runtime: RuntimeInformation.ProcessArchitecture is not a JIT constant

Description

RuntimeInformation.ProcessArchitecture currently isn’t a JIT time constant so it doesn’t participate in dead branch elimination and it also isn’t inlined. Since the API has a simillar usage as OperatingSystem APIs which are JIT constants, the expected behaviour would be for it to be as optimized as them. The simple solution would be to store the value in a static readonly field and return that instead, which would be optimized in T1.

Thinking about it though, I think that since the process architecture will be always the same as the one dotnet running it was built for, wouldn’t such implementation as the one below be valid?

        public static Architecture ProcessArchitecture
        {
            get
            {
#if TARGET_ARM64
                return Architecture.Arm64;
#elif TARGET_ARM
                return Architecture.Arm;
#elif TARGET_AMD64
                return Architecture.X64;
#elif TARGET_X86
                return Architecture.X86;
#elif TARGET_WASM
                return Architecture.Wasm;
#elif TARGET_S390X
                return Architecture.S390x;
#else
#error Unknown Architecture
#endif
            }
        }

Configuration

SharpLab Core CLR 5.0.721.25508 on amd64

Regression?

Probably not

Data

SharpLab