[Bug gcov-profile/70773] New: Profiling makes sudoku solver slower

["tulipawn at gmail dot com" <gcc-bugzilla at gcc dot gnu dot org>]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=70773

            Bug ID: 70773
           Summary: Profiling makes sudoku solver slower
           Product: gcc
           Version: 5.3.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: gcov-profile
          Assignee: unassigned at gcc dot gnu.org
          Reporter: tulipawn at gmail dot com
  Target Milestone: ---

Created attachment 38334
  --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=38334&action=edit
.c, .i and .gcda files

Compiling the attached sudoku solver the usual way and running the benchmark:

$ gcc -O3  -Wall sudoku.c -o sudokuC
$ time ./sudokuC 1>&2 > /dev/null

takes 1.25s, whereas doing a profile build:

$ gcc -O3  -Wall sudoku.c -o sudokuC -fprofile-generate
$ time ./sudokuC 1>&2 > /dev/null
$ gcc -O3  -Wall sudoku.c -o sudokuC -fprofile-use
$ time ./sudokuC 1>&2 > /dev/null

takes 1.5s which means it's 20% slower. Probably shouldn't happen.