Changing interaction of compiler and architecture

Program optimizations that have been exclusively done by either the architecture or the compiler are now being done by both. This blurred distinction offers opportunities to optimize performance and redefine the compiler-architecture interface. We describe an optimization continuum with compile time and post run time as end points and show how different classes of optimizations fall within it. Most current commercial compilers are still at the compile-time end point, and only a few research efforts are venturing beyond it. As the gap between architecture and compiler closes, there are also attempts to completely redefine the architecture-compiler interface to increase both performance and architectural flexibility.