[mono] Tracking: Implement `System.Runtime.Intrinsics.Arm.Rdm`

[imhameed]

System.Runtime.Intrinsics.Arm.Rdm:

• IsSupported
• MultiplyRoundedDoublingAndAddSaturateHigh
• MultiplyRoundedDoublingAndSubtractSaturateHigh
• MultiplyRoundedDoublingBySelectedScalarAndAddSaturateHigh
• MultiplyRoundedDoublingBySelectedScalarAndSubtractSaturateHigh

System.Runtime.Intrinsics.Arm.Rdm.Arm64:

• IsSupported
• MultiplyRoundedDoublingAndAddSaturateHighScalar
• MultiplyRoundedDoublingAndSubtractSaturateHighScalar
• MultiplyRoundedDoublingScalarBySelectedScalarAndAddSaturateHigh
• MultiplyRoundedDoublingScalarBySelectedScalarAndSubtractSaturateHigh

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[mihir-b-shah]

Hi I was interested in working on this issue, I was wondering are there any tests available for this or should I be writing my own corresponding tests? Thank you!

[imhameed]

Hi @mihir-b-shah,

Awesome. There are tests available but they are currently disabled. The existing tests are located here:

• https://github.com/dotnet/runtime/tree/64da821c7b3e60f9aeaf2c3d544d33d19e2fc82e/src/tests/JIT/HardwareIntrinsics/Arm/Rdm.Arm64
• https://github.com/dotnet/runtime/tree/64da821c7b3e60f9aeaf2c3d544d33d19e2fc82e/src/tests/JIT/HardwareIntrinsics/Arm/Rdm

Other intrinsics-on-Mono work is being done right now, and by looking at some of these commits you should be able to get a feel for what you'll need to do. Here's an example:

• [mono] Add support for Arm intrinsics Sha256 #47337

[SamMonoRT]

Need #48475 to implement a subset of these