LDLAR Load LOAcquire register This instruction loads a 32-bit word or 64-bit doubleword from memory, and writes it to a register. If the destination register is not one of WZR or XZR, LDLAR loads from memory with Acquire semantics. For more information about memory ordering semantics, see Load LOAcquire, Store LORelease and Load-Acquire, Load-AcquirePC, and Store-Release. For information about addressing modes, see Load/Store addressing modes. This instruction is a data-independent-time instruction as described in About PSTATE.DIT. 1 x 0 0 1 0 0 0 1 1 0 (1) (1) (1) (1) (1) 0 (1) (1) (1) (1) (1) 0 LDLAR <Wt>, [<Xn|SP>{, #0}] 1 LDLAR <Xt>, [<Xn|SP>{, #0}] if !IsFeatureImplemented(FEAT_LOR) then EndOfDecode(Decode_UNDEF); end; let t : integer{} = UInt(Rt); let n : integer{} = UInt(Rn); let elsize : integer{} = 8 << UInt(size); let regsize : integer{} = if elsize == 64 then 64 else 32; let acquire : boolean = t != 31; let tagchecked : boolean = n != 31; <Wt> Is the 32-bit name of the general-purpose register to be transferred, encoded in the "Rt" field. <Xn|SP> Is the 64-bit name of the general-purpose base register or stack pointer, encoded in the "Rn" field. <Xt> Is the 64-bit name of the general-purpose register to be transferred, encoded in the "Rt" field. var address : bits(64); let dbytes : integer{} = elsize DIV 8; let accdesc : AccessDescriptor = CreateAccDescLOR(MemOp_LOAD, tagchecked, acquire, t); if n == 31 then CheckSPAlignment(); address = SP{64}(); else address = X{64}(n); end; let data : bits(elsize) = Mem{elsize}(address, accdesc); X{regsize}(t) = ZeroExtend{regsize}(data); 2026-03-12 12:23:09 2025-09_rel_asl1