Basic support for OpenCL (experimental)

Basic support for OpenCL

Problem: OpenCL cannot import stdint.h. Temporary fix: define custom opencl_stdint.h (defines currently only int64_t `)

TODO:

• implement opencl_stdint.h
• implement shard_mem, textures, built-in functions
• avoid CUDA intrinsics (fast_div)

pystencils/backends/cbackend.py

@@ -168,11 +168,13 @@ class CBackend:
         return result
 
     def _print(self, node):
+        if isinstance(node, str):
+            return node
         for cls in type(node).__mro__:
             method_name = "_print_" + cls.__name__
             if hasattr(self, method_name):
                 return getattr(self, method_name)(node)
-        raise NotImplementedError(self.__class__ + " does not support node of type " + str(type(node)))
+        raise NotImplementedError(str(self.__class__) + " does not support node of type " + str(type(node)))
 
     def _print_Type(self, node):
         return str(node)