Initializing floating point variable with large literal
<pre><code>#include &lt;stdio.h&gt;

int main(void) {
    double x = 0.12345678901234567890123456789;
    printf("%0.16f\n", x);
    return 0;
};
</code></pre>

<p>In the code above I'm initializing <code>x</code> with literal that is too large to be represented by the IEEE 754 double. On my PC with gcc 4.9.2 it works well. The literal is rounded to the nearest value that fits into double. I'm wondering what happens behind the scene (on the compiler level) in this case? Does this behaviour depend on the platform? Is it legal?</p>