https://gcc.gnu.org/bugzilla/show_bug.cgi?id=90181
--- Comment #5 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
Actually it is not as bad if you use preprocessor tricks.
Like this code from glibc for aarch64:
# undef INTERNAL_SYSCALL_RAW
# define INTERNAL_SYSCALL_RAW(name, err, nr, args...) \
({ long _sys_result; \
{ \
LOAD_ARGS_##nr (args) \
register long _x8 asm ("x8") = (name); \
asm volatile ("svc 0 // syscall " # name \
: "=r" (_x0) : "r"(_x8) ASM_ARGS_##nr : "memory"); \
_sys_result = _x0; \
} \
_sys_result; })
# define LOAD_ARGS_0() \
register long _x0 asm ("x0");
# define LOAD_ARGS_1(x0) \
long _x0tmp = (long) (x0); \
LOAD_ARGS_0 () \
_x0 = _x0tmp;
# define LOAD_ARGS_2(x0, x1) \
long _x1tmp = (long) (x1); \
LOAD_ARGS_1 (x0) \
register long _x1 asm ("x1") = _x1tmp;
# define LOAD_ARGS_3(x0, x1, x2) \
long _x2tmp = (long) (x2); \
LOAD_ARGS_2 (x0, x1) \
register long _x2 asm ("x2") = _x2tmp;
# define LOAD_ARGS_4(x0, x1, x2, x3) \
long _x3tmp = (long) (x3); \
LOAD_ARGS_3 (x0, x1, x2) \
register long _x3 asm ("x3") = _x3tmp;
# define LOAD_ARGS_5(x0, x1, x2, x3, x4) \
long _x4tmp = (long) (x4); \
LOAD_ARGS_4 (x0, x1, x2, x3) \
register long _x4 asm ("x4") = _x4tmp;
# define LOAD_ARGS_6(x0, x1, x2, x3, x4, x5) \
long _x5tmp = (long) (x5); \
LOAD_ARGS_5 (x0, x1, x2, x3, x4) \
register long _x5 asm ("x5") = _x5tmp;
# define LOAD_ARGS_7(x0, x1, x2, x3, x4, x5, x6)\
long _x6tmp = (long) (x6); \
LOAD_ARGS_6 (x0, x1, x2, x3, x4, x5) \
register long _x6 asm ("x6") = _x6tmp;
# define ASM_ARGS_0
# define ASM_ARGS_1 , "r" (_x0)
# define ASM_ARGS_2 ASM_ARGS_1, "r" (_x1)
# define ASM_ARGS_3 ASM_ARGS_2, "r" (_x2)
# define ASM_ARGS_4 ASM_ARGS_3, "r" (_x3)
# define ASM_ARGS_5 ASM_ARGS_4, "r" (_x4)
# define ASM_ARGS_6 ASM_ARGS_5, "r" (_x5)
# define ASM_ARGS_7 ASM_ARGS_6, "r" (_x6)
