[patch] Allow building libgfortran as a DLL

[Steve Kargl]

On Tue, Aug 04, 2009 at 02:51:19PM +0100, Dave Korn wrote:
> Tim Prince wrote:
> > Dave Korn wrote:
> > 
> >>
> >>   I took a quick step through it in the debugger.  It's possibly an
> >> excess-precision FP thing.  Can you point me at what code in the gfortran
> >> startup is meant to set the FP precision and rounding (etc.) modes?
> >>
> > 
> > All these years I've been working with the apparent misconception that
> > gnu compilers left these at hardware/OS default, with the possible
> > exception of -ffast-math which should attempt to set abrupt underflow
> > for SSE.
> 
>   That's the difference between a compiler and a language runtime support
> library.  I don't know for a fact if fortran's runtime initialises the FPU but
> the Ada runtime, for example, does.
> 

See set_fpu() in 

troutmask:sgk[206] ls config/fpu*
config/fpu-387.h        config/fpu-generic.h    config/fpu-sysv.h
config/fpu-aix.h        config/fpu-glibc.h

It only sets/unsets the mask for exceptions.  The precision, AFAIK, is
determined by the OS.
 
-- 
Steve