An interesting, older paper that explores how to bridge the "ninja gap" between naive code and hand-optimized code is Can Traditional Programming Bridge the Nin

An interesting, older paper that explores how to bridge the "ninja gap" between naive code and hand-optimized code is Can Traditional Programming Bridge the Ninja Performance Gap for Parallel Computing Applications? <https://web.eecs.umich.edu/~msmelyan/papers/isca-2012-paper.pdf https://web.eecs.umich.edu/~msmelyan/papers/isca-2012-paper....>. They reduce the ninja gap for a range of benchmarks from 24x to 1.3x by relying on "smart" compilers and using only basic program transformations---no intrinsics!