Minimize memory consumed by FEC.LightExpression.Expression

[dadhi]

The expression with multiple sub-expressions like Expression.Call contain their arguments in array.

We may provide overloads with separate 1, 2, 3, 4, 5, or more arguments, and store them not in array but inlined.

If we futher make some expressions into a struct, e.g. ParameterExpression we can gain an additional savings.

[dzmitry-lahoda]

What way contributor may check that his changes do good in terms of performance? Could it be running all tests as part of specific bench? As of now I do not know how to do it.

[dzmitry-lahoda]

Using stucts may lead to the case when in parameters and ref returns may be appear best way to work with them. But in this case code for LINQ and FEC expressions may be different.

[dzmitry-lahoda]

Another alternative to have limit number of params to 255 #89 and pass small array by ref and call it with by ref return. So we may store items in most optimal array instead doing overloads.

[dadhi]

@dzmitry-lahoda I will review #89, thanks for reminder

[dadhi]

Another thing what is bothering me is that FEC almost always has a Gen1, Gen2 allocations vs Expression.Compile does not. Check the benchmarks in #72.

[dadhi]

We may provide overloads with separate 1, 2, 3, 4, 5, or more arguments, and store them not in array but inlined.

It is still an actual thing to look at.

[dadhi]

Added specialized versions for the few arguments.

[dadhi]

todo:

• InvocationExpression

[dadhi]

The work is completed for all major expressions, the remaining are Switch, TryCatch and Loop can be tackled separately when time permits or with contributions.