+=head2 Floating Point Considerations
+
+Prior to 5.8.0, Perl simply accepted the default floating point options of the
+C compiler, namely representing doubles with D_FLOAT on VAX and G_FLOAT on
+Alpha. Single precision floating point values are represented in F_FLOAT
+format when either D_FLOAT or G_FLOAT is in use for doubles. Beginning with
+5.8.0, Alpha builds now use IEEE floating point formats by default, which in
+VMS parlance are S_FLOAT for singles and T_FLOAT for doubles. IEEE is not
+available on VAX, so F_FLOAT and D_FLOAT remain the defaults for singles and
+doubles respectively. The available non-default options are G_FLOAT on VAX
+and D_FLOAT or G_FLOAT on Alpha.
+
+The use of IEEE on Alpha introduces NaN, infinity, and denormalization
+capabilities not available with D_FLOAT and G_FLOAT. When using one of those
+non-IEEE formats, silent underflow and overflow are emulated in the conversion
+of strings to numbers, but it is preferable to get the real thing by using
+IEEE where possible.
+
+Regardless of what floating point format you consider preferable, be aware
+that the choice may have an impact on compatibility with external libraries,
+such as database interfaces, and with existing data, such as data created with
+the C<pack> function and written to disk, or data stored via the Storable
+extension. For example, a C<pack("d", $foo)")> will create a D_FLOAT,
+G_FLOAT, or T_FLOAT depending on what your Perl was configured with. When
+written to disk, the value can only be retrieved later by a Perl configured
+with the same floating point option that was in effect when it was created.
+
+To obtain a non-IEEE build on Alpha, simply answer no to the "Use IEEE math?"
+question during the configuration. To obtain an option different from the C
+compiler default on either VAX or Alpha, put in the option that you want in
+answer to the "Any additional cc flags?" question. For example, to obtain a
+G_FLOAT build on VAX, put in C</FLOAT=G_FLOAT>.
+
+=head2 Multinet issues with Perl on VMS
+
+Prior to the release of Perl 5.8.0 it was noted that the regression
+test for lib/Net/hostent (in file [.lib.Net]hostent.t) will fail owing
+to problems with the hostent structure returned by C calls to either
+gethostbyname() or gethostbyaddr() using DEC or Compaq C with a
+Multinet TCP/IP stack. The problem was noted in Multinet 4.3A
+using either Compaq C 6.5 or DEC C 6.0, and with Multinet 4.2A
+using DEC C 5.2, but could easily affect other versions of Multinet.
+Process Software Inc. has acknowledged a bug in the Multinet version
+of UCX$IPC_SHR and has provided an ECO for it. The ECO is called
+UCX_LIBRARY_EMULATION-010_A044 and is available from:
+
+ http://www.multinet.process.com/eco.html
+
+As of this writing, the ECO is only available for Multinet versions
+4.3A and later. You may determine the version of Multinet that you
+are running using the command:
+
+ multinet show /version
+
+from the DCL command prompt.
+
+If the ECO is unavailable for your version of Multinet and you are
+unable to upgrade, you might try using Perl programming constructs
+such as:
+
+ $address = substr($gethostbyname_addr,0,4);
+
+to temporarily work around the problem, or if you are brave
+and do not mind the possibility of breaking IPv6 addresses,
+you might modify the pp_sys.c file to add an ad-hoc correction
+like so:
+
+
+ --- pp_sys.c;1 Thu May 30 14:42:17 2002
+ +++ pp_sys.c Thu May 30 12:54:02 2002
+ @@ -4684,6 +4684,10 @@
+ }
+ #endif
+
+ + if (hent) {
+ + hent->h_length = 4;
+ + }
+ +
+ if (GIMME != G_ARRAY) {
+ PUSHs(sv = sv_newmortal());
+ if (hent) {
+
+then re-compile and re-test your perl. After the installation
+of the Multinet ECO you ought to back out any such changes though.
+