https://svn.boost.org/trac10/ticket/12075 <p> The following program demonstrates the bug: </p> <pre class="wiki">#include &lt;iostream&gt; #include &lt;limits&gt; #include &lt;boost/multiprecision/float128.hpp&gt; boost::multiprecision::float128 typedef binary128; int main() { std::cout &lt;&lt; "boost " BOOST_LIB_VERSION &lt;&lt; "\n"; std::cout &lt;&lt; "boost denorm_min: " &lt;&lt; std::numeric_limits&lt;binary128&gt;::denorm_min() &lt;&lt; "\n"; __float128 trueDenormMin=0; *reinterpret_cast&lt;char*&gt;(&amp;trueDenormMin)=1; // craft the denormal manually std::cout &lt;&lt; "true denorm_min: " &lt;&lt; binary128(trueDenormMin) &lt;&lt; "\n"; } </pre><p> Its output is </p> <pre class="wiki">boost 1_60 boost denorm_min: 0 true denorm_min: 6.47518e-4966 </pre> en-us /htdocs/site/boost.png https://svn.boost.org/trac10/ticket/12075 Trac 1.4.3 John Maddock Sun, 20 Mar 2016 09:29:41 GMT https://svn.boost.org/trac10/ticket/12075#comment:1 https://svn.boost.org/trac10/ticket/12075#comment:1 <ul> <li><strong>status</strong> <span class="trac-field-old">new</span> → <span class="trac-field-new">closed</span> </li> <li><strong>resolution</strong> → <span class="trac-field-new">fixed</span> </li> </ul> <p> Fixed in <a class="ext-link" href="https://github.com/boostorg/multiprecision/commit/eec1c310d569dcade360ca7834a71556cf6b6473"><span class="icon">​</span>https://github.com/boostorg/multiprecision/commit/eec1c310d569dcade360ca7834a71556cf6b6473</a>. </p> Ticket