LDAPURH Load-acquire RCpc register halfword (unscaled) This instruction calculates an address from a base register and an immediate offset, loads a halfword from memory, zero-extends it, and writes it to a register. If the destination register is not one of WZR or XZR, LDAPURH loads from memory with AcquirePC semantics. For more information about memory ordering semantics, see 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. 0 1 0 1 1 0 0 1 0 1 0 0 0 LDAPURH <Wt>, [<Xn|SP>{, #<simm>}] if !IsFeatureImplemented(FEAT_LRCPC2) then EndOfDecode(Decode_UNDEF); end; let offset : bits(64) = SignExtend{}(imm9); <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. <simm> Is the optional signed immediate byte offset, in the range -256 to 255, defaulting to 0 and encoded in the "imm9" field. let t : integer{} = UInt(Rt); let n : integer{} = UInt(Rn); let datasize : integer{} = 16; let acquirepc : boolean = TRUE; let tagchecked : boolean = n != 31; var address : bits(64); let accdesc : AccessDescriptor = CreateAccDescLDAcqPC(tagchecked, acquirepc, t); if n == 31 then CheckSPAlignment(); address = SP{64}(); else address = X{64}(n); end; address = AddressAdd(address, offset, accdesc); let data : bits(datasize) = Mem{datasize}(address, accdesc); X{32}(t) = ZeroExtend{32}(data); 2026-03-26 20:27:25 2026-03_rel