Re: Floating point differences between executables sharing a DLL

Hello,

I am encountering the following scenario while compiling a project
under Visual Studio 2005 with the floating point model set as
precise.

Two executables A and B share a common dll C. Both call the
function func() in C with the same input and get slightly different
floating point results. Below is what func() looks like:

const long double pi = atanl(1.0) * 4.0;

long double func(long double myVar) {
  long double res = myVar * pi / 180.0;

  return res;

}

Changing func() into the following gives the same result (although
different from the first version) in both executables:

const long double pi = atanl(1.0) * 4.0;

long double func(long double myVar) {
  long double intermediateRes = pi / 180.0;
  long double res = myVar * intermediateRes;

  return res;

}

Does anyone know why this is happening?

Thanks