CODEWITHSUNDEEP
c#optimizationcompilation
Dave
Dave

Reputation: 12457

For time-critical C# code, should I value static methods in my struct (over non-static ones)?

From some researching, I know the static method below can get JIT inlined. But can the non-static ones get inlined as well?

If the code is really time-critical, should I bother valuing this kind of static methods over non-static ones?

public struct PixelData
{
    public readonly uint raw;

    public PixelData(uint raw)
    {
        this.raw = raw;
    }

    //JIT inlines this
    static bool HasLineOfSight(PixelData p)
    {
        return (p.raw & 0x8000) != 0;
    }

    //But what about this?
    int GetWeight()
    {
        return (int)(raw & 0x3FFF);
    }

}

Upvotes: 0

Views: 223

Answers (2)

dav_i
dav_i

Reputation: 28097

You could apply [MethodImpl(MethodImplOptions.AggressiveInlining)] to the method to try and force inlining:

[MethodImpl(MethodImplOptions.AggressiveInlining)]
int GetWeight()
{
    return (int)(raw & 0x3FFF);
}

However, from this programmer.se answer you can see that inlining vs. not actually makes very little difference:

Results

struct get property                               : 0.3097832 seconds
struct inline get property                        : 0.3079076 seconds
struct method call with params                    : 1.0925033 seconds
struct inline method call with params             : 1.0930666 seconds
struct method call without params                 : 1.5211852 seconds
struct intline method call without params         : 1.2235001 seconds

You're best letting the compiler do its thing until you find that you're seeing some real measurable performance issues.

Upvotes: 3

Zero
Zero

Reputation: 330

MSDN: Static Classes and Static Class Members

A call to a static method generates a call instruction in Microsoft intermediate language (MSIL), whereas a call to an instance method generates a callvirt instruction, which also checks for a null object references. However, most of the time the performance difference between the two is not significant.

Upvotes: 1

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