Re: Estimation of π using Leibniz series

[def]

Maybe you have some special Nim settings in your nim.cfg, Jehan? For me it's 
~3.5 seconds with an i7 6700k for both gcc-5 and clang. Or are you using an 
older Nim release? I'm running the current devel branch. **Are you on Mac OS X 
by chance? We're calling c stdlib function for pow and they may be 
significantly faster. Optimizing pow(-1.0, ...) seems pretty reasonable.** 
Compiling for x86 instead of x86-64 also makes this twice as slow here.