RMIF Rotate, mask insert flags This instruction performs a rotation right of a value held in a general-purpose register by an immediate value, and then inserts a selection of the bottom four bits of the result of the rotation into the PSTATE flags, under the control of a second immediate mask. This instruction is a data-independent-time instruction as described in About PSTATE.DIT. 1 0 1 1 1 0 1 0 0 0 0 0 0 0 0 1 0 RMIF <Xn>, #<shift>, #<mask> if !IsFeatureImplemented(FEAT_FlagM) then EndOfDecode(Decode_UNDEF); end; let imm : integer{} = UInt(imm6); let flagmask : bits(4) = mask; let n : integer{} = UInt(Rn); <Xn> Is the 64-bit name of the general-purpose source register, encoded in the "Rn" field. <shift> Is the shift amount, in the range 0 to 63, defaulting to 0 and encoded in the "imm6" field. <mask> Is the flag bit mask, an immediate in the range 0 to 15, which selects the bits that are inserted into the NZCV condition flags, encoded in the "mask" field. let reg : bits(64) = X{}(n); let flags : bits(4) = (reg::reg)[imm+3:imm]; if flagmask[3] == '1' then PSTATE.N = flags[3]; end; if flagmask[2] == '1' then PSTATE.Z = flags[2]; end; if flagmask[1] == '1' then PSTATE.C = flags[1]; end; if flagmask[0] == '1' then PSTATE.V = flags[0]; end; 2026-03-12 12:23:09 2025-09_rel_asl1