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Re: mips64 ieee754 data structures
- From: Alexandre Oliva <aoliva at redhat dot com>
- To: libc-alpha at sources dot redhat dot com
- Date: 14 Mar 2003 03:40:35 -0300
- Subject: Re: mips64 ieee754 data structures
- Organization: GCC Team, Red Hat
- References: <orznnyfrg0.fsf@free.redhat.lsd.ic.unicamp.br>
On Mar 14, 2003, Alexandre Oliva <aoliva at redhat dot com> wrote:
> This patch introduces data structures describing the internal
> structures of float, double and long double on o32, n32 and n64. They
> only differ in long double, in that it's the same as double on o32 and
> a 128-bit IEEE quad on mips64-linux (it's a completely different,
> unsupported animal on say Irix).
In private discussion, Roland suggested me to try to fold all of
mips/ieee754.h, ieee754/ieee754.h and ieee754/ldbl-128/ieee754.h into
a single file. This patch implements this solution. It may enable
other port maintainers to get rid of their port-specific ieee754.h as
well. Using float.h instead of __LONG_DOUBLE_BIT__ like the earlier
revision of the patch did, enables us to remain compilable with GCC
3.2 as well. Ok?
> +#if 0
> + union ieee754_double pair[2];
> +#else
> + /* This is all wrong! This is not the format used for long
> + doubles. */
Oops. This should have been removed a long time ago, when it was
decided that mips64-linux would use IEEE quads, and not the
non-standard pair-of-doubles format used on IRIX.
Index: ChangeLog
2003-03-14 Alexandre Oliva <aoliva at redhat dot com>
* sysdeps/ieee754/ldbl-128/ieee754.h: Merge into... *
sysdeps/ieee754/ieee754.h: This file. Include float.h. Use
LDBL_MANT_DIG to tell which long double format to use. Add
support for long double that is identical to double.
Index: sysdeps/ieee754/ieee754.h
===================================================================
RCS file: /cvs/glibc/libc/sysdeps/ieee754/ieee754.h,v
retrieving revision 1.12
diff -u -p -r1.12 ieee754.h
--- sysdeps/ieee754/ieee754.h 6 Jul 2001 04:55:54 -0000 1.12
+++ sysdeps/ieee754/ieee754.h 14 Mar 2003 06:37:19 -0000
@@ -1,4 +1,5 @@
-/* Copyright (C) 1992, 1995, 1996, 1999 Free Software Foundation, Inc.
+/* Copyright (C) 1992, 1995, 1996, 1999, 2002, 2003
+ Free Software Foundation, Inc.
This file is part of the GNU C Library.
The GNU C Library is free software; you can redistribute it and/or
@@ -23,6 +24,8 @@
#include <endian.h>
+#include <float.h>
+
__BEGIN_DECLS
union ieee754_float
@@ -126,6 +129,65 @@ union ieee754_double
#define IEEE754_DOUBLE_BIAS 0x3ff /* Added to exponent. */
+#if LDBL_MANT_DIG == 113
+
+union ieee854_long_double
+ {
+ long double d;
+
+ /* This is the IEEE 854 quad-precision format. */
+ struct
+ {
+#if __BYTE_ORDER == __BIG_ENDIAN
+ unsigned int negative:1;
+ unsigned int exponent:15;
+ /* Together these comprise the mantissa. */
+ unsigned int mantissa0:16;
+ unsigned int mantissa1:32;
+ unsigned int mantissa2:32;
+ unsigned int mantissa3:32;
+#endif /* Big endian. */
+#if __BYTE_ORDER == __LITTLE_ENDIAN
+ /* Together these comprise the mantissa. */
+ unsigned int mantissa3:32;
+ unsigned int mantissa2:32;
+ unsigned int mantissa1:32;
+ unsigned int mantissa0:16;
+ unsigned int exponent:15;
+ unsigned int negative:1;
+#endif /* Little endian. */
+ } ieee;
+
+ /* This format makes it easier to see if a NaN is a signalling NaN. */
+ struct
+ {
+#if __BYTE_ORDER == __BIG_ENDIAN
+ unsigned int negative:1;
+ unsigned int exponent:15;
+ unsigned int quiet_nan:1;
+ /* Together these comprise the mantissa. */
+ unsigned int mantissa0:15;
+ unsigned int mantissa1:32;
+ unsigned int mantissa2:32;
+ unsigned int mantissa3:32;
+#endif /* Big endian. */
+#if __BYTE_ORDER == __LITTLE_ENDIAN
+ /* Together these comprise the mantissa. */
+ unsigned int mantissa3:32;
+ unsigned int mantissa2:32;
+ unsigned int mantissa1:32;
+ unsigned int mantissa0:15;
+ unsigned int quiet_nan:1;
+ unsigned int exponent:15;
+ unsigned int negative:1;
+#endif /* Little endian. */
+ } ieee_nan;
+#endif
+ };
+
+#define IEEE854_LONG_DOUBLE_BIAS 0x3fff /* Added to exponent. */
+
+#elif LDBL_MANT_DIG == 64
union ieee854_long_double
{
@@ -193,6 +255,71 @@ union ieee854_long_double
};
#define IEEE854_LONG_DOUBLE_BIAS 0x3fff
+
+#elif LDBL_MANT_DIG == 53
+
+union ieee854_long_double
+ {
+ long double d;
+
+ /* This is the IEEE 754 double-precision format. */
+ struct
+ {
+#if __BYTE_ORDER == __BIG_ENDIAN
+ unsigned int negative:1;
+ unsigned int exponent:11;
+ /* Together these comprise the mantissa. */
+ unsigned int mantissa0:20;
+ unsigned int mantissa1:32;
+#endif /* Big endian. */
+#if __BYTE_ORDER == __LITTLE_ENDIAN
+# if __FLOAT_WORD_ORDER == BIG_ENDIAN
+ unsigned int mantissa0:20;
+ unsigned int exponent:11;
+ unsigned int negative:1;
+ unsigned int mantissa1:32;
+# else
+ /* Together these comprise the mantissa. */
+ unsigned int mantissa1:32;
+ unsigned int mantissa0:20;
+ unsigned int exponent:11;
+ unsigned int negative:1;
+# endif
+#endif /* Little endian. */
+ } ieee;
+
+ /* This format makes it easier to see if a NaN is a signalling NaN. */
+ struct
+ {
+#if __BYTE_ORDER == __BIG_ENDIAN
+ unsigned int negative:1;
+ unsigned int exponent:11;
+ unsigned int quiet_nan:1;
+ /* Together these comprise the mantissa. */
+ unsigned int mantissa0:19;
+ unsigned int mantissa1:32;
+#else
+# if __FLOAT_WORD_ORDER == BIG_ENDIAN
+ unsigned int mantissa0:19;
+ unsigned int quiet_nan:1;
+ unsigned int exponent:11;
+ unsigned int negative:1;
+ unsigned int mantissa1:32;
+# else
+ /* Together these comprise the mantissa. */
+ unsigned int mantissa1:32;
+ unsigned int mantissa0:19;
+ unsigned int quiet_nan:1;
+ unsigned int exponent:11;
+ unsigned int negative:1;
+# endif
+#endif
+ } ieee_nan;
+ };
+
+#define IEEE854_LONG_DOUBLE_BIAS 0x3ff /* Added to exponent. */
+
+#endif /* LDBL_MANT_DIG == 53 */
__END_DECLS
Index: sysdeps/ieee754/ldbl-128/ieee754.h
===================================================================
RCS file: sysdeps/ieee754/ldbl-128/ieee754.h
diff -N sysdeps/ieee754/ldbl-128/ieee754.h
--- sysdeps/ieee754/ldbl-128/ieee754.h 6 Jul 2001 04:55:55 -0000 1.2
+++ /dev/null 1 Jan 1970 00:00:00 -0000
@@ -1,171 +0,0 @@
-/* Copyright (C) 1992, 1995, 1996, 1999 Free Software Foundation, Inc.
- This file is part of the GNU C Library.
-
- The GNU C Library is free software; you can redistribute it and/or
- modify it under the terms of the GNU Lesser General Public
- License as published by the Free Software Foundation; either
- version 2.1 of the License, or (at your option) any later version.
-
- The GNU C Library is distributed in the hope that it will be useful,
- but WITHOUT ANY WARRANTY; without even the implied warranty of
- MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
- Lesser General Public License for more details.
-
- You should have received a copy of the GNU Lesser General Public
- License along with the GNU C Library; if not, write to the Free
- Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
- 02111-1307 USA. */
-
-#ifndef _IEEE754_H
-
-#define _IEEE754_H 1
-#include <features.h>
-
-#include <endian.h>
-
-__BEGIN_DECLS
-
-union ieee754_float
- {
- float f;
-
- /* This is the IEEE 754 single-precision format. */
- struct
- {
-#if __BYTE_ORDER == __BIG_ENDIAN
- unsigned int negative:1;
- unsigned int exponent:8;
- unsigned int mantissa:23;
-#endif /* Big endian. */
-#if __BYTE_ORDER == __LITTLE_ENDIAN
- unsigned int mantissa:23;
- unsigned int exponent:8;
- unsigned int negative:1;
-#endif /* Little endian. */
- } ieee;
-
- /* This format makes it easier to see if a NaN is a signalling NaN. */
- struct
- {
-#if __BYTE_ORDER == __BIG_ENDIAN
- unsigned int negative:1;
- unsigned int exponent:8;
- unsigned int quiet_nan:1;
- unsigned int mantissa:22;
-#endif /* Big endian. */
-#if __BYTE_ORDER == __LITTLE_ENDIAN
- unsigned int mantissa:22;
- unsigned int quiet_nan:1;
- unsigned int exponent:8;
- unsigned int negative:1;
-#endif /* Little endian. */
- } ieee_nan;
- };
-
-#define IEEE754_FLOAT_BIAS 0x7f /* Added to exponent. */
-
-
-union ieee754_double
- {
- double d;
-
- /* This is the IEEE 754 double-precision format. */
- struct
- {
-#if __BYTE_ORDER == __BIG_ENDIAN
- unsigned int negative:1;
- unsigned int exponent:11;
- /* Together these comprise the mantissa. */
- unsigned int mantissa0:20;
- unsigned int mantissa1:32;
-#endif /* Big endian. */
-#if __BYTE_ORDER == __LITTLE_ENDIAN
- /* Together these comprise the mantissa. */
- unsigned int mantissa1:32;
- unsigned int mantissa0:20;
- unsigned int exponent:11;
- unsigned int negative:1;
-#endif /* Little endian. */
- } ieee;
-
- /* This format makes it easier to see if a NaN is a signalling NaN. */
- struct
- {
-#if __BYTE_ORDER == __BIG_ENDIAN
- unsigned int negative:1;
- unsigned int exponent:11;
- unsigned int quiet_nan:1;
- /* Together these comprise the mantissa. */
- unsigned int mantissa0:19;
- unsigned int mantissa1:32;
-#else
- /* Together these comprise the mantissa. */
- unsigned int mantissa1:32;
- unsigned int mantissa0:19;
- unsigned int quiet_nan:1;
- unsigned int exponent:11;
- unsigned int negative:1;
-#endif
- } ieee_nan;
- };
-
-#define IEEE754_DOUBLE_BIAS 0x3ff /* Added to exponent. */
-
-
-union ieee854_long_double
- {
- long double d;
-
- /* This is the IEEE 854 quad-precision format. */
- struct
- {
-#if __BYTE_ORDER == __BIG_ENDIAN
- unsigned int negative:1;
- unsigned int exponent:15;
- /* Together these comprise the mantissa. */
- unsigned int mantissa0:16;
- unsigned int mantissa1:32;
- unsigned int mantissa2:32;
- unsigned int mantissa3:32;
-#endif /* Big endian. */
-#if __BYTE_ORDER == __LITTLE_ENDIAN
- /* Together these comprise the mantissa. */
- unsigned int mantissa3:32;
- unsigned int mantissa2:32;
- unsigned int mantissa1:32;
- unsigned int mantissa0:16;
- unsigned int exponent:15;
- unsigned int negative:1;
-#endif /* Little endian. */
- } ieee;
-
- /* This format makes it easier to see if a NaN is a signalling NaN. */
- struct
- {
-#if __BYTE_ORDER == __BIG_ENDIAN
- unsigned int negative:1;
- unsigned int exponent:15;
- unsigned int quiet_nan:1;
- /* Together these comprise the mantissa. */
- unsigned int mantissa0:15;
- unsigned int mantissa1:32;
- unsigned int mantissa2:32;
- unsigned int mantissa3:32;
-#else
- /* Together these comprise the mantissa. */
- unsigned int mantissa3:32;
- unsigned int mantissa2:32;
- unsigned int mantissa1:32;
- unsigned int mantissa0:15;
- unsigned int quiet_nan:1;
- unsigned int exponent:15;
- unsigned int negative:1;
-#endif
- } ieee_nan;
- };
-
-#define IEEE854_LONG_DOUBLE_BIAS 0x3fff /* Added to exponent. */
-
-__END_DECLS
-
-#endif /* ieee754.h */
--
Alexandre Oliva Enjoy Guarana', see http://www.ic.unicamp.br/~oliva/
Red Hat GCC Developer aoliva at {redhat dot com, gcc.gnu.org}
CS PhD student at IC-Unicamp oliva at {lsd dot ic dot unicamp dot br, gnu.org}
Free Software Evangelist Professional serial bug killer