[Bug tree-optimization/30997] FRE does not simplify comparisons in COND_EXPRs
rguenth at gcc dot gnu dot org
gcc-bugzilla@gcc.gnu.org
Mon Dec 3 15:44:00 GMT 2007
------- Comment #2 from rguenth at gcc dot gnu dot org 2007-12-03 15:44 -------
Re-confirmed with SCCVN. Note that while it value numbers the COND_EXPR on
the RHS it does not simplify the condition in the COND_EXPR stmt:
Value numbering tmp_3 stmt = tmp_3 = a_2(D) > 2;
Setting value number of tmp_3 to tmp_3
<bb 2>:
tmp_3 = a_2(D) > 2;
if (a_2(D) > 2)
goto <bb 4>;
else
goto <bb 3>;
Even if you teach FRE to do elimination in COND_EXPR statements (which it
does not do), the COND_EXPR condition has no value handle associated and
a lookup with the expression in the PRE table fails.
--
rguenth at gcc dot gnu dot org changed:
What |Removed |Added
----------------------------------------------------------------------------
CC| |dberlin at gcc dot gnu dot
| |org
Status|UNCONFIRMED |NEW
Ever Confirmed|0 |1
Last reconfirmed|0000-00-00 00:00:00 |2007-12-03 15:44:44
date| |
Summary|FRE does not value number |FRE does not simplify
|comparisons in COND_EXPRs |comparisons in COND_EXPRs
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=30997
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