+@node Floating Types
+@section Additional Floating Types
+@cindex additional floating types
+@cindex @code{__float80} data type
+@cindex @code{__float128} data type
+@cindex @code{w} floating point suffix
+@cindex @code{q} floating point suffix
+@cindex @code{W} floating point suffix
+@cindex @code{Q} floating point suffix
+
+As an extension, the GNU C compiler supports additional floating
+types, @code{__float80} and @code{__float128} to support 80bit
+(@code{XFmode}) and 128 bit (@code{TFmode}) 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} or @samp{W}
+in a literal constant of type @code{__float80} and @samp{q} or @samp{Q}
+for @code{_float128}. You can declare complex types using the
+corresponding internal complex type, @code{XCmode} for @code{__float80}
+type and @code{TCmode} for @code{__float128} type:
+
+@smallexample
+typedef _Complex float __attribute__((mode(TC))) _Complex128;
+typedef _Complex float __attribute__((mode(XC))) _Complex80;
+@end smallexample
+
+Not all targets support additional floating point types. @code{__float80}
+is supported on i386, x86_64 and ia64 targets and target @code{__float128}
+is supported on x86_64 and ia64 targets.
+