Pointers from Shared Memory, Constant memory into global memory

Accelerated Computing CUDA CUDA Programming and Performance
1

Hi,

I would like to do the following. Is it safe ?

constant int * constMemToGlobalMem[1024];

constMemToGlobalMem contains integer pointer in global memory space. i.e. I’m strong the address of integer arrays in global memory space in constant memory space.

global void myKernel()
{
shared int * myThreadBlockPtr = constMemToGlobalMem[blockId.x]; // <------------ Here the warning is produced.
// Is the above statement legal. It is a shared memory pointer pointing to an address in constant memory space that points to global memory space ?
myThreadBlockPtr[threadId.x] = 10;
}

When I compile my code I get the following warning ./test.cu(17): Warning: Cannot tell what pointer points to, assuming global memory space

Regards,
Suresh Kumar

2

Yes, it’s safe. In this case, nvcc has assumed correctly – your pointers inside the constMemToGlobalMem array refer to the global memory space.

3

Thank you. Is there any way for the me to tell the compiler that the pointer is supposed to point to a constant space or global memory space or the shared memory space ?