[Bug ipa/96337] [10/11 Regression] GCC 10.2: twice as slow for -O2 -march=x86-64 vs. GCC 9.3/8.4

rguenth at gcc dot gnu.org gcc-bugzilla@gcc.gnu.org
Tue Jul 28 06:04:04 GMT 2020


https://gcc.gnu.org/bugzilla/show_bug.cgi?id=96337

Richard Biener <rguenth at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
          Component|rtl-optimization            |ipa
            Summary|GCC 10.2: twice as slow for |[10/11 Regression] GCC
                   |-O2 -march=x86-64 vs. GCC   |10.2: twice as slow for -O2
                   |9.3/8.4                     |-march=x86-64 vs. GCC
                   |                            |9.3/8.4
           Keywords|                            |missed-optimization
                 CC|                            |hubicka at gcc dot gnu.org,
                   |                            |marxin at gcc dot gnu.org

--- Comment #3 from Richard Biener <rguenth at gcc dot gnu.org> ---
Well, the workloads tested are not -O2 workloads but yes, distros likely still
will use -O2 for them unless the package itself overrides.

But IIRC the main change was that -O2 -fprofile-use no longer uses -O3
inliner settings, the settings for -O2 itself were not changed much?  Honza?


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