working with SVE vectors as usual, and happened upon the INDEX instruction. it essentially works sorta like APL's iota function. as in, it generates a monotonically increasing set of values, given a starting value and step to increment by. so e.g.:
; Assume z0 is a 128-bit vector for brevity
INDEX z0.b, #0, #1
will fill all the byte elements of z0 like:
msb[15,14,13,12,11,10,9,8,7,6,5,4,3,2,1,0]lsb
super useful for setting up table indices for use with TBL and TBX in some cases without needing to go to memory or do other shenanigans
