I am developing OpenCL code on Snow Leopard and understand that the OpenCL just-in-time compilation is done by Clang/LLVM. Is the C preprocessor used at all? Is there a way to set preprocessing definitions with the compiler? What definitions exist?
I would like the code to be aware of whether it is compiled for CPU or GPU so I for instance can use printf statements for debugging.
the clBuildProgram API takes compiler arguments (the const char * options parameter).
-D MYMACRO is understood, so is -D MYMACRO=value.
As to what predefined macros, see the OpenCL specification for a full list (Section 6.9). A non exhaustive list:
__FILE____LINE____OPENCL_VERSION__You can also use the OpenCL "preprocessor" to define definitions (like in C):
#define dot3(x1, y1, z1, x2, y2, z2) ((x1)*(x2) + (y1)*(y2) + (z1)*(z2))
(notice the brackets, they are important because you can insert any Expression in the Variables and the expression gets correctly evaluated)
This helps to improve the speed of your Application.
