Table Of Contents
Table Of Contents

CudaModule

class mxnet.rtc.CudaModule(source, options=(), exports=())[source]

Compile and run CUDA code from Python.

In CUDA 7.5, you need to prepend your kernel definitions with ‘extern “C”’ to avoid name mangling:

source = r'''
extern "C" __global__ void axpy(const float *x, float *y, float alpha) {
    int i = threadIdx.x + blockIdx.x * blockDim.x;
    y[i] += alpha * x[i];
}
'''
module = mx.rtc.CudaModule(source)
func = module.get_kernel("axpy", "const float *x, float *y, float alpha")
x = mx.nd.ones((10,), ctx=mx.gpu(0))
y = mx.nd.zeros((10,), ctx=mx.gpu(0))
func.launch([x, y, 3.0], mx.gpu(0), (1, 1, 1), (10, 1, 1))
print(y)

Starting from CUDA 8.0, you can instead export functions by name. This also allows you to use templates:

source = r'''
template<typename DType>
__global__ void axpy(const DType *x, DType *y, DType alpha) {
    int i = threadIdx.x + blockIdx.x * blockDim.x;
    y[i] += alpha * x[i];
}
'''
module = mx.rtc.CudaModule(source, exports=['axpy<float>', 'axpy<double>'])
func32 = module.get_kernel("axpy<float>", "const float *x, float *y, float alpha")
x = mx.nd.ones((10,), dtype='float32', ctx=mx.gpu(0))
y = mx.nd.zeros((10,), dtype='float32', ctx=mx.gpu(0))
func32.launch([x, y, 3.0], mx.gpu(0), (1, 1, 1), (10, 1, 1))
print(y)

func64 = module.get_kernel("axpy<double>", "const double *x, double *y, double alpha")
x = mx.nd.ones((10,), dtype='float64', ctx=mx.gpu(0))
y = mx.nd.zeros((10,), dtype='float64', ctx=mx.gpu(0))
func32.launch([x, y, 3.0], mx.gpu(0), (1, 1, 1), (10, 1, 1))
print(y)
Parameters:
  • source (str) – Complete source code.
  • options (tuple of str) – Compiler flags. For example, use “-I/usr/local/cuda/include” to add cuda headers to include path.
  • exports (tuple of str) – Export kernel names.
__init__(source, options=(), exports=())[source]

Initialize self. See help(type(self)) for accurate signature.

Methods

__init__(source[, options, exports]) Initialize self.
get_kernel(name, signature) Get CUDA kernel from compiled module.