[Bug tree-optimization/20544] New: missed tree-fold opportunity (shift of shifted value).

[rearnsha at gcc dot gnu dot org]

This code should really be simplified to a single shift before the end of the
tree optimization passes.  Once we've expanded to RTL this is likely to be too
complex to simplify on a 32-bit machine.

unsigned long long int shifttwice(unsigned long long int v)
{
        return v << 31 << 1;
}

-- 
           Summary: missed tree-fold opportunity (shift of shifted value).
           Product: gcc
           Version: 4.1.0
            Status: UNCONFIRMED
          Keywords: missed-optimization
          Severity: minor
          Priority: P3
         Component: tree-optimization
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: rearnsha at gcc dot gnu dot org
                CC: gcc-bugs at gcc dot gnu dot org


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=20544