[Bug rtl-optimization/78200] [7 Regression] 429.mcf of cpu2006 regresses in GCC trunk for avx2 target.

[rguenth at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=78200

--- Comment #13 from Richard Biener <rguenth at gcc dot gnu.org> ---
When I compare GCC 6 (r241818) against trunk (r241997) with -Ofast
-march=native (on Haswell) I get

429.mcf          9120        230       39.7 S    9120        240       38.0 *
429.mcf          9120        227       40.1 S    9120        244       37.4 S
429.mcf          9120        230       39.7 *    9120        237       38.6 S

thats ~5% regression.  Profiling that shows

 20.89%        398295  mcf_peak.amd64-  mcf_peak.amd64-m64-gcc42-nn  [.]
primal_bea_mpp                             
 18.34%        349619  mcf_base.amd64-  mcf_base.amd64-m64-gcc42-nn  [.]
primal_bea_mpp                             
 15.45%        294258  mcf_peak.amd64-  mcf_peak.amd64-m64-gcc42-nn  [.]
refresh_potential                          
 13.53%        257796  mcf_base.amd64-  mcf_base.amd64-m64-gcc42-nn  [.]
refresh_potential