Programmable table lookup/permute using vector of element indices.
Read each element of the second source (index) vector and use it to select an element from the first source (table) vector and place the indexed element in the corresponding element of the destination vector. If an index value is greater than or equal to the number of vector elements then place zero in the destination vector element. Since the index values address a whole vector register this instruction is not 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 | 1 | 0 | 0 | Zn | Zd |
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
size:
|
<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; for e = 0 to elements-1 integer idx = UInt(Elem[operand2, e, esize]); Elem[result, e, esize] = if idx < elements then Elem[operand1, idx, esize] else Zeros(); Z[d] = result;
Release: 00rel4.1-manual
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