Greedy topological sort of the binst graph to minimize qubit allocations / deallocations #1099
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…ons / deallocations
| if TYPE_CHECKING: | ||
| from qualtran import BloqInstance | ||
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| _INFINITY: int = int(1e18) |
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Eventually, I want to set _INFINITY + binst.i as the priority instead of _INFINITY; assuming we can make binst.i preserve insertion order following #1098
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In that case, a name other than "infinity" should be used if we're going to literally do "infinity + 1" as a meaningful distinction :p
| goal to minimize qubit allocations and deallocations by pushing allocations to the | ||
| right and de-allocations to the left. | ||
| """ | ||
| yield from nx.lexicographical_topological_sort(binst_graph, key=_priority) |
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this function has slimmed down considerably! Thanks @anurudhp
| reg_2 / \textrm{\scalebox{0.5}{QAny(2)}} | ||
| reg_3:on G:width=25:shape=box \textrm{\scalebox{0.8}{alloc}} | ||
| reg_3 / \textrm{\scalebox{0.5}{QAny(1)}} | ||
| selection G:width=121:shape=box \textrm{\scalebox{0.8}{StatePreparationAliasSampling}} reg G:width=37:shape=box \textrm{\scalebox{0.8}{sigma\_mu}} reg_1 G:width=17:shape=box \textrm{\scalebox{0.8}{alt}} reg_2 G:width=21:shape=box \textrm{\scalebox{0.8}{keep}} reg_3 G:width=65:shape=box \textrm{\scalebox{0.8}{less\_than\_equal}} |
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should we scrap this test? I guess it sortof forces you to look at the circuit so you can paste in the new data but it's not very DAMP https://testing.googleblog.com/2019/12/testing-on-toilet-tests-too-dry-make.html
mpharrigan
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please consider changing the documentation & name for "infinity" if we're going to be doing meaningful arithmetic on it
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This PR adds a new stable greedy topological sorting method and changes the default topological sort to use this method when iterating over nodes of a bloq instance graph.
This is useful to
Fixes the issue mentioned in #963 (comment), would be useful for #1097 and can be improved by addressing #1098