[Bug c/103670] New: Incorrect optimization of loop termination: Early exit with any optimization

[robert.muench at saphirion dot com via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=103670

            Bug ID: 103670
           Summary: Incorrect optimization of loop termination: Early exit
                    with any optimization
           Product: gcc
           Version: 10.3.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c
          Assignee: unassigned at gcc dot gnu.org
          Reporter: robert.muench at saphirion dot com
  Target Milestone: ---

Created attachment 51981
  --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=51981&action=edit
Assembly output with & without -Os optimization

Whenever any -Ox option is used, the loop exits after 3 rounds, even the
counter should run for 6 rounds. Without any -O option, the code works as
expected.