[Bug tree-optimization/70046] [6 Regression] 410.bwaves regression on Haswell

[amker at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=70046

--- Comment #2 from amker at gcc dot gnu.org ---
I checked "-Ofast -march=native/-march=haswell" for GCC@230647 on Xeon, there
is no regression.  I also checked "-Ofast -mtune=core-avx2" for GCC@230689,
there is no regression either.
I looked into the generated assembly and the hot loops (the innermost two) is
actually improved by the change with these options.

So do I need some other options?  Or it's a u-arch hazard that doesn't exist on
Xeon?

Thanks.