Instruction Syntax

Mnemonic	Format	Flags
blrl		LK = 1

Instruction Encoding

Field	Bits	Description
Primary Opcode	0-5	010011 (0x13)
BO	6-10	01000 (Branch Option)
BI	11-15	00000 (Branch Input - always)
BD	16-29	00000000000000 (unused)
LK	31	Link bit (1)

Operation

NIA ← LR
LR ← CIA + 4

BLRL branches to the address in the Link Register and saves the return address (CIA + 4) in the Link Register.

1. Sets the next instruction address (NIA) to the value in LR
2. Stores the return address (CIA + 4) in LR

Note: BLRL is a derived form of the BCLR instruction with LK=1.

Affected Registers

• LR (Link Register) - updated with return address

Examples

# Call function pointer and return
mtlr r4      # Set LR to function address
blrl         # Branch to LR and save return address
# ...
blr          # Return

# Tail call optimization
mtlr r5      # Set LR to next function
blrl         # Branch to LR and save return address

Related Instructions

bclr, blr, bl, b