Bug ID: 85416
           Summary: Massive performance regression when switching on
           Product: gcc
           Version: 8.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: tree-optimization
          Assignee: unassigned at gcc dot
  Target Milestone: ---

Created attachment 43945
Test case

When compiling the attached test case with

g++ -O3 -std=c++14

and measuring the runtime via

time ./a.out

I get a CPU time of roughly 1.3 seconds

Recompiling with

g++ -O3 -std=c++14 -march=native

increases run time to over 8 seconds.

CPU: Intel Core i5-5300U

This was measured on trunk (gcc version 8.0.1 20180411), but I see similar
performance degradations already in gcc 5.4.

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