INDEX (scalars)

Create index starting from and incremented by general-purpose register

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 scalar integer operand for each subsequent element. The scalar source operands are general-purpose registers 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.

313029282726252423222120191817161514131211109876543210
00000100size1Rm010011RnZd

INDEX <Zd>.<T>, <R><n>, <R><m>

if !IsFeatureImplemented(FEAT_SVE) && !IsFeatureImplemented(FEAT_SME) then UNDEFINED; constant integer esize = 8 << UInt(size); constant integer n = UInt(Rn); constant integer m = UInt(Rm); constant integer d = UInt(Zd);

Assembler Symbols

<Zd>

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
<n>

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

<m>

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

Operation

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); constant bits(esize) operand2 = X[m, esize]; constant integer element2 = SInt(operand2); bits(VL) result; for e = 0 to elements-1 constant integer index = element1 + e * element2; Elem[result, e, esize] = index<esize-1:0>; Z[d, VL] = result;

Operational information

If FEAT_SVE2 is implemented or FEAT_SME is implemented, then if PSTATE.DIT is 1:


Internal version only: aarchmrs v2024-03_relA, pseudocode v2024-03_rel, sve v2024-03_rel ; Build timestamp: 2024-03-26T09:45

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