Yes, this seems like one reasonable approach. The current approach of compiling to a "least common denominator" and then updating this denominator every decade or so seems insufficient. Instead of interpreting the absence of a "-march=" flag to mean optimize for nothing, maybe it can mean that multiple optimizations are automatically compiled and the appropriate one is selected at runtime. Alternatively, maybe we need to move away from the idea of compiling a single binary that runs on all platforms, and encourage greater use of platform specific compilations.