Lookup table read with 6-bit indices (16-bit)
This instruction copies indexed 16-bit elements from the low 512 bits of the two table vectors to the destination vector using packed 6-bit indices from a segment in the bottom three quarters of the source vector register.
This instruction is unpredicated.
This instruction requires that the Effective SVE vector length is at least 512 bits.
| 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 | i1 | 1 | 1 | Zm | 1 | 0 | 1 | 0 | 1 | 1 | Zn | Zd | ||||||||||||
if !IsFeatureImplemented(FEAT_SVE2p3) && !IsFeatureImplemented(FEAT_SME2p3) then EndOfDecode(Decode_UNDEF); end; if MaxImplementedAnyVL() < 512 then EndOfDecode(Decode_UNDEF); end; let isize : integer{} = 6; let esize : integer{} = 16; let m : integer = UInt(Zm); let n : integer = UInt(Zn); let d : integer = UInt(Zd); let part : integer = UInt(i1);
| <Zd> |
Is the name of the destination scalable vector register, encoded in the "Zd" field. |
| <Zn1> |
Is the name of the first table vector register, encoded as "Zn". |
| <Zn2> |
Is the name of the second table vector register, encoded as "Zn" plus 1 modulo 32. |
| <Zm> |
Is the name of the source scalable vector register, encoded in the "Zm" field. |
| <index> |
Is the vector segment index, in the range 0 to 1, encoded in the "i1" field. |
CheckSVEEnabled(); let VL : integer{} = CurrentVL(); if VL < 512 then EndOfDecode(Decode_UNDEF); end; let elements : integer = VL DIV esize; let ibase : integer = elements * part; let indexes : bits(VL) = Z{}(m); // Only bottom 3/4 used let table : bits(1024) = Z{VL}((n+1) MOD 32)[511:0] :: Z{VL}(n+0)[511:0]; var result : bits(VL); for e = 0 to elements-1 do let index : integer = UInt(indexes[(ibase + e)*:isize]); let res : bits(esize) = table[index*:esize]; result[e*:esize] = res; end; Z{VL}(d) = result;
This instruction is a data-independent-time instruction as described in About PSTATE.DIT.
2025-09_diff_tag 2025-11-28 16:29:05
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