vinserth

Vector Insert Halfword

vinserth vD, vB, UIM

Inserts a halfword from a GPR into a vector.

Encoding

Binary Layout

4

0:5

vD

6:10

UIM

11:15

vB

16:20

845

21:31

 

Format VX-form

Opcode 0x1000034D

Extension VMX (AltiVec)

Operands

• vD
  Target Vector
• vB
  Source GPR
• UIM
  Index

Example

vinserth vd, vb, uim

Registers Altered

MSR

Related

More in VMX (AltiVec)

Reference

View in PowerISA v3.1C Specification ↗ OPF Power ISA v3.1C

Description

Inserts the low-order 16 bits of general-purpose register vB into vD at the halfword position specified by UIM, leaving other halfword elements of vD unchanged. The halfword index (0-7) is provided by the 3-bit immediate UIM. No status flags are affected. This instruction is part of the VMX (AltiVec) extension.

Operation

index ← UIM[1:3]
vD[index*16 : index*16+15] ← vB[48:63]

Programming Note

The vinserth instruction is used to insert a halfword from one vector register into another at a specified index. Ensure that the Vector Facility (MSR.VEC) is enabled; otherwise, a Vector_Unavailable exception will be raised. The destination vector's remaining byte elements remain unchanged after the insertion.