from akida.core import (Layer, LayerParams, LayerType)
[docs]
class Shiftmax(Layer):
"""A function similar to the softmax.
Instead of using e as base, it uses 2 and a shift. So we replace
.. math::
softmax(x_i) = \\frac{e^{x_i}}{sum(e^{x_k})}
with
.. math::
shiftmax(x_i) = \\frac{2^{x_i}}{round(log2(sum(2^{x_k})))}
This is evaluated with a shift.
Args:
output_bits (int, optional): output bitwidth. Defaults to 8.
buffer_bits (int, optional): internal bitwidth. Defaults to 32.
post_op_buffer_bits (int, optional): internal bitwidth for post operations. Defaults to 32.
"""
def __init__(self,
output_bits=8,
buffer_bits=32,
post_op_buffer_bits=32,
name=""):
try:
params = LayerParams(
LayerType.Shiftmax, {
"output_bits": output_bits,
"buffer_bits": buffer_bits,
"post_op_buffer_bits": post_op_buffer_bits,
})
# Call parent constructor to initialize C++ bindings
# Note that we invoke directly __init__ instead of using super, as
# specified in pybind documentation
Layer.__init__(self, params, name)
except BaseException:
self = None
raise