[icelusxl]

> "rotate and mask" series of instructions

Sounds a lot like the PowerPC's rlwinm instruction.

The PowerPC 600 series, part 5: Rotates and shifts

https://devblogs.microsoft.com/oldnewthing/20180810-00/?p=99...

[throwawaylinux]

SPU is significantly derivative from PowerPC, so that's quite expected.