[Bug rtl-optimization/37471] New: Move invariant pulls too many cmps out of a loop

[pinskia at gcc dot gnu dot org]

I was looking at some code generation for an internal benchmark when I noticed
this.  With the current trunk on powerpc, we get a mfcr which is slow for the
cell (and most likely other PPCs too) as we pulled too many cmps with some
loops.
A simple example:
int f(int b, int l, int d, int c, int e)
{
  int i = 0;
  for(i = 0;i< l;i ++)
  {
    if (b)
      g();
    if (c)
      g();
    if (d)
      g();
    if (e)
      g();
  }
}


-- 
           Summary: Move invariant pulls too many cmps out of a loop
           Product: gcc
           Version: 4.4.0
            Status: UNCONFIRMED
          Keywords: missed-optimization
          Severity: normal
          Priority: P3
         Component: rtl-optimization
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: pinskia at gcc dot gnu dot org
GCC target triplet: powerpc*-*-*


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=37471