Floating-point negated fused multiply-add vectors (predicated), writing multiplicand [Zdn = -Za + -Zdn * Zm]
Multiply the corresponding active floating-point elements of the first and second source vectors and add to elements of the third (addend) vector without intermediate rounding. Destructively place the negated results in the destination and first source (multiplicand) 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 | 1 | 1 | 0 | 0 | 1 | 0 | 1 | size | 1 | Za | 1 | 1 | 0 | Pg | Zm | Zdn | |||||||||||||||
| N | op | ||||||||||||||||||||||||||||||
if !HaveSVE() && !HaveSME() then UNDEFINED; if size == '00' then UNDEFINED; integer esize = 8 << UInt(size); integer g = UInt(Pg); integer dn = UInt(Zdn); integer m = UInt(Zm); integer a = UInt(Za); boolean op1_neg = TRUE; boolean op3_neg = TRUE;
| <Zdn> |
Is the name of the first source and destination scalable vector register, encoded in the "Zdn" field. |
| <T> |
Is the size specifier,
encoded in
|
| <Pg> |
Is the name of the governing scalable predicate register P0-P7, encoded in the "Pg" field. |
| <Zm> |
Is the name of the second source scalable vector register, encoded in the "Zm" field. |
| <Za> |
Is the name of the third source scalable vector register, encoded in the "Za" field. |
CheckSVEEnabled(); integer elements = VL DIV esize; bits(PL) mask = P[g]; bits(VL) operand1 = Z[dn]; bits(VL) operand2 = if AnyActiveElement(mask, esize) then Z[m] else Zeros(); bits(VL) operand3 = if AnyActiveElement(mask, esize) then Z[a] else Zeros(); bits(VL) result; for e = 0 to elements-1 if ElemP[mask, e, esize] == '1' then bits(esize) element1 = Elem[operand1, e, esize]; bits(esize) element2 = Elem[operand2, e, esize]; bits(esize) element3 = Elem[operand3, e, esize]; if op1_neg then element1 = FPNeg(element1); if op3_neg then element3 = FPNeg(element3); Elem[result, e, esize] = FPMulAdd(element3, element1, element2, FPCR[]); else Elem[result, e, esize] = Elem[operand1, e, esize]; Z[dn] = result;
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:
Internal version only: isa v33.11seprel, AdvSIMD v29.05, pseudocode v2021-09_rel, sve v2021-09_rc3d ; Build timestamp: 2021-10-06T11:41
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