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| <title>Using the GNU Compiler Collection (GCC): Floating Types</title> |
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| <a name="Additional-Floating-Types"></a> |
| <h3 class="section">6.11 Additional Floating Types</h3> |
| <a name="index-additional-floating-types"></a> |
| <a name="index-_005f_005ffloat80-data-type"></a> |
| <a name="index-_005f_005ffloat128-data-type"></a> |
| <a name="index-w-floating-point-suffix"></a> |
| <a name="index-q-floating-point-suffix"></a> |
| <a name="index-W-floating-point-suffix"></a> |
| <a name="index-Q-floating-point-suffix"></a> |
| |
| <p>As an extension, GNU C supports additional floating |
| types, <code>__float80</code> and <code>__float128</code> to support 80-bit |
| (<code>XFmode</code>) and 128-bit (<code>TFmode</code>) floating types. |
| Support for additional types includes the arithmetic operators: |
| add, subtract, multiply, divide; unary arithmetic operators; |
| relational operators; equality operators; and conversions to and from |
| integer and other floating types. Use a suffix ‘<samp>w</samp>’ or ‘<samp>W</samp>’ |
| in a literal constant of type <code>__float80</code> and ‘<samp>q</samp>’ or ‘<samp>Q</samp>’ |
| for <code>_float128</code>. You can declare complex types using the |
| corresponding internal complex type, <code>XCmode</code> for <code>__float80</code> |
| type and <code>TCmode</code> for <code>__float128</code> type: |
| </p> |
| <div class="smallexample"> |
| <pre class="smallexample">typedef _Complex float __attribute__((mode(TC))) _Complex128; |
| typedef _Complex float __attribute__((mode(XC))) _Complex80; |
| </pre></div> |
| |
| <p>Not all targets support additional floating-point types. <code>__float80</code> |
| and <code>__float128</code> types are supported on i386, x86_64 and IA-64 targets. |
| The <code>__float128</code> type is supported on hppa HP-UX targets. |
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