I don't think compilers are a good example. The economics of software development has won a long time ago. For example in Gamedev with well known soft real-time requirements people (mostly) stopped doing that machine code dance many hardware generations ago. Like it happened with memory optimizations: people measure memory in GB now not in KB =)

I am sure programmers cherish every case when they can do micro optimization but in the retrospect the high level cuts is what made the system fit the perf or memory budget.