Analyzing Code Produced with GCC Compilers

Chapter 2 discussed the various types of optimizations that GCC’s C compiler can perform for you. Some of these optimizations are automatic, whereas others only make sense based on the characteristics of the application you are trying to optimize. For example, you can only decide where and if to use optimizations such as unrolling or inlining loops after studying your application and identifying loops that might benefit from these optimizations. (Unrolling or inlining loops means to insert the code for each iteration of a loop in sequence so that a loop is no longer present; the loop is replaced by a series of sequential statements that explicitly perform the contents of the loop for each value of the variable that controls the loop.)