[Bug tree-optimization/37542] New: PRE doesn't simplify during phi-translation

[rguenth at gcc dot gnu dot org]

Related to the XFAIL of gcc.dg/tree-ssa/ssa-pre-15.c (PR37145).  The general
issue is that PRE doesn't simplify expressions during phi-translation
which can be seen for example for

int foo (int i, int b)
{
  int j = 1;
  if (b)
    j = i;
  return j - i;
}

where j - i is partially redundant.


-- 
           Summary: PRE doesn't simplify during phi-translation
           Product: gcc
           Version: 4.4.0
            Status: UNCONFIRMED
          Keywords: missed-optimization
          Severity: normal
          Priority: P3
         Component: tree-optimization
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: rguenth at gcc dot gnu dot org


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=37542