At the time I recall https://dl.acm.org/doi/pdf/10.1145/301631.301683 being an oft-discussed data point - speeding up DEC Alpha code by recompiling it into different DEC Alpha code using runtime statistics.

This was commonly cited in forum debates about whether Java and C# could come close to the performance of compiled languages. ("JITs and GCs are fast enough, and runtime stats mean they can even be faster!" was a common refrain, but not actually as true in 1999 as it is in 2025)