[Bug tree-optimization/19938] Missed jump threading opportunity due to signedness difference

pinskia at gcc dot gnu dot org gcc-bugzilla@gcc.gnu.org
Mon Feb 14 00:26:00 GMT 2005


------- Additional Comments From pinskia at gcc dot gnu dot org  2005-02-13 18:04 -------
Confirmed, but note the following in the tree level is really invalid:
  D.1187_17 = (unsigned int) length_4;
  if (j_16 != D.1187_17) goto <L2>; else goto <L4>;

as j_16 is signed and we are comparing against an unsigned type.

In which case this is an IV-OPT problem, very closely related to PR 19937 (which by the way is a wrong-
code regression).

If someone would add more checking we would have caught this earlier.

-- 
           What    |Removed                     |Added
----------------------------------------------------------------------------
  BugsThisDependsOn|                            |19937
           Severity|enhancement                 |normal
             Status|UNCONFIRMED                 |NEW
     Ever Confirmed|                            |1
   Last reconfirmed|0000-00-00 00:00:00         |2005-02-13 18:04:35
               date|                            |


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=19938



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