[Bug tree-optimization/125713] [14/15/16/17 Regression] wrong code at -O1 on x86_64-linux-gnu since r14-2709

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

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=125713

--- Comment #6 from Richard Biener <rguenth at gcc dot gnu.org> ---
Possibly

-  if (v_8 == _20)
+  ivtmp.21_2 = ivtmp.21_12 + 274202625;
+  if (w_28 == _22)

where

-  v_8 = v_26 + -274202625;

but

+  _23 = (unsigned short) w_28;
+  _29 = _23 + 65534;
+  w_10 = (short int) _29;

so the IV equality might be bogus.