Say, in the following disassembled instructions:
lbl:
ldaxr x8, [x9]
add x8, x8, #1
stlxr wip0, x8, [x9]
cbnz wip0, lbl
What is wip0?
wip0 is in fact an alias for w16, see section "6.3.1 Use of IP0 and IP1 by the linker"of the Procedure Call Standard for the Arm® 64-bit Architecture
(AArch64)