lxvrbx

Load VSX Vector Rightmost Byte Indexed X-form

lxvrbx XT,RA,RB

Loads a byte from memory into the rightmost byte of a VSX vector register.

Encoding

Binary Layout

0

0:5

T

6:10

RA

11:15

RB

16:20

13

21:25

TX

26:31

 

Format X-form

Opcode 0x7C00001A

Extension VSX

Operands

• XT
  Target Vector-Specific Register
• RA
  Source General Purpose Register
• RB
  Source General Purpose Register

Example

lxvrbx vs1, r4, r5

Registers Altered

MSR

Related

More in VSX

Reference

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

Description

Loads a single byte from memory and places it in the rightmost (least significant) byte position of a VSX register, with all other bytes set to 0. The effective address is computed as RA|0 + RB. No status fields are modified by this instruction.

Operation

EA ← (RA=0 ? 0 : GPR[RA]) + GPR[RB]
VSR[XT] ← (0x00000000000000000000000000 || MEM(EA, 1))

Programming Note

The lxvrbx instruction is used to load a single byte from memory into the rightmost byte of a VSX vector register. Ensure that the VSX facility is enabled in the MSR register; otherwise, an exception will be raised. The address calculation involves adding two general-purpose registers, RA and RB, where RA can be zero. This instruction zeroes out all other bytes in the target vector register except for the rightmost byte.