2005-12-16 Jon Grimm <jgrimm2@us.ibm.com>

[thirdparty/gcc.git] / gcc / doc / extend.texi

diff --git a/gcc/doc/extend.texi b/gcc/doc/extend.texi
index 341d6248cdedfbed42ad963cc661d95f45eb6d54..0d54654adce8b1799ee89c3e76a42e17e514eeac 100644 (file)
--- a/gcc/doc/extend.texi
+++ b/gcc/doc/extend.texi
@@ -1,5 +1,6 @@
-@c Copyright (C) 1988,1989,1992,1993,1994,1996,1998,1999,2000,2001,2002,2003,2004,2005
-@c Free Software Foundation, Inc.
+@c Copyright (C) 1988, 1989, 1992, 1993, 1994, 1996, 1998, 1999, 2000,
+@c 2001, 2002, 2003, 2004, 2005 Free Software Foundation, Inc.
+
 @c This is part of the GCC manual.
 @c For copying conditions, see the file gcc.texi.
 
@@ -32,6 +33,7 @@ extensions, accepted by GCC in C89 mode and in C++.
 * Conditionals::        Omitting the middle operand of a @samp{?:} expression.
 * Long Long::          Double-word integers---@code{long long int}.
 * Complex::             Data types for complex numbers.
+* Decimal Float::      Decimal Floating Point. 
 * Hex Floats::          Hexadecimal floating-point constants.
 * Zero Length::         Zero-length arrays.
 * Variable Length::     Arrays whose length is computed at run time.
@@ -813,6 +815,42 @@ If the variable's actual name is @code{foo}, the two fictitious
 variables are named @code{foo$real} and @code{foo$imag}.  You can
 examine and set these two fictitious variables with your debugger.
 
+@node Decimal Float
+@section Decimal Floating Point
+@cindex decimal floating point
+@cindex @code{_Decimal32} data type
+@cindex @code{_Decimal64} data type
+@cindex @code{_Decimal128} data type
+@cindex @code{df} integer suffix
+@cindex @code{dd} integer suffix
+@cindex @code{dl} integer suffix
+@cindex @code{DF} integer suffix
+@cindex @code{DD} integer suffix
+@cindex @code{DL} integer suffix
+
+GNU C supports decimal floating point types in addition to the
+standard floating-point types.  This extension supports decimal
+floating-point arithmetic as defined in IEEE-754R, the proposed
+revision of IEEE-754.  The C language extension is defined in ISO/IEC
+DTR 24732, Draft 5.  Support for this functionality will change when
+it is accepted into the C standard and might change for new drafts
+of the proposal.  Calling conventions for any target might also change.
+Not all targets support decimal floating point.
+
+Support for decimal floating point includes the arithmetic operators
+add, subtract, multiply, divide; unary arithmetic operators;
+relational operators; equality operators; and conversions to and from
+integer and other floating-point types.  Use a suffix @samp{df} or
+@samp{DF} in a literal constant of type @code{_Decimal32}, @samp{dd}
+or @samp{DD} for @code{_Decimal64}, and @samp{dl} or @samp{DL} for
+@code{_Decimal128}.
+
+Passing a decimal floating-point value as an argument to a function
+without a prototype is undefined.
+
+Types @code{_Decimal32}, @code{_Decimal64}, and @code{_Decimal128}
+are supported by the DWARF2 debug information format.
+
 @node Hex Floats
 @section Hex Floats
 @cindex hex floats
@@ -5661,6 +5699,18 @@ Similar to @code{__builtin_huge_val}, except a warning is generated
 if the target floating-point format does not support infinities.
 @end deftypefn
 
+@deftypefn {Built-in Function} _Decimal32 __builtin_infd32 (void)
+Similar to @code{__builtin_inf}, except the return type is @code{_Decimal32}.
+@end deftypefn
+
+@deftypefn {Built-in Function} _Decimal64 __builtin_infd64 (void)
+Similar to @code{__builtin_inf}, except the return type is @code{_Decimal64}.
+@end deftypefn
+
+@deftypefn {Built-in Function} _Decimal128 __builtin_infd128 (void)
+Similar to @code{__builtin_inf}, except the return type is @code{_Decimal128}.
+@end deftypefn
+
 @deftypefn {Built-in Function} float __builtin_inff (void)
 Similar to @code{__builtin_inf}, except the return type is @code{float}.
 This function is suitable for implementing the ISO C99 macro @code{INFINITY}.
@@ -5687,6 +5737,18 @@ This function, if given a string literal, is evaluated early enough
 that it is considered a compile-time constant.
 @end deftypefn
 
+@deftypefn {Built-in Function} _Decimal32 __builtin_nand32 (const char *str)
+Similar to @code{__builtin_nan}, except the return type is @code{_Decimal32}.
+@end deftypefn
+
+@deftypefn {Built-in Function} _Decimal64 __builtin_nand64 (const char *str)
+Similar to @code{__builtin_nan}, except the return type is @code{_Decimal64}.
+@end deftypefn
+
+@deftypefn {Built-in Function} _Decimal128 __builtin_nand128 (const char *str)
+Similar to @code{__builtin_nan}, except the return type is @code{_Decimal128}.
+@end deftypefn
+
 @deftypefn {Built-in Function} float __builtin_nanf (const char *str)
 Similar to @code{__builtin_nan}, except the return type is @code{float}.
 @end deftypefn