[Bug tree-optimization/101508] [9/10/11/12 Regression] Possible undefined behaviour in cpp program using "unsigned" type starting with r9-4145

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

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=101508

Jakub Jelinek <jakub at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |amker at gcc dot gnu.org
             Status|UNCONFIRMED                 |NEW
   Last reconfirmed|                            |2021-07-19
            Summary|Possible undefined          |[9/10/11/12 Regression]
                   |behaviour in cpp program    |Possible undefined
                   |using "unsigned" type       |behaviour in cpp program
                   |starting from GCC 9         |using "unsigned" type
                   |                            |starting with r9-4145
   Target Milestone|---                         |9.5
     Ever confirmed|0                           |1

--- Comment #1 from Jakub Jelinek <jakub at gcc dot gnu.org> ---
Started with r9-4145-ga81e2c6240655f60a49c16e0d8bbfd2ba40bba51
Simplified C testcase:
int
main ()
{
  unsigned i;
  for (i = 0; i < 3; ++i)
    {
      if (i > i * 2)
        __builtin_abort ();
    }
  return 0;
}