pynvrtc - Python Bindings to NVRTC
The pynvrtc package is a Python binding for NVRTC, the CUDA runtime compilation library from NVIDIA. This library takes CUDA source input and produces NVIDIA PTX output suitable for execution on NVIDIA GPUs on any platform. Please see the CUDA 9.2 documentation for a complete description of NVRTC.
The pynvrtc package does not have any external dependencies and can be
$ pip install pynvrtc
Note, however, that the package does require the NVRTC library to be present at runtime. See below for instructions on how to set the search path.
There are two primary interfaces with pynvrtc; a low-level interface which provides users with direct access to the NVRTC API, and a high-level interface which provides a Pythonic API for the compiler routines in NVRTC.
The low-level interface can be found in the
pynvrtc.interface module. An
instance of the interface can be obtained by calling the
from pynvrtc.interface import NVRTCInterface inter = NVRTCInterface()
By default, the
NVRTCInterface object will attempt to load the NVRTC
shared library from
LD_LIBRARY_PATH on Linux,
PATH on Windows. An optional parameter to the
constructor provides the absolute path to the NVRTC shared library and
overwrites the system search path. For example, on Linux:
from pynvrtc.interface import NVRTCInterface inter = NVRTCInterface('/usr/local/cuda-9.2/lib64/libnvrtc.so')
NOTE: It is important that the specified binary match the architecture of the Python interpreter under which your program is running.
Once an interface object is created, it provides access to all of the NVRTC
API functions as regular Python functions. However, instead of returning a
NVRTC status code, each function returns either a string (for output
functions) or None. If an error occurs within NVRTC, an
exception is raised with the corresponding status code.
Note that the
functions are not exposed. Instead, the
nvrtcGetPTX functions automatically determine the correct size
and return a UTF-8 encoded Python string.
from pynvrtc.interface import NVRTCInterface, NVRTCException src = ... ## Populate CUDA source code inter = NVRTCInterface() try: prog = inter.nvrtcCreateProgram(src, 'simple.cu', , ); inter.nvrtcCompileProgram(prog, ['-ftz=true']) ptx = inter.nvrtcGetPTX(prog) except NVRTCException as e: print('Error: %s' % repr(e))
For clients wanting a higher-level interface to NVRTC, the
pynvrtc.compiler provides such an interface. The usage is similar to
that of the
NVRTCInterface class, but the API is more Pythonic and you do
not need to worry about maintaining NVRTC objects.
from pynvrtc.compiler import Program, ProgramException src = ... ## Populate CUDA source code try: prog = Program(src, 'simple.cu') ptx = prog.compile(['-ftz=1']) except ProgramException as e: print('Error: %s' % repr(e))
Program constructor accepts an optional
path to the NVRTC library.
samples/ptxgen.py for a complete example of a CUDA source to
PTX compiler using the higher-level interface.