You copied the Doc URL to your clipboard.

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.


INDEX <Zd>.<T>, <R><n>, #<imm>

if !HaveSVE() then UNDEFINED;
integer esize = 8 << UInt(size);
integer n = UInt(Rn);
integer d = UInt(Zd);
integer imm = SInt(imm5);

Assembler Symbols


Is the name of the destination scalable vector register, encoded in the "Zd" field.

<T> Is the size specifier, encoded in size:
size <T>
00 B
01 H
10 S
11 D
<R> Is a width specifier, encoded in size:
size <R>
01 W
x0 W
11 X

Is the number [0-30] of the source general-purpose register or the name ZR (31), encoded in the "Rn" field.


Is the signed immediate operand, in the range -16 to 15, encoded in the "imm5" field.


integer elements = VL DIV esize;
bits(esize) operand1 = X[n];
integer element1 = SInt(operand1);
bits(VL) result;

for e = 0 to elements-1
    integer index = element1 + e * imm;
    Elem[result, e, esize] = index<esize-1:0>;

Z[d] = result;