-#define __VA_ALIGNED_SIZE(x) ((sizeof(x) + sizeof(int) - 1) & ~(sizeof(int) - 1))
-
-#define va_start(ap, last) ((ap) = (void *)(((char *)&(last)) + __VA_ALIGNED_SIZE(last)))
-#define va_end(ap) ((void)0)
-#define va_copy(dest, src) ((dest) = (src))
-
-#if 0
-#define va_arg(ap, type) \
- ( ((ap) = (va_list)((char *)(ap) + sizeof(type))), \
- *(type *)(void *)((char *)(ap) - sizeof(type)) )
+#if __GNUC__ >= 3
+#define va_start(v,l) __builtin_va_start(v,l)
+#define va_end(v) __builtin_va_end(v)
+#define va_arg(v,l) __builtin_va_arg(v,l)
+#define va_copy(d,s) __builtin_va_copy(d,s)
+#else
+#include <bits/stdarg.h>