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

This signed integer multiply-add 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 adds these values to 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

(FEAT_SME2)

31 | 30 | 29 | 28 | 27 | 26 | 25 | 24 | 23 | 22 | 21 | 20 | 19 | 18 | 17 | 16 | 15 | 14 | 13 | 12 | 11 | 10 | 9 | 8 | 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 |

1 | 1 | 0 | 0 | 0 | 0 | 0 | 1 | 1 | 1 | 0 | 0 | Zm | i3h | Rv | 1 | i3l | Zn | 0 | 0 | off3 | |||||||||||

U | S |

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;

(FEAT_SME2)

31 | 30 | 29 | 28 | 27 | 26 | 25 | 24 | 23 | 22 | 21 | 20 | 19 | 18 | 17 | 16 | 15 | 14 | 13 | 12 | 11 | 10 | 9 | 8 | 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 |

1 | 1 | 0 | 0 | 0 | 0 | 0 | 1 | 1 | 1 | 0 | 1 | Zm | 0 | Rv | 1 | i3h | Zn | 0 | 0 | 0 | i3l | off2 | |||||||||

U | S |

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;

(FEAT_SME2)

31 | 30 | 29 | 28 | 27 | 26 | 25 | 24 | 23 | 22 | 21 | 20 | 19 | 18 | 17 | 16 | 15 | 14 | 13 | 12 | 11 | 10 | 9 | 8 | 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 |

1 | 1 | 0 | 0 | 0 | 0 | 0 | 1 | 1 | 1 | 0 | 1 | Zm | 1 | Rv | 1 | i3h | Zn | 0 | 0 | 0 | 0 | i3l | off2 | ||||||||

U | S |

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;

<Wv> |
Is the 32-bit name of the vector select register W8-W11, encoded in the "Rv" field. |

<Zn> |
Is the name of the first source scalable vector register, encoded in the "Zn" field. |

<Zn4> |
Is the name of the fourth scalable vector register of the first source multi-vector group, encoded as "Zn" times 4 plus 3. |

<Zn2> |
Is the name of the second scalable vector register of the first source multi-vector group, encoded as "Zn" times 2 plus 1. |

<Zm> |
Is the name of the second source scalable vector register Z0-Z15, encoded in the "Zm" field. |

<index> |
Is the element index, in the range 0 to 7, encoded in the "i3h:i3l" fields. |

CheckStreamingSVEAndZAEnabled(); constant integer VL = CurrentVL; constant integer elements = VL DIV esize; constant integer vectors = VL DIV 8; constant integer vstride = vectors DIV nreg; constant integer eltspersegment = 128 DIV esize; constant bits(32) vbase = X[v, 32]; integer vec = (UInt(vbase) + offset) MOD vstride; bits(VL) result; vec = vec - (vec MOD 2); for r = 0 to nreg-1 constant bits(VL) operand1 = Z[n+r, VL]; constant bits(VL) operand2 = Z[m, VL]; for i = 0 to 1 constant bits(VL) operand3 = ZAvector[vec + i, VL]; for e = 0 to elements-1 constant integer segmentbase = e - (e MOD eltspersegment); constant integer s = 2 * segmentbase + index; constant integer element1 = SInt(Elem[operand1, 2 * e + i, esize DIV 2]); constant integer element2 = SInt(Elem[operand2, s, esize DIV 2]); constant bits(esize) product = (element1 * element2)<esize-1:0>; Elem[result, e, esize] = Elem[operand3, e, esize] + product; ZAvector[vec + i, VL] = result; vec = vec + vstride;

If PSTATE.DIT is 1:

- The execution time of this instruction is independent of:
- The values of the data supplied in any of its registers.
- The values of the NZCV flags.

- The response of this instruction to asynchronous exceptions does not vary based on:
- The values of the data supplied in any of its registers.
- The values of the NZCV flags.

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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