GLU Variants Improve Transformer
Gated Linear Units (arXiv:1612.08083) consist of the component-wise product
of two linear projections, one of which is first passed through a sigmoid
function. Variations on GLU are possible, using different nonlinear (or even
linear) functions in place of sigmoid. We test these variants in the
feed-forward sublayers of the Transformer (arXiv:1706.03762)
sequence-to-sequence model, and find that some of them yield quality
improvements over the typically-used ReLU or GELU activations.