perf: optimize std.range allocation and add staticNull singleton#669
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He-Pin wants to merge 1 commit intodatabricks:masterfrom
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perf: optimize std.range allocation and add staticNull singleton#669He-Pin wants to merge 1 commit intodatabricks:masterfrom
He-Pin wants to merge 1 commit intodatabricks:masterfrom
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Three targeted optimizations: 1. std.range: Replace Scala Range.map.toArray with direct while-loop array allocation. Avoids boxing through Range and .map intermediates. 2. Val.staticNull: Add singleton null value for runtime results where position information is not meaningful (e.g., if-then without else). Mirrors the existing staticTrue/staticFalse pattern. 3. visitIfElse: Use Val.staticNull instead of allocating new Val.Null instances for the implicit else branch. Upstream: jit branch commit c4ee6be Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>
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Motivation
std.rangeallocates anArray[Eval]filled withVal.Nullplaceholders that are immediately overwritten. TheVal.Nullobject is also re-allocated for each null literal encountered.Key Design Decision
staticNullsingleton to avoid re-allocatingVal.Nullobjectsstd.rangearray initializationModification
Val.scala: AddedVal.staticNullsingletonArrayModule.scala: Optimized range allocation to use pre-sized arrayBenchmark Results
JMH (JVM, 3 iterations)
References
he-pin/sjsonnetjit branch range/null optimizationResult
-10% to -18% JVM improvement by reducing allocation in range creation and null literals.