Operation

CheckCapabilitiesEnabled(); VirtualAddress base; Capability data; boolean rt_unknown = FALSE; boolean rn_unknown = FALSE; if s == t then Constraint c = ConstrainUnpredictable(Unpredictable_DATAOVERLAP); assert c IN {Constraint_UNKNOWN, Constraint_NONE, Constraint_UNDEF, Constraint_NOP}; case c of when Constraint_UNKNOWN rt_unknown = TRUE; // store UNKNOWN value when Constraint_NONE rt_unknown = FALSE; // store original value when Constraint_UNDEF UNDEFINED; when Constraint_NOP EndOfInstruction(); if s == n && n != 31 then Constraint c = ConstrainUnpredictable(Unpredictable_BASEOVERLAP); assert c IN {Constraint_UNKNOWN, Constraint_NONE, Constraint_UNDEF, Constraint_NOP}; case c of when Constraint_UNKNOWN rn_unknown = TRUE; // address is UNKNOWN when Constraint_NONE rn_unknown = FALSE; // address is original base when Constraint_UNDEF UNDEFINED; when Constraint_NOP EndOfInstruction(); if rn_unknown then base = VirtualAddress UNKNOWN; else base = BaseReg[n]; if rt_unknown then data = Capability UNKNOWN; else data = C[t]; bits(64) cap_required = CAP_PERM_STORE; if CapIsTagSet(data) then cap_required = cap_required OR CAP_PERM_STORE_CAP; if CapIsLocal(data) then cap_required = cap_required OR CAP_PERM_STORE_LOCAL; bits(64) addr = VAddress(base); VACheckAddress(base, addr, CAPABILITY_DBYTES, cap_required, acctype); bit status = '1'; if AArch64.ExclusiveMonitorsPass(addr, CAPABILITY_DBYTES) then MemC[addr, acctype] = data; status = ExclusiveMonitorsStatus(); X[s] = ZeroExtend(status, 32);