[Bug target/81616] Update -mtune=generic for the current Intel and AMD processors

hubicka at ucw dot cz gcc-bugzilla@gcc.gnu.org
Wed Nov 29 19:55:00 GMT 2017


--- Comment #34 from Jan Hubicka <hubicka at ucw dot cz> ---
> So gcc loses on mt19937ar.c without -mno-avx2
> But gcc wins big on matrix.c, especially with -mprefer-vector-width=none
> -mno-fma

It is because llvm does not use vgather at all unless avx512 is present.  I
look into the vgather cost model tomorrow.


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