- macros have undefined behavior if T is signed and has padding bits
- (i.e., bits that do not contribute to the value), or if T uses
- signed-magnitude representation. If this is a problem for you,
- please let us know how to fix it for your host. */
-#define TYPE_MINIMUM(t) ((t) (TYPE_SIGNED (t) \
- ? ~ (t) 0 << (sizeof (t) * CHAR_BIT - 1) : (t) 0))
-#define TYPE_MAXIMUM(t) ((t) (~ (t) 0 - TYPE_MINIMUM (t)))
-
-/* Bound on length of the string representing an integer value or type T.
- Subtract 1 for the sign bit if t is signed; log10 (2.0) < 146/485;
- add 1 for integer division truncation; add 1 more for a minus sign
- if needed. */
-#define INT_STRLEN_BOUND(t) \
- ((sizeof (t) * CHAR_BIT - 1) * 146 / 485 + 2)
-
-/* Bound on buffer size needed to represent an integer value or type T,
+ macros have undefined behavior if T is signed and has padding bits.
+ If this is a problem for you, please let us know how to fix it for
+ your host. */
+# define TYPE_MINIMUM(t) \
+ ((t) (! TYPE_SIGNED (t) \
+ ? (t) 0 \
+ : TYPE_SIGNED_MAGNITUDE (t) \
+ ? ~ (t) 0 \
+ : ~ TYPE_MAXIMUM (t)))
+# define TYPE_MAXIMUM(t) \
+ ((t) (! TYPE_SIGNED (t) \
+ ? (t) -1 \
+ : ((((t) 1 << (sizeof (t) * CHAR_BIT - 2)) - 1) * 2 + 1)))
+
+/* Return zero if T can be determined to be an unsigned type.
+ Otherwise, return 1.
+ When compiling with GCC, INT_STRLEN_BOUND uses this macro to obtain a
+ tighter bound. Otherwise, it overestimates the true bound by one byte
+ when applied to unsigned types of size 2, 4, 16, ... bytes.
+ The symbol signed_type_or_expr__ is private to this header file. */
+# if __GNUC__ >= 2
+# define signed_type_or_expr__(t) TYPE_SIGNED (__typeof__ (t))
+# else
+# define signed_type_or_expr__(t) 1
+# endif
+
+/* Bound on length of the string representing an unsigned integer
+ value representable in B bits. log10 (2.0) < 146/485. The
+ smallest value of B where this bound is not tight is 2621. */
+# define INT_BITS_STRLEN_BOUND(b) (((b) * 146 + 484) / 485)
+
+/* Bound on length of the string representing an integer type or expression T.
+ Subtract 1 for the sign bit if T is signed, and then add 1 more for
+ a minus sign if needed. */
+# define INT_STRLEN_BOUND(t) \
+ (INT_BITS_STRLEN_BOUND (sizeof (t) * CHAR_BIT - signed_type_or_expr__ (t)) \
+ + signed_type_or_expr__ (t))
+
+/* Bound on buffer size needed to represent an integer type or expression T,