Conditional compare negative (register)
This instruction sets the value of the condition flags to the result of the comparison of a register value and the inverse of another register value if the condition is TRUE, and an immediate value otherwise.
| 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 |
| sf | 0 | 1 | 1 | 1 | 0 | 1 | 0 | 0 | 1 | 0 | Rm | cond | 0 | 0 | Rn | 0 | nzcv | ||||||||||||||
| op | S | o2 | o3 | ||||||||||||||||||||||||||||
let n : integer{} = UInt(Rn); let m : integer{} = UInt(Rm); let datasize : integer{} = 32 << UInt(sf); let condition : bits(4) = cond; var flags : bits(4) = nzcv;
| <Wn> |
Is the 32-bit name of the first general-purpose source register, encoded in the "Rn" field. |
| <Wm> |
Is the 32-bit name of the second general-purpose source register, encoded in the "Rm" field. |
| <nzcv> |
Is the flag bit specifier, an immediate in the range 0 to 15, giving the alternative state for the 4-bit NZCV condition flags, encoded in the "nzcv" field. |
| <Xn> |
Is the 64-bit name of the first general-purpose source register, encoded in the "Rn" field. |
| <Xm> |
Is the 64-bit name of the second general-purpose source register, encoded in the "Rm" field. |
if ConditionHolds(condition) then let operand1 : bits(datasize) = X{}(n); let operand2 : bits(datasize) = X{datasize}(m); (-, flags) = AddWithCarry{datasize}(operand1, operand2, '0'); end; PSTATE.[N,Z,C,V] = flags;
This instruction is a data-independent-time instruction as described in About PSTATE.DIT.
2026-03_rel 2026-03-26 20:48:11
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