sim: smp: make option available again

At some point we want this to work, but it's not easy to test if
the configure option isn't available.  Restore it, but keep the
default off.

sim/Makefile.in

@@ -241,6 +241,7 @@ am__aclocal_m4_deps = $(top_srcdir)/../config/acx.m4 \
 	$(top_srcdir)/m4/sim_ac_option_profile.m4 \
 	$(top_srcdir)/m4/sim_ac_option_reserved_bits.m4 \
 	$(top_srcdir)/m4/sim_ac_option_scache.m4 \
+	$(top_srcdir)/m4/sim_ac_option_smp.m4 \
 	$(top_srcdir)/m4/sim_ac_option_stdio.m4 \
 	$(top_srcdir)/m4/sim_ac_option_trace.m4 \
 	$(top_srcdir)/m4/sim_ac_option_warnings.m4 \

sim/aclocal.m4

@@ -1188,6 +1188,7 @@ m4_include([m4/sim_ac_option_inline.m4])
 m4_include([m4/sim_ac_option_profile.m4])
 m4_include([m4/sim_ac_option_reserved_bits.m4])
 m4_include([m4/sim_ac_option_scache.m4])
+m4_include([m4/sim_ac_option_smp.m4])
 m4_include([m4/sim_ac_option_stdio.m4])
 m4_include([m4/sim_ac_option_trace.m4])
 m4_include([m4/sim_ac_option_warnings.m4])

sim/config.h.in

@@ -468,6 +468,9 @@
 /* Sim cache szie */
 #undef WITH_SCACHE
 
+/* Sim SMP settings */
+#undef WITH_SMP
+
 /* How to route I/O */
 #undef WITH_STDIO
 

sim/configure

@@ -1004,6 +1004,7 @@ enable_sim_inline
 enable_sim_profile
 enable_sim_reserved_bits
 enable_sim_scache
+enable_sim_smp
 enable_sim_stdio
 enable_sim_trace
 enable_werror
@@ -1780,6 +1781,8 @@ Optional Features:
                           instruction
   --enable-sim-scache=size
                           Specify simulator execution cache size
+  --enable-sim-smp=n      Specify number of processors to configure for
+                          (default 1)
   --enable-sim-stdio      Specify whether to use stdio for console
                           input/output
   --enable-sim-trace=opts Enable tracing of simulated programs
@@ -12442,7 +12445,7 @@ else
   lt_dlunknown=0; lt_dlno_uscore=1; lt_dlneed_uscore=2
   lt_status=$lt_dlunknown
   cat > conftest.$ac_ext <<_LT_EOF
-#line 12445 "configure"
+#line 12448 "configure"
 #include "confdefs.h"
 
 #if HAVE_DLFCN_H
@@ -12548,7 +12551,7 @@ else
   lt_dlunknown=0; lt_dlno_uscore=1; lt_dlneed_uscore=2
   lt_status=$lt_dlunknown
   cat > conftest.$ac_ext <<_LT_EOF
-#line 12551 "configure"
+#line 12554 "configure"
 #include "confdefs.h"
 
 #if HAVE_DLFCN_H
@@ -16080,6 +16083,31 @@ _ACEOF
 { $as_echo "$as_me:${as_lineno-$LINENO}: result: $sim_scache" >&5
 $as_echo "$sim_scache" >&6; }
 
+{ $as_echo "$as_me:${as_lineno-$LINENO}: checking number of sim cpus to support" >&5
+$as_echo_n "checking number of sim cpus to support... " >&6; }
+default_sim_smp="0"
+sim_smp="$default_sim_smp"
+# Check whether --enable-sim-smp was given.
+if test "${enable_sim_smp+set}" = set; then :
+  enableval=$enable_sim_smp; case "${enableval}" in
+  yes)	sim_smp="5";;
+  no)	sim_smp="0";;
+  *)	sim_smp="$enableval";;
+esac
+fi
+sim_igen_smp="-N ${sim_smp}"
+if test "x$sim_smp" = x0; then :
+
+else
+
+cat >>confdefs.h <<_ACEOF
+#define WITH_SMP $sim_smp
+_ACEOF
+
+fi
+{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $sim_smp" >&5
+$as_echo "$sim_smp" >&6; }
+
 { $as_echo "$as_me:${as_lineno-$LINENO}: checking for sim stdio debug behavior" >&5
 $as_echo_n "checking for sim stdio debug behavior... " >&6; }
 sim_stdio="0"

sim/configure.ac

@@ -180,6 +180,7 @@ SIM_AC_OPTION_INLINE
 SIM_AC_OPTION_PROFILE
 SIM_AC_OPTION_RESERVED_BITS
 SIM_AC_OPTION_SCACHE
+SIM_AC_OPTION_SMP
 SIM_AC_OPTION_STDIO
 SIM_AC_OPTION_TRACE
 SIM_AC_OPTION_WARNINGS

sim/m4/sim_ac_option_smp.m4

@@ -12,20 +12,26 @@ dnl GNU General Public License for more details.
 dnl
 dnl You should have received a copy of the GNU General Public License
 dnl along with this program.  If not, see <http://www.gnu.org/licenses/>.
-AC_DEFUN([SIM_AC_OPTION_SMP],
-[
+AC_DEFUN([SIM_AC_OPTION_SMP], [dnl
 AC_MSG_CHECKING([number of sim cpus to support])
-default_sim_smp="ifelse([$1],,5,[$1])"
-sim_smp="$default_sim_smp""
+dnl TODO: We should increase the default to use smp at some point.  When we do,
+dnl the ppc/configure sim-smp option should be merged.  See the WITH_SMP check
+dnl below for more cleanups too.
+default_sim_smp="0"
+sim_smp="$default_sim_smp"
 AC_ARG_ENABLE(sim-smp,
 [AS_HELP_STRING([--enable-sim-smp=n],
-		[Specify number of processors to configure for (default ${default_sim_smp})])],
+		[Specify number of processors to configure for (default 1)])],
 [case "${enableval}" in
   yes)	sim_smp="5";;
   no)	sim_smp="0";;
   *)	sim_smp="$enableval";;
 esac])dnl
 sim_igen_smp="-N ${sim_smp}"
-AC_DEFINE_UNQUOTED([WITH_SMP], [$sim_smp], [Sim SMP settings])
+dnl NB: The ppc code uses a diff default because its smp works.  That is why
+dnl we don't unconditionally enable WITH_SMP here.  Once we unify ppc, we can
+dnl make this unconditional.
+AS_VAR_IF([sim_smp], [0], [], [dnl
+  AC_DEFINE_UNQUOTED([WITH_SMP], [$sim_smp], [Sim SMP settings])])
 AC_MSG_RESULT($sim_smp)
 ])