Bitwise Bit Clear (immediate) on flags field performs a bitwise AND of the flags field of a capability and the complement of an immediate value and writes the result to the flags field of the destination Capability register. If the source capability is sealed, the Capability Tag written to the destination Capability register is cleared.
| 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 | 1 | imm8 | 0 | 0 | 0 | Cn | Cd | |||||||||||||||
integer n = UInt(Cn); integer d = UInt(Cd); bits(8) mask = imm8;
| <Cd|CSP> |
Is the capability name of the destination register or stack pointer, encoded in the "Cd" field. |
| <Cn|CSP> |
Is the capability name of the source register or stack pointer, encoded in the "Cn" field. |
| <imm> |
Is the unsigned immediate operand, in the range 0 to 255, encoded in the "imm8" field. |
CheckCapabilitiesEnabled(); Capability operand = if n == 31 then CSP[] else C[n]; bits(64) oldvalue = CapGetValue(operand); bits(8) newflags = oldvalue<63:56> AND NOT mask; bits(64) newvalue = newflags : oldvalue<55:0>; Capability result = CapSetFlags(operand,newvalue); if CapIsSealed(operand) then result = CapWithTagClear(result); if d == 31 then CSP[] = result; else 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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