http://gcc.gnu.org/bugzilla/show_bug.cgi?id=56415
Richard Biener <rguenth at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
Target Milestone|--- |4.8.0
Summary|Performance regression |[4.8 Regression]
|after fix for 56273 |Performance regression
| |after fix for 56273
--- Comment #4 from Richard Biener <rguenth at gcc dot gnu.org> 2013-02-21
10:44:38 UTC ---
Ok, the fact is that with changes like
@@ -917,7 +839,7 @@
_201 = *_111[_200];
t[6] = _201;
_206 = _108;
- if (_108 == 8)
+ if (_108 > 7)
goto <bb 18>;
@@ -906,7 +828,7 @@
_187 = *_111[_186];
t[5] = _187;
_192 = _108;
- if (_108 != 6)
+ if (_108 > 6)
goto <bb 17>;
else
goto <bb 7>;
we weaken range information on one code-path but improve it on another.
We should be still able to figure out the original ranges though, so
this change probably only papered over the other PR.
I'll revert that change.
