updated HPUX notes.

README

@@ -363,11 +363,18 @@ AIX:	A complete overhaul of the shared library support is now in
 	like "cc_r".  For full C++ module support, set CC="xlC_r" (or
 	CC="xlC" without thread support).
 
-HP-UX:	When using threading, you may have to add -D_REENTRANT to the
+HP-UX:  When using threading, you may have to add -D_REENTRANT to the
 	OPT variable in the top-level Makefile; reported by Pat Knight,
 	this seems to make a difference (at least for HP-UX 10.20)
-	even though pyconfig.h defines it. Experience seems to show that
-        building with HP's compiler works best if you set CC="cc -Ae".
+	even though pyconfig.h defines it. This seems unnecessary when
+	using HP/UX 11 and later - threading seems to work "out of the 
+	box".
+
+HP-UX ia64: When building on the ia64 (Itanium) platform using HP's 
+	compiler, some experience has shown that the compiler's 
+	optimiser produces a completely broken version of python 
+	(see http://www.python.org/sf/814976). To work around this, 
+	edit the Makefile and remove -O from the OPT line.
 
 HP PA-RISC 2.0: A recent bug report (http://www.python.org/sf/546117)
 	suggests that the C compiler in this 64-bit system has bugs