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## SQDMULH (vectors)

Signed saturating doubling multiply high (unpredicated).

Multiply then double the corresponding signed elements of the first and second source vectors, and place the most significant half of the results in the corresponding elements of the destination vector register. Each result element is saturated to the N-bit element's signed integer range -2(N-1) to (2(N-1) )-1. 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 0 0 0 0 1 0 0 size 1 Zm 0 1 1 1 0 0 Zn Zd R

SQDMULH <Zd>.<T>, <Zn>.<T>, <Zm>.<T>

```if !HaveSVE2() then UNDEFINED;
integer esize = 8 << UInt(size);
integer n = UInt(Zn);
integer m = UInt(Zm);
integer d = UInt(Zd);```

### 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
 Is the name of the first source scalable vector register, encoded in the "Zn" field.
 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;

for e = 0 to elements-1
integer element1 = SInt(Elem[operand1, e, esize]);
integer element2 = SInt(Elem[operand2, e, esize]);
integer res = 2 * element1 * element2;
Elem[result, e, esize] = SignedSat(res >> esize, esize);

Z[d] = result;```