support for math_functions.h

[mxmlnkn]

I got the following when porting by search and replace from CUDA to cupla:

error: there are no arguments to ‘max’ that depend on a template parameter, so a declaration of ‘max’ must be available

cupla should provide such a function (also simple min was missing). CUDA provides this in math_functions.h which is included by common_functions.h which is included by cuda_runtime.h. I didn't include this manually, but I guess nvcc did include this for me just like it is unnecessary to write #include <cuda.h> in a .cu file.

I guess min and max are not the only missing functions, henceforth the title.

The problem is, that std::max and so on can't be called from a device function.

Current workaround:

#ifndef max
#   define max( a, b ) ( ((a) > (b)) ? (a) : (b) )
#endif
#ifndef min
#   define min( a, b ) ( ((a) < (b)) ? (a) : (b) )
#endif