[Bug middle-end/32503] New: __builtin_powi - optimize for other exponents besides 2 and 0.5

["burnus at gcc dot gnu dot org" <gcc-bugzilla at gcc dot gnu dot org>]

http://gcc.gnu.org/ml/gcc-patches/2007-06/msg01172.html (PR 32239):

"At the moment the vectorizer only vectorizes builtin_pow if the exponent is
either 2 or 0.5. whereas if we expand constant exponents in the gfortran
frontend (gfc_conv_cst_int_power) it vectorizes for other constant integer
powers as well (the expansion by the frontend generates a number of calls to
builtin_pow with exponent 2.0)."

Expected: The same optimization is done for multiple of 2 (and -2) - as it is
currently in the Fortran FE. (If this has been implemented in the ME, please
inform the Fortraners to remove the expansion there.)

Additionally: It would be great if there would be a variant for long integers
(8 byte integers) and long long (16 byte integers) as PR32239 could only use
__builtin_powi for int4 and not for int8 or int16.


-- 
           Summary: __builtin_powi - optimize for other exponents besides 2
                    and 0.5
           Product: gcc
           Version: 4.3.0
            Status: UNCONFIRMED
          Keywords: missed-optimization
          Severity: normal
          Priority: P3
         Component: middle-end
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: burnus at gcc dot gnu dot org


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=32503