How to calculate pi

MS is famous for such things. The standard answer is Gnu C/C++.

In many realtime systems, the 64-bit floats are generated directly from a template, by writing the mantissa directly into a pre-formed

64-bit float This can be done in assembly or in C using bitwise parallel logic operators.

I recall a famous story from the 1990s, when Microsoft was building their own versions of standard UNIX tools. There was a meeting where MS was presenting their Korn shell, and the presenter got into an argument with a middle-aged guy about the required behavior. The audience soon started to titter.

Turned out that they were trying to tell David Korn how the Korn Shell ought to work - they had no idea who that guy was. A classic Microsoft Moment (TM).

The MS-proof alternative is Gnu C/C++ under Linux.

Agree.

Joe Gwinn

Yes, of course. My point is if you have 64 bit integers and can apply scaling (effectively making fixed-point math) then you don't need FP.

The gcc libraries for AVR have hand-coded full 64-bit support in ASM, but it's still just a 16-bit chip and long division isn't very quick. Reciprocal multiplication is much quicker, and in my example didn't need

64x64, just 32x32.

CH

It still can but only if you are running Win10 *and* have a state of the art graphics card otherwise it point blank refuses to install at all. Their online cloud service is even less user friendly.

GCC/GFORTRAN was easily path of least resistance (and free).

It works well enough. However, many of my clients require that it also works on Mickeysoft because they use that compiler (don't ask me why!).

*Wonderful* and entirely believable too!

I'm using it under Win7 via MinGW_G64 which works well enough.

Code still has to work correctly on both compilers...