[RFA] Support true 'long double' size.

[Pierre Muller <muller@ics.u-strasbg.fr>]

At 20:51 18/02/2003, Andrew Cagney wrote:

>>Index: doublest.c
>>===================================================================
>>RCS file: /cvs/src/src/gdb/doublest.c,v
>>retrieving revision 1.11
>>diff -u -p -r1.11 doublest.c
>>--- doublest.c  4 Dec 2002 05:40:40 -0000       1.11
>>+++ doublest.c  17 Feb 2003 16:07:19 -0000
>>@@ -633,6 +633,8 @@ floatformat_from_length (int len)
>>     return TARGET_DOUBLE_FORMAT;
>>   else if (len * TARGET_CHAR_BIT == TARGET_LONG_DOUBLE_BIT)
>>     return TARGET_LONG_DOUBLE_FORMAT;
>>+  else if (len * TARGET_CHAR_BIT == TARGET_LONG_DOUBLE_BIT_ALTERNATE)
>>+    return TARGET_LONG_DOUBLE_FORMAT;
>> 
>>   return NULL;
>> }
>
>Would simply adding:
>
>else if (TARGET_LONG_DOUBLE_FORMAT != NULL
>    && len * TARGET_CHAR_BIT == TARGET_LONG_DOUBLE_FORMAT->totalsize)
>  ..
>
>to the end of that if() chain work? (and the other alternatives as well of course).

Yes this works and has the same functionality 
for the i386 specific problem.

>Otherwize, yes, I can't see any other way of handling this problem :-(

The old patch might still be usefull for other processors,
but I am not sure about that.

So here is a new simplified patch proposal:

ChangeLog entry:

2003-03-11 Pierre Muller  <muller@ics.u-strasbg.fr>

        * doublest.c (floatformat_from_length): Accept also
        the real size of 'long double' type.

Index: doublest.c
===================================================================
RCS file: /cvs/src/src/gdb/doublest.c,v
retrieving revision 1.12
diff -p -u -r1.12 doublest.c
--- doublest.c  27 Feb 2003 18:08:25 -0000      1.12
+++ doublest.c  11 Mar 2003 12:17:52 -0000
@@ -633,6 +633,14 @@ floatformat_from_length (int len)
     return TARGET_DOUBLE_FORMAT;
   else if (len * TARGET_CHAR_BIT == TARGET_LONG_DOUBLE_BIT)
     return TARGET_LONG_DOUBLE_FORMAT;
+  /* On i386 the 'long double' type takes 96 bits,
+     while the real number of used bits is only 80,
+     both in processor and in memory.
+     The code below accepts the real bit size.  */
+  else if ((TARGET_LONG_DOUBLE_FORMAT)
+          && (len * TARGET_CHAR_BIT ==
+               TARGET_LONG_DOUBLE_FORMAT->totalsize))
+    return TARGET_LONG_DOUBLE_FORMAT;

   return NULL;
 }




Pierre Muller
Institut Charles Sadron
6,rue Boussingault
F 67083 STRASBOURG CEDEX (France)
mailto:muller@ics.u-strasbg.fr
Phone : (33)-3-88-41-40-07  Fax : (33)-3-88-41-40-99