-#define abs(x) __builtin_choose_expr(sizeof(x) == sizeof(s64), ({ \
- s64 __x = (x); \
- (__x < 0) ? -__x : __x; \
- }), ({ \
- long ret; \
- if (sizeof(x) == sizeof(long)) { \
- long __x = (x); \
- ret = (__x < 0) ? -__x : __x; \
- } else { \
- int __x = (x); \
- ret = (__x < 0) ? -__x : __x; \
- } \
- ret; \
- }))
+#define abs(x) __abs_choose_expr(x, long long, \
+ __abs_choose_expr(x, long, \
+ __abs_choose_expr(x, int, \
+ __abs_choose_expr(x, short, \
+ __abs_choose_expr(x, char, \
+ __builtin_choose_expr( \
+ __builtin_types_compatible_p(typeof(x), char), \
+ (char)({ signed char __x = (x); __x<0?-__x:__x; }), \
+ ((void)0)))))))
+
+#define __abs_choose_expr(x, type, other) __builtin_choose_expr( \
+ __builtin_types_compatible_p(typeof(x), signed type) || \
+ __builtin_types_compatible_p(typeof(x), unsigned type), \
+ ({ signed type __x = (x); __x < 0 ? -__x : __x; }), other)