STUMAX, STUMAXL Atomic unsigned maximum on word or doubleword in memory, without return This instruction atomically loads a 32-bit word or 64-bit doubleword from memory, compares it against the value held in a register, and stores the larger value back to memory, treating the values as unsigned numbers. STUMAX does not have release semantics. STUMAXL stores to memory with release semantics, as described in Load-Acquire, Store-Release. For information about addressing modes, see Load/Store addressing modes. If PSTATE.DIT is 1, the timing of this instruction is insensitive to the value of the data being loaded or stored. LDUMAX, LDUMAXA, LDUMAXAL, LDUMAXL 1 x 1 1 1 0 0 0 0 1 0 1 1 0 0 0 1 1 1 1 1 0 0 STUMAX <Ws>, [<Xn|SP>] LDUMAX <Ws>, WZR, [<Xn|SP>] Unconditionally 0 1 STUMAXL <Ws>, [<Xn|SP>] LDUMAXL <Ws>, WZR, [<Xn|SP>] Unconditionally 1 0 STUMAX <Xs>, [<Xn|SP>] LDUMAX <Xs>, XZR, [<Xn|SP>] Unconditionally 1 1 STUMAXL <Xs>, [<Xn|SP>] LDUMAXL <Xs>, XZR, [<Xn|SP>] Unconditionally <Ws> Is the 32-bit name of the general-purpose register holding the data value to be operated on with the contents of the memory location, encoded in the "Rs" field. <Xn|SP> Is the 64-bit name of the general-purpose base register or stack pointer, encoded in the "Rn" field. <Xs> Is the 64-bit name of the general-purpose register holding the data value to be operated on with the contents of the memory location, encoded in the "Rs" field.