[Bug tree-optimization/103195] New: tfft2 text grows by 70% with -Ofast between g:52fa771758635d9c53cddb9116e5a66fae592230...a97fdde627e64202940112009d45d17f85e4cc61

[hubicka at gcc dot gnu.org via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=103195

            Bug ID: 103195
           Summary: tfft2 text grows by 70% with -Ofast between
                    g:52fa771758635d9c53cddb9116e5a66fae592230...a97fdde62
                    7e64202940112009d45d17f85e4cc61
           Product: gcc
           Version: 12.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: tree-optimization
          Assignee: unassigned at gcc dot gnu.org
          Reporter: hubicka at gcc dot gnu.org
  Target Milestone: ---

This is seen at LTN here

https://lnt.opensuse.org/db_default/v4/CPP/24179
https://lnt.opensuse.org/db_default/v4/CPP/graph?highlight_run=24179&plot.0=14.799.4

and similarly on other testers.  Performance is not improved so it looks like
bit extreme even for -Ofast. It would be nice to know why such growth happens.