A spill metric is a
heuristic metric used by
register allocators to decide which registers to spill. Popular spill metrics are:
* ''cost'' / ''degree'' - introduced in
Chaitin's algorithm Chaitin's algorithm is a bottom-up, graph coloring register allocation algorithm that uses cost/degree as its spill metric. It is named after its designer, Gregory Chaitin. Chaitin's algorithm was the first register allocation algorithm that made u ...
* ''cost'' / ''degree
2'' - emphasizes the spill's effect on neighbours
* ''cost'' - emphasizes
run time
* minimising number of spill operations
Where ''cost'' is the estimated cost of spilling a value from registers into memory.
Digital registers
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