PMULLB
Polynomial multiply long (bottom)
Polynomial multiply over [0, 1] the corresponding even-numbered elements of the first and second source vectors, and place the results in the overlapping double-width elements of the destination vector. This instruction is unpredicated.
ID_AA64ZFR0_EL1.AES indicates whether the 128-bit element variant is implemented. The 128-bit element variant is illegal when executed in Streaming SVE mode, unless FEAT_SME_FA64 is implemented and enabled.
Green
False
True
SM_0_only
It has encodings from 2 classes:
16-bit or 64-bit elements
and
128-bit element
0
1
0
0
0
1
0
1
!= 00
0
0
1
1
0
1
0
PMULLB <Zd>.<T>, <Zn>.<Tb>, <Zm>.<Tb>
if !IsFeatureImplemented(FEAT_SVE2) && !IsFeatureImplemented(FEAT_SME) then UNDEFINED;
if size<0> == '0' then UNDEFINED;
constant integer esize = 8 << UInt(size);
constant integer n = UInt(Zn);
constant integer m = UInt(Zm);
constant integer d = UInt(Zd);
0
1
0
0
0
1
0
1
0
0
0
0
1
1
0
1
0
PMULLB <Zd>.Q, <Zn>.D, <Zm>.D
if !IsFeatureImplemented(FEAT_SVE_PMULL128) then UNDEFINED;
constant integer esize = 128;
constant integer n = UInt(Zn);
constant integer m = UInt(Zm);
constant integer d = UInt(Zd);
<Zd>
Is the name of the destination scalable vector register, encoded in the "Zd" field.
<T>
Is the size specifier,
<Zn>
Is the name of the first source scalable vector register, encoded in the "Zn" field.
<Tb>
Is the size specifier,
<Zm>
Is the name of the second source scalable vector register, encoded in the "Zm" field.
if esize < 128 then CheckSVEEnabled(); else CheckNonStreamingSVEEnabled();
constant integer VL = CurrentVL;
constant integer elements = VL DIV esize;
constant bits(VL) operand1 = Z[n, VL];
constant bits(VL) operand2 = Z[m, VL];
bits(VL) result;
for e = 0 to elements-1
constant bits(esize DIV 2) element1 = Elem[operand1, 2*e + 0, esize DIV 2];
constant bits(esize DIV 2) element2 = Elem[operand2, 2*e + 0, esize DIV 2];
Elem[result, e, esize] = PolynomialMult(element1, element2);
Z[d, VL] = result;