[Bug middle-end/65855] SCEV / SCCP missing optimization: triangular numbers

[rguenth at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=65855

Richard Biener <rguenth at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
            Summary|missing optimization:       |SCEV / SCCP missing
                   |triangular numbers          |optimization: triangular
                   |                            |numbers

--- Comment #7 from Richard Biener <rguenth at gcc dot gnu.org> ---
From the duplicate a related testcase:

int square(int x) {
  int result = 0;
  for (int i = 0; i < x; ++i)
    result += x;
  return result;
}

is not optimized into return x * x; while llvm can do that.