[Bug target/57150] New: GCC when targeting power7 spills long double using VSX instructions.

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

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=57150

             Bug #: 57150
           Summary: GCC when targeting power7 spills long double using VSX
                    instructions.
    Classification: Unclassified
           Product: gcc
           Version: 4.9.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: target
        AssignedTo: unassigned@gcc.gnu.org
        ReportedBy: meissner@gcc.gnu.org


Created attachment 30008
  --> http://gcc.gnu.org/bugzilla/attachment.cgi?id=30008
Cut down example to show the problem, using -mcpu=power7 -m64

In the glibc file e_scalbl.c, the compiler is using VSX stxvd2x and lxvd2x
instructions to spill long double, even though only 1/2 of the register is
used.  The compiler should use scalar load/store instructions.