vextractuh

Vector Extract Unsigned Halfword

vextractuh RA, vB, UIM

Extracts a halfword from a vector into a GPR.

Details

Extracts an unsigned halfword element from vB at the position specified by UIM and stores the zero-extended 16-bit value into general-purpose register RA. 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.

Pseudocode Operation

index ← UIM[1:3]
RA ← (0x0000) || vB[index*16 : index*16+15]

Programming Note

The vextractuh instruction extracts an unsigned halfword from a vector register at a specified index. Ensure the index is within bounds to avoid undefined behavior. This instruction operates in user privilege level and does not generate exceptions for valid indices.

Example

vextractuh r4, vb, uim

Encoding

Binary Layout
4
0
RA
6
UIM
11
vB
16
589
21
 
Format VX-form
Opcode 0x1000024D
Extension VMX (AltiVec)

Operands

  • RA
    Target GPR
  • vB
    Source Vector
  • UIM
    Index