C#: Refactor SSA liveness logic - #449
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Simplify liveness analysis by avoiding the two extra copies of `liveAtRank()` (and other auxiliary predicates) for fields/captured variables analysis.
calumgrant
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Nov 19, 2018
calumgrant
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Some minor questions, but otherwise LGTM.
| /** | ||
| * Same as `ref()`, but extended to include implicit call definitions | ||
| * for fields and properties. | ||
| * Holds if source varible `v` is likely to be live at any node inside basic |
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Document that this is an overestimate. Perhaps liveCandidate, possiblyLive or liveInBB or something?
| bb.getNode(i) = call.getAControlFlowNode() and | ||
| call.getEnclosingCallable() = fp.getEnclosingCallable() and | ||
| relevantDefinition(_, fp.getAssignable(), _) | ||
| getARuntimeTarget(call).hasBody() |
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What is hasBody signifying?
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It just makes the computation faster, as we only care about calls to methods that either call other methods or perform an update.
calumgrant
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Nov 20, 2018
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Simplify liveness analysis by avoiding the two extra copies of
liveAtRank()(and other auxiliary predicates) for fields/captured variables analysis.In addition to simplifying the logic, this also has a positive performance impact, for example:
Before:
After:
@calumgrant