5.4. Writing Device FunctionsΒΆ

HSA device functions are functions that will run on the device but can only be invoked from a kernel or another device function. Unlike a kernel function, a device function can return a value like normal functions. To define a device function the kwarg device must be set to True in the roc.jit decorator:

from numba import roc

def a_device_function(a, b):
    return a + b

An example of using a device function:

from numba import roc
import numpy as np

def kernel(an_array):
    pos = roc.get_global_id(0)
    if pos < an_array.size:  # Check array boundaries
        an_array[pos] = a_device_function(1, pos) # call device function

@roc.jit(device = True)
def a_device_function(a, b):
    return a + b

n = 16
x = np.zeros(n)

kernel[1, n](x)