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 <h3 class="section">4.6 Floating point</h3>

      <ul>
 <li><cite>The accuracy of the floating-point operations and of the library
 functions in </cite><code>&lt;math.h&gt;</code><cite> and </cite><code>&lt;complex.h&gt;</code><cite> that return floating-point
 results (C90 and C99 5.2.4.2.2).</cite>

      <p>The accuracy is unknown.

      <li><cite>The rounding behaviors characterized by non-standard values
 of </cite><code>FLT_ROUNDS</code><cite>
 (C90 and C99 5.2.4.2.2).</cite>

      <p>GCC does not use such values.

      <li><cite>The evaluation methods characterized by non-standard negative
 values of </cite><code>FLT_EVAL_METHOD</code><cite> (C99 5.2.4.2.2).</cite>

      <p>GCC does not use such values.

      <li><cite>The direction of rounding when an integer is converted to a
 floating-point number that cannot exactly represent the original
 value (C90 6.2.1.3, C99 6.3.1.4).</cite>

      <p>C99 Annex F is followed.

      <li><cite>The direction of rounding when a floating-point number is
 converted to a narrower floating-point number (C90 6.2.1.4, C99
 6.3.1.5).</cite>

      <p>C99 Annex F is followed.

      <li><cite>How the nearest representable value or the larger or smaller
 representable value immediately adjacent to the nearest representable
 value is chosen for certain floating constants (C90 6.1.3.1, C99
 6.4.4.2).</cite>

      <p>C99 Annex F is followed.

      <li><cite>Whether and how floating expressions are contracted when not
 disallowed by the </cite><code>FP_CONTRACT</code><cite> pragma (C99 6.5).</cite>

      <p>Expressions are currently only contracted if
 <samp><span class="option">-funsafe-math-optimizations</span></samp> or <samp><span class="option">-ffast-math</span></samp> are used.
 This is subject to change.

      <li><cite>The default state for the </cite><code>FENV_ACCESS</code><cite> pragma (C99 7.6.1).</cite>

      <p>This pragma is not implemented, but the default is to &ldquo;off&rdquo; unless
 <samp><span class="option">-frounding-math</span></samp> is used in which case it is &ldquo;on&rdquo;.

      <li><cite>Additional floating-point exceptions, rounding modes, environments,
 and classifications, and their macro names (C99 7.6, C99 7.12).</cite>

      <p>This is dependent on the implementation of the C library, and is not
 defined by GCC itself.

      <li><cite>The default state for the </cite><code>FP_CONTRACT</code><cite> pragma (C99 7.12.2).</cite>

      <p>This pragma is not implemented.  Expressions are currently only
 contracted if <samp><span class="option">-funsafe-math-optimizations</span></samp> or
 <samp><span class="option">-ffast-math</span></samp> are used.  This is subject to change.

      <li><cite>Whether the &ldquo;inexact&rdquo; floating-point exception can be raised
 when the rounded result actually does equal the mathematical result
 in an IEC 60559 conformant implementation (C99 F.9).</cite>

      <p>This is dependent on the implementation of the C library, and is not
 defined by GCC itself.

      <li><cite>Whether the &ldquo;underflow&rdquo; (and &ldquo;inexact&rdquo;) floating-point
 exception can be raised when a result is tiny but not inexact in an
 IEC 60559 conformant implementation (C99 F.9).</cite>

      <p>This is dependent on the implementation of the C library, and is not
 defined by GCC itself.

 </ul>

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	<hr>
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	<h3 class="section">4.6 Floating point</h3>

	<ul>
	<li><cite>The accuracy of the floating-point operations and of the library
	functions in </cite><code><math.h></code><cite> and </cite><code><complex.h></code><cite> that return floating-point
	results (C90 and C99 5.2.4.2.2).</cite>

	<p>The accuracy is unknown.

	<li><cite>The rounding behaviors characterized by non-standard values
	of </cite><code>FLT_ROUNDS</code><cite>
	(C90 and C99 5.2.4.2.2).</cite>

	<p>GCC does not use such values.

	<li><cite>The evaluation methods characterized by non-standard negative
	values of </cite><code>FLT_EVAL_METHOD</code><cite> (C99 5.2.4.2.2).</cite>

	<p>GCC does not use such values.

	<li><cite>The direction of rounding when an integer is converted to a
	floating-point number that cannot exactly represent the original
	value (C90 6.2.1.3, C99 6.3.1.4).</cite>

	<p>C99 Annex F is followed.

	<li><cite>The direction of rounding when a floating-point number is
	converted to a narrower floating-point number (C90 6.2.1.4, C99
	6.3.1.5).</cite>

	<p>C99 Annex F is followed.

	<li><cite>How the nearest representable value or the larger or smaller
	representable value immediately adjacent to the nearest representable
	value is chosen for certain floating constants (C90 6.1.3.1, C99
	6.4.4.2).</cite>

	<p>C99 Annex F is followed.

	<li><cite>Whether and how floating expressions are contracted when not
	disallowed by the </cite><code>FP_CONTRACT</code><cite> pragma (C99 6.5).</cite>

	<p>Expressions are currently only contracted if
	<samp><span class="option">-funsafe-math-optimizations</span></samp> or <samp><span class="option">-ffast-math</span></samp> are used.
	This is subject to change.

	<li><cite>The default state for the </cite><code>FENV_ACCESS</code><cite> pragma (C99 7.6.1).</cite>

	<p>This pragma is not implemented, but the default is to “off” unless
	<samp><span class="option">-frounding-math</span></samp> is used in which case it is “on”.

	<li><cite>Additional floating-point exceptions, rounding modes, environments,
	and classifications, and their macro names (C99 7.6, C99 7.12).</cite>

	<p>This is dependent on the implementation of the C library, and is not
	defined by GCC itself.

	<li><cite>The default state for the </cite><code>FP_CONTRACT</code><cite> pragma (C99 7.12.2).</cite>

	<p>This pragma is not implemented. Expressions are currently only
	contracted if <samp><span class="option">-funsafe-math-optimizations</span></samp> or
	<samp><span class="option">-ffast-math</span></samp> are used. This is subject to change.

	<li><cite>Whether the “inexact” floating-point exception can be raised
	when the rounded result actually does equal the mathematical result
	in an IEC 60559 conformant implementation (C99 F.9).</cite>

	<p>This is dependent on the implementation of the C library, and is not
	defined by GCC itself.

	<li><cite>Whether the “underflow” (and “inexact”) floating-point
	exception can be raised when a result is tiny but not inexact in an
	IEC 60559 conformant implementation (C99 F.9).</cite>

	<p>This is dependent on the implementation of the C library, and is not
	defined by GCC itself.

	</ul>

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