free c/c++ compilers have; loop unrolling, function inlining, dead code elimination.
Loop unrolling is not necessarily an optimization (it is if you have a long pipeline and no cache, it isn't if you have a short pipeline and a large cache). And the BlitzMAX compiler does eliminate dead code, but doing so is not an optimization (as dead code is never executed, it has no effect on the performance of the program). So by telling a compiler to optimize your code to make use of SIMD instructions means your lazy and your code is sloppy?
I don't consider the use of SIMD instructions an optimization, so much as a different build target. Right, its better to do it by hand and make your code even less portable.
Since when did I become an advocate for optimizing things by hand? Have you even been following the discussion? Let me just quote myself here a couple of times, to get you up to speed:"If you compile your C++ program for a target architecture of (say) i386, and then run it on any different processor, the C++ version will be considerably slower than a C# version." - FlameDuck
"Catch-22 eh? Your program is either slow and works on everything, or fast, and only works on the fastest CPUs. Hrmmm." - FlameDuck
"Unless you have an intimate understanding of how your compiler (regardless of language) translates your source code into binary code, and likewise have an intimate understanding of all your build targets (including hardware and operating system quirks) there is no way you can effectively optimize a program." - FlameDuck
So instead of thinking optimisation, think "better method".
Already tried that suggestion. They didn't buy it.