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Fix canonical NaN on m68k


The canonical NaN on m68k has a mantissa of all one bits.  This is true
for all m68k variants, not only Coldfire.  Tested on m68k-linux and
ia64-linux.

Andreas.

2007-06-03  Andreas Schwab  <schwab@suse.de>

	* config/m68k/m68k.c (override_options): Don't override
	REAL_MODE_FORMAT.
	* config/m68k/m68k-modes.def (SF, DF): Define to use
	motorola_single_format and motorola_double_format, resp.
	* real.c (motorola_single_format): Renamed from
	coldfire_single_format.
	(motorola_double_format): Renamed from coldfire_double_format.
	(encode_ieee_extended): Generate a proper canonical NaN image
	respecting canonical_nan_lsbs_set.
	(ieee_extended_motorola_format): Set canonical_nan_lsbs_set to
	true.
	* real.h: Adjust declarations.

Index: gcc/real.c
===================================================================
--- gcc/real.c	(revision 125293)
+++ gcc/real.c	(working copy)
@@ -1,6 +1,6 @@
 /* real.c - software floating point emulation.
    Copyright (C) 1993, 1994, 1995, 1996, 1997, 1998, 1999,
-   2000, 2002, 2003, 2004, 2005 Free Software Foundation, Inc.
+   2000, 2002, 2003, 2004, 2005, 2007 Free Software Foundation, Inc.
    Contributed by Stephen L. Moshier (moshier@world.std.com).
    Re-written by Richard Henderson <rth@redhat.com>
 
@@ -2774,7 +2774,7 @@ const struct real_format mips_single_for
     true
   };
 
-const struct real_format coldfire_single_format =
+const struct real_format motorola_single_format =
   {
     encode_ieee_single,
     decode_ieee_single,
@@ -3019,7 +3019,7 @@ const struct real_format mips_double_for
     true
   };
 
-const struct real_format coldfire_double_format =
+const struct real_format motorola_double_format =
   {
     encode_ieee_double,
     decode_ieee_double,
@@ -3082,7 +3082,15 @@ encode_ieee_extended (const struct real_
       if (fmt->has_nans)
 	{
 	  image_hi |= 32767;
-	  if (HOST_BITS_PER_LONG == 32)
+	  if (r->canonical)
+	    {
+	      if (fmt->canonical_nan_lsbs_set)
+		{
+		  sig_hi = (1 << 30) - 1;
+		  sig_lo = 0xffffffff;
+		}
+	    }
+	  else if (HOST_BITS_PER_LONG == 32)
 	    {
 	      sig_hi = r->sig[SIGSZ-1];
 	      sig_lo = r->sig[SIGSZ-2];
@@ -3364,7 +3372,7 @@ const struct real_format ieee_extended_m
     true,
     true,
     true,
-    false
+    true
   };
 
 const struct real_format ieee_extended_intel_96_format =
Index: gcc/real.h
===================================================================
--- gcc/real.h	(revision 125293)
+++ gcc/real.h	(working copy)
@@ -1,6 +1,6 @@
 /* Definitions of floating-point access for GNU compiler.
    Copyright (C) 1989, 1991, 1994, 1996, 1997, 1998, 1999,
-   2000, 2002, 2003, 2004, 2005 Free Software Foundation, Inc.
+   2000, 2002, 2003, 2004, 2005, 2007 Free Software Foundation, Inc.
 
    This file is part of GCC.
 
@@ -254,10 +254,10 @@ extern unsigned int real_hash (const REA
 /* Target formats defined in real.c.  */
 extern const struct real_format ieee_single_format;
 extern const struct real_format mips_single_format;
-extern const struct real_format coldfire_single_format;
+extern const struct real_format motorola_single_format;
 extern const struct real_format ieee_double_format;
 extern const struct real_format mips_double_format;
-extern const struct real_format coldfire_double_format;
+extern const struct real_format motorola_double_format;
 extern const struct real_format ieee_extended_motorola_format;
 extern const struct real_format ieee_extended_intel_96_format;
 extern const struct real_format ieee_extended_intel_96_round_53_format;
Index: gcc/config/m68k/m68k-modes.def
===================================================================
--- gcc/config/m68k/m68k-modes.def	(revision 125293)
+++ gcc/config/m68k/m68k-modes.def	(working copy)
@@ -1,5 +1,5 @@
 /* M68k extra machine modes. 
-   Copyright (C) 2003, 2004 Free Software Foundation, Inc.
+   Copyright (C) 2003, 2004, 2007 Free Software Foundation, Inc.
 
 This file is part of GCC.
 
@@ -18,5 +18,9 @@ along with GCC; see the file COPYING.  I
 the Free Software Foundation, 51 Franklin Street, Fifth Floor,
 Boston, MA 02110-1301, USA.  */
 
+/* These differ in the representation of the canonical NaN.  */
+RESET_FLOAT_FORMAT (SF, motorola_single_format);
+RESET_FLOAT_FORMAT (DF, motorola_double_format);
+
 /* 80-bit floating point (IEEE extended, in a 96-bit field) */
 FRACTIONAL_FLOAT_MODE (XF, 80, 12, ieee_extended_motorola_format);
Index: gcc/config/m68k/m68k.c
===================================================================
--- gcc/config/m68k/m68k.c	(revision 125293)
+++ gcc/config/m68k/m68k.c	(working copy)
@@ -1,6 +1,6 @@
 /* Subroutines for insn-output.c for Motorola 68000 family.
    Copyright (C) 1987, 1993, 1994, 1995, 1996, 1997, 1998, 1999, 2000,
-   2001, 2003, 2004, 2005, 2006
+   2001, 2003, 2004, 2005, 2006, 2007
    Free Software Foundation, Inc.
 
 This file is part of GCC.
@@ -541,12 +541,6 @@ override_options (void)
 	      : (m68k_cpu_flags & FL_COLDFIRE) != 0 ? FPUTYPE_COLDFIRE
 	      : FPUTYPE_68881);
 
-  if (TARGET_COLDFIRE_FPU)
-    {
-      REAL_MODE_FORMAT (SFmode) = &coldfire_single_format;
-      REAL_MODE_FORMAT (DFmode) = &coldfire_double_format;
-    }
-
   /* Sanity check to ensure that msep-data and mid-sahred-library are not
    * both specified together.  Doing so simply doesn't make sense.
    */

-- 
Andreas Schwab, SuSE Labs, schwab@suse.de
SuSE Linux Products GmbH, Maxfeldstraße 5, 90409 Nürnberg, Germany
PGP key fingerprint = 58CA 54C7 6D53 942B 1756  01D3 44D5 214B 8276 4ED5
"And now for something completely different."


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