Floating-point reciprocal exponent (predicated).
Invert the exponent leaving the fractional part unchanged of each active floating-point element of the source vector, and place the results in the corresponding elements of the destination vector. Inactive elements in the destination vector register remain unmodified.
The result of this instruction can be used with FMULX to convert arbitrary elements in mathematical vector space to "unit vectors" or "direction vectors" of 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 | 1 | 0 | 0 | 1 | 0 | 1 | Pg | Zn | Zd |
if !HaveSVE() then UNDEFINED; if size == '00' then UNDEFINED; integer esize = 8 << UInt(size); integer g = UInt(Pg); integer n = UInt(Zn); integer d = UInt(Zd);
<Zd> |
Is the name of the destination scalable vector register, encoded in the "Zd" 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 source scalable vector register, encoded in the "Zn" field. |
CheckSVEEnabled(); integer elements = VL DIV esize; bits(PL) mask = P[g]; bits(VL) operand = Z[n]; bits(VL) result = Z[d]; for e = 0 to elements-1 bits(esize) element = Elem[operand, e, esize]; if ElemP[mask, e, esize] == '1' then Elem[result, e, esize] = FPRecpX(element, FPCR); Z[d] = result;
This instruction might be immediately preceded in program order by a MOVPRFX instruction that conforms to all of the following requirements, otherwise the behavior of either or both instructions is unpredictable:
Internal version only: isa v30.44, AdvSIMD v27.08, pseudocode v8.5-2019-06_rc2-5-g22901f2, sve v2019-06_rc4 ; Build timestamp: 2019-06-26T22:04
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