* doc/autoconf.texi (Function Portability): Mention C right shifts.

diff --git a/ChangeLog b/ChangeLog
index 886dadc4b0e81b425e739f3fc77289a1ea44b751..2a97a882bb1d929c660a1a6dda70b718ad68bd52 100644 (file)
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,7 @@
+2001-08-28  Kevin Ryde  <user42@zip.com.au>
+
+       * doc/autoconf.texi (Function Portability): Mention C right shifts.
+
 2001-08-27  Tim Van Holder  <tim.van.holder@pandora.be>
 
        * lib/autotest/general.m4: Reword some messages.

diff --git a/doc/autoconf.texi b/doc/autoconf.texi
index 038e8fdb0589221fceb326eec89abb8ac2c1e27c..33e5380e4f9b735b0a109d069db7f17c85246019 100644 (file)
--- a/doc/autoconf.texi
+++ b/doc/autoconf.texi
@@ -3373,6 +3373,13 @@ that are open.  For example, on Windows 9x and ME, such a call would fail;
 on DOS it could even lead to file system corruption, as the file might end
 up being written to after the OS has removed it.
 
+@item Signed @code{>>}
+Normally the C @code{>>} right shift of a signed type replicates the
+high bit, giving a so-called ``arithmetic'' shift.  But care should be
+taken since the ISO C standard doesn't require that behaviour.  On those
+few processors without a native arithmetic shift (for instance Cray
+vector systems) zero bits may be shifted in, the same as a shift of an
+unsigned type.
 @end table