[Bug libstdc++/93584] New: std::string::find_first_not_of is about 9X slower than strspn

[rafael at espindo dot la]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=93584

            Bug ID: 93584
           Summary: std::string::find_first_not_of is about 9X slower than
                    strspn
           Product: gcc
           Version: 9.2.1
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: libstdc++
          Assignee: unassigned at gcc dot gnu.org
          Reporter: rafael at espindo dot la
  Target Milestone: ---

Created attachment 47779
  --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=47779&action=edit
testcase

In the attached test program the benchmark function takes 0.26837 seconds if
calling std::string::find_first_not_of and 0.0291547 seconds if calling strspn.