Add verbiage about hardware facilities.

git-svn-id: svn://svn.valgrind.org/valgrind/trunk@12886 a5019735-40e9-0310-863c-91ae7b9d1cf9

diff --git a/README.s390 b/README.s390
index 6802c4ac989c482acf043414e8f60798c64492ea..3c3e29f964106b7a1c0907f0f08daca283756ccb 100644 (file)
--- a/README.s390
+++ b/README.s390
@@ -20,6 +20,18 @@ Limitations
   instead of just 1 read/write.
 
 
+Hardware facilities
+-------------------
+Valgrind does not require that the host machine has the same hardware
+facilities as the machine for which the client program was compiled.
+This is convenient. The JIT compiler will translate the client instructions
+according to the facilities available on the host.
+This means, though, that probing for hardware facilities by issuing
+instructions from that facility and observing whether SIGILL is thrown
+may not work. As a consequence, programs that attempt to do so may
+behave differently. It is believed that this is a rare use case.
+
+
 Recommendations
 ---------------
 Applications should be compiled with -fno-builtin to avoid