li

Load Immediate

li RT, SIM

Loads a 16-bit signed immediate into a register. (Alias for 'addi RT, 0, SIM').

Encoding

Binary Layout

14

0:5

RT

6:10

0

11:15

SIM

16:31

 

Format D-form

Opcode 0x38000000

Extension Base

Operands

• RT
  Target
• SIM
  Immediate

Example

li r3, 4

Related

More in Base

Reference

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

Description

Loads a 16-bit signed immediate value into the target register. This is an assembly-language alias for 'addi RT, 0, SIM' that simplifies loading small constants. No condition register flags are affected.

Operation

RT ← sign_extend(SIM, 16)

Programming Note

The `li` instruction is commonly used for initializing or resetting registers to specific values. Ensure the immediate value fits within the 32-bit signed integer range to avoid unexpected behavior. This instruction operates at user privilege level and does not generate exceptions unless there are issues with the instruction encoding.