Unsigned absolute difference and accumulate long (bottom)
Compute the absolute difference between even-numbered unsigned elements of the second source vector and corresponding elements of the first source vector, and destructively add to the overlapping double-width elements of the addend vector. This instruction is unpredicated.
| 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 |
| 0 | 1 | 0 | 0 | 0 | 1 | 0 | 1 | size | 0 | Zm | 1 | 1 | 0 | 0 | 1 | 0 | Zn | Zda | |||||||||||||
| U | T | ||||||||||||||||||||||||||||||
if !HaveSVE2() && !HaveSME() then UNDEFINED; if size == '00' then UNDEFINED; constant integer esize = 8 << UInt(size); integer n = UInt(Zn); integer m = UInt(Zm); integer da = UInt(Zda);
| <Zda> |
Is the name of the third source and destination scalable vector register, encoded in the "Zda" field. |
| <T> |
Is the size specifier,
encoded in
|
| <Zn> |
Is the name of the first source scalable vector register, encoded in the "Zn" field. |
| <Tb> |
Is the size specifier,
encoded in
|
| <Zm> |
Is the name of the second source scalable vector register, encoded in the "Zm" field. |
CheckSVEEnabled(); constant integer VL = CurrentVL; constant integer elements = VL DIV esize; bits(VL) operand1 = Z[n, VL]; bits(VL) operand2 = Z[m, VL]; bits(VL) result = Z[da, VL]; for e = 0 to elements-1 integer element1 = UInt(Elem[operand1, 2*e + 0, esize DIV 2]); integer element2 = UInt(Elem[operand2, 2*e + 0, esize DIV 2]); bits(esize) absdiff = Abs(element1 - element2)<esize-1:0>; Elem[result, e, esize] = Elem[result, e, esize] + absdiff; Z[da, VL] = result;
If FEAT_SVE2 is implemented or FEAT_SME is implemented, then if PSTATE.DIT is 1:
This instruction might be immediately preceded in program order by a MOVPRFX instruction. The MOVPRFX instruction must conform to all of the following requirements, otherwise the behavior of the MOVPRFX and this instruction is unpredictable:
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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