Control dependences arising due to conditionals (and loops) are not included in the synchronization graph, since they are by definition intra thread dependences and are automatically obeyed. Consider the following example:
par (I){
a[i] = ...; /* s1 */
if (c[f(i)]){ /* s2 */
.. = a[g(i)]; /* s3 */
}
}
Statement s3 is control dependent on s2. However,
for all i, thread i of the statement always executes 
before 
, hence there is no need for the control
dependence in the synchronization graph. The only other point
of note in conditionals is that
the body of the
conditional needs to be split at points where dependence
arcs originate and terminate so that
global (and other) synchronizations may be inserted.