On Tue, Dec 19, 2017 at 12:05 PM Chris Hopkins <cbehopk...@gmail.com> wrote:
... > was slower than: ... Without more information the conclusion that the optimization is not there cannot be established. Inspect the real produced machine code. I guess you'll find that the machine code differs in cache-line alignment only, and that's the cause of the observed effect. Even changing whitespace in a program can potentially move the code in the binary. > So I assume the Go compiler doesn't try and do this analysis in a Compile time vs Execution time tradeoff. I think this kind of DCE was in at the date of the first public release. > Anyway Hope that is useful to someone. It has certainly changed the way I will write my (profiled) inner loops. I don't think that's a good idea. The bug, if any, in the compiler should be fixed. OTOH, adjusting code to a particular compiler/version/whitespace will hurt as soon as anything of that changes. Generally, benchmarking short inner loops is often unreliable enough to render it unusable. -- -j -- You received this message because you are subscribed to the Google Groups "golang-nuts" group. To unsubscribe from this group and stop receiving emails from it, send an email to golang-nuts+unsubscr...@googlegroups.com. For more options, visit https://groups.google.com/d/optout.
