Yeah, 'materialism' isn't perhaps the best word since the being made of atoms part is often irrelevant in Egan's work. The connotation of materialism is being made of the math that the atoms obey, without any rule-excepting magic, and Egan has that in spades when cogsci is otherwise usually the part in even otherwise hard SF where whatever magical asspull the author needs to move the plot happens.

The idea of singularity and AI originates with Stanislaw Lem. Vinge was following his lead.

I guess you're talking about Golem XIV? I was talking about what early MIRI was inspired by, and they talked a bunch about Vinge and pretty much nothing about Lem. And I. J. Good's 1965 Ultraintelligent Machine paper predates Golem.