[Bug target/49226] problematic _Complex long double argument passing

[rsandifo at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=49226

--- Comment #2 from rsandifo at gcc dot gnu.org <rsandifo at gcc dot gnu.org> ---
Created attachment 31497
  --> http://gcc.gnu.org/bugzilla/attachment.cgi?id=31497&action=edit
attempt to avoid invalid hard regs

This patch uses the equivalent integer modes instead of
:XC and :XF when passing arguments in GPRs.  I worked
through the before and after asm and they seem to be
equivalent, but I'd appreciate it if someone with
access to ia64 could try it out.

The after asm seems to be worse, but this kind of usage
shouldn't occur in performance-critical code anyway.  I think
if the speed :XC and :XF GPR handling is a concern we'd be
better off making the modes valid.