I'm adding wasmjs target support for my application, and I have found an inconsistency between wasmj...

loke

12/30/2023, 4:18 PM

I'm adding wasmjs target support for my application, and I have found an inconsistency between wasmjs and all other platforms (I've tested on JVM, Linux and JS). The following code returns -0.0 for all these platforms, but 0.0 on wasmjs. Is this a bug?

Copy code

fun opDouble(x: Double, y: Double) =
     if (x == 0.0) y else (y % x).let { result -> if (result != 0.0 && ((x < 0 && y > 0) || (x > 0 && y < 0))) x + result else result }
 opDouble(2.0, -2.0)

Robert Jaros

12/30/2023, 4:36 PM

The

operator returns different values on different targets. https://pl.kotl.in/V9JlKwE5c

Robert Jaros

12/30/2023, 4:37 PM

I'm not sure what the Kotlin specification says about this kind of operation.

loke

12/30/2023, 4:38 PM

Your example is interesting, and also raises more questions. The JS target result doesn't match my observations.

loke

12/30/2023, 4:38 PM

In any case, I want to call this a bug, since the arithmetic operations are supposed to behave the same, no?

Robert Jaros

12/30/2023, 4:40 PM

It's probably hard question. Users of Kotlin on JVM would probably want to have the results like Java, but users of Kotlin/JS would like to have the results match those of JS 🙂

loke

12/30/2023, 4:43 PM

That's fair, but at least JS and wasm should be the same, no?

Robert Jaros

12/30/2023, 4:43 PM

No idea 🙂 Probably.

Svyatoslav Kuzmich [JB]

12/30/2023, 6:37 PM

Thanks. Added your case to the issue https://youtrack.jetbrains.com/issue/KT-58681/K-Wasm-division-remainder-has-a-wrong-sign

ephemient

12/30/2023, 6:39 PM