[Bug middle-end/17886] New: variable rotate and long long rotate should be better optimized

[ak at muc dot de]

gcc can detect the (x << y)|(x >> (bitwidth-y)) idiom for rotate and convert
it into the machine rotate instruction. But it only works when y is a constant
and is not long long.

Enhancement request is to handle it for long long too (on 32bit) and
to handle variable shifts.

The attached test case should use rol in f1-f4

-- 
           Summary: variable rotate and long long rotate should be better
                    optimized
           Product: gcc
           Version: 4.0.0
            Status: UNCONFIRMED
          Severity: enhancement
          Priority: P2
         Component: middle-end
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: ak at muc dot de
                CC: gcc-bugs at gcc dot gnu dot org
GCC target triplet: i386-linux


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=17886