https://gcc.gnu.org/bugzilla/show_bug.cgi?id=86973
--- Comment #1 from Michael Matz <matz at gcc dot gnu.org> ---
I can reproduce the same error without any va-args:
% cat bug.i
extern void foo(void *);
__attribute__((sysv_abi))
void a(__attribute__((__vector_size__(8 * sizeof(double)))) double b){
foo(0);
}
% ./cc1 -mabi=ms -mavx512f pr86973.i
pr86973.i:4:5: internal compiler error: in expand_call, at calls.c:4218
4 | foo(0);
So, are you absolutely sure that r222173 (which delayed expansion of va_arg
until pass_stdarg) is the one that introduced this error? As far as I can
determine this is some interaction between backend and call setup going
wrong, which specifically is about a sysv_abi function (with large param)
calling a ms_abi function.
