[Bug target/84280] [6/7/8 Regression] Performance regression in g++-7 with Eigen for non-AVX2 CPUs

[marxin at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=84280

Martin Liška <marxin at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|WAITING                     |NEW
                 CC|                            |aoliva at gcc dot gnu.org,
                   |                            |marxin at gcc dot gnu.org

--- Comment #15 from Martin Liška <marxin at gcc dot gnu.org> ---
I can confirm that on my Haswell machine:
model name      : Intel(R) Core(TM) i7-4770 CPU @ 3.40GHz

I see regression with -march=core2 -mtune=core2 -O3 starting from r226901
(first time in GCC 5.x).

Time difference is:
0:00:14.975390
vs
0:00:11.889274