[Bug c/95049] New: GCC never terminates with trivial input program

[luis at luismarques dot eu]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=95049

            Bug ID: 95049
           Summary: GCC never terminates with trivial input program
           Product: gcc
           Version: 9.1.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c
          Assignee: unassigned at gcc dot gnu.org
          Reporter: luis at luismarques dot eu
  Target Milestone: ---

Since at least GCC 9.1 the following trivial program results in an infinite
compilation time when compiling with -O2 or higher. This continues to happen
with GCC trunk as of the date of filing this bug.

void a() {
  for (int b; b; b = !b) {
  }
}