https://gcc.gnu.org/bugzilla/show_bug.cgi?id=125266
Richard Sandiford <rsandifo at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
Resolution|INVALID |FIXED
--- Comment #14 from Richard Sandiford <rsandifo at gcc dot gnu.org> ---
(In reply to H.J. Lu from comment #13)
> I am using
>
> /* Return the descriptor of the function ABI type from the command
> line. */
>
> static const predefined_function_abi &
> ix86_command_line_abi (void)
> {
> auto &command_line_abi = function_abis[ABI_COMMAND_LINE];
> if (!command_line_abi.initialized_p ())
> {
> /* NB: Make a copy of the default function ABI before it is
> changed by ix86_conditional_register_usage. */
> HARD_REG_SET full_reg_clobbers
> = default_function_abi.full_reg_clobbers ();
> command_line_abi.initialize (ABI_COMMAND_LINE, full_reg_clobbers);
> }
> return command_line_abi;
> }
>
> to get the command line function ABI. ix86_command_line_abi is first called
> from
>
> static void
> ix86_conditional_register_usage (void)
> {
> int i, c_mask;
>
> if (cfun)
> {
> /* NB: Call ix86_command_line_abi to make a copy of the default
> function ABI from the command line before it is changed. */
> ix86_command_line_abi ();
>
> It seems to work.
That seems quite complicated. Why do you need it? Normally the default
function ABI is a property of the configuration, not the command line.
Also: the default ABI is (by definition) the ABI that describes which registers
are preserved on exception edges.
I don't know if you've looked at it, but aarch64 already uses function_abi for
preserve_none. Like x86, aarch64 allows the target to be changed with function
attributes, which has the effect of enabling and disabling registers. But
aarch64_conditional_register_usage doesn't depend on cfun at all.
