[Bug middle-end/43184] New: gcc could not vectorize floating point reduction statements

["changpeng dot fang at amd dot com" <gcc-bugzilla at gcc dot gnu dot org>]

gcc 4.5 could not vectorize floating point reductions.
float sum(float a[], int n) {
 int i;
 float total=0.0;
 for(i=0; i< n; i++)
  total += a[i];
 return total;
}

"gcc -O3 -fdump-tree-vect-all" shows:
foo.c:4: note: Unsupported pattern.
foo.c:4: note: not vectorized: unsupported use in stmt.
foo.c:4: note: unexpected pattern.
foo.c:1: note: vectorized 0 loops in function.

I have verified that gcc can vectorize integer reduction, but not float and
double.


-- 
           Summary: gcc could not vectorize floating point reduction
                    statements
           Product: gcc
           Version: 4.5.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: middle-end
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: changpeng dot fang at amd dot com


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=43184