Fork channel

Create a new channel as a copy of main.

Rename channel

Rename main to:

Delete channel

Delete main? This cannot be undone.

ldp-offset-predictable.txt
# RUN: llvm-mc -triple=aarch64 -disassemble < %s 2>&1 | FileCheck %s
# RUN: llvm-mc -triple=arm64 -disassemble < %s 2>&1 | FileCheck %s

# Stores are OK.
0xe0 0x83 0x00 0xa9
# CHECK-NOT: potentially undefined instruction encoding
# CHECK: stp x0, x0, [sp, #8]