I also do DSP development and looking at the x86 architecture it almost seems pointless to try to predict what the processor is doing. Out of order execution? R

I also do DSP development and looking at the x86 architecture it almost seems pointless to try to predict what the processor is doing. Out of order execution? Register renaming? The only way I can be sure assembly is faster than generated C is by profiling, which isn't even exact anyway without isolating the operating system. For us, latency and determinism are the most important requirements of any processor, and it's very hard to get that on x86 without writing your own OS. But that negates the entire advantage of using the x86 platform with so much available code written on top of other kernels.