INDEX (scalar, immediate)
Create index starting from general-purpose register and incremented by immediate
Populates the destination vector by setting the first element to the first signed scalar integer operand and monotonically incrementing the value by the second signed immediate integer operand for each subsequent element. The scalar source operand is a general-purpose register in which only the least significant bits corresponding to the vector element size are used and any remaining bits are ignored. This instruction is unpredicated.
Green
False
True
0
0
0
0
0
1
0
0
1
0
1
0
0
0
1
INDEX <Zd>.<T>, <R><n>, #<imm>
if !IsFeatureImplemented(FEAT_SVE) && !IsFeatureImplemented(FEAT_SME) then UNDEFINED;
constant integer esize = 8 << UInt(size);
constant integer n = UInt(Rn);
constant integer d = UInt(Zd);
constant integer imm = SInt(imm5);
<Zd>
Is the name of the destination scalable vector register, encoded in the "Zd" field.
<T>
Is the size specifier,
size
<T>
00
B
01
H
10
S
11
D
<R>
Is a width specifier,
<n>
Is the number [0-30] of the source general-purpose register or the name ZR (31), encoded in the "Rn" field.
<imm>
Is the signed immediate operand, in the range -16 to 15, encoded in the "imm5" field.
CheckSVEEnabled();
constant integer VL = CurrentVL;
constant integer PL = VL DIV 8;
constant integer elements = VL DIV esize;
constant bits(esize) operand1 = X[n, esize];
constant integer element1 = SInt(operand1);
bits(VL) result;
for e = 0 to elements-1
constant integer index = element1 + e * imm;
Elem[result, e, esize] = index<esize-1:0>;
Z[d, VL] = result;