[Bug rtl-optimization/54524] [4.6/4.7/4.8 Regression] Spurious add on sum of bitshifts (forward-propagate issue)

[pinskia at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=54524



--- Comment #6 from Andrew Pinski <pinskia at gcc dot gnu.org> 2012-09-22 
22:26:37 UTC ---

I think this code:

  /* (LTU/GEU (PLUS a C) C), where C is constant, can be simplified to

     (GEU/LTU a -C).  Likewise for (LTU/GEU (PLUS a C) a).  */



Is what is causing the issue as that is only true if C is non-zero.