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.

Details

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.

Pseudocode 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.

Example

lxvrbx vs1, r4, r5

Encoding

Binary Layout
0
0
T
6
RA
11
RB
16
13
21
TX
26
 
Format X-form
Opcode 0x7C00001A
Extension VSX
Registers Altered MSR

Operands

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