REV64 Reverse bytes This instruction reverses the byte order in a 64-bit general-purpose register. When assembling for Armv8.2, an assembler must support this pseudo-instruction. It is OPTIONAL whether an assembler supports this pseudo-instruction when assembling for an architecture earlier than Armv8.2. REV 1 1 0 1 1 0 1 0 1 1 0 0 0 0 0 0 0 0 0 0 1 1 REV64 <Xd>, <Xn> REV <Xd>, <Xn> Never <Xd> Is the 64-bit name of the general-purpose destination register, encoded in the "Rd" field. <Xn> Is the 64-bit name of the general-purpose source register, encoded in the "Rn" field. 2026-03-26 20:27:25 2026-03_rel