Re: FLOATING-POINT CONSISTENCY, -FFLOAT-STORE, AND X86

[Dave Love <d.love@dl.ac.uk>]

>>>>> "Marc" == Marc Lehmann <pcg@goof.com> writes:

 >> What's the guarantee that crt0 sets up extended precision on
 >> whichever systems are of interest?

 Marc> I have no idea. Do _you_ have one?

No, or I wouldn't have asked.  AFAIR the startup settings of the FPU
changed at some stage in the past, though.

 >> Is it currently consistent across all the x86 platforms we run on?

 Marc> Definitely not. But does that mean we should break linux-libm
 Marc> (for example) because solaris behavuour wasn't consistent
 Marc> before(?).

Of course not.  I need libm to work; that's why I keep asking the
question.  I presume that glibc would need to conform on another
platform that did define this.

 Marc> How about implementing the __setfpucw functionality as found on
 Marc> linux? Creating a library (-lrdble) should be trivial then.

I don't have the information, expertise or interest in that.  I called
__setfpucw, but I'm not even sure it works across Linuxes.  I'd do
newlib and cygwin32 as well, given appropriate doc and a way of
figuring out that they're in use; AFAIR they seem to have the facility
but don't say how to drive it.  I'd expect people with an interest to
contribute the (presumably trivial) additions.