LUTI2 Lookup table read with 2-bit indices This instruction copies indexed 8-bit or 16-bit elements from the low 128 bits of the table vector to the destination vector using packed 2-bit indices from a segment of the source vector. 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. This instruction is unpredicated. Green False True It has encodings from 2 classes: Byte and Halfword 0 1 0 0 0 1 0 1 1 1 0 1 1 0 0 LUTI2 <Zd>.B, { <Zn>.B }, <Zm>[<index>] if ((!IsFeatureImplemented(FEAT_SVE2) && !IsFeatureImplemented(FEAT_SME2)) || !IsFeatureImplemented(FEAT_LUT)) then UNDEFINED; constant integer isize = 2; constant integer esize = 8; constant integer m = UInt(Zm); constant integer n = UInt(Zn); constant integer d = UInt(Zd); constant integer part = UInt(i2); 0 1 0 0 0 1 0 1 1 1 0 1 1 0 LUTI2 <Zd>.H, { <Zn>.H }, <Zm>[<index>] if ((!IsFeatureImplemented(FEAT_SVE2) && !IsFeatureImplemented(FEAT_SME2)) || !IsFeatureImplemented(FEAT_LUT)) then UNDEFINED; constant integer isize = 2; constant integer esize = 16; constant integer m = UInt(Zm); constant integer n = UInt(Zn); constant integer d = UInt(Zd); constant integer part = UInt(i3h:i3l); <Zd> Is the name of the destination scalable vector register, encoded in the "Zd" field. <Zn> Is the name of the table vector register, encoded in the "Zn" field. <Zm> Is the name of the source scalable vector register, encoded in the "Zm" field. <index> For the byte variant: is the vector segment index, in the range 0 to 3, encoded in the "i2" field. <index> For the halfword variant: is the vector segment index, in the range 0 to 7, encoded in the "i3h:i3l" fields. CheckSVEEnabled(); constant integer VL = CurrentVL; constant integer elements = VL DIV esize; constant integer ibase = elements * part; constant bits(VL) indices = Z[m, VL]; constant bits(VL) table = Z[n, VL]; bits(VL) result; for e = 0 to elements-1 constant integer index = UInt(Elem[indices, ibase + e, isize]); Elem[result, e, esize] = Elem[table, index, esize]; Z[d, VL] = result;