commit f5aee5eeb88a99a8fb9d2b57971b0bda035ebc65
Author: Alan Modra <amodra@gmail.com>
Date:   Tue Aug 20 06:42:19 2013 +0000

    	* doublest.c (convert_floatformat_to_doublest): Use fmt->split_half
    	for IBM long double nan and inf.
    	(floatformat_is_negative, floatformat_classify,
    	floatformat_mantissa): Similarly.
    	(floatformat_ieee_single, floatformat_ieee_double,
    	floatformat_ieee_quad, floatformat_arm_ext,
    	floatformat_ia64_spill): Delete unused vars.
    	(_initialize_doublest): Delete unused function.
    	* gdbtypes.c (floatformats_ibm_long_double): Use new big- and
    	little-endian variants of floatformat_ibm_long_double.

Index: gdb-7.6.1/gdb/doublest.c
===================================================================
--- gdb-7.6.1.orig/gdb/doublest.c
+++ gdb-7.6.1/gdb/doublest.c
@@ -190,7 +190,8 @@ convert_floatformat_to_doublest (const s
     {
       double dto;
 
-      floatformat_to_double (fmt, from, &dto);
+      floatformat_to_double (fmt->split_half ? fmt->split_half : fmt,
+			     from, &dto);
       *to = (DOUBLEST) dto;
       return;
     }
@@ -561,6 +562,11 @@ floatformat_is_negative (const struct fl
   gdb_assert (fmt->totalsize
 	      <= FLOATFORMAT_LARGEST_BYTES * FLOATFORMAT_CHAR_BIT);
 
+  /* An IBM long double (a two element array of double) always takes the
+     sign of the first double.  */
+  if (fmt->split_half)
+    fmt = fmt->split_half;
+
   order = floatformat_normalize_byteorder (fmt, uval, newfrom);
 
   if (order != fmt->byteorder)
@@ -587,6 +593,13 @@ floatformat_classify (const struct float
   gdb_assert (fmt->totalsize
 	      <= FLOATFORMAT_LARGEST_BYTES * FLOATFORMAT_CHAR_BIT);
 
+  /* An IBM long double (a two element array of double) can be classified
+     by looking at the first double.  inf and nan are specified as
+     ignoring the second double.  zero and subnormal will always have
+     the second double 0.0 if the long double is correctly rounded.  */
+  if (fmt->split_half)
+    fmt = fmt->split_half;
+
   order = floatformat_normalize_byteorder (fmt, uval, newfrom);
 
   if (order != fmt->byteorder)
@@ -669,6 +682,16 @@ floatformat_mantissa (const struct float
   gdb_assert (fmt->totalsize
 	      <= FLOATFORMAT_LARGEST_BYTES * FLOATFORMAT_CHAR_BIT);
 
+  /* For IBM long double (a two element array of double), return the
+     mantissa of the first double.  The problem with returning the
+     actual mantissa from both doubles is that there can be an
+     arbitrary number of implied 0's or 1's between the mantissas
+     of the first and second double.  In any case, this function
+     is only used for dumping out nans, and a nan is specified to
+     ignore the value in the second double.  */
+  if (fmt->split_half)
+    fmt = fmt->split_half;
+
   order = floatformat_normalize_byteorder (fmt, uval, newfrom);
 
   if (order != fmt->byteorder)
@@ -926,27 +949,3 @@ convert_typed_floating (const void *from
       floatformat_from_doublest (to_fmt, &d, to);
     }
 }
-
-const struct floatformat *floatformat_ieee_single[BFD_ENDIAN_UNKNOWN];
-const struct floatformat *floatformat_ieee_double[BFD_ENDIAN_UNKNOWN];
-const struct floatformat *floatformat_ieee_quad[BFD_ENDIAN_UNKNOWN];
-const struct floatformat *floatformat_arm_ext[BFD_ENDIAN_UNKNOWN];
-const struct floatformat *floatformat_ia64_spill[BFD_ENDIAN_UNKNOWN];
-
-extern void _initialize_doublest (void);
-
-extern void
-_initialize_doublest (void)
-{
-  floatformat_ieee_single[BFD_ENDIAN_LITTLE] = &floatformat_ieee_single_little;
-  floatformat_ieee_single[BFD_ENDIAN_BIG] = &floatformat_ieee_single_big;
-  floatformat_ieee_double[BFD_ENDIAN_LITTLE] = &floatformat_ieee_double_little;
-  floatformat_ieee_double[BFD_ENDIAN_BIG] = &floatformat_ieee_double_big;
-  floatformat_arm_ext[BFD_ENDIAN_LITTLE]
-    = &floatformat_arm_ext_littlebyte_bigword;
-  floatformat_arm_ext[BFD_ENDIAN_BIG] = &floatformat_arm_ext_big;
-  floatformat_ia64_spill[BFD_ENDIAN_LITTLE] = &floatformat_ia64_spill_little;
-  floatformat_ia64_spill[BFD_ENDIAN_BIG] = &floatformat_ia64_spill_big;
-  floatformat_ieee_quad[BFD_ENDIAN_LITTLE] = &floatformat_ia64_quad_little;
-  floatformat_ieee_quad[BFD_ENDIAN_BIG] = &floatformat_ia64_quad_big;
-}
Index: gdb-7.6.1/gdb/gdbtypes.c
===================================================================
--- gdb-7.6.1.orig/gdb/gdbtypes.c
+++ gdb-7.6.1/gdb/gdbtypes.c
@@ -110,8 +110,8 @@ const struct floatformat *floatformats_v
   &floatformat_vax_d
 };
 const struct floatformat *floatformats_ibm_long_double[BFD_ENDIAN_UNKNOWN] = {
-  &floatformat_ibm_long_double,
-  &floatformat_ibm_long_double
+  &floatformat_ibm_long_double_big,
+  &floatformat_ibm_long_double_little
 };
 
 /* Should opaque types be resolved?  */