SSA-based register allocation does copy-coalescing afterwards [0] or integrated [1]. This is the NP-hard part. Of course, there are fast heuristics [2] which ar

SSA-based register allocation does copy-coalescing afterwards [0] or integrated [1]. This is the NP-hard part. Of course, there are fast heuristics [2] which are "pretty good". [0] https://pp.info.uni-karlsruhe.de/publication.php?id=hack06cc https://pp.info.uni-karlsruhe.de/publication.php?id=hack06cc [1] https://pp.info.uni-karlsruhe.de/publication.php?id=buchwald11cc https://pp.info.uni-karlsruhe.de/publication.php?id=buchwald... [2] https://pp.info.uni-karlsruhe.de/publication.php?id=braun10cc https://pp.info.uni-karlsruhe.de/publication.php?id=braun10c...