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<h5 class="subsubsection">A.5.3.3 IEEE Floating Point</h5>

<p><a name="index-IEEE-floating-point-representation-3810"></a><a name="index-floating-point_002c-IEEE-3811"></a>
Here is an example showing how the floating type measurements come out
for the most common floating point representation, specified by the
<cite>IEEE Standard for Binary Floating Point Arithmetic (ANSI/IEEE Std
754-1985)</cite>.  Nearly all computers designed since the 1980s use this
format.

   <p>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.

   <p>So, for an implementation that uses this representation for the
<code>float</code> data type, appropriate values for the corresponding
parameters are:

<pre class="smallexample">     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
</pre>
   <p>Here are the values for the <code>double</code> data type:

<pre class="smallexample">     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
</pre>
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