Really? Dmd version and system? (here: dmd from git, ubuntu 11.10 64bit) ./app 50000000
Your version: real 0m14.674s My version: real 0m13.644s Your version: imd dSquared = dx ^^ 2 + dy ^^ 2 + dz ^^ 2; imd mag = dt / (dSquared * sqrt(dSquared)); My version: imd dSquared = sqrt(dx ^^ 2 + dy ^^ 2 + dz ^^ 2); imd mag = dt / (dSquared * dSquared^^2); // That is: dt / (dSquared^^3); Probably vars evaluation works better on my example? Btw: imd dSquared = sqrt(dx*dx + dy*dy + dz*dz); imd mag = dt / (dSquared*dSquared*dSquared); real 0m13.574s Il giorno ven, 25/11/2011 alle 08.14 -0500, bearophile ha scritto: > Andrea Fontana: > > > Hmm reading code i verified that i can gain a 10% writing: > > > > imd dSquared = sqrt(dx ^^ 2 + dy ^^ 2 + dz ^^ 2); > > imd mag = dt / (dSquared * dSquared^^2); > > > > Around line 115. Give it a try... > > My version performs a sqrt and one multiplication, while your version > performs one sqrt and two multiplications. On my PC my version is faster. > > Bye, > bearophile
