Re: Reporting bugs: there is nothing to gain in frustrating reporters

[Toon Moene <toon at moene dot indiv dot nluug dot nl>]

Robert Dewar wrote:

> > Well, I haven't studied this to such a great detail because I (according 
> > to Kahan) belong to the group of people who "don't care about floating 
> > point accuracy because their code is so robust they can even run on 
> > Cray's", but doesn't this mean that we can solve it in the compiler by 
> > having its run time library provide this functionality ?

> You are mixing issues, the issue of extra precision on the x86 has nothing
> whatever with whether or not such values can be stored in memory (they can),
> and Kahan's inaccurate impression that there is a problem in extending the
> stack, if indeed you are quoting him accurately, is not relevant.

Hmmm, lets be careful here.  In my original reply I said "I do not have 
a link just right now", which means I might recall things incorrectly.

I have read accounts (in a distant past) that the original purpose of 
the x87 stack of 80-bit floating point values was to have a cache on the 
processor (initially 8 registers) and the rest supported by "the 
operating system".  That could of course well be the common run time 
library.

If your experience is that such a support (of an indefinite number of 
80-bit floating point registers) could easily be provided by the run 
time library of <language> compiler, that indicates to me that GCC could 
provide such support.

The new thing I learned from your mail is the above.  If GCC can support 
this, than we can properly solve PR/323.  This is independent of whether 
I recall the thing I read in the past correctly.

Hope this helps,

--
Toon Moene - e-mail: toon@moene.indiv.nluug.nl - phone: +31 346 214290
Saturnushof 14, 3738 XG  Maartensdijk, The Netherlands
A maintainer of GNU Fortran 95: http://gcc.gnu.org/fortran/
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Fortran & C