"register" keyword in CUDA
cuda
Solution
You can use `register` in CUDA C/C++ if you want to. In any context, it is only a hint to the compiler. It may be ignored. There is no stated guarantee that it does anything at all.
I think these statements are pretty much true for most language implementations of `register`.
I also think it's quite likely that the compiler can do a better job than you can of deciding what should be in registers, and appropriate priority.
The typical CUDA C/C++ mechanisms for controlling register usage work at a higher level, they are:
- the `-maxrregcount` compile switch
- the launch bounds directive.
Problem
I have a large program that uses all the registers I allocated per thread (64) and spills to local memory. I would like to be able to tell the compiler which variables should remain in registers at all cost, and which ones I don't really care about. Does the "register" C/C++ keyword work in nvcc? Is there a different mechanism perhaps? Thanks!