The architecture of a production optimizing compiler for Pascal is described, and the structure of the optimizer is detailed. The compiler performs both interprocedural and global optimizations, in addition to optimization of basic blocks. We have found that a high-level structured language such as Pascal provides unique opportunities for effective optimization, but that standard optimization techniques must be extended to take advantage of these opportunities. These issues are considered in our discussion of the optimization algorithms we have developed and the sequence in which we apply them.