C.1.13 体系结构 (J.3.13)

• 为头文件 <float.h>、<limits.h> 和 <stdint.h> 中指定的宏分配的值或表达式 (5.2.4.2, 7.18.2, 7.18.3)。

  • 下面是可用于 <float.h> 中所指定宏的值或表达式：

    #define CHAR_BIT 8 /* max # of bits in a “char” */
    #define SCHAR_MIN (-128) /* min value of a “signed char” */
    #define SCHAR_MAX 127 /* max value of a “signed char” */
    #define CHAR_MIN SCHAR_MIN /* min value of a “char” */
    #define CHAR_MAX SCHAR_MAX /* max value of a “char” */
    #define MB_LEN_MAX 5
    #define SHRT_MIN (-32768) /* min value of a “short int” */
    #define SHRT_MAX 32767 /* max value of a “short int” */
    #define USHRT_MAX 65535 /* max value of “unsigned short int” */
    #define INT_MIN (-2147483647-1) /* min value of an “int” */
    #define INT_MAX 2147483647 /* max value of an “int” */
    #define UINT_MAX 4294967295U /* max value of an “unsigned int” */
    #define LONG_MIN (-2147483647L-1L)
    #define LONG_MAX 2147483647L /* max value of a “long int” */
    #define ULONG_MAX 4294967295UL /* max value of “unsigned long int” */
    #define LLONG_MIN (-9223372036854775807LL-1LL)
    #define LLONG_MAX 9223372036854775807LL
    #define ULLONG_MAX 18446744073709551615ULL
    
    #define FLT_RADIX 2
    #define FLT_MANT_DIG 24
    #define DBL_MANT_DIG 53
    #define LDBL_MANT_DIG 64
    
    #if defined(__sparc)
    #define DECIMAL_DIG 36
    #elif defined(__i386)
    #define DECIMAL_DIG 21
    #endif
    #define FLT_DIG 6
    #define DBL_DIG 15
    #if defined(__sparc)
    #define LDBL_DIG 33
    #elif defined(__i386)
    #define LDBL_DIG 18
    #endif
    
    #define FLT_MIN_EXP (-125)
    #define DBL_MIN_EXP (-1021)
    #define LDBL_MIN_EXP (-16381)
    
    #define FLT_MIN_10_EXP (-37)
    #define DBL_MIN_10_EXP (-307)
    #define LDBL_MIN_10_EXP (-4931)
    
    #define FLT_MAX_EXP (+128)
    #define DBL_MAX_EXP (+1024)
    #define LDBL_MAX_EXP (+16384)
    
    #define FLT_EPSILON 1.192092896E-07F
    #define DBL_EPSILON 2.2204460492503131E-16
    
    #if defined(__sparc)
    #define LDBL_EPSILON 1.925929944387235853055977942584927319E-34L
    #elif defined(__i386)
    #define LDBL_EPSILON 1.0842021724855044340075E-19L
    #endif
    
    #define FLT_MIN 1.175494351E-38F
    #define DBL_MIN 2.2250738585072014E-308
    
    #if defined(__sparc)
    #define LDBL_MIN 3.362103143112093506262677817321752603E-4932L
    #elif defined(__i386)
    #define LDBL_MIN 3.3621031431120935062627E-4932L
    #endif

  下面是可用于 <limits.h> 中所指定宏的值或表达式：

  #define INT8_MAX (127)
  #define INT16_MAX (32767)
  #define INT32_MAX (2147483647)
  #define INT64_MAX (9223372036854775807LL)
  
  #define INT8_MIN (-128)
  #define INT16_MIN (-32767-1)
  #define INT32_MIN (-2147483647-1)
  #define INT64_MIN (-9223372036854775807LL-1)
  
  #define UINT8_MAX (255U)
  #define UINT16_MAX (65535U)
  #define UINT32_MAX (4294967295U)
  #define UINT64_MAX (18446744073709551615ULL)
  
  #define INT_LEAST8_MIN INT8_MIN
  #define INT_LEAST16_MIN INT16_MIN
  #define INT_LEAST32_MIN INT32_MIN
  #define INT_LEAST64_MIN INT64_MIN
  
  #define INT_LEAST8_MAX INT8_MAX
  #define INT_LEAST16_MAX INT16_MAX
  #define INT_LEAST32_MAX INT32_MAX
  #define INT_LEAST64_MAX INT64_MAX
  
  #define UINT_LEAST8_MAX UINT8_MAX
  #define UINT_LEAST16_MAX UINT16_MAX
  #define UINT_LEAST32_MAX UINT32_MAX
  #define UINT_LEAST64_MAX UINT64_MAX

• 下面是可用于 <stdint.h> 中所指定宏的值或表达式：

  #define INT_FAST8_MIN INT8_MIN
  #define INT_FAST16_MIN INT16_MIN
  #define INT_FAST32_MIN INT32_MIN
  #define INT_FAST64_MIN INT64_MIN
  
  #define INT_FAST8_MAX INT8_MAX
  #define INT_FAST16_MAX INT16_MAX
  #define INT_FAST32_MAX INT32_MAX
  #define INT_FAST64_MAX INT64_MAX
  
  #define UINT_FAST8_MAX UINT8_MAX
  #define UINT_FAST16_MAX UINT16_MAX
  #define UINT_FAST32_MAX UINT32_MAX
  #define UINT_FAST64_MAX UINT64_MAX

• 在任何对象（如果此国际标准中未明确指定）中字节的数值、顺序和编码 (6.2.6.1)。

本章中其他位置的内容定义了 1999 C 标准中未明确指定的对象的实现定义数值、顺序和编码。

• sizeof 操作符结果的值 (6.5.3.4)。

  下表列出了 sizeof 的结果。