SQXTNB

Signed saturating extract narrow (bottom)

Saturate the signed integer value in each source element to half the original source element width, and place the results in the even-numbered half-width destination elements, while setting the odd-numbered elements to zero.

313029282726252423222120191817161514131211109876543210
010001010tszh1tszl000010000ZnZd
UT

SQXTNB <Zd>.<T>, <Zn>.<Tb>

if !HaveSVE2() && !HaveSME() then UNDEFINED; bits(3) tsize = tszh:tszl; integer esize; case tsize of when '001' esize = 16; when '010' esize = 32; when '100' esize = 64; otherwise UNDEFINED; integer n = UInt(Zn); 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 tszh:tszl:

tszh tszl <T>
0 00 RESERVED
0 01 B
0 10 H
x 11 RESERVED
1 00 S
1 01 RESERVED
1 10 RESERVED
<Zn>

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

<Tb>

Is the size specifier, encoded in tszh:tszl:

tszh tszl <Tb>
0 00 RESERVED
0 01 H
0 10 S
x 11 RESERVED
1 00 D
1 01 RESERVED
1 10 RESERVED

Operation

CheckSVEEnabled(); integer elements = VL DIV esize; bits(VL) operand1 = Z[n]; bits(VL) result; integer halfesize = esize DIV 2; for e = 0 to elements-1 integer element1 = SInt(Elem[operand1, e, esize]); bits(halfesize) res = SignedSat(element1, halfesize); Elem[result, 2*e + 0, halfesize] = res; Elem[result, 2*e + 1, halfesize] = Zeros(); Z[d] = result;


Internal version only: isa v33.11seprel, AdvSIMD v29.05, pseudocode v2021-09_rel, sve v2021-09_rc3d ; Build timestamp: 2021-10-06T11:41

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