Implement atomic_inc_not_zero and atomic64_inc_not_zero. At the
moment we use atomic*_add_unless which requires us to put 0 and
1 constants into registers. We can also avoid a subtract by
saving the original value in a second temporary.
This removes 3 instructions from fget:
- c0000000001b63c0: 39 00 00 00 li r8,0
- c0000000001b63c4: 39 40 00 01 li r10,1
...
- c0000000001b63e8: 7c 0a 00 50 subf r0,r10,r0
Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
a6cf7ed511