ZERO (quad-vector)
Zero ZA quad-vector groups
The instruction zeroes one, two, or four ZA quad-vector groups.
The quad-vector group within all of, each half of, or each quarter of the ZA array is selected by the sum of the vector select register and offset range, modulo all, half, or quarter the number of ZA array vectors.
The vector group symbol, VGx2 or VGx4, indicates that the ZA operand consists of two or four ZA quad-vector groups respectively.
Green
True
SM_1_only
It has encodings from 3 classes:
One ZA quad-vector
,
Two ZA quad-vectors
and
Four ZA quad-vectors
1
1
0
0
0
0
0
0
0
0
0
0
1
1
1
0
1
0
0
0
0
0
0
0
0
0
0
0
ZERO ZA.D[<Wv>, <offs1>:<offs4>]
if !IsFeatureImplemented(FEAT_SME2p1) then UNDEFINED;
constant integer v = UInt('010':Rv);
constant integer offset = UInt(off2:'00');
constant integer ngrp = 1;
constant integer nvec = 4;
1
1
0
0
0
0
0
0
0
0
0
0
1
1
1
1
0
0
0
0
0
0
0
0
0
0
0
0
0
ZERO ZA.D[<Wv>, <offs1>:<offs4>, VGx2]
if !IsFeatureImplemented(FEAT_SME2p1) then UNDEFINED;
constant integer v = UInt('010':Rv);
constant integer offset = UInt(o1:'00');
constant integer ngrp = 2;
constant integer nvec = 4;
1
1
0
0
0
0
0
0
0
0
0
0
1
1
1
1
1
0
0
0
0
0
0
0
0
0
0
0
0
ZERO ZA.D[<Wv>, <offs1>:<offs4>, VGx4]
if !IsFeatureImplemented(FEAT_SME2p1) then UNDEFINED;
constant integer v = UInt('010':Rv);
constant integer offset = UInt(o1:'00');
constant integer ngrp = 4;
constant integer nvec = 4;
<Wv>
Is the 32-bit name of the vector select register W8-W11, encoded in the "Rv" field.
<offs1>
For the one ZA quad-vector variant: is the first vector select offset, encoded as "off2" field times 4.
<offs1>
For the four ZA quad-vectors and two ZA quad-vectors variant: is the first vector select offset, encoded as "o1" field times 4.
<offs4>
For the one ZA quad-vector variant: is the fourth vector select offset, encoded as "off2" field times 4 plus 3.
<offs4>
For the four ZA quad-vectors and two ZA quad-vectors variant: is the fourth vector select offset, encoded as "o1" field times 4 plus 3.
CheckStreamingSVEAndZAEnabled();
constant integer VL = CurrentVL;
constant integer vectors = VL DIV 8;
constant integer vstride = vectors DIV ngrp;
constant bits(32) vbase = X[v, 32];
integer vec = (UInt(vbase) + offset) MOD vstride;
vec = vec - (vec MOD nvec);
for r = 0 to ngrp-1
for i = 0 to nvec-1
ZAvector[vec + i, VL] = Zeros(VL);
vec = vec + vstride;