@regehr @resistor @barrelshifter anyway I know about the funnel variants mostly from the HW side, e.g. stuff like this https://iccd.et.tudelft.nl/2008/proceedings/626huntzicker.pdf ("Energy-Delay Tradeoffs in 32-bit Static Shifter Designs", Huntzicker et al. 2008). Data-reversal shifters are e.g. in https://web.archive.org/web/20170706054724id_/https://www.princeton.edu/~rblee/ELE572Papers/Fall04Readings/Shifter_Schulte.pdf ("Design alternatives for barrel shifters", Pillmeier et al. 2002)