A Heuristic Scheduler for Port-Constrained Floating-Point Pipelines

Algorithm 1

Heuristic minimum-resource schedule.

for  each port vertex 𝑣∈𝑉   do

 𝑒(𝑣) = Port_Sched(𝑣,𝑃,𝐹);

  𝑉=𝑉−{𝑣};

end

while  𝑉≠∅   do

  for  each operation vertex  𝑣∈𝑉   do

   if  Prev_Sched (Pred(𝑣), 𝐸)   then

     if  Conflict(E, RAT(𝑜_𝑣), DII)   then

      e(𝑣) = e(𝑣) + 1;

     else

      e(𝑣) = MAX (Pred(𝑣),  𝐸);

       UpdateRAT(𝑣,𝑜_𝑣,𝑒(𝑣));

      𝑒(𝑣)=𝑒(𝑣)+𝐷_𝑣;

      𝑉=𝑉−{𝑣};

     end

   end

  end

end

Conflict(E, RAT(𝑜_𝑣), DII)

  for each functional unit r ∈R do

  L = RAT(𝑜_𝑣,𝑟);

  while  𝐿≠∅  do

   if  𝑒(𝑣)≡ First(𝐿) (mod DII)   then

    break;

  end

  L = Next(L);

 end

  if  𝐿=∅   then

  return  false;

 end

  end

return  true;