In which memory space are Built-in Variables stored?
in global, local, shared, registers ?
such as: gridDim, blockIdx, blockDim, threadIdx, warpSize.
So if I access threadIdx.x or blockDim.x for example very often during a kernel, should I better copy it to a register?
//use threadIdx.x directly multiple times
unsigned int threadId = threadIdx.x; //use threadIdx multiple times
There are no informations about this in the Nvidia programming guide!
Till now I only used new registers if my desired threadId needs to be calculated and cannot directly retreived by for example threadIdx.x
Edit: In some other threads I found they should reside in shared memory, so this thread can be closed