Document problems with DEC C 5.9.x on Digital Unix 4.0f.

diff --git a/etc/MACHINES b/etc/MACHINES
index d2a6f40b75c0711dc3ad13b63f8cbdab0ca07d94..87bbaa6e8eaae4c1f20cfb00e08b55c7df7f5d0c 100644 (file)
--- a/etc/MACHINES
+++ b/etc/MACHINES
@@ -75,6 +75,11 @@ Alpha (DEC) running OSF/1 or GNU/Linux (alpha-dec-osf1, alpha-dec-linux-gnu)
 
       configure --x-includes=/usr/include --x-libraries=/usr/shlib
 
+  DEC C compiler version 5.9 (DEC C V5.9-005 on Digital UNIX V4.0f)
+  is reported to produce bogus binaries of Emacs 21.2 when the
+  command-line switches "-O4 -arch ev6 -tune ev6" are used.  Using
+  just -O4 produces a good executable.
+
   For 4.0 revision 564, and 4.0A and 4.0B, Emacs 20 seems to work
   with no special configuration options.  However, if you use GCC as
   your compiler, you will need version 2.8.1 or later, as older