What can you do to help?

OpenCL built-ins

I have intentionally put off filling out all of the OpenCL built-in functions.

If you see an error like:

  File "/Users/sean/indigo_workspace/Clyther/clyther/", line 249, in translate
    eval(redirect_error_to_function) #use the @cly.developer function decorator to turn this off and see stack trace ...
  File "examples/", line 16, in <module>
    a[0] = clrt.clamp(x, 0, 1)
AttributeError: 'module' object has no attribute 'clamp'

Then I have not yet added this function definition to the CLyther runtime module. Fortunately this is easy for you!

To add this to CLyther you can define clamp like so:

import opencl as cl
from clyther.rttt import RuntimeFunction, RuntimeType, gentype, sgentype, ugentype

clamp = RuntimeFunction('clamp', # Name of the function
                        lambda argtype, *args: argtype, # Return type.
                        gentype(), sgentype(), sgentype(), # Argument types
                        doc='Returns min(max(x, minval), maxval)',  # Docstrng
                        emulate=lambda x, minval, maxval : min(max(x, minval), maxval # Pure python function for emulation mode.

Once you get this working you can put it in the Python clyther.runtime module following the Nice Git development Model and send me a pull request. Or send me a patch file via email

If the function has an existing python equivalent. i.e. acos then you could specify the builtin argument:

acos = RuntimeFunction('acos', # Name of the function
                        lambda argtype: argtype, # Return type.
                        gentype() # Argument types
                        doc='Returns acos(value)',  # Docstring
                        builtin=math.acos # Alternate function

This will allow clyther.runtime.acos() and math.acos() to be used interchangeably.


My goal is to make OpenCL as easy and friendly to use as possible. If you get an error that is not intuitive please post an issue on the GitHub issue tracker.

Transformation Pipeline

CLyther transforms a Python ast into an OpecnCL ast and then compiles it using OpenCL for Python. The ast transformation pipline can be found at clyther.pipeline.


I would like to get a chunk of the core numpy functionality reproduced.


I have just whipped up the documentation and I am notorious for my spelling typos. Please let me know! All documentation and other input is most welcome.

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