DSP What Should I Avoid?

Question

I'm starting with dsp programming right now, and I'm writing my first low level classes and functions. Since I want functions to be fast (or finally inefficient), I often wonder what I should use and what I should avoid in functions that are called in the sample.

I know that learning speed changes quite a bit, but I think that some of you, at least, can use the rule or just experience. :)

conditional statements

If I need to use conditions, it switchshould be faster than a block if / else if, right? Are there differences between using two if-statements or if-else? Somewhere I read what elseto avoid, but I don’t know why.

Also, compared to multiplication, is there a rough estimate of how long an if-block takes? Because in some cases, using the use of multiplication by zero can be used instead of if-statements:

//something could be an int either 1 or 0:
if(something) {
    signal += something_else;
}
// or:
signa+ += something*something_else;

functions and function pointers

Instead of using conditional statements, you can use a pointer function. Instead of using conditions in each call, the pointer can be redirected to a specific function. However, for each call, the pointer had to be interpreted in order to call the desired function. So I don’t know if that would help or not.

I also wonder if the call function affects. If so, boxing functions should be avoided, right?

Variables

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Answer 1

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Answer 2

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