Tape Machine (#30)

Adds a tape machine way of executing the code.
The tape machine is a series of FunctionCall objects, which can either be called one by one, or be used to generate expressions to make up a function.

Reviewed-on: Rubydragon/MetagraphOptimization.jl#30
Co-authored-by: Anton Reinhard <anton.reinhard@proton.me>
Co-committed-by: Anton Reinhard <anton.reinhard@proton.me>

src/scheduler/greedy.jl

@@ -14,7 +14,7 @@ function schedule_dag(::GreedyScheduler, graph::DAG, machine::Machine)
         enqueue!(nodeQueue, node => 0)
     end
 
-    schedule = Vector{Node}()
+    schedule = Vector{FunctionCall}()
     sizehint!(schedule, length(graph.nodes))
 
     # keep an accumulated cost of things scheduled to this device so far
@@ -35,7 +35,12 @@ function schedule_dag(::GreedyScheduler, graph::DAG, machine::Machine)
             deviceAccCost[lowestDevice] = compute_effort(task(node))
         end
 
-        push!(schedule, node)
+        if (node isa DataTaskNode && length(node.children) == 0)
+            push!(schedule, get_init_function_call(node, entry_device(machine)))
+        else
+            push!(schedule, get_function_call(node)...)
+        end
+
         for parent in parents(node)
             # reduce the priority of all parents by one
             if (!haskey(nodeQueue, parent))