code:
q = &a;
- if (p)
+ if (p) {
+ <data dependency barrier>
q = &b;
- <data dependency barrier>
+ }
x = *q;
This will not have the desired effect because there is no actual data
required is:
q = &a;
- if (p)
+ if (p) {
+ <read barrier>
q = &b;
- <read barrier>
+ }
x = *q;