spicysharkco opened a new pull request, #26394: URL: https://github.com/apache/datafusion/pull/26394
## Which issue does this PR close? - Closes #26333. ## Rationale for this change Spark's `Atan2` adds `0.0` to both arguments before calling `atan2`, which turns `-0.0` into `0.0`. The source comment says why: "With codegen, the values returned by -0.0 and 0.0 are different. Handled with +0.0". Both the interpreted path and the codegen path do it: - `nullSafeEval`: `math.atan2(input1.asInstanceOf[Double] + 0.0, input2.asInstanceOf[Double] + 0.0)` - `doGenCode`: `java.lang.Math.atan2($c1 + 0.0, $c2 + 0.0)` https://github.com/apache/spark/blob/v4.0.0/sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/expressions/mathExpressions.scala#L1229-L1239 `SparkAtan2` passed the raw arguments to `f64::atan2`, so a `-0.0` argument could give a different result, for example `-pi` for `atan2(-0.0, -1.0)` where Spark returns `pi`. ## What changes are included in this PR? - `SparkAtan2` adds `0.0` to both arguments before calling `f64::atan2`. - `atan2.slt`: the expectation for `atan2(-0.0, -1.0)` was the C99 result and is now the Spark result, `3.141592653589793`. ## What is the testing strategy for this PR? New cases in `datafusion/sqllogictest/test_files/spark/math/atan2.slt`: - `query R` cases for `atan2(0.0, -0.0)` and `atan2(-0.0, -0.0)`, and an array-path query over those two plus `atan2(-0.0, -1.0)`. - A `query T` check on the string form of `atan2(-0.0, 1.0)`, `atan2(-0.0, 0.0)`, `atan2(0.0, -0.0)` and `atan2(-0.0, -0.0)`, which must be `0.0` and not `-0.0`. A numeric `query R` cannot tell the two apart. The expected values come from the Spark code above (`-0.0 + 0.0` is `0.0`), and match the three queries in the issue. These cases fail on `main` and pass with this change. ## Are there any user-facing changes? `atan2` in `datafusion-spark` now returns the Spark result when either argument is `-0.0`. No API change. -- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. To unsubscribe, e-mail: [email protected] For queries about this service, please contact Infrastructure at: [email protected] --------------------------------------------------------------------- To unsubscribe, e-mail: [email protected] For additional commands, e-mail: [email protected]
