Extend this attribute to cover long double ABIs, for 64-bit too.
This patch also corrects an error that crept in to code setting
rs6000_passes_float. See the added comment. Passing IEEE128 values
in vsx regs ought to set both Tag_GNU_Power_ABI_FP and
Tag_GNU_Power_ABI_Vector. Also adds a new option, default on, that
disables output of .gnu_attribute assembly directives.
* config/rs6000/sysv4.opt (mgnu-attribute): New option.
* doc/invoke.texi: Document it.
* config/rs6000/rs6000.c (HAVE_LD_PPC_GNU_ATTR_LONG_DOUBLE): Define.
(rs6000_passes_float): Comment.
(rs6000_passes_long_double): New static var.
(call_ABI_of_interest): Return false unless rs6000_gnu_attr is set.
(init_cumulative_args): Set up to emit fp .gnu_attribute for
ELF 64-bit ABIs as well as 32-bit ELF. Correct rs6000_passes_float
to include fp values returned in vectors.
Set rs6000_passes_long_double.
(rs6000_function_arg_advance_1): Likewise for function args.
(rs6000_elf_file_end): Emit fp .gnu_attribute for ELF 64-bit ABIs,
and SPE. Emit long double tag value too.
(rs6000_opt_vars): Add gnu-attr.
* configure.ac (HAVE_LD_PPC_GNU_ATTR_LONG_DOUBLE): New ppc32 test.
* configure: Regenerate.
* config.in: Regenerate.
From-SVN: r240601
