IA-64 (Itanium) had a register stack that was used for a lot of the things memory stacks are used for[1]. It's basically a set of virtual registers into a large

IA-64 (Itanium) had a register stack that was used for a lot of the things memory stacks are used for[1]. It's basically a set of virtual registers into a large register file that's then spilled out to main memory as necessary if the stack grows large enough. So I don't think it's an idea that's completely gone away, it's probably just that until relatively recently the complexity involved in doing it with modern code (with deep stacks with large stack frames) was not really a worthwhile use of die space. And now x86 and arm are so thoroughly dominant that other paradigms have difficulty getting traction. [1] https://devblogs.microsoft.com/oldnewthing/20050421-28/?p=35833 https://devblogs.microsoft.com/oldnewthing/20050421-28/?p=35...