Should we still be optimizing “in the small”?

Question

I was changing my for loop to increment using ++i instead of i++ and got to thinking, is this really necessary anymore? Surely today\'s compilers

Answer 1

I still do things like ra<<=1; instead of ra*=2; And will continue to. But the compilers (as bad as they are) and more importantly the speed of the computers is so fast that these optimizations are often lost in the noise. As a general question, no it is not worth it, if you are specifically on a resource limited platform (say a microcontroller) where every extra clock really counts then you probably already do this and probably do a fair amount of assembler tuning. As a habit I try not to give the compiler too much extra work, but for code readability and reliability I dont go out of my way.

The bottom line for performance though has never changed. Find some way to time your code, measure to find the low hanging fruit and fix it. Mike D. hit the nail on the head in his response. I have too many times seen people worry about specific lines of code not realizing that they are either using a poor compiler or by changing one compiler option they could see several times increase in execution performance.