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

[meissner at gcc dot gnu.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: unassig...@gcc.gnu.org

        ReportedBy: meiss...@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.