[Bug middle-end/35342] New: Full unrolling limitation -- inner most loop only

["xinliangli at gmail dot com" <gcc-bugzilla at gcc dot gnu dot org>]

Short trip counted loop nest (perfect or not) is not fully unrolled, only the
innnermost loop:
(-O3 -fno-tree-vectorize)

#ifndef TC
#define TC 3
#endif
int a[100][100];
int foo(void)
{
     int i, j;

     for (i = 0; i < TC; i ++)
     {
        for (j = 0; j < TC; j++)
          a[2*i][j] += a[i][j];
     }

     return 0;
}


-- 
           Summary: Full unrolling limitation -- inner most loop only
           Product: gcc
           Version: unknown
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: middle-end
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: xinliangli at gmail dot com


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=35342