if I have a structure like this:
struct x
{
cl_mem a;
cl_mem b;
};
struct x cpu_struct_x;
cl_mem gpu_struct_x;
gpu_struct_x = clCreateBuffer(..., sizeof(struct x), ...);
cpu_struct_x.a = clCreateBuffer(..., sizeof(cl_uint) * N, ...);
cpu_struct_x.b = clCreateBuffer(..., sizeof(cl_float) * M, ...);
and on the GPU:
struct x
{
uint *a;
float *b;
};
can I do:
clEnqueueWriteBuffer(..., gpu_struct_x, ..., sizeof(struct x), &cpu_struct_x, ...); ?
I need this, because I have many lists, and I just want to pass a pointer to a structure which contains pointers to all the lists to the kernels.
I thought this, because I understand cl_mem objects as simple pointers, and I'm not sure that's true...
Thank you 
[edit] And what about pointer arithmetics? If I want to copy from element 2 can I do
clEnqueueReadBuffer(..., cl_mem_vector + sizeof(dim_element) * 2 , ...); ?
-I found out I can't do that, so how could I read only a part of a vector, starting with index N ?
he didn't notice that, thank you
And about the cl_mems? if the kernel reads a a cl_mem object from a struct like the one above, does it interpret it correctly as a memory location, or does passing the cl_mem as a parameter for the kernel change it in a way, so the significance of the bits is different between cl_mem on host and pointer on device?
that's bad, I was hoping it could work 
so the only way to send cl_mems' is though kernel parameters?
Originally posted by: mihzaha that's bad, I was hoping it could work
I am sure no implementor will support your request forever.
so the only way to send cl_mems' is though kernel parameters?
Remember you are sending data containing cl_mem not cl_mem.
I hope I'm not to insistent Please forgive me. I'm very new and I didn't quite understand the language.
I ment that it's bad for me, because I already did the structures with that organisation, not that the implementation is bad 
And it's not a request, it just was an idea I hope could have worked.
I'll try to explain what I'm trying to do:
-I have many arrays (9 arrays) and a few other parameters (they all reside in the device memory).
-In one kernel I need 2 arrays in the general case, but once in a while I have to do something complicated and use all the other arrays.
-I thought it would be a waste to send every time 9 pointers to the arrays + 9 values characterizing the arrays, so I wanted to only send the arrays I want (2) + a pointer to a structure residing in global memory containing pointers to all the other arrays and parameters, in case I need to go the long way.
Since I saw that I can pass as kernel parameter something like (sizeof(cl_mem), cl_mem) and read it like (__global *pointer_to_array), I imagined that cl_mem is something like void*, so I thought to make a structure of cl_mems, but you say it's totally illegal.
If I'm not to insistent I would like to know what is that object and how can I sent the pointers as I mentioned.
Mihai
