At university, one of the exercises in the HPC class was to optimise a piece of Fortran code. I managed to beat the TA's code by other means, but missed one of

At university, one of the exercises in the HPC class was to optimise a piece of Fortran code. I managed to beat the TA's code by other means, but missed one of his significant optimisations: manually unrolling a dot product. This was on Intel's Fortran compiler, though admittedly almost 10 years ago. (It did already support autovectorisation etc. at the time) Anyway, goes to show you still need to look at the disassembly and do plenty of profiling with Fortran binaries too. No such thing as a free lunch.