EXTR Extract register This instruction extracts a register from a pair of registers. If PSTATE.DIT is 1: The execution time of this instruction is independent of: The values of the data supplied in any of its registers. The values of the NZCV flags. The response of this instruction to asynchronous exceptions does not vary based on: The values of the data supplied in any of its registers. The values of the NZCV flags. This instruction is used by the alias ROR (immediate) Rn == Rm See below for details of when the alias is preferred. 0 0 1 0 0 1 1 1 0 0 0 0 EXTR <Wd>, <Wn>, <Wm>, #<lsb> 1 1 EXTR <Xd>, <Xn>, <Xm>, #<lsb> if N != sf then UNDEFINED; if sf == '0' && imms<5> == '1' then UNDEFINED; constant integer d = UInt(Rd); constant integer n = UInt(Rn); constant integer m = UInt(Rm); constant integer datasize = 32 << UInt(sf); constant integer lsb = UInt(imms); <Wd> Is the 32-bit name of the general-purpose destination register, encoded in the "Rd" field. <Wn> Is the 32-bit name of the first general-purpose source register, encoded in the "Rn" field. <Wm> Is the 32-bit name of the second general-purpose source register, encoded in the "Rm" field. <lsb> For the 32-bit variant: is the least significant bit position from which to extract, in the range 0 to 31, encoded in the "imms" field. <lsb> For the 64-bit variant: is the least significant bit position from which to extract, in the range 0 to 63, encoded in the "imms" field. <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 first general-purpose source register, encoded in the "Rn" field. <Xm> Is the 64-bit name of the second general-purpose source register, encoded in the "Rm" field. Alias Conditions bits(datasize) result; constant bits(datasize) operand1 = X[n, datasize]; constant bits(datasize) operand2 = X[m, datasize]; constant bits(2*datasize) concat = operand1:operand2; result = concat<(lsb+datasize)-1:lsb>; X[d, datasize] = result;