[Bug target/58139] PowerPC volatile VSX register live across call

[macro@linux-mips.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=58139

Maciej W. Rozycki <macro@linux-mips.org> changed:

           What    |Removed                     |Added
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                 CC|                            |macro@linux-mips.org

--- Comment #13 from Maciej W. Rozycki <macro@linux-mips.org> ---
This breaks Power SPE targets, at least the Linux OS, almost surely EABI
too.  Seen in 4.8 powerpc-linux-gnu g++ and libstdc++ testing as some 700
regressions e.g. with these compiler options:

-mcpu=8540 -mfloat-gprs=single -mspe=yes -mabi=spe

The cause is a DWARF2 unwinder abort triggered by:

gcc_assert (size == sizeof(_Unwind_Word));

in _Unwind_SetSpColumn and the cause is with this change applied `size'
is 8 whereas `sizeof(_Unwind_Word)' is 4.  Previously `size' was 4.

For 4.8 please revert unless a better fix can be made within the
available time frame.  Let me know if I can assist with testing.