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mips64 ieee754 data structures


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).  Ok?

Index: ChangeLog
2003-03-14  Alexandre Oliva  <aoliva at redhat dot com>

	* sysdeps/mips/ieee754.h: New file.

Index: sysdeps/mips/ieee754.h
--- /dev/null	2002-10-04 15:48:04.000000000 -0300
+++ sysdeps/mips/ieee754.h	2003-01-15 12:28:31.000000000 -0200
@@ -0,0 +1,230 @@
+/* Copyright (C) 1992, 1995, 1996, 1999, 2002 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.  */
+
+
+#if __LONG_DOUBLE_BIT__ == 128
+
+union ieee854_long_double
+  {
+    long double d;
+
+#if 0
+    union ieee754_double pair[2];
+#else
+    /* This is all wrong!  This is not the format used for long
+       doubles.  */
+
+    /* 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;
+#endif
+  };
+
+#define IEEE854_LONG_DOUBLE_BIAS 0x3fff /* Added to exponent.  */
+
+#else
+
+union ieee854_long_double
+  {
+    long double d;
+
+    /* This is the IEEE 854 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 IEEE854_LONG_DOUBLE_BIAS	0x3ff /* Added to exponent.  */
+
+#endif
+
+__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

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