(libc.info.gz) IEEE Floating Point

Info Catalog (libc.info.gz) Floating Point Parameters (libc.info.gz) Floating Type Macros
 
 A.5.3.3 IEEE Floating Point
 ...........................
 
 Here is an example showing how the floating type measurements come out
 for the most common floating point representation, specified by the
 'IEEE Standard for Binary Floating Point Arithmetic (ANSI/IEEE Std
 754-1985)'.  Nearly all computers designed since the 1980s use this
 format.
 
    The IEEE single-precision float representation uses a base of 2.
 There is a sign bit, a mantissa with 23 bits plus one hidden bit (so the
 total precision is 24 base-2 digits), and an 8-bit exponent that can
 represent values in the range -125 to 128, inclusive.
 
    So, for an implementation that uses this representation for the
 'float' data type, appropriate values for the corresponding parameters
 are:
 
      FLT_RADIX                             2
      FLT_MANT_DIG                         24
      FLT_DIG                               6
      FLT_MIN_EXP                        -125
      FLT_MIN_10_EXP                      -37
      FLT_MAX_EXP                         128
      FLT_MAX_10_EXP                      +38
      FLT_MIN                 1.17549435E-38F
      FLT_MAX                 3.40282347E+38F
      FLT_EPSILON             1.19209290E-07F
 
    Here are the values for the 'double' data type:
 
      DBL_MANT_DIG                         53
      DBL_DIG                              15
      DBL_MIN_EXP                       -1021
      DBL_MIN_10_EXP                     -307
      DBL_MAX_EXP                        1024
      DBL_MAX_10_EXP                      308
      DBL_MAX         1.7976931348623157E+308
      DBL_MIN         2.2250738585072014E-308
      DBL_EPSILON     2.2204460492503131E-016
 
Info Catalog (libc.info.gz) Floating Point Parameters (libc.info.gz) Floating Type Macros
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