MLS
Multiply-subtract vectors (predicated), writing addend [Zda = Zda - Zn * Zm].
Multiply the corresponding active elements of the first and second source vectors and subtract from elements of the third source (addend) vector. Destructively place the results in the destination and third source (addend) vector. Inactive elements in the destination vector register remain unmodified.
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 |
0 | 0 | 0 | 0 | 0 | 1 | 0 | 0 | size | 0 | Zm | 0 | 1 | 1 | Pg | Zn | Zda | |||||||||||||||
op |
if !HaveSVE() then UNDEFINED; integer esize = 8 << UInt(size); integer g = UInt(Pg); integer n = UInt(Zn); integer m = UInt(Zm); integer da = UInt(Zda); boolean sub_op = TRUE;
Assembler Symbols
<Zda> |
Is the name of the third source and destination scalable vector register, encoded in the "Zda" field. |
<T> |
Is the size specifier,
encoded in
size:
|
<Pg> |
Is the name of the governing scalable predicate register P0-P7, encoded in the "Pg" field. |
<Zn> |
Is the name of the first source scalable vector register, encoded in the "Zn" field. |
<Zm> |
Is the name of the second source scalable vector register, encoded in the "Zm" field. |
Operation
CheckSVEEnabled(); integer elements = VL DIV esize; bits(PL) mask = P[g]; bits(VL) operand1 = Z[n]; bits(VL) operand2 = Z[m]; bits(VL) operand3 = Z[da]; bits(VL) result; for e = 0 to elements-1 integer element1 = UInt(Elem[operand1, e, esize]); integer element2 = UInt(Elem[operand2, e, esize]); if ElemP[mask, e, esize] == '1' then integer product = element1 * element2; if sub_op then Elem[result, e, esize] = Elem[operand3, e, esize] - product; else Elem[result, e, esize] = Elem[operand3, e, esize] + product; else Elem[result, e, esize] = Elem[operand3, e, esize]; Z[da] = result;
Operational information
This instruction might be immediately preceded in program order by a MOVPRFX instruction. The MOVPRFX instruction must conform to all of the following requirements, otherwise the behavior of the MOVPRFX and this instruction is unpredictable:
- The MOVPRFX instruction must be unpredicated, or be predicated using the same governing predicate register and source element size as this instruction.
- The MOVPRFX instruction must specify the same destination register as this instruction.
- The destination register must not refer to architectural register state referenced by any other source operand register of this instruction.