PACDB, PACDZB Pointer Authentication Code for data address, using key B This instruction computes and inserts a Pointer Authentication Code for a data address, using a modifier and key B. The address is in the general-purpose register that is specified by <Xd>. The modifier is: In the general-purpose register or stack pointer that is specified by <Xn|SP> for PACDB. The value zero, for PACDZB. 1 1 0 1 1 0 1 0 1 1 0 0 0 0 0 1 0 0 0 1 1 0 PACDB <Xd>, <Xn|SP> 1 1 1 1 1 1 PACDZB <Xd> if !IsFeatureImplemented(FEAT_PAuth) then UNDEFINED; boolean source_is_sp = FALSE; constant integer d = UInt(Rd); constant integer n = UInt(Rn); if Z == '0' then // PACDB if n == 31 then source_is_sp = TRUE; else // PACDZB if n != 31 then UNDEFINED; <Xd> Is the 64-bit name of the general-purpose destination register, encoded in the "Rd" field. <Xn|SP> Is the 64-bit name of the general-purpose source register or stack pointer, encoded in the "Rn" field. if source_is_sp then X[d, 64] = AddPACDB(X[d, 64], SP[]); else X[d, 64] = AddPACDB(X[d, 64], X[n, 64]);