I've recently picked up Michael Abrash's *The Zen of Assembly Language* (from 1990) and was reading a section on how instruction prefetching is not always advantageous such as the case when branching occurs (a jump). This is because all of the instructions that were prefetched are no longer the ones to be executed and so more instructions must be fetched.

This reminded me of an optimization from another old book, *Tricks of the Game Programming Gurus* by Andre LaMothe in which he suggests that when setting up your conditional statements, you put the most frequently (or expected) path first. 

For example:

```
if (booleanThatIsMostLikelyToBeTrue)
{
   // ...expected code
   // also the code that would've been prefetched
}
else
{
   // ...exceptional or less likely code
}

```

My questions are:

1) Was LaMothe's optimization suggested with this in mind? (I no longer have the book)

2) Is this type of optimization still a worthwhile programming habit on modern machine? (maybe prefetching is handled differently than it used to be?)