Floating-point down convert and narrow to BFloat16 (top, predicated)
Convert to BFloat16 from single-precision in each active floating-point element of the source vector, and place the results in the odd-numbered 16-bit elements of the destination vector, leaving the even-numbered elements unchanged. Inactive elements in the destination vector register remain unmodified.
ID_AA64ZFR0_EL1.BF16 indicates whether this instruction is implemented.
| 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 | 0 | 1 | 0 | 0 | 0 | 1 | 0 | 1 | 0 | 1 | 0 | 1 | Pg | Zn | Zd | ||||||||||
if (!HaveSVE() && !HaveSME()) || !HaveBF16Ext() then UNDEFINED; 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. |
| <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(); constant integer VL = CurrentVL; constant integer PL = VL DIV 8; constant integer elements = VL DIV 32; bits(PL) mask = P[g, PL]; bits(VL) operand = if AnyActiveElement(mask, 32) then Z[n, VL] else Zeros(VL); bits(VL) result = Z[d, VL]; for e = 0 to elements-1 if ActivePredicateElement(mask, e, 32) then bits(32) element = Elem[operand, e, 32]; Elem[result, 2*e+1, 16] = FPConvertBF(element, FPCR); Z[d, VL] = result;
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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