SMLSL (multiple and indexed vector)

Multi-vector signed integer multiply-subtract long by indexed element

This signed integer multiply-subtract long instruction multiplies each signed 16-bit element in the one, two, or four first source vectors with each signed 16-bit indexed element of the second source vector, widens each product to 32-bits and destructively subtracts these values from the corresponding 32-bit elements of the ZA double-vector groups.

The elements within the second source vector are specified using an immediate element index which selects the same element position within each 128-bit vector segment. The index range is from 0 to 7, encoded in 3 bits.

The double-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 double-vector groups respectively. The vector group symbol is preferred for disassembly, but optional in assembler source code.

This instruction is unpredicated.

It has encodings from 3 classes: One ZA double-vector , Two ZA double-vectors and Four ZA double-vectors

One ZA double-vector
(FEAT_SME2)

if !IsFeatureImplemented(FEAT_SME2) then UNDEFINED; constant integer esize = 32; constant integer v = UInt('010':Rv); constant integer n = UInt(Zn); constant integer m = UInt('0':Zm); constant integer offset = UInt(off3:'0'); constant integer index = UInt(i3h:i3l); constant integer nreg = 1;

Two ZA double-vectors
(FEAT_SME2)

if !IsFeatureImplemented(FEAT_SME2) then UNDEFINED; constant integer esize = 32; constant integer v = UInt('010':Rv); constant integer n = UInt(Zn:'0'); constant integer m = UInt('0':Zm); constant integer offset = UInt(off2:'0'); constant integer index = UInt(i3h:i3l); constant integer nreg = 2;

Four ZA double-vectors
(FEAT_SME2)

if !IsFeatureImplemented(FEAT_SME2) then UNDEFINED; constant integer esize = 32; constant integer v = UInt('010':Rv); constant integer n = UInt(Zn:'00'); constant integer m = UInt('0':Zm); constant integer offset = UInt(off2:'0'); constant integer index = UInt(i3h:i3l); constant integer nreg = 4;