msgsndu

Message Send Ultravisor

msgsndu RB

Sends a message to other threads in the system.

Encoding

Binary Layout

18

0:5

LI

6:29

AA

30

LK

31

 

Format X-form

Opcode 0x7C00009C

Extension Privileged

Operands

• RB
  Source General Purpose Register

Example

msgsndu r5

Related

More in Privileged

Reference

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

Description

The instruction sends a message to other threads in the system. The message type and destination thread(s) are specified in RB.

Operation

msgtype ← GPR(RB)32:36
payload ← GPR(RB)37:63
if (msgtype = 0x05)
then
    send_msg(msgtype, payload)

Programming Note

If msgsndu is used to notify the receiver that updates have been made to storage, a sync should be placed between the stores and the msgsndu. See Section 6.9.2.