C# vs C - Big performance difference

Question

I\'m finding massive performance differences between similar code in C anc C#.

The C code is:

#include 
#include 
#inclu         


        

Answer 1

I'll keep it brief, it is already marked answered. C# has the great advantage of having a well defined floating point model. That just happens to match the native operation mode of the FPU and SSE instruction set on x86 and x64 processors. No coincidence there. The JITter compiles Math.Sqrt() to a few inline instructions.

Native C/C++ is saddled with years of backwards compatibility. The /fp:precise, /fp:fast and /fp:strict compile options are the most visible. Accordingly, it must call a CRT function that implements sqrt() and checks the selected floating point options to adjust the result. That's slow.