Floating-point multiply-extended vectors (predicated)
Multiply active floating-point elements of the first source vector by corresponding floating-point elements of the second source vector except that ∞×0.0 gives 2.0 instead of NaN, and destructively place the results in the corresponding elements of the first source vector. Inactive elements in the destination vector register remain unmodified.
The instruction can be used with FRECPX to safely convert arbitrary elements in mathematical vector space to unit vectors or direction vectors with length 1.
| 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 | 0 | 0 | 1 | 0 | 1 | 0 | 1 | 0 | 0 | Pg | Zm | Zdn | |||||||||||
if !HaveSVE() && !HaveSME() then UNDEFINED; if size == '00' then UNDEFINED; constant integer esize = 8 << UInt(size); integer g = UInt(Pg); integer dn = UInt(Zdn); integer m = UInt(Zm);
| <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. |
CheckSVEEnabled(); constant integer VL = CurrentVL; constant integer PL = VL DIV 8; constant integer elements = VL DIV esize; bits(PL) mask = P[g, PL]; bits(VL) operand1 = Z[dn, VL]; bits(VL) operand2 = if AnyActiveElement(mask, esize) then Z[m, VL] else Zeros(VL); bits(VL) result; for e = 0 to elements-1 bits(esize) element1 = Elem[operand1, e, esize]; if ActivePredicateElement(mask, e, esize) then bits(esize) element2 = Elem[operand2, e, esize]; Elem[result, e, esize] = FPMulX(element1, element2, FPCR); else Elem[result, e, esize] = element1; Z[dn, VL] = 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: aarchmrs v2023-12_rel, pseudocode v2023-12_rel, sve v2023-12_rel ; Build timestamp: 2023-12-15T16:46
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