floating point control on windows
We recommend calling Rwin_fpset() which is exported by R.dll and is known
to do the trick. As it contains
_controlfp(_PC_64, _MCW_PC);
it may be that the args you used are incorrect (and I am not on Windows
to check the docs, but note that is the form used in the URL you cite).
On Mon, 29 Aug 2005, Chris Paulse wrote:
Hi, I'm sure that this question has come up many times before. When I load an R extension dll I've built with the Microsoft compiler, I get the warning:
Warning message: DLL attempted to change FPU control word from 8001f to 9001f So, what I did to try to fix the problem (to my knowledge, Microsoft will not support compile time switching of floating point control until version 8.0 of their compiler - see: http://blogs.msdn.com/ericflee) was to place the following statement inside R_init_mylib:
_controlfp(_MCW_PC, _PC_64); // use extended precision for operations in x87 FPU This didn't fix my problem. I ended up sprinkling these liberally throughout my code, but that didn't help. One thing I do like about the Microsoft compiler is the debugging facility. But, I'll definitely switch to gcc if this is necessary to get rid of the problem.
Brian D. Ripley, ripley at stats.ox.ac.uk Professor of Applied Statistics, http://www.stats.ox.ac.uk/~ripley/ University of Oxford, Tel: +44 1865 272861 (self) 1 South Parks Road, +44 1865 272866 (PA) Oxford OX1 3TG, UK Fax: +44 1865 272595