#71252 disable AtanPiTest for android x86

[mkhamoyan]

Disabling AtanPiTest on android x86 due to #71252

[dotnet-issue-labeler]

I couldn't figure out the best area label to add to this PR. If you have write-permissions please help me learn by adding exactly one area label.

[mkhamoyan]

/azp run runtime-extra-platforms

[azure-pipelines]

Azure Pipelines successfully started running 1 pipeline(s).

[steveisok]

/cc @tannergooding

[stephentoub]

It looks like this is being disabled due to #71252? We typically use [ActiveIssue(...)] for that. If that's not feasible because it doesn't support the exact condition, you can at least add the issue link as a comment next to the attribute. Otherwise it's likely we'll miss this in the future and it'll remain permanently disabled.

[tannergooding]

As per the comment by @drewnoakes on #71252, this is very likely a bug in Mono.

We have existing tests validating Math.Atan(-0.0) returns -0.0.

Likewise, -0.0 / PositiveNonZero (e.g. -0.0 / Math.PI) is -0.0. More specifically the result of x / y for a positive or negative zero, is 0 with the sign taken as an xor of the signs of x and y. So (and extend to any -y or +y rather than -1/+1):

• -0 / -1 = +0
• -0 / +1 = -0
• +0 / -1 = -0
• +0 / +1 = +0

Therefore Math.Atan(-0.0) / Math.PI which is the effective current implementation of double.AtanPi(double x) should be -0.0. This is the result on RyuJIT (and required answer per the IEEE 754 spec), so this is likely an error specific to Mono (potentially to Mono Android/x86).

[mkhamoyan]

/azp run runtime-extra-platforms

[azure-pipelines]

Pull request contains merge conflicts.

[mkhamoyan]

Closing this as Atan2PiTest is already changed only for 64bit by this commit