Splice two vectors under predicate control
Select a region from the first source vector and copy it to the lowest-numbered elements of the result. Then set any remaining elements of the result to a copy of the lowest-numbered elements from the second source vector. The region is selected using the first and last true elements in the vector select predicate register. The result is placed destructively in the destination and first source vector, or constructively in the destination vector.
It has encodings from 2 classes: Constructive and Destructive
| 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 | 1 | size | 1 | 0 | 1 | 1 | 0 | 1 | 1 | 0 | 0 | Pv | Zn | Zd | |||||||||||
if !IsFeatureImplemented(FEAT_SVE2) && !IsFeatureImplemented(FEAT_SME) then EndOfDecode(Decode_UNDEF); constant integer esize = 8 << UInt(size); constant integer v = UInt(Pv); constant integer dst = UInt(Zd); constant integer s1 = UInt(Zn); constant integer s2 = (s1 + 1) MOD 32;
| 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 | 1 | size | 1 | 0 | 1 | 1 | 0 | 0 | 1 | 0 | 0 | Pv | Zm | Zdn | |||||||||||
if !IsFeatureImplemented(FEAT_SVE) && !IsFeatureImplemented(FEAT_SME) then EndOfDecode(Decode_UNDEF); constant integer esize = 8 << UInt(size); constant integer v = UInt(Pv); constant integer dst = UInt(Zdn); constant integer s1 = dst; constant integer s2 = UInt(Zm);
| <Zd> |
Is the name of the destination scalable vector register, encoded in the "Zd" field. |
| <T> |
Is the size specifier,
encoded in
|
| <Pv> |
Is the name of the vector select predicate register P0-P7, encoded in the "Pv" field. |
| <Zn1> |
Is the name of the first scalable vector register of the source multi-vector group, encoded in the "Zn" field. |
| <Zn2> |
Is the name of the second scalable vector register of the source multi-vector group, encoded in the "Zn" field. |
| <Zdn> |
Is the name of the first source and destination scalable vector register, encoded in the "Zdn" 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; constant bits(PL) mask = P[v, PL]; constant bits(VL) operand1 = if AnyActiveElement(mask, esize) then Z[s1, VL] else Zeros(VL); constant bits(VL) operand2 = Z[s2, VL]; bits(VL) result; integer x = 0; boolean active = FALSE; constant integer lastnum = LastActiveElement(mask, esize); if lastnum >= 0 then for e = 0 to lastnum active = active || ActivePredicateElement(mask, e, esize); if active then Elem[result, x, esize] = Elem[operand1, e, esize]; x = x + 1; constant integer nelements = (elements - x) - 1; for e = 0 to nelements Elem[result, x, esize] = Elem[operand2, e, esize]; x = x + 1; Z[dst, VL] = result;
For the "Destructive" variant:
The destructive variant of this instruction might be immediately preceded in program order by a MOVPRFX instruction. The MOVPRFX must conform to all of the following requirements, otherwise the behavior of the MOVPRFX and the destructive variant of this instruction is CONSTRAINED UNPREDICTABLE:
Internal version only: aarchmrs v2024-12_rel, pseudocode v2024-12_rel ; Build timestamp: 2024-12-15T22:18
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