https://gcc.gnu.org/bugzilla/show_bug.cgi?id=100955
Jakub Jelinek <jakub at gcc dot gnu.org> changed:
What |Removed |Added
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CC| |jakub at gcc dot gnu.org
--- Comment #2 from Jakub Jelinek <jakub at gcc dot gnu.org> ---
There is no reason not to lower __builtin_va_start (&arg, 0) to arg = .VA_START
();
for the problematic cases of __builtin_va_list being a struct and add support
for expanding both __builtin_va_start (&arg, 0) and arg = .VA_START () using
some helper code. We already similarly transform __builtin_va_start (&arg, 0)
to arg = __builtin_next_arg (0) if __builtin_va_list is a pointer (e.g. ia32).
And for the x86_64 style __builtin_va_list
where it is struct [1] we already emit the optimal code.
I'm surprised aarch64 uses a struct rather than struct [1], that must be
terribly inefficient even if you simply pass down va_list through several
functions.
