diff options
Diffstat (limited to 'lib/intprops.h')
| -rw-r--r-- | lib/intprops.h | 45 |
1 files changed, 22 insertions, 23 deletions
diff --git a/lib/intprops.h b/lib/intprops.h index a278497b744..31521395e2a 100644 --- a/lib/intprops.h +++ b/lib/intprops.h @@ -21,6 +21,7 @@ #define _GL_INTPROPS_H #include <limits.h> +#include <verify.h> /* Return a value with the common real type of E and V and the value of V. */ #define _GL_INT_CONVERT(e, v) (0 * (e) + (v)) @@ -36,17 +37,6 @@ an integer. */ #define TYPE_IS_INTEGER(t) ((t) 1.5 == 1) -/* True if negative values of the signed integer type T use two's - complement, ones' complement, or signed magnitude representation, - respectively. Much GNU code assumes two's complement, but some - people like to be portable to all possible C hosts. */ -#define TYPE_TWOS_COMPLEMENT(t) ((t) ~ (t) 0 == (t) -1) -#define TYPE_ONES_COMPLEMENT(t) ((t) ~ (t) 0 == 0) -#define TYPE_SIGNED_MAGNITUDE(t) ((t) ~ (t) 0 < (t) -1) - -/* True if the signed integer expression E uses two's complement. */ -#define _GL_INT_TWOS_COMPLEMENT(e) (~ _GL_INT_CONVERT (e, 0) == -1) - /* True if the real type T is signed. */ #define TYPE_SIGNED(t) (! ((t) 0 < (t) -1)) @@ -55,18 +45,10 @@ #define EXPR_SIGNED(e) (_GL_INT_NEGATE_CONVERT (e, 1) < 0) -/* Minimum and maximum values for integer types and expressions. These - 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. */ +/* Minimum and maximum values for integer types and expressions. */ /* The maximum and minimum values for the integer type T. */ -#define TYPE_MINIMUM(t) \ - ((t) (! TYPE_SIGNED (t) \ - ? (t) 0 \ - : TYPE_SIGNED_MAGNITUDE (t) \ - ? ~ (t) 0 \ - : ~ TYPE_MAXIMUM (t))) +#define TYPE_MINIMUM(t) ((t) ~ TYPE_MAXIMUM (t)) #define TYPE_MAXIMUM(t) \ ((t) (! TYPE_SIGNED (t) \ ? (t) -1 \ @@ -76,7 +58,7 @@ after integer promotion. E should not have side effects. */ #define _GL_INT_MINIMUM(e) \ (EXPR_SIGNED (e) \ - ? - _GL_INT_TWOS_COMPLEMENT (e) - _GL_SIGNED_INT_MAXIMUM (e) \ + ? ~ _GL_SIGNED_INT_MAXIMUM (e) \ : _GL_INT_CONVERT (e, 0)) #define _GL_INT_MAXIMUM(e) \ (EXPR_SIGNED (e) \ @@ -85,8 +67,25 @@ #define _GL_SIGNED_INT_MAXIMUM(e) \ (((_GL_INT_CONVERT (e, 1) << (sizeof ((e) + 0) * CHAR_BIT - 2)) - 1) * 2 + 1) +/* This include file assumes that signed types are two's complement without + padding bits; the above macros have undefined behavior otherwise. + If this is a problem for you, please let us know how to fix it for your host. + As a sanity check, test the assumption for some signed types that + <limits.h> bounds. */ +verify (TYPE_MINIMUM (signed char) == SCHAR_MIN); +verify (TYPE_MAXIMUM (signed char) == SCHAR_MAX); +verify (TYPE_MINIMUM (short int) == SHRT_MIN); +verify (TYPE_MAXIMUM (short int) == SHRT_MAX); +verify (TYPE_MINIMUM (int) == INT_MIN); +verify (TYPE_MAXIMUM (int) == INT_MAX); +verify (TYPE_MINIMUM (long int) == LONG_MIN); +verify (TYPE_MAXIMUM (long int) == LONG_MAX); +#ifdef LLONG_MAX +verify (TYPE_MINIMUM (long long int) == LLONG_MIN); +verify (TYPE_MAXIMUM (long long int) == LLONG_MAX); +#endif -/* Return 1 if the __typeof__ keyword works. This could be done by +/* Does the __typeof__ keyword work? This could be done by 'configure', but for now it's easier to do it by hand. */ #if (2 <= __GNUC__ || defined __IBM__TYPEOF__ \ || (0x5110 <= __SUNPRO_C && !__STDC__)) |