conditional select

ARM64's csel, which picks one of two registers depending on the flags and writes it to a third, with no jump.

csel xd, xn, xm, cond writes xn to xd if cond holds and xm otherwise; csinc, csinv and csneg variants increment, invert or negate the second choice (cset is csinc with zero registers).

Examples

ARM64 cmp w0, w1 then csel w0, w0, w1, lt keeps the smaller of the two.