include:

2007-11-07  Joseph Myers  <joseph@codesourcery.com>
	    Daniel Jacobowitz  <dan@codesourcery.com>

	* floatformat.h (struct floatformat): Add split_half field.
	(floatformat_ibm_long_double): New.

libiberty:
2007-11-07  Joseph Myers  <joseph@codesourcery.com>
	    Daniel Jacobowitz  <dan@codesourcery.com>

	* floatformat.c (mant_bits_set): New.
	(floatformat_to_double): Use it.  Note no special handling of
	split formats.
	(floatformat_from_double): Note no special handing of split
	formats.
	(floatformat_ibm_long_double_is_valid,
	floatformat_ibm_long_double): New.
	(floatformat_ieee_single_big, floatformat_ieee_single_little,
	floatformat_ieee_double_big, floatformat_ieee_double_little,
	floatformat_ieee_double_littlebyte_bigword, floatformat_vax_f,
	floatformat_vax_d, floatformat_vax_g, floatformat_i387_ext,
	floatformat_m68881_ext, floatformat_i960_ext,
	floatformat_m88110_ext, floatformat_m88110_harris_ext,
	floatformat_arm_ext_big, floatformat_arm_ext_littlebyte_bigword,
	floatformat_ia64_spill_big, floatformat_ia64_spill_little,
	floatformat_ia64_quad_big, floatformat_ia64_quad_little): Update
	for addition of split_half field.

gdb:
2007-11-07  Joseph Myers  <joseph@codesourcery.com>
	    Daniel Jacobowitz  <dan@codesourcery.com>

	* gdbtypes.c (floatformats_ibm_long_double): New.
	* gdbtypes.h (floatformats_ibm_long_double): Declare.
	* ia64-tdep.c (floatformat_ia64_ext): Update for addition of
	split_half field.
	* mips-tdep.c (n32n64_floatformat_always_valid,
	floatformat_n32n64_long_double_big, floatformats_n32n64_long):
	Remove.
	(mips_gdbarch_init): Use floatformats_ibm_long_double instead of
	floatformats_n32n64_long.
	* ppc-linux-tdep.c (ppc_linux_init_abi): Use 128-bit IBM long
	double.
	* doublest.c (convert_floatformat_to_doublest,
	convert_doublest_to_floatformat): Handle split floating-point
	formats.
	* ppc-sysv-tdep.c (ppc_sysv_abi_push_dummy_call): Handle IBM long
	double arguments.
	(ppc64_sysv_abi_push_dummy_call): Likewise.
	(do_ppc_sysv_return_value): Handle IBM long double return.

12 files changed, 435 insertions, 90 deletions

diff --git a/gdb/ChangeLog b/gdb/ChangeLog
index ab6711e..518bd17 100644
--- a/gdb/ChangeLog
+++ b/gdb/ChangeLog
@@ -1,3 +1,25 @@
+2007-11-07  Joseph Myers  <joseph@codesourcery.com>
+	    Daniel Jacobowitz  <dan@codesourcery.com>
+
+	* gdbtypes.c (floatformats_ibm_long_double): New.
+	* gdbtypes.h (floatformats_ibm_long_double): Declare.
+	* ia64-tdep.c (floatformat_ia64_ext): Update for addition of
+	split_half field.
+	* mips-tdep.c (n32n64_floatformat_always_valid,
+	floatformat_n32n64_long_double_big, floatformats_n32n64_long):
+	Remove.
+	(mips_gdbarch_init): Use floatformats_ibm_long_double instead of
+	floatformats_n32n64_long.
+	* ppc-linux-tdep.c (ppc_linux_init_abi): Use 128-bit IBM long
+	double.
+	* doublest.c (convert_floatformat_to_doublest,
+	convert_doublest_to_floatformat): Handle split floating-point
+	formats.
+	* ppc-sysv-tdep.c (ppc_sysv_abi_push_dummy_call): Handle IBM long
+	double arguments.
+	(ppc64_sysv_abi_push_dummy_call): Likewise.
+	(do_ppc_sysv_return_value): Handle IBM long double return.
+
 2007-11-07  Vladimir Prus  <vladimir@codesourcery.com>
 
 	Fix crash when a variable object being deleted
diff --git a/gdb/doublest.c b/gdb/doublest.c
index c7ca993..3ec6dd3 100644
--- a/gdb/doublest.c
+++ b/gdb/doublest.c
@@ -200,6 +200,24 @@ convert_floatformat_to_doublest (const struct floatformat *fmt,
   if (order != fmt->byteorder)
     ufrom = newfrom;
 
+  if (fmt->split_half)
+    {
+      double dtop, dbot;
+      floatformat_to_double (fmt->split_half, ufrom, &dtop);
+      /* Preserve the sign of 0, which is the sign of the top
+	 half.  */
+      if (dtop == 0.0)
+	{
+	  *to = (DOUBLEST) dtop;
+	  return;
+	}
+      floatformat_to_double (fmt->split_half,
+			     ufrom + fmt->totalsize / FLOATFORMAT_CHAR_BIT / 2,
+			     &dbot);
+      *to = (DOUBLEST) dtop + (DOUBLEST) dbot;
+      return;
+    }
+
   exponent = get_field (ufrom, order, fmt->totalsize, fmt->exp_start,
 			fmt->exp_len);
   /* Note that if exponent indicates a NaN, we can't really do anything useful
@@ -392,6 +410,30 @@ convert_doublest_to_floatformat (CONST struct floatformat *fmt,
   memcpy (&dfrom, from, sizeof (dfrom));
   memset (uto, 0, (fmt->totalsize + FLOATFORMAT_CHAR_BIT - 1) 
                     / FLOATFORMAT_CHAR_BIT);
+
+  if (fmt->split_half)
+    {
+      /* Use static volatile to ensure that any excess precision is
+	 removed via storing in memory, and so the top half really is
+	 the result of converting to double.  */
+      static volatile double dtop, dbot;
+      double dtopnv, dbotnv;
+      dtop = (double) dfrom;
+      /* If the rounded top half is Inf, the bottom must be 0 not NaN
+	 or Inf.  */
+      if (dtop + dtop == dtop && dtop != 0.0)
+	dbot = 0.0;
+      else
+	dbot = (double) (dfrom - (DOUBLEST) dtop);
+      dtopnv = dtop;
+      dbotnv = dbot;
+      floatformat_from_double (fmt->split_half, &dtopnv, uto);
+      floatformat_from_double (fmt->split_half, &dbotnv,
+			       (uto
+				+ fmt->totalsize / FLOATFORMAT_CHAR_BIT / 2));
+      return;
+    }
+
   if (dfrom == 0)
     return;			/* Result is zero */
   if (dfrom != dfrom)		/* Result is NaN */
diff --git a/gdb/gdbtypes.c b/gdb/gdbtypes.c
index dc1e203..8d81097 100644
--- a/gdb/gdbtypes.c
+++ b/gdb/gdbtypes.c
@@ -95,6 +95,10 @@ const struct floatformat *floatformats_vax_d[BFD_ENDIAN_UNKNOWN] = {
   &floatformat_vax_d,
   &floatformat_vax_d
 };
+const struct floatformat *floatformats_ibm_long_double[BFD_ENDIAN_UNKNOWN] = {
+  &floatformat_ibm_long_double,
+  &floatformat_ibm_long_double
+};
 
 struct type *builtin_type_ieee_single;
 struct type *builtin_type_ieee_double;
diff --git a/gdb/gdbtypes.h b/gdb/gdbtypes.h
index 484b99d..10a354b 100644
--- a/gdb/gdbtypes.h
+++ b/gdb/gdbtypes.h
@@ -1099,6 +1099,7 @@ extern const struct floatformat *floatformats_ia64_spill[BFD_ENDIAN_UNKNOWN];
 extern const struct floatformat *floatformats_ia64_quad[BFD_ENDIAN_UNKNOWN];
 extern const struct floatformat *floatformats_vax_f[BFD_ENDIAN_UNKNOWN];
 extern const struct floatformat *floatformats_vax_d[BFD_ENDIAN_UNKNOWN];
+extern const struct floatformat *floatformats_ibm_long_double[BFD_ENDIAN_UNKNOWN];
 
 extern struct type *builtin_type_ieee_single;
 extern struct type *builtin_type_ieee_double;
diff --git a/gdb/ia64-tdep.c b/gdb/ia64-tdep.c
index cd2daf8..47f7f54 100644
--- a/gdb/ia64-tdep.c
+++ b/gdb/ia64-tdep.c
@@ -329,7 +329,7 @@ floatformat_valid (const struct floatformat *fmt, const void *from)
 const struct floatformat floatformat_ia64_ext =
 {
   floatformat_little, 82, 0, 1, 17, 65535, 0x1ffff, 18, 64,
-  floatformat_intbit_yes, "floatformat_ia64_ext", floatformat_valid
+  floatformat_intbit_yes, "floatformat_ia64_ext", floatformat_valid, NULL
 };
 
 const struct floatformat *floatformats_ia64_ext[2] =
diff --git a/gdb/mips-tdep.c b/gdb/mips-tdep.c
index 44e4aeb..98757c9 100644
--- a/gdb/mips-tdep.c
+++ b/gdb/mips-tdep.c
@@ -199,38 +199,6 @@ struct gdbarch_tdep
   int register_size;
 };
 
-static int
-n32n64_floatformat_always_valid (const struct floatformat *fmt,
-                                 const void *from)
-{
-  return 1;
-}
-
-/* FIXME: brobecker/2004-08-08: Long Double values are 128 bit long.
-   They are implemented as a pair of 64bit doubles where the high
-   part holds the result of the operation rounded to double, and
-   the low double holds the difference between the exact result and
-   the rounded result.  So "high" + "low" contains the result with
-   added precision.  Unfortunately, the floatformat structure used
-   by GDB is not powerful enough to describe this format.  As a temporary
-   measure, we define a 128bit floatformat that only uses the high part.
-   We lose a bit of precision but that's probably the best we can do
-   for now with the current infrastructure.  */
-
-static const struct floatformat floatformat_n32n64_long_double_big =
-{
-  floatformat_big, 128, 0, 1, 11, 1023, 2047, 12, 52,
-  floatformat_intbit_no,
-  "floatformat_n32n64_long_double_big",
-  n32n64_floatformat_always_valid
-};
-
-static const struct floatformat *floatformats_n32n64_long[BFD_ENDIAN_UNKNOWN] =
-{
-  &floatformat_n32n64_long_double_big,
-  &floatformat_n32n64_long_double_big
-};
-
 const struct mips_regnum *
 mips_regnum (struct gdbarch *gdbarch)
 {
@@ -5585,7 +5553,7 @@ mips_gdbarch_init (struct gdbarch_info info, struct gdbarch_list *arches)
       set_gdbarch_ptr_bit (gdbarch, 32);
       set_gdbarch_long_long_bit (gdbarch, 64);
       set_gdbarch_long_double_bit (gdbarch, 128);
-      set_gdbarch_long_double_format (gdbarch, floatformats_n32n64_long);
+      set_gdbarch_long_double_format (gdbarch, floatformats_ibm_long_double);
       break;
     case MIPS_ABI_N64:
       set_gdbarch_push_dummy_call (gdbarch, mips_n32n64_push_dummy_call);
@@ -5597,7 +5565,7 @@ mips_gdbarch_init (struct gdbarch_info info, struct gdbarch_list *arches)
       set_gdbarch_ptr_bit (gdbarch, 64);
       set_gdbarch_long_long_bit (gdbarch, 64);
       set_gdbarch_long_double_bit (gdbarch, 128);
-      set_gdbarch_long_double_format (gdbarch, floatformats_n32n64_long);
+      set_gdbarch_long_double_format (gdbarch, floatformats_ibm_long_double);
       break;
     default:
       internal_error (__FILE__, __LINE__, _("unknown ABI in switch"));
diff --git a/gdb/ppc-linux-tdep.c b/gdb/ppc-linux-tdep.c
index a82c95e..95d127e 100644
--- a/gdb/ppc-linux-tdep.c
+++ b/gdb/ppc-linux-tdep.c
@@ -896,15 +896,13 @@ ppc_linux_init_abi (struct gdbarch_info info,
 {
   struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
 
-  /* NOTE: jimb/2004-03-26: The System V ABI PowerPC Processor
-     Supplement says that long doubles are sixteen bytes long.
-     However, as one of the known warts of its ABI, PPC GNU/Linux uses
-     eight-byte long doubles.  GCC only recently got 128-bit long
-     double support on PPC, so it may be changing soon.  The
-     Linux[sic] Standards Base says that programs that use 'long
-     double' on PPC GNU/Linux are non-conformant.  */
-  /* NOTE: cagney/2005-01-25: True for both 32- and 64-bit.  */
-  set_gdbarch_long_double_bit (gdbarch, 8 * TARGET_CHAR_BIT);
+  /* PPC GNU/Linux uses either 64-bit or 128-bit long doubles; where
+     128-bit, they are IBM long double, not IEEE quad long double as
+     in the System V ABI PowerPC Processor Supplement.  We can safely
+     let them default to 128-bit, since the debug info will give the
+     size of type actually used in each case.  */
+  set_gdbarch_long_double_bit (gdbarch, 16 * TARGET_CHAR_BIT);
+  set_gdbarch_long_double_format (gdbarch, floatformats_ibm_long_double);
 
   /* Handle PPC GNU/Linux 64-bit function pointers (which are really
      function descriptors) and 32-bit secure PLT entries.  */
diff --git a/gdb/ppc-sysv-tdep.c b/gdb/ppc-sysv-tdep.c
index 5dc90f1..21947aa 100644
--- a/gdb/ppc-sysv-tdep.c
+++ b/gdb/ppc-sysv-tdep.c
@@ -53,6 +53,8 @@ ppc_sysv_abi_push_dummy_call (struct gdbarch *gdbarch, struct value *function,
   int argspace = 0;		/* 0 is an initial wrong guess.  */
   int write_pass;
 
+  gdb_assert (tdep->wordsize == 4);
+
   regcache_cooked_read_unsigned (regcache,
 				 gdbarch_sp_regnum (current_gdbarch),
 				 &saved_sp);
@@ -141,6 +143,35 @@ ppc_sysv_abi_push_dummy_call (struct gdbarch *gdbarch, struct value *function,
 		  argoffset += 8;
 		}
 	    }
+	  else if (TYPE_CODE (type) == TYPE_CODE_FLT
+		   && len == 16
+		   && !tdep->soft_float
+		   && (gdbarch_long_double_format (current_gdbarch)
+		       == floatformats_ibm_long_double))
+	    {
+	      /* IBM long double passed in two FP registers if
+		 available, otherwise 8-byte aligned stack.  */
+	      if (freg <= 7)
+		{
+		  if (write_pass)
+		    {
+		      regcache_cooked_write (regcache,
+					     tdep->ppc_fp0_regnum + freg,
+					     val);
+		      regcache_cooked_write (regcache,
+					     tdep->ppc_fp0_regnum + freg + 1,
+					     val + 8);
+		    }
+		  freg += 2;
+		}
+	      else
+		{
+		  argoffset = align_up (argoffset, 8);
+		  if (write_pass)
+		    write_memory (sp + argoffset, val, len);
+		  argoffset += 16;
+		}
+	    }
 	  else if (len == 8
 		   && (TYPE_CODE (type) == TYPE_CODE_INT	/* long long */
 		       || TYPE_CODE (type) == TYPE_CODE_FLT))	/* double */
@@ -159,13 +190,6 @@ ppc_sysv_abi_push_dummy_call (struct gdbarch *gdbarch, struct value *function,
 		    write_memory (sp + argoffset, val, len);
 		  argoffset += 8;
 		}
-	      else if (tdep->wordsize == 8)
-		{
-		  if (write_pass)
-		    regcache_cooked_write (regcache,
-					   tdep->ppc_gp0_regnum + greg, val);
-		  greg += 1;
-		}
 	      else
 		{
 		  /* Must start on an odd register - r3/r4 etc.  */
@@ -183,6 +207,41 @@ ppc_sysv_abi_push_dummy_call (struct gdbarch *gdbarch, struct value *function,
 		  greg += 2;
 		}
 	    }
+	  else if (len == 16 && TYPE_CODE (type) == TYPE_CODE_FLT
+		   && (gdbarch_long_double_format (current_gdbarch)
+		       == floatformats_ibm_long_double))
+	    {
+	      /* Soft-float IBM long double passed in four consecutive
+		 registers, or on the stack.  The registers are not
+		 necessarily odd/even pairs.  */
+	      if (greg > 7)
+		{
+		  greg = 11;
+		  argoffset = align_up (argoffset, 8);
+		  if (write_pass)
+		    write_memory (sp + argoffset, val, len);
+		  argoffset += 16;
+		}
+	      else
+		{
+		  if (write_pass)
+		    {
+		      regcache_cooked_write (regcache,
+					     tdep->ppc_gp0_regnum + greg + 0,
+					     val + 0);
+		      regcache_cooked_write (regcache,
+					     tdep->ppc_gp0_regnum + greg + 1,
+					     val + 4);
+		      regcache_cooked_write (regcache,
+					     tdep->ppc_gp0_regnum + greg + 2,
+					     val + 8);
+		      regcache_cooked_write (regcache,
+					     tdep->ppc_gp0_regnum + greg + 3,
+					     val + 12);
+		    }
+		  greg += 4;
+		}
+	    }
 	  else if (len == 16
 		   && TYPE_CODE (type) == TYPE_CODE_ARRAY
 		   && TYPE_VECTOR (type)
@@ -376,6 +435,55 @@ do_ppc_sysv_return_value (struct gdbarch *gdbarch, struct type *type,
 	}
       return RETURN_VALUE_REGISTER_CONVENTION;
     }
+  if (TYPE_CODE (type) == TYPE_CODE_FLT
+      && TYPE_LENGTH (type) == 16
+      && !tdep->soft_float
+      && (gdbarch_long_double_format (current_gdbarch)
+	  == floatformats_ibm_long_double))
+    {
+      /* IBM long double stored in f1 and f2.  */
+      if (readbuf)
+	{
+	  regcache_cooked_read (regcache, tdep->ppc_fp0_regnum + 1, readbuf);
+	  regcache_cooked_read (regcache, tdep->ppc_fp0_regnum + 2,
+				readbuf + 8);
+	}
+      if (writebuf)
+	{
+	  regcache_cooked_write (regcache, tdep->ppc_fp0_regnum + 1, writebuf);
+	  regcache_cooked_write (regcache, tdep->ppc_fp0_regnum + 2,
+				 writebuf + 8);
+	}
+      return RETURN_VALUE_REGISTER_CONVENTION;
+    }
+  if (TYPE_CODE (type) == TYPE_CODE_FLT
+      && TYPE_LENGTH (type) == 16
+      && (gdbarch_long_double_format (current_gdbarch)
+	  == floatformats_ibm_long_double))
+    {
+      /* Soft-float IBM long double stored in r3, r4, r5, r6.  */
+      if (readbuf)
+	{
+	  regcache_cooked_read (regcache, tdep->ppc_gp0_regnum + 3, readbuf);
+	  regcache_cooked_read (regcache, tdep->ppc_gp0_regnum + 4,
+				readbuf + 4);
+	  regcache_cooked_read (regcache, tdep->ppc_gp0_regnum + 5,
+				readbuf + 8);
+	  regcache_cooked_read (regcache, tdep->ppc_gp0_regnum + 6,
+				readbuf + 12);
+	}
+      if (writebuf)
+	{
+	  regcache_cooked_write (regcache, tdep->ppc_gp0_regnum + 3, writebuf);
+	  regcache_cooked_write (regcache, tdep->ppc_gp0_regnum + 4,
+				 writebuf + 4);
+	  regcache_cooked_write (regcache, tdep->ppc_gp0_regnum + 5,
+				 writebuf + 8);
+	  regcache_cooked_write (regcache, tdep->ppc_gp0_regnum + 6,
+				 writebuf + 12);
+	}
+      return RETURN_VALUE_REGISTER_CONVENTION;
+    }
   if ((TYPE_CODE (type) == TYPE_CODE_INT && TYPE_LENGTH (type) == 8)
       || (TYPE_CODE (type) == TYPE_CODE_FLT && TYPE_LENGTH (type) == 8))
     {
@@ -768,6 +876,41 @@ ppc64_sysv_abi_push_dummy_call (struct gdbarch *gdbarch, struct value *function,
 	      greg++;
 	      gparam = align_up (gparam + TYPE_LENGTH (type), tdep->wordsize);
 	    }
+	  else if (TYPE_CODE (type) == TYPE_CODE_FLT
+		   && TYPE_LENGTH (type) == 16
+		   && (gdbarch_long_double_format (current_gdbarch)
+		       == floatformats_ibm_long_double))
+	    {
+	      /* IBM long double stored in two doublewords of the
+		 parameter save area and corresponding registers.  */
+	      if (write_pass)
+		{
+		  if (!tdep->soft_float && freg <= 13)
+		    {
+		      regcache_cooked_write (regcache,
+                                             tdep->ppc_fp0_regnum + freg,
+					     val);
+		      if (freg <= 12)
+			regcache_cooked_write (regcache,
+					       tdep->ppc_fp0_regnum + freg + 1,
+					       val + 8);
+		    }
+		  if (greg <= 10)
+		    {
+		      regcache_cooked_write (regcache,
+					     tdep->ppc_gp0_regnum + greg,
+					     val);
+		      if (greg <= 9)
+			regcache_cooked_write (regcache,
+					       tdep->ppc_gp0_regnum + greg + 1,
+					       val + 8);
+		    }
+		  write_memory (gparam, val, TYPE_LENGTH (type));
+		}
+	      freg += 2;
+	      greg += 2;
+	      gparam = align_up (gparam + TYPE_LENGTH (type), tdep->wordsize);
+	    }
 	  else if (TYPE_LENGTH (type) == 16 && TYPE_VECTOR (type)
 		   && TYPE_CODE (type) == TYPE_CODE_ARRAY
 		   && tdep->ppc_vr0_regnum >= 0)
diff --git a/include/ChangeLog b/include/ChangeLog
index f3dc433..1bde4c5 100644
--- a/include/ChangeLog
+++ b/include/ChangeLog
@@ -1,3 +1,9 @@
+2007-11-07  Joseph Myers  <joseph@codesourcery.com>
+	    Daniel Jacobowitz  <dan@codesourcery.com>
+
+	* floatformat.h (struct floatformat): Add split_half field.
+	(floatformat_ibm_long_double): New.
+
 2007-11-05  Danny Smith  <dannysmith@users.sourceforge.net>
 
 	* coff/pe.h (COFF_ENCODE_ALIGNMENT) Define.
diff --git a/include/floatformat.h b/include/floatformat.h
index f1bd7f6..c5f60a3 100644
--- a/include/floatformat.h
+++ b/include/floatformat.h
@@ -85,6 +85,13 @@ struct floatformat
 
   /* Validator method.  */
   int (*is_valid) (const struct floatformat *fmt, const void *from);
+
+  /* Is the format actually the sum of two smaller floating point
+     formats (IBM long double, as described in
+     gcc/config/rs6000/darwin-ldouble-format)?  If so, this is the
+     smaller format in question, and the fields sign_start through
+     intbit describe the first half.  If not, this is NULL.  */
+  const struct floatformat *split_half;
 };
 
 /* floatformats for IEEE single and double, big and little endian.  */
@@ -118,6 +125,8 @@ extern const struct floatformat floatformat_ia64_spill_big;
 extern const struct floatformat floatformat_ia64_spill_little;
 extern const struct floatformat floatformat_ia64_quad_big;
 extern const struct floatformat floatformat_ia64_quad_little;
+/* IBM long double (double+double).  */
+extern const struct floatformat floatformat_ibm_long_double;
 
 /* Convert from FMT to a double.
    FROM is the address of the extended float.
diff --git a/libiberty/ChangeLog b/libiberty/ChangeLog
index 781a961..78e74e5 100644
--- a/libiberty/ChangeLog
+++ b/libiberty/ChangeLog
@@ -1,3 +1,24 @@
+2007-11-07  Joseph Myers  <joseph@codesourcery.com>
+	    Daniel Jacobowitz  <dan@codesourcery.com>
+
+	* floatformat.c (mant_bits_set): New.
+	(floatformat_to_double): Use it.  Note no special handling of
+	split formats.
+	(floatformat_from_double): Note no special handing of split
+	formats.
+	(floatformat_ibm_long_double_is_valid,
+	floatformat_ibm_long_double): New.
+	(floatformat_ieee_single_big, floatformat_ieee_single_little,
+	floatformat_ieee_double_big, floatformat_ieee_double_little,
+	floatformat_ieee_double_littlebyte_bigword, floatformat_vax_f,
+	floatformat_vax_d, floatformat_vax_g, floatformat_i387_ext,
+	floatformat_m68881_ext, floatformat_i960_ext,
+	floatformat_m88110_ext, floatformat_m88110_harris_ext,
+	floatformat_arm_ext_big, floatformat_arm_ext_littlebyte_bigword,
+	floatformat_ia64_spill_big, floatformat_ia64_spill_little,
+	floatformat_ia64_quad_big, floatformat_ia64_quad_little): Update
+	for addition of split_half field.
+
 2007-09-06  Tom Tromey  <tromey@redhat.com>
 
 	* pexecute.txh (pex_free): Document process killing.
diff --git a/libiberty/floatformat.c b/libiberty/floatformat.c
index c5abbb1..07af726 100644
--- a/libiberty/floatformat.c
+++ b/libiberty/floatformat.c
@@ -56,6 +56,7 @@ Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston, MA 02110-1301, USA.
 #endif
 #endif
 
+static int mant_bits_set (const struct floatformat *, const unsigned char *);
 static unsigned long get_field (const unsigned char *,
                                 enum floatformat_byteorders,
                                 unsigned int,
@@ -82,28 +83,32 @@ const struct floatformat floatformat_ieee_single_big =
   floatformat_big, 32, 0, 1, 8, 127, 255, 9, 23,
   floatformat_intbit_no,
   "floatformat_ieee_single_big",
-  floatformat_always_valid
+  floatformat_always_valid,
+  NULL
 };
 const struct floatformat floatformat_ieee_single_little =
 {
   floatformat_little, 32, 0, 1, 8, 127, 255, 9, 23,
   floatformat_intbit_no,
   "floatformat_ieee_single_little",
-  floatformat_always_valid
+  floatformat_always_valid,
+  NULL
 };
 const struct floatformat floatformat_ieee_double_big =
 {
   floatformat_big, 64, 0, 1, 11, 1023, 2047, 12, 52,
   floatformat_intbit_no,
   "floatformat_ieee_double_big",
-  floatformat_always_valid
+  floatformat_always_valid,
+  NULL
 };
 const struct floatformat floatformat_ieee_double_little =
 {
   floatformat_little, 64, 0, 1, 11, 1023, 2047, 12, 52,
   floatformat_intbit_no,
   "floatformat_ieee_double_little",
-  floatformat_always_valid
+  floatformat_always_valid,
+  NULL
 };
 
 /* floatformat for IEEE double, little endian byte order, with big endian word
@@ -114,7 +119,8 @@ const struct floatformat floatformat_ieee_double_littlebyte_bigword =
   floatformat_littlebyte_bigword, 64, 0, 1, 11, 1023, 2047, 12, 52,
   floatformat_intbit_no,
   "floatformat_ieee_double_littlebyte_bigword",
-  floatformat_always_valid
+  floatformat_always_valid,
+  NULL
 };
 
 /* floatformat for VAX.  Not quite IEEE, but close enough.  */
@@ -124,21 +130,24 @@ const struct floatformat floatformat_vax_f =
   floatformat_vax, 32, 0, 1, 8, 129, 0, 9, 23,
   floatformat_intbit_no,
   "floatformat_vax_f",
-  floatformat_always_valid
+  floatformat_always_valid,
+  NULL
 };
 const struct floatformat floatformat_vax_d =
 {
   floatformat_vax, 64, 0, 1, 8, 129, 0, 9, 55,
   floatformat_intbit_no,
   "floatformat_vax_d",
-  floatformat_always_valid
+  floatformat_always_valid,
+  NULL
 };
 const struct floatformat floatformat_vax_g =
 {
   floatformat_vax, 64, 0, 1, 11, 1025, 0, 12, 52,
   floatformat_intbit_no,
   "floatformat_vax_g",
-  floatformat_always_valid
+  floatformat_always_valid,
+  NULL
 };
 
 static int floatformat_i387_ext_is_valid (const struct floatformat *fmt,
@@ -170,7 +179,8 @@ const struct floatformat floatformat_i387_ext =
   floatformat_little, 80, 0, 1, 15, 0x3fff, 0x7fff, 16, 64,
   floatformat_intbit_yes,
   "floatformat_i387_ext",
-  floatformat_i387_ext_is_valid
+  floatformat_i387_ext_is_valid,
+  NULL
 };
 const struct floatformat floatformat_m68881_ext =
 {
@@ -178,7 +188,8 @@ const struct floatformat floatformat_m68881_ext =
   floatformat_big, 96, 0, 1, 15, 0x3fff, 0x7fff, 32, 64,
   floatformat_intbit_yes,
   "floatformat_m68881_ext",
-  floatformat_always_valid
+  floatformat_always_valid,
+  NULL
 };
 const struct floatformat floatformat_i960_ext =
 {
@@ -186,14 +197,16 @@ const struct floatformat floatformat_i960_ext =
   floatformat_little, 96, 16, 17, 15, 0x3fff, 0x7fff, 32, 64,
   floatformat_intbit_yes,
   "floatformat_i960_ext",
-  floatformat_always_valid
+  floatformat_always_valid,
+  NULL
 };
 const struct floatformat floatformat_m88110_ext =
 {
   floatformat_big, 80, 0, 1, 15, 0x3fff, 0x7fff, 16, 64,
   floatformat_intbit_yes,
   "floatformat_m88110_ext",
-  floatformat_always_valid
+  floatformat_always_valid,
+  NULL
 };
 const struct floatformat floatformat_m88110_harris_ext =
 {
@@ -202,7 +215,8 @@ const struct floatformat floatformat_m88110_harris_ext =
   floatformat_big,128, 0, 1, 11,  0x3ff,  0x7ff, 12, 52,
   floatformat_intbit_no,
   "floatformat_m88110_ext_harris",
-  floatformat_always_valid
+  floatformat_always_valid,
+  NULL
 };
 const struct floatformat floatformat_arm_ext_big =
 {
@@ -210,7 +224,8 @@ const struct floatformat floatformat_arm_ext_big =
   floatformat_big, 96, 0, 17, 15, 0x3fff, 0x7fff, 32, 64,
   floatformat_intbit_yes,
   "floatformat_arm_ext_big",
-  floatformat_always_valid
+  floatformat_always_valid,
+  NULL
 };
 const struct floatformat floatformat_arm_ext_littlebyte_bigword =
 {
@@ -218,35 +233,138 @@ const struct floatformat floatformat_arm_ext_littlebyte_bigword =
   floatformat_littlebyte_bigword, 96, 0, 17, 15, 0x3fff, 0x7fff, 32, 64,
   floatformat_intbit_yes,
   "floatformat_arm_ext_littlebyte_bigword",
-  floatformat_always_valid
+  floatformat_always_valid,
+  NULL
 };
 const struct floatformat floatformat_ia64_spill_big =
 {
   floatformat_big, 128, 0, 1, 17, 65535, 0x1ffff, 18, 64,
   floatformat_intbit_yes,
   "floatformat_ia64_spill_big",
-  floatformat_always_valid
+  floatformat_always_valid,
+  NULL
 };
 const struct floatformat floatformat_ia64_spill_little =
 {
   floatformat_little, 128, 0, 1, 17, 65535, 0x1ffff, 18, 64,
   floatformat_intbit_yes,
   "floatformat_ia64_spill_little",
-  floatformat_always_valid
+  floatformat_always_valid,
+  NULL
 };
 const struct floatformat floatformat_ia64_quad_big =
 {
   floatformat_big, 128, 0, 1, 15, 16383, 0x7fff, 16, 112,
   floatformat_intbit_no,
   "floatformat_ia64_quad_big",
-  floatformat_always_valid
+  floatformat_always_valid,
+  NULL
 };
 const struct floatformat floatformat_ia64_quad_little =
 {
   floatformat_little, 128, 0, 1, 15, 16383, 0x7fff, 16, 112,
   floatformat_intbit_no,
   "floatformat_ia64_quad_little",
-  floatformat_always_valid
+  floatformat_always_valid,
+  NULL
+};
+
+static int
+floatformat_ibm_long_double_is_valid (const struct floatformat *fmt,
+				      const void *from)
+{
+  const unsigned char *ufrom = (const unsigned char *) from;
+  const struct floatformat *hfmt = fmt->split_half;
+  long top_exp, bot_exp;
+  int top_nan = 0;
+
+  top_exp = get_field (ufrom, hfmt->byteorder, hfmt->totalsize,
+		       hfmt->exp_start, hfmt->exp_len);
+  bot_exp = get_field (ufrom + 8, hfmt->byteorder, hfmt->totalsize,
+		       hfmt->exp_start, hfmt->exp_len);
+
+  if (top_exp == hfmt->exp_nan)
+    top_nan = mant_bits_set (hfmt, ufrom);
+
+  /* A NaN is valid with any low part.  */
+  if (top_nan)
+    return 1;
+
+  /* An infinity, zero or denormal requires low part 0 (positive or
+     negative).  */
+  if (top_exp == hfmt->exp_nan || top_exp == 0)
+    {
+      unsigned int mant_bits, mant_off;
+      int mant_bits_left;
+
+      if (bot_exp != 0)
+	return 0;
+
+      return !mant_bits_set (hfmt, ufrom + 8);
+    }
+
+  /* The top part is now a finite normal value.  The long double value
+     is the sum of the two parts, and the top part must equal the
+     result of rounding the long double value to nearest double.  Thus
+     the bottom part must be <= 0.5ulp of the top part in absolute
+     value, and if it is < 0.5ulp then the long double is definitely
+     valid.  */
+  if (bot_exp < top_exp - 53)
+    return 1;
+  if (bot_exp > top_exp - 53 && bot_exp != 0)
+    return 0;
+  if (bot_exp == 0)
+    {
+      /* The bottom part is 0 or denormal.  Determine which, and if
+	 denormal the first two set bits.  */
+      int first_bit = -1, second_bit = -1, cur_bit;
+      for (cur_bit = 0; cur_bit < hfmt->man_len; cur_bit++)
+	if (get_field (ufrom + 8, hfmt->byteorder, hfmt->totalsize,
+		       hfmt->man_start + cur_bit, 1))
+	  {
+	    if (first_bit == -1)
+	      first_bit = cur_bit;
+	    else
+	      {
+		second_bit = cur_bit;
+		break;
+	      }
+	  }
+      /* Bottom part 0 is OK.  */
+      if (first_bit == -1)
+	return 1;
+      /* The real exponent of the bottom part is -first_bit.  */
+      if (-first_bit < top_exp - 53)
+	return 1;
+      if (-first_bit > top_exp - 53)
+	return 0;
+      /* The bottom part is at least 0.5ulp of the top part.  For this
+	 to be OK, the bottom part must be exactly 0.5ulp (i.e. no
+	 more bits set) and the top part must have last bit 0.  */
+      if (second_bit != -1)
+	return 0;
+      return !get_field (ufrom, hfmt->byteorder, hfmt->totalsize,
+			 hfmt->man_start + hfmt->man_len - 1, 1);
+    }
+  else
+    {
+      /* The bottom part is at least 0.5ulp of the top part.  For this
+	 to be OK, it must be exactly 0.5ulp (i.e. no explicit bits
+	 set) and the top part must have last bit 0.  */
+      if (get_field (ufrom, hfmt->byteorder, hfmt->totalsize,
+		     hfmt->man_start + hfmt->man_len - 1, 1))
+	return 0;
+      return !mant_bits_set (hfmt, ufrom + 8);
+    }
+}
+
+const struct floatformat floatformat_ibm_long_double =
+{
+  floatformat_big, 128, 0, 1, 11, 1023, 2047, 12, 52,
+  floatformat_intbit_no,
+  "floatformat_ibm_long_double",
+  floatformat_always_valid,
+  &floatformat_ieee_double_big
 };
 
 
@@ -254,6 +372,30 @@ const struct floatformat floatformat_ia64_quad_little =
 #define min(a, b) ((a) < (b) ? (a) : (b))
 #endif
 
+/* Return 1 if any bits are explicitly set in the mantissa of UFROM,
+   format FMT, 0 otherwise.  */
+static int
+mant_bits_set (const struct floatformat *fmt, const unsigned char *ufrom)
+{
+  unsigned int mant_bits, mant_off;
+  int mant_bits_left;
+
+  mant_off = fmt->man_start;
+  mant_bits_left = fmt->man_len;
+  while (mant_bits_left > 0)
+    {
+      mant_bits = min (mant_bits_left, 32);
+
+      if (get_field (ufrom, fmt->byteorder, fmt->totalsize,
+		     mant_off, mant_bits) != 0)
+	return 1;
+
+      mant_off += mant_bits;
+      mant_bits_left -= mant_bits;
+    }
+  return 0;
+}
+
 /* Extract a field which starts at START and is LEN bits long.  DATA and
    TOTAL_LEN are the thing we are extracting it from, in byteorder ORDER.  */
 static unsigned long
@@ -310,6 +452,10 @@ floatformat_to_double (const struct floatformat *fmt,
   int mant_bits_left;
   int special_exponent;		/* It's a NaN, denorm or zero */
 
+  /* Split values are not handled specially, since the top half has
+     the correctly rounded double value (in the only supported case of
+     split values).  */
+
   exponent = get_field (ufrom, fmt->byteorder, fmt->totalsize,
 			fmt->exp_start, fmt->exp_len);
 
@@ -318,26 +464,7 @@ floatformat_to_double (const struct floatformat *fmt,
      don't try to preserve the type of NaN.  FIXME.  */
   if ((unsigned long) exponent == fmt->exp_nan)
     {
-      int nan;
-
-      mant_off = fmt->man_start;
-      mant_bits_left = fmt->man_len;
-      nan = 0;
-      while (mant_bits_left > 0)
-	{
-	  mant_bits = min (mant_bits_left, 32);
-
-	  if (get_field (ufrom, fmt->byteorder, fmt->totalsize,
-			 mant_off, mant_bits) != 0)
-	    {
-	      /* This is a NaN.  */
-	      nan = 1;
-	      break;
-	    }
-
-	  mant_off += mant_bits;
-	  mant_bits_left -= mant_bits;
-	}
+      int nan = mant_bits_set (fmt, ufrom);
 
       /* On certain systems (such as GNU/Linux), the use of the
 	 INFINITY macro below may generate a warning that can not be
@@ -474,6 +601,10 @@ floatformat_from_double (const struct floatformat *fmt,
   dfrom = *from;
   memset (uto, 0, fmt->totalsize / FLOATFORMAT_CHAR_BIT);
 
+  /* Split values are not handled specially, since a bottom half of
+     zero is correct for any value representable as double (in the
+     only supported case of split values).  */
+
   /* If negative, set the sign bit.  */
   if (dfrom < 0)
     {