[Bug target/53512] New: SH Target: Allow fsca and fsrra for non-SH4A

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

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=53512

             Bug #: 53512
           Summary: SH Target: Allow fsca and fsrra for non-SH4A
    Classification: Unclassified
           Product: gcc
           Version: 4.8.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: target
        AssignedTo: unassigned@gcc.gnu.org
        ReportedBy: olegendo@gcc.gnu.org
                CC: kkojima@gcc.gnu.org
            Target: sh4*-*-*


Currently the fsca and fsrra insns are available only for SH4A.  However, there
are some SH4 variants around (e.g. SH7091) that also support those insns.
My idea was to add the following options:
  -mfsca, -mno-fsca
  -mfsrra, -mno-fsrra
...to be able to manually enable/disable the respective insns.  On SH4A -mfsca
and -mfsrra would be enabled by default when setting 
-funsafe-math-optimizations, which would preserve the current behavior.
Any objections?