LDSETP, LDSETPA, LDSETPAL, LDSETPL Atomic bit set on quadword in memory Atomic bit set on quadword in memory atomically loads a 128-bit quadword from memory, performs a bitwise OR with the value held in a pair of registers on it, and stores the result back to memory. The value initially loaded from memory is returned in the same pair of registers. LDSETPA and LDSETPAL load from memory with acquire semantics. LDSETPL and LDSETPAL store to memory with release semantics. LDSETP has neither acquire nor release semantics. If PSTATE.DIT is 1, the timing of this instruction is insensitive to the value of the data being loaded or stored. 0 0 0 1 1 0 0 1 1 0 0 1 1 0 0 0 0 LDSETP <Xt1>, <Xt2>, [<Xn|SP>] 1 0 LDSETPA <Xt1>, <Xt2>, [<Xn|SP>] 1 1 LDSETPAL <Xt1>, <Xt2>, [<Xn|SP>] 0 1 LDSETPL <Xt1>, <Xt2>, [<Xn|SP>] if !HaveLSE128() then UNDEFINED; if Rt == '11111' then UNDEFINED; if Rt2 == '11111' then UNDEFINED; integer t = UInt(Rt); integer t2 = UInt(Rt2); integer n = UInt(Rn); MemAtomicOp op; case opc of when '001' op = MemAtomicOp_BIC; when '011' op = MemAtomicOp_ORR; boolean acquire = A == '1'; boolean release = R == '1'; boolean tagchecked = n != 31; <Xt1> Is the 64-bit name of the first general-purpose register to be transferred, encoded in the "Rt" field. <Xt2> Is the 64-bit name of the second general-purpose register to be transferred, encoded in the "Rt2" field. <Xn|SP> Is the 64-bit name of the general-purpose base register or stack pointer, encoded in the "Rn" field. bits(64) address; bits(64) value1 = X[t, 64]; bits(64) value2 = X[t2, 64]; bits(128) data; bits(128) store_value; AccessDescriptor accdesc = CreateAccDescAtomicOp(op, acquire, release, tagchecked); if n == 31 then CheckSPAlignment(); address = SP[]; else address = X[n, 64]; store_value = if BigEndian(accdesc.acctype) then value1:value2 else value2:value1; bits(128) comparevalue = bits(128) UNKNOWN; // Irrelevant when not executing CAS data = MemAtomic(address, comparevalue, store_value, accdesc); if BigEndian(accdesc.acctype) then X[t, 64] = data<127:64>; X[t2, 64] = data<63:0>; else X[t, 64] = data<63:0>; X[t2, 64] = data<127:64>;