SQDMULH (multiple vectors)

Multi-vector signed saturating doubling multiply high

Multiply then double the corresponding signed elements of the two or four first and second source vectors, and destructively place the most significant half of the result in the corresponding elements of the two or four first source vectors. 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.

It has encodings from 2 classes: Two registers and Four registers

Two registers
(FEAT_SME2)

313029282726252423222120191817161514131211109876543210
11000001size1Zm010110100000Zdn0

SQDMULH { <Zdn1>.<T>-<Zdn2>.<T> }, { <Zdn1>.<T>-<Zdn2>.<T> }, { <Zm1>.<T>-<Zm2>.<T> }

if !IsFeatureImplemented(FEAT_SME2) then UNDEFINED; constant integer esize = 8 << UInt(size); constant integer dn = UInt(Zdn:'0'); constant integer m = UInt(Zm:'0'); constant integer nreg = 2;

Four registers
(FEAT_SME2)

313029282726252423222120191817161514131211109876543210
11000001size1Zm0010111100000Zdn00

SQDMULH { <Zdn1>.<T>-<Zdn4>.<T> }, { <Zdn1>.<T>-<Zdn4>.<T> }, { <Zm1>.<T>-<Zm4>.<T> }

if !IsFeatureImplemented(FEAT_SME2) then UNDEFINED; constant integer esize = 8 << UInt(size); constant integer dn = UInt(Zdn:'00'); constant integer m = UInt(Zm:'00'); constant integer nreg = 4;

Assembler Symbols

<Zdn1>

For the two registers variant: is the name of the first scalable vector register of the destination and first source multi-vector group, encoded as "Zdn" times 2.

For the four registers variant: is the name of the first scalable vector register of the destination and first source multi-vector group, encoded as "Zdn" times 4.

<T>

Is the size specifier, encoded in size:

size <T>
00 B
01 H
10 S
11 D
<Zdn4>

Is the name of the fourth scalable vector register of the destination and first source multi-vector group, encoded as "Zdn" times 4 plus 3.

<Zdn2>

Is the name of the second scalable vector register of the destination and first source multi-vector group, encoded as "Zdn" times 2 plus 1.

<Zm1>

For the two registers variant: is the name of the first scalable vector register of the second source multi-vector group, encoded as "Zm" times 2.

For the four registers variant: is the name of the first scalable vector register of the second source multi-vector group, encoded as "Zm" times 4.

<Zm4>

Is the name of the fourth scalable vector register of the second source multi-vector group, encoded as "Zm" times 4 plus 3.

<Zm2>

Is the name of the second scalable vector register of the second source multi-vector group, encoded as "Zm" times 2 plus 1.

Operation

CheckStreamingSVEEnabled(); constant integer VL = CurrentVL; constant integer elements = VL DIV esize; array [0..3] of bits(VL) results; for r = 0 to nreg-1 constant bits(VL) operand1 = Z[dn+r, VL]; constant bits(VL) operand2 = Z[m+r, VL]; for e = 0 to elements-1 constant integer element1 = SInt(Elem[operand1, e, esize]); constant integer element2 = SInt(Elem[operand2, e, esize]); constant integer res = 2 * element1 * element2; Elem[results[r], e, esize] = SignedSat(res >> esize, esize); for r = 0 to nreg-1 Z[dn+r, VL] = results[r];


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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