next up previous

4.10 Using CMMD and the Vector Units

By writing the node program in a data parallel language (CMF or C*), it is possible for a control parallel program also to take advantage of the vector units. Such a program is compiled in the normal fashion, but is linked differently.

Example
Suppose we have a node program called myprog.fcm that uses CMMD. It is compiled and linked to use the vector units as follows.

cmf -vu -c myprog.fcm
cmf -node myprog.o -o myprog

Even though it is optional, using the -vu flag does improve the speed significantly. For instance, try compiling the example program
/usr/examples/cmmd/hostless/cmf/n-body-bc/n-body-bc.FCM
with and without the -vu flag. You will notice the difference in the execution times of the two versions.