C++: Fix performance of IR AliasAnalysis #38
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The check that an instruction is in the same function as its operands is hopefully redundant and can be removed. Just to be sure, I've added the check to a sanity query. This check turned out to cause bad performance in the alias analysis because it got inlined into `AliasAnalysis::resultEscapes` and then pulled out to a loop-invariant predicate that got a bad join order. With this check removed, the `ssa/AliasAnalysis.qll` file is orders of magnitude faster.
Now that it's been simplified to be the same as `getOperand`, it doesn't seem to have a purpose.
dave-bartolomeo
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You're right, that check looks redundant. I'm glad speeding up alias analysis was this straightforward.
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Kotlin: Handle zero-width locations for generated elements
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add a query for finding rank[1]
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add a query for finding rank[1]
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These are now in Kotlin github#38
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Ensure event sources are available for triggering events
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I thought the bad performance of
AliasAnalysiswas due to recursion through double negation, but it turns out that the QL compiler optimized that perfectly well. Instead it was due to a bad join order inInstruction.hasUse, which was caused by a check that I don't think is necessary. Do you agree, @dave-bartolomeo?The first commit fixes performance, and the second commit is cleanup.