You copied the Doc URL to your clipboard.

## UABALT

Unsigned absolute difference and accumulate long (top).

Compute the absolute difference between odd-numbered unsigned elements of the second source vector and corresponding elements of the first source vector, and destructively add to the overlapping double-width elements of the addend vector. This instruction is unpredicated.

 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 size 0 Zm 1 1 0 0 1 1 Zn Zda

#### SVE2

UABALT <Zda>.<T>, <Zn>.<Tb>, <Zm>.<Tb>

```if !HaveSVE2() then UNDEFINED;
if size == '00' then UNDEFINED;
integer esize = 8 << UInt(size);
integer n = UInt(Zn);
integer m = UInt(Zm);
integer da = UInt(Zda);```

### Assembler Symbols

 Is the name of the third source and destination scalable vector register, encoded in the "Zda" field.
<T> Is the size specifier, encoded in size:
size <T>
00 RESERVED
01 H
10 S
11 D
 Is the name of the first source scalable vector register, encoded in the "Zn" field.
<Tb> Is the size specifier, encoded in size:
size <Tb>
00 RESERVED
01 B
10 H
11 S
 Is the name of the second source scalable vector register, encoded in the "Zm" field.

### Operation

```CheckSVEEnabled();
integer elements = VL DIV esize;
bits(VL) operand1 = Z[n];
bits(VL) operand2 = Z[m];
bits(VL) result = Z[da];

for e = 0 to elements-1
integer element1 = UInt(Elem[operand1, 2*e + 1, esize DIV 2]);
integer element2 = UInt(Elem[operand2, 2*e + 1, esize DIV 2]);
integer element3 = UInt(Elem[result, e, esize]);
integer res = element3 + Abs(element1 - element2);
Elem[result, e, esize] = res<esize-1:0>;

Z[da] = result;```