Lookup table read with 4-bit indexes
Copy 16-bit or 32-bit elements from ZT0 to four destination vectors using packed 4-bit indices from a segment of the source vector register. A segment corresponds to a portion of the source vector that is consumed in order to fill the destination vector. The segment is selected by the vector segment index modulo the total number of segments.
This instruction is unpredicated.
It has encodings from 2 classes: Consecutive and Strided
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 |
1 | 1 | 0 | 0 | 0 | 0 | 0 | 0 | 1 | 0 | 0 | 0 | 1 | 0 | 1 | i1 | 1 | 0 | size | 0 | 0 | Zn | Zd | 0 | 0 |
if !HaveSME2() then UNDEFINED; if size == '00' || size == '11' then UNDEFINED; constant integer esize = 8 << UInt(size); integer isize = 4; integer n = UInt(Zn); integer dstride = 1; integer d = UInt(Zd:'00'); integer imm = UInt(i1); constant integer nreg = 4;
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 |
1 | 1 | 0 | 0 | 0 | 0 | 0 | 0 | 1 | 0 | 0 | 1 | 1 | 0 | 1 | i1 | 1 | 0 | size | 0 | 0 | Zn | D | 0 | 0 | Zd |
if !HaveSME2p1() then UNDEFINED; if size != '01' then UNDEFINED; constant integer esize = 8 << UInt(size); integer isize = 4; integer n = UInt(Zn); integer dstride = 4; integer d = UInt(D:'00':Zd); integer imm = UInt(i1); constant integer nreg = 4;
<Zd2> |
Is the name of the second destination scalable vector register Z4-Z7 or Z20-Z23 of a multi-vector sequence, encoded as "D:'01':Zd". |
<Zd3> |
Is the name of the third destination scalable vector register Z8-Z11 or Z24-Z27 of a multi-vector sequence, encoded as "D:'10':Zd". |
<T> |
Is the size specifier,
encoded in
|
<Zn> |
Is the name of the source scalable vector register, encoded in the "Zn" field. |
<index> |
Is the vector segment index, in the range 0 to 1, encoded in the "i1" field. |
CheckStreamingSVEEnabled(); CheckSMEZT0Enabled(); constant integer VL = CurrentVL; constant integer elements = VL DIV esize; integer segments = esize DIV (isize * nreg); integer segment = imm MOD segments; bits(VL) indexes = Z[n, VL]; bits(512) table = ZT0[512]; for r = 0 to nreg-1 integer base = (segment * nreg + r) * elements; bits(VL) result = Z[d, VL]; for e = 0 to elements-1 integer index = UInt(Elem[indexes, base+e, isize]); Elem[result, e, esize] = Elem[table, index, 32]<esize-1:0>; Z[d, VL] = result; d = d + dstride;
Internal version only: isa v33.53, AdvSIMD v29.11, pseudocode v2022-09_rel, sve v2022-09_rel ; Build timestamp: 2022-09-30T16:37
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