Check Subset, setting flags and conditionally unseal checks if a capability is a subset of a testing capability. If the capability is a valid sealed capability, and the testing capability is a valid unsealed capability, the operation unseals the capability and writes it to the destination Capability register. The instruction updates the condition flags based on the result.
| 31 | 30 | 29 | 28 | 27 | 26 | 25 | 24 | 23 | 22 | 21 | 20 | 19 | 18 | 17 | 16 | 15 | 14 | 13 | 12 | 11 | 10 | 9 | 8 | 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 |
| 1 | 1 | 0 | 0 | 0 | 0 | 1 | 0 | 1 | 1 | 0 | Cm | 1 | 0 | 0 | 0 | 1 | 0 | Cn | Cd | ||||||||||||
| opc | |||||||||||||||||||||||||||||||
integer d = UInt(Cd); integer n = UInt(Cn); integer m = UInt(Cm);
| <Cd> |
Is the capability name of the destination register, encoded in the "Cd" field. |
| <Cn|CSP> |
Is the capability name of the first source register or stack pointer, encoded in the "Cn" field. |
| <Cm|CSP> |
Is the capability name of the second source register or stack pointer, encoded in the "Cm" field. |
CheckCapabilitiesEnabled(); Capability operand1 = if n == 31 then CSP[] else C[n]; Capability testingcap = if m == 31 then CSP[] else C[m]; Capability result = operand1; if CapIsSubSetOf(operand1,testingcap) && CapGetTag(operand1) == CapGetTag(testingcap) then if CapIsTagSet(testingcap) && !CapIsSealed(testingcap) && CapIsTagSet(operand1) && CapIsSealed(operand1) then result = CapUnseal(operand1); PSTATE.<N,Z,C,V> = '1000'; else PSTATE.<N,Z,C,V> = '0000'; C[d] = result;
Internal version only: isa v32.13, AdvSIMD v29.04, pseudocode morello-2022-01_rc2, capabilities morello-2022-01_rc2 ; Build timestamp: 2022-01-11T11:23
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