Andy, Scott-
8 cycles, even parity in bits 0-4, X not trashed. Lucky thing I emailed to
Scott to establish priority on the algorithm. :-)
But in all fairness, taking into account the amount of time it takes to type
in the Warren-style documentation it was probably a pretty even heat.
Note that you can bring it down to 7 cycles by working in X instead of fsr,
but who wants to roach their data?

Brian


 swapf X,W     ;   fsr:           W:
 xorwf X,W     ;-----------    -----------
 movwf   fsr     ;   ABCDEFGH    ABCDEFGH
                        ;xorEFGHABCD    xorEFGHABCD
                        ;
 rrf     fsr,F   ;   -ABCDEFG       ABCDEFGH
                        ;xor-EFGHABC    xorEFGHABCD
                        ;
 rrf     fsr,F   ;   --ABCDEF       ABCDEFGH
                        ;xor--EFGHAB    xorEFGHABCD
                        ;
 xorwf   fsr,F   ;   --ABCDEF       ABCDEFGH
                        ;xor--EFGHAB    xorEFGHABCD
                        ;xorABCDEFGH
                        ;xorEFGHABCD
                        ;
 rrf     fsr,W   ;   --ABCDEF       ---ABCDE
                        ;xor--EFGHAB    xor---EFGHA
                        ;xorABCDEFGH    xor-ABCDEFG
                        ;xorEFGHABCD    xor-EFGHABC
                        ;
 xorwf   fsr,F   ;   --ABCDEF       ---ABCDE
                        ;xor--EFGHAB    xor---EFGHA
                        ;xorABCDEFGH    xor-ABCDEFG
                        ;xorEFGHABCD    xor-EFGHABC
                        ;xor---ABCDE
                        ;xor---EFGHA
                        ;xor-ABCDEFG
                        ;xor-EFGHABC