__builtin_apply issue

[Aurelien Buhrig]

Hi,

I'm trying to make __builtin_apply work for my backend (especially
gcc.dg/torture/stackalign/builtin-apply-2.c).

My target saves unnamed args to the stack, and puts named arguments into
registers (as much as possible).

For example in the following testcase:

void foo(char *name, double d, double e, double f, int g)
{
  ...
}

void bar(char *name, ...)
{
  __builtin_apply(foo, __builtin_apply_args(), 64);
}

In this example, foo expects first arguments to be in argument
registers, but bar arguments are into the stack (only).
expand_builtin_apply and expand_builtin_apply_args correctly copy
incoming args block from the stack to outgoing_args block (stack) and
set parameter registers as they were at the beginning of bar function,
and then call foo (using the "standard" untyped_call). But there is no
mechanism to copy incoming args from stack to argument registers.

How and where to handle such a case which seems to depend on both caller
and callee fndecl?

Thanks in advance,
Aurélien