Subtract immediate value
This instruction subtracts an optionally-shifted immediate value from a register value, and writes the result to the destination register.
| 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 | 0 | 0 | 0 | 1 | 0 | sh | imm12 | Rn | Rd | |||||||||||||||||||
| op | S | ||||||||||||||||||||||||||||||
constant integer d = UInt(Rd); constant integer n = UInt(Rn); constant integer datasize = 32 << UInt(sf); constant bits(24) imm = if sh == '0' then Zeros(12):imm12 else imm12:Zeros(12);
| <Wd|WSP> |
Is the 32-bit name of the destination general-purpose register or stack pointer, encoded in the "Rd" field. |
| <Wn|WSP> |
Is the 32-bit name of the source general-purpose register or stack pointer, encoded in the "Rn" field. |
| <imm> |
Is an unsigned immediate, in the range 0 to 4095, encoded in the "imm12" field. |
| <shift> |
Is the optional left shift to apply to the immediate, defaulting to LSL #0 and
encoded in
|
| <Xd|SP> |
Is the 64-bit name of the destination general-purpose register or stack pointer, encoded in the "Rd" field. |
| <Xn|SP> |
Is the 64-bit name of the source general-purpose register or stack pointer, encoded in the "Rn" field. |
constant bits(datasize) operand1 = if n == 31 then SP[datasize] else X[n, datasize]; constant bits(datasize) operand2 = ZeroExtend(imm, datasize); bits(datasize) result; (result, -) = AddWithCarry(operand1, NOT(operand2), '1'); if d == 31 then SP[64] = ZeroExtend(result, 64); else X[d, datasize] = result;
If PSTATE.DIT is 1:
Internal version only: aarchmrs v2024-12_rel, pseudocode v2024-12_rel ; Build timestamp: 2024-12-15T22:18
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