+#if test "x$ARCHTYPE" = "xx86" -a "x$host_cpu" != "xi386" -a "x$host_cpu" != "xi486" -a "x$host_cpu" != "xi586"; then
+#For now, using lock; addl compatibility mode even for i686, because the
+#Pentium III is seen as a i686, but lacks mfence instruction.
+#Only using fence for x86_64.
+if test "x$ARCHTYPE" = "xx86" -a "x$host_cpu" != "xi386" -a "x$host_cpu" != "xi486" -a "x$host_cpu" != "xi586" -a "x$host_cpu" != "xi686"; then