Arithmetic Shift Right Variable shifts a register value right by a variable number of bits, shifting in copies of its sign bit, and writes the result to the destination register. The remainder obtained by dividing the second source register by the data size defines the number of bits by which the first source register is right-shifted.
This instruction is used by the alias ASR (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 | 0 | 0 | 1 | 1 | 0 | 1 | 0 | 1 | 1 | 0 | Rm | 0 | 0 | 1 | 0 | 1 | 0 | Rn | Rd | ||||||||||||
| S | op2 | ||||||||||||||||||||||||||||||
integer d = UInt(Rd); integer n = UInt(Rn); integer m = UInt(Rm); constant integer datasize = 32 << UInt(sf); ShiftType shift_type = DecodeShift(op2);
| <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 holding a shift amount from 0 to 31 in its bottom 5 bits, 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 holding a shift amount from 0 to 63 in its bottom 6 bits, encoded in the "Rm" field. |
bits(datasize) result; bits(datasize) operand2 = X[m, datasize]; result = ShiftReg(n, shift_type, UInt(operand2) MOD datasize, datasize); X[d, datasize] = result;
If PSTATE.DIT is 1:
Internal version only: aarchmrs v2023-12_rel, pseudocode v2023-12_rel, sve v2023-12_rel ; Build timestamp: 2023-12-15T16:46
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