On Tue, 21 Jan 2014, Richard Sandiford wrote: > And as you imply, o32+fp64 is already an established ABI so I think we > have to support the current form alongside any new one. I agree with > Joseph that it'd be better to realign the stack dynamically instead. > This is what x86 does, so it's well tested within gcc.
With glibc, o32+fp64 is not established - the glibc patch submitted in November needs more work as I noted in my review, likely to include dynamic linker names distinct from those used for o32+fp32. So it would be possible to declare that only a new form is supported with glibc (more generally, with the Linux kernel, given the lack of current kernel support for o32+fp64 stated in the glibc discussion), with appropriate configure checks preventing building glibc with an old-ABI o32+fp64 compiler (and ideally a #error in some glibc header disallowing building programs with an old-ABI o32+fp64 compiler). -- Joseph S. Myers jos...@codesourcery.com