi,

I'm trying to work with string (array of char) with OpenCL.

Do you think it is possible to do ?

Something like :

1 - Pass a char buffer to a kernel
2 - Put string into the char array (strcat, strcpy)
3 - Convert integer and float to string

etc ...

Thanks 

[Sheeep]

1 - you have to use cl_char instead of char in Hostcode

2-  in host code:

           cl_char host_char[stringname.length()];

           const *char pointer = stringname.c_str();

           for(int i=0;i<stringname.length();i++){

                 host_char=   pointer ;    

           }

3 - to convert int and float you string s=""+int/float or use sstream. Note: strings are only availible in hostcode:

#include <sstream>

stringstream converter;

int i=100;

std::string s;

converter<<i;

converter>>s;

converter.clear();

you can do the same with floats

[spectral]

Thanks but,

I don't need the 'host' code I need the 'kernel' code ... can you help me wth this ?

[Sheeep]

you can't use strings in the kernel...

string is a additional class in c++, which is not supported in opencl.

you have to use char array. but be carefull, you cannot use arrays with dynamic length in opencl.

so you have to know, how long you char array wil be, before you start the kernel.

psydocode:

__kernel void example(__global char* in, __global char *out, __global int *length_in, __global int* length_out){

          for(int i=0;i< length_out[0];i+=2){

                out[ i]=in[ i];

                out[i+1]=in[ i];

          }

}

in this case length_out =2* length_in

note that worksize 1. so it don't work parallen and may be slow.

example:

in =hello; length_in=5;

out_length=10;

run kernel

--> out=hheelloo;

[genaganna]

Originally posted by: viewon01 Hi,

I'm trying to work with string (array of char) with OpenCL.

Do you think it is possible to do ?

Something like :

1 - Pass a char buffer to a kernel 2 - Put string into the char array (strcat, strcpy) 3 - Convert integer and float to string

etc ...

  You can write kernels to implement such fuction.