https://gcc.gnu.org/bugzilla/show_bug.cgi?id=81616

--- Comment #27 from Jan Hubicka <hubicka at ucw dot cz> ---
Hi,
one of problem here is use of vgather instruction.  It is hardly a win on Zen
architecture.
It is also on my TODO to adjust the code model to disable it for most loops.  I
only want
to benchmark if it is a win at all in some cases or not at all to set proper
weights.
You can disable it with -mno-avx2

Still the code is bit worse than for -march=amdfam10 -mtune=k8 which is bit
funny.
I will take a look at that.

Honza

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