Combining Fetch&Adds at Switch
Suppose
Fetch&Add(V,e) and Fetch&Add(V,f) arrive at a switch together …
–Form
the sum f+e
–Send
Fetch&Add(V,f+e) on to the memory
–Store
e locally
–When
g0 is returned by the memory
•Return
g0 as response to Fetch&Add(V,e)
•Return
g0+e as response to Fetch&Add(V,f)
Switch
F&E(V,e+f)
g0
F&E(V,f)
g0+e
F&E(V,e)
g0