SPLICE

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.

The Destructive encoding of 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: The MOVPRFX instruction must be unpredicated. The MOVPRFX instruction must specify the same destination register as this instruction. The destination register must not refer to architectural register state referenced by any other source operand register of this instruction.

It has encodings from 2 classes: Constructive and Destructive

Constructive

if !HaveSVE2() && !HaveSME() then UNDEFINED; constant integer esize = 8 << UInt(size); integer v = UInt(Pv); integer dst = UInt(Zd); integer s1 = UInt(Zn); integer s2 = (s1 + 1) MOD 32;

Destructive

if !HaveSVE() && !HaveSME() then UNDEFINED; constant integer esize = 8 << UInt(size); integer v = UInt(Pv); integer dst = UInt(Zdn); integer s1 = dst; integer s2 = UInt(Zm);