Interestingly, it appears based on https://en.wikipedia.org/wiki/Intel_iAPX_432#The_project's_failures https://en.wikipedia.org/wiki/Intel_iAPX_432#The_project'

Interestingly, it appears based on https://en.wikipedia.org/wiki/Intel_iAPX_432#The_project's_failures https://en.wikipedia.org/wiki/Intel_iAPX_432#The_project's_f... the procedure call instruction was a heavyweight thing designed to maximise features and it could branch much more quickly - but their compilers didn't handle that out of the box.