Programmable table lookup in single vector table (merging)
Reads each element of the second source (index) vector and uses its value to select an indexed element from a table of elements in the first source vector, and places the indexed element in the destination vector element corresponding to the index vector element. If an index value is greater than or equal to the number of vector elements then the corresponding destination vector element is left unchanged.
Since the index values can select any element in a vector this operation is not naturally vector length agnostic.
| 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 | 0 | 0 | 0 | 0 | 1 | 0 | 1 | size | 1 | Zm | 0 | 0 | 1 | 0 | 1 | 1 | Zn | Zd | |||||||||||||
if !HaveSVE2() && !HaveSME() then UNDEFINED; integer esize = 8 << UInt(size); integer n = UInt(Zn); integer m = UInt(Zm); integer d = UInt(Zd);
| <Zd> |
Is the name of the destination scalable vector register, encoded in the "Zd" field. |
| <T> |
Is the size specifier,
encoded in
|
| <Zn> |
Is the name of the first source scalable vector register, encoded in the "Zn" field. |
| <Zm> |
Is the name of the second source scalable vector register, encoded in the "Zm" field. |
CheckSVEEnabled(); integer elements = VL DIV esize; bits(VL) operand1 = Z[n]; bits(VL) operand2 = Z[m]; bits(VL) result = Z[d]; for e = 0 to elements-1 integer element2 = UInt(Elem[operand2, e, esize]); if element2 < elements then Elem[result, e, esize] = Elem[operand1, element2, esize]; Z[d] = result;
If FEAT_SVE2 is enabled or FEAT_SME is enabled, then when PSTATE.DIT is 1:
Internal version only: isa v33.11seprel, AdvSIMD v29.05, pseudocode v2021-09_rel, sve v2021-09_rc3d ; Build timestamp: 2021-10-06T11:41
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