FIO, powerpc-darwin mangling patch [7.x and earlier].

[Iain Sandoe]

Hi,

So it turns out that the Darwin PPC port was  broken essentially “forever” 
(before the tidy-up in 8.2) with respect to mangling the symbols for __ibm128 
type (the default long double for the port).

In 7.x and earlier (at least back to Apple’s 4.2.1) the use passes right 
through rs6000_mangle_type, which causes it to mangle to ‘e’ - which is the 
representation for long double as a 64b value (-mlong-double-64).

This is fixable, even quite easily, but I think it’s better to have the break 
in the upstream sources on a major boundary (so we leave it alone and have the 
correction in 8+)

In due course, I will apply the following fix to my “vendor” branches (7, 6 and 
5) for anyone who actually cares.

cheers
Iain

diff --git a/gcc/config/rs6000/rs6000.c b/gcc/config/rs6000/rs6000.c
index d377e24..ccb771b 100644
--- a/gcc/config/rs6000/rs6000.c
+++ b/gcc/config/rs6000/rs6000.c
@@ -35375,6 +35375,10 @@ rs6000_mangle_type (const_tree type)
       && !TARGET_IEEEQUAD)
     return "g";

+  if (TARGET_MACHO && type == long_double_type_node
+      && TREE_INT_CST_LOW (TYPE_SIZE (type)) == 128)
+    return "g";
+
   /* For all other types, use normal C++ mangling.  */
   return NULL;
 }