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SQDMULLT (vectors)

Signed saturating doubling multiply long (top).

Multiply the corresponding odd-numbered signed elements of the first and second source vectors, double and place the results in the overlapping double-width elements of the destination vector. Each result element is saturated to the double-width N-bit element's signed integer range -2(N-1) to (2(N-1) )-1. This instruction is unpredicated.

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01000101size0Zm011001ZnZd
UT

SQDMULLT <Zd>.<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 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 RESERVED
01 H
10 S
11 D
<Zn>

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
<Zm>

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, 2*e + 1, esize DIV 2]);
    integer element2 = SInt(Elem[operand2, 2*e + 1, esize DIV 2]);
    integer res = 2 * element1 * element2;
    Elem[result, e, esize] = SignedSat(res, esize);

Z[d] = result;