[R] Questions about Preserving registers

[David Lennartsson]

Duncan Murdoch wrote:

>On Thu, 10 Jun 2004 09:12:05 -0700 (PDT), Thomas Lumley
><tlumley at u.washington.edu> wrote :
>
>  
>
>>>DLL attempted to change FPU control word from 9001f to 90003
>>>
>>>I read the instruction on Duncan Murdoch’s website about preserving
>>>registers, but I still don’t understand it. For example,
>>>      
>>>
>>This code is for Delphi.  You would need to see how to set the FPU control
>>work in Powerstation Fortran, which should be described in its manual.
>>
>>The warning is harmless, so you could just ignore it.  The warning means
>>that R has done the change for you.
>>    
>>
>
>I think it's better to try to fix it.  R only checks once (on
>loading); if Fortran makes the change again, then R code might go
>wrong later, and if Fortran depends on the original value, then the
>Fortran code might not work properly.
>
>Duncan Murdoch
>  
>
Hi,

yes, I have seen this happen when loadíng the precompiled yacas dll into 
R (package to be released). I have not
bothered to dig deeper and I have no idea of how to get and set the FPU 
control word in the wrapper. Is there
a compiler macro or does it have to be done with assembler?

David