On Tue, 27 Jul 2021, Geert Uytterhoeven wrote:
On Tue, Jul 27, 2021 at 11:50 AM Finn Thain <fthain@xxxxxxxxxxxxxx> wrote:
On Tue, 27 Jul 2021, Uwe Kleine-König wrote:
Apart from that, the compiler might already assume dev->driver being
non-NULL after to_nubus_driver(dev->driver) was called.
I don't understand how a compiler can make that assumption. But then,
I don't know why compilers do a lot of the things they do...
It is one of those recent optimizations people have been complaining
about. Once you have dereferenced a pointer, compilers may remove all
further NULL-checks, assuming they can't happen, as the code would have
crashed anyway before due to the dereference.
But that's the point -- there is no dereference, just pointer arithmetic.
Good luck running on bare metal with RAM at zero ;-)
Quite.
