[Bug middle-end/82004] New: SPEC CPU2017 628.pop2_s miscompare

[andrey.y.guskov at intel dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=82004

            Bug ID: 82004
           Summary: SPEC CPU2017 628.pop2_s miscompare
           Product: gcc
           Version: 8.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: middle-end
          Assignee: unassigned at gcc dot gnu.org
          Reporter: andrey.y.guskov at intel dot com
  Target Milestone: ---

I`m seeing a miscompare in 628.pop2_s compiled with the following option set:

-m64 -march=core-avx2 -mfpmath=sse -Ofast -funroll-loops -fconvert=big-endian
-fopenmp

The guilty revision is r251230. Despite exp(log(c)*x) being faster, it seems to
lack the precision of pow(c,x).