Allow casting bool to int explicitly

[MineCake147E]

Sometimes I need to convert bool values into some kind of integral type(such as uint) like:

public static int U(int y) => y > 0 ? 1 : 0;

which currently generates (on SharpLab x64 Release)

C.U(Int32)
    L0000: test ecx, ecx
    L0002: jg L0007
    L0004: xor eax, eax
    L0006: ret
    L0007: mov eax, 0x1
    L000c: ret

while

public static bool G(int y) => y > 0;

becomes

C.G(Int32)
    L0000: test ecx, ecx
    L0002: setg al
    L0005: movzx eax, al
    L0008: ret

I need both codes compiles into same code as G(that uses setg instruction instead of jg).

Proposal

By allowing conversion from bool to int like:

public static int U(int y) => (int)(y > 0);

it can be compiled into

C.U(Int32)
    L0000: test ecx, ecx
    L0002: setg al
    L0005: movzx eax, al
    L0008: ret

[stephentoub]

https://sharplab.io/#v2:EYLgxg9gTgpgtADwGwBYA0AXEBDAzgWwB8ABAJgEYBYAKGIAYACY8gOgCUBXAOwwEt8YLAMIR8AB14AbGFADKMgG68wMXAG4aNYgGYmpBkIYBvGgzNNdzJA148GAVQAUtjAwCeASlPmT1c/4ZgCAhJQIYAXncGAD4GOg0/ALNiAHYHLlxsADNBAEFcAB4gkLRAtwwYaMdYLMCPBP8AXxpGoA

using System.Runtime.CompilerServices;

public class C {
    public static int U(int y)
    {
        bool b = y > 0;
        return Unsafe.As<bool, byte>(ref b);
    }
}

results in:

C.U(Int32)
    L0000: test ecx, ecx
    L0002: setg al
    L0005: movzx eax, al
    L0008: ret

[MineCake147E]

I'm glad to know that.
Thank you for teaching me.
Closing.

[GrabYourPitchforks]

Related: dotnet/coreclr#16138, where we considered making this change in the existing method Convert.ToInt32(bool) but it was rejected in favor of waiting for the JIT to optimize the pattern.