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Re: Second Draft "Unsafe fp optimizations" project description.


dewar@gnat.com wrote:

> <<E.g., if we want to say that optimization -fblah will cause overflow
> when the inputs to the (transformed) expression are in the subset X of
> all representable floating point numbers, we have to assume a model - my
> suggestion is to use the IEEE-754 model.
> >>

> But this is meaningless, there *is* no "IEEE-754" model for evaluation of
> floating-point expressions in high level languages. So this model needs
> a lot of filling out. I refer again to Sam Figueroa's PhD thesis which is
> all about such models.

Ah, OK - I see what you mean now.  I have some hours on Friday to visit
the nearest University Library (University of Utrecht).  Presumably
they  do not have that thesis, but there probably is a book that
discusses/uses his results.  Do you have a suggestion ?  Thanks.

[ Yesterday I promised to send in a third revision of the proposed web
  page today - unfortunately, I'm too tired to do a good job on it, so 
  it'll have to wait. ]

-- 
Toon Moene - mailto:toon@moene.indiv.nluug.nl - phoneto: +31 346 214290
Saturnushof 14, 3738 XG  Maartensdijk, The Netherlands
Maintainer, GNU Fortran 77: http://gcc.gnu.org/onlinedocs/g77_news.html
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