Subtract with carry
This instruction subtracts a register value and the value of NOT (Carry flag) from a register value, and writes the result to the destination register.
This instruction is used by the alias NGC.
| 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 | 1 | 0 | 1 | 1 | 0 | 1 | 0 | 0 | 0 | 0 | Rm | 0 | 0 | 0 | 0 | 0 | 0 | Rn | Rd | ||||||||||||
| op | S | ||||||||||||||||||||||||||||||
let d : integer{} = UInt(Rd); let n : integer{} = UInt(Rn); let m : integer{} = UInt(Rm); let datasize : integer{} = 32 << UInt(sf);
| <Wd> |
Is the 32-bit name of the general-purpose destination register, encoded in the "Rd" field. |
| <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. |
| <Xd> |
Is the 64-bit name of the general-purpose destination register, encoded in the "Rd" 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. |
| Alias | Is preferred when |
|---|---|
| NGC | Rn == '11111' |
let operand1 : bits(datasize) = X{}(n); let operand2 : bits(datasize) = NOT(X{datasize}(m)); var result : bits(datasize); (result, -) = AddWithCarry{datasize}(operand1, operand2, PSTATE.C); X{datasize}(d) = result;
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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