https://gcc.gnu.org/bugzilla/show_bug.cgi?id=83651
Aldy Hernandez <aldyh at gcc dot gnu.org> changed:
What |Removed |Added
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CC| |aldyh at gcc dot gnu.org
--- Comment #3 from Aldy Hernandez <aldyh at gcc dot gnu.org> ---
(In reply to Arnd Bergmann from comment #0)
> If there is enough interest in addressing the slowdown, it should be
> possible to create a version of the kernel AES implementation that can be
> run in user space, as the current method of reproducing the results is
> fairly tedious.
I would say that a 20% slowdown is significant enough that we should definitely
look into this. A user space version would help immensely here.
> The source code is apparently derived from a common source, but has evolved
> in different ways, and the version from the kernel appears to be much faster
> overall.
It looks like you have various benchmarks based on different code bases. This
is not good for reproduceability and diagnosing the problem. Could we settle
on one, and ideally a (simple) user space version? This will drastically
increase the likelihood of finding a solution :).
Also, is this a GCC 8 regression? It looks like in most of the benchmarks you
post, GCC 8 performs pretty close to 4.x. Again, settling on one benchmark,
preferably in user space, would really help.
Thanks.
